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Supplementary Methods and Tables 1-4 from Genetic Variation at the CYP19A1 Locus Predicts Circulating Estrogen Levels but not Breast Cancer Risk in Postmenopausal Women

The CYP19A1 gene encodes the enzyme aromatase, which is responsible for the final step in the biosynthesis of estrogens. In this study, we used a systematic two-step approach that included gene resequencing and a haplotype-based analysis to comprehensively survey common genetic variation across the CYP19A1 locus in relation to circulating postmenopausal steroid hormone levels and breast cancer risk. This study was conducted among 5,356 invasive breast cancer cases and 7,129 controls comprised primarily of White women of European descent drawn from five large prospective cohorts within the National Cancer Institute Breast and Prostate Cancer Cohort Consortium. A high-density single-nucleotide polymorphism (SNP) map of 103 common SNPs (≥5% frequency) was used to identify the linkage disequilibrium and haplotype patterns across the CYP19A1 locus, and 19 haplotype-tagging SNPs were selected to provide high predictability of the common haplotype patterns. We found haplotype-tagging SNPs and common haplotypes spanning the coding and proximal 5′ region of CYP19A1 to be significantly associated with a 10% to 20% increase in endogenous estrogen levels in postmenopausal women [effect per copy of the two-SNP haplotype rs749292-rs727479 (A-A) versus noncarriers; P = 4.4 × 10−15]. No significant associations were observed, however, with these SNPs or common haplotypes and breast cancer risk. Thus, although genetic variation in CYP19A1 produces measurable differences in estrogen levels among postmenopausal women, the magnitude of the change was insufficient to contribute detectably to breast cancer. [Cancer Res 2007;67(5):1893–7]

Cadmium and lead have been classified as carcinogens by the International Agency for Research on Cancer. However, their associations with breast cancer risk are unknown despite their persistence in ...

Background Full-term pregnancy (FTP) at an early age confers long-term protection against breast cancer. Previously, we reported that a FTP imprints a specific gene expression profile in the breast of postmenopausal women. Herein, we evaluated gene expression changes induced by parity in the breast of premenopausal women. Methods Gene expression profiling of normal breast tissue from 30 nulliparous (NP) and 79 parous (P) premenopausal volunteers was performed using Affymetrix microarrays. In addition to a discovery/validation analysis, we conducted an analysis of gene expression differences in P vs. NP women as a function of time since last FTP. Finally, a laser capture microdissection substudy was performed to compare the gene expression profile in the whole breast biopsy with that in the epithelial and stromal tissues. Results Discovery/validation analysis identified 43 differentially expressed genes in P vs. NP breast. Analysis of expression as a function of time since FTP revealed 286 differentially expressed genes (238 up- and 48 downregulated) comparing all P vs. all NP, and/or P women whose last FTP was less than 5 years before biopsy vs. all NP women. The upregulated genes showed three expression patterns: (1) transient: genes upregulated after FTP but whose expression levels returned to NP levels. These genes were mainly related to immune response, specifically activation of T cells. (2) Long-term changing: genes upregulated following FTP, whose expression levels decreased with increasing time since FTP but did not return to NP levels. These were related to immune response and development. (3) Long-term constant: genes that remained upregulated in parous compared to nulliparous breast, independently of time since FTP. These were mainly involved in development/cell differentiation processes, and also chromatin remodeling. Lastly, we found that the gene expression in whole tissue was a weighted average of the expression in epithelial and stromal tissues. Conclusions Genes transiently activated by FTP may have a role in protecting the mammary gland against neoplastically transformed cells through activation of T cells. Furthermore, chromatin remodeling and cell differentiation, represented by the genes that are maintained upregulated long after the FTP, may be responsible for the lasting preventive effect against breast cancer. Electronic supplementary material The online version of this article (10.1186/s13058-019-1128-x) contains supplementary material, which is available to authorized users.

BackgroundObesity is an established risk factor for several common chronic diseases such as breast and colorectal cancer, metabolic and cardiovascular diseases; however, the biological basis for these relationships is not fully understood. To explore the association of obesity with these conditions, we investigated peripheral blood leucocyte (PBL) DNA methylation markers for adiposity and their contribution to risk of incident breast and colorectal cancer and myocardial infarction.MethodsDNA methylation profiles (Illumina Infinium® HumanMethylation450 BeadChip) from 1941 individuals from four population-based European cohorts were analysed in relation to body mass index, waist circumference, waist-hip and waist-height ratio within a meta-analytical framework. In a subset of these individuals, data on genome-wide gene expression level, biomarkers of glucose and lipid metabolism were also available. Validation of methylation markers associated with all adiposity measures was performed in 358 individuals. Finally, we investigated the association of obesity-related methylation marks with breast, colorectal cancer and myocardial infarction within relevant subsets of the discovery population.ResultsWe identified 40 CpG loci with methylation levels associated with at least one adiposity measure. Of these, one CpG locus (cg06500161) in ABCG1 was associated with all four adiposity measures (P = 9.07×10−8 to 3.27×10−18) and lower transcriptional activity of the full-length isoform of ABCG1 (P = 6.00×10−7), higher triglyceride levels (P = 5.37×10−9) and higher triglycerides-to-HDL cholesterol ratio (P = 1.03×10−10). Of the 40 informative and obesity-related CpG loci, two (in IL2RB and FGF18) were significantly associated with colorectal cancer (inversely, P P ConclusionOur results suggest that epigenetic changes, in particular altered DNA methylation patterns, may be an intermediate biomarker at the intersection of obesity and obesity-related diseases, and could offer clues as to underlying biological mechanisms.

The C → T mutation signature caused by APOBEC family members contributes to the development of breast cancer (BC). Also overexpression of APOBEC3B and a ~29.5-kb deletion polymorphism between APOBEC3A and APOBEC3B have been associated with increased BC risk.We investigated in a population-based study, with 782 Swedish BC cases and 1559 controls, associations between potentially functional germline variants in APOBEC3A or APOBEC3B gene and BC risk and survival. Additionally, we identified deletion polymorphism carriers and explored possible associations with BC.No evidence of association between any germline variant, including the deletion polymorphism, and BC risk or survival was observed. Only APOBEC3A promoter polymorphism rs5757402 was associated with low stage (OR = 0.69, 95 % CI 0.50-0.96, dominant model).The reported association between the deletion polymorphism and BC risk was not confirmed in the Swedish population, nor did any genotyped germline variant show any association with BC risk or survival.

International audience; Forkhead box O3 (FOXO3) has a wide range of functions: it promotes tumor suppression, cell cycle arrest, repair of damaged DNA, detoxification of reactive oxygen species, apoptosis and plays a pivotal role in promoting longevity. FOXO3 is a key downstream target of the PI3K-Akt pathway in response to cellular stimulation by growth factors or insulin and has been proposed as a bridge between ageing and tumor suppression. Three SNPs in the FOXO3 gene (rs3800231, rs9400239 and rs479744) that have been shown to be strongly and consistently associated with longevity, were examined in relation to PC risk in a case control study of 1571 incident PC cases and 1840 controls nested within the European Prospective Investigation into Cancer and Nutrition (EPIC). There was no statistically significant association between the SNPs and PC risk regardless of the model of inheritance (dominant, codominant and recessive). The associations were not modified by disease aggressiveness, circulating levels of steroid sex hormones, or IGFs or BMI. We conclude that polymorphisms in the FOXO3 gene that are associated with longevity are not major risk factors for PC risk, in this population of Caucasian men.

Background The single nucleotide polymorphism rs7566605, located in the promoter of the INSIG2 gene, has been the subject of a strong scientific effort aimed to elucidate its possible association with body mass index (BMI). The first report showing that rs7566605 could be associated with body fatness was a genome-wide association study (GWAS) which used BMI as the primary phenotype. Many follow-up studies sought to validate the association of rs7566605 with various markers of obesity, with several publications reporting inconsistent findings. BMI is considered to be one of the measures of choice to evaluate body fatness and there is evidence that body fatness is related with an increased risk of breast cancer (BC). Methods we tested in a large-scale association study (3,973 women, including 1,269 invasive BC cases and 2,194 controls), nested within the EPIC cohort, the involvement of rs7566605 as predictor of BMI and BC risk. Results and Conclusions In this study we were not able to find any statistically significant association between this SNP and BMI, nor did we find any significant association between the SNP and an increased risk of breast cancer overall and by subgroups of age, or menopausal status.

Objectives. To examine the relationship between ‘‘traditional Sami’’ dietary pattern and mortality in a general northern Swedish population. Study design. Population-based cohort study. Methods. We examined 77,319 subjects from the Va¨sterbotten Intervention Program (VIP) cohort. A traditional Sami diet score was constructed by adding 1 point for intake above the median level of red meat, fatty fish, total fat, berries and boiled coffee, and 1 point for intake below the median of vegetables, bread and fibre. Hazard ratios (HR) for mortality were calculated by Cox regression. Results. Increasing traditional Sami diet scores were associated with slightly elevated all-cause mortality in men [Multivariate HR per 1-point increase in score 1.04 (95% CI 1.01-1.07), p=0.018], but not for women [Multivariate HR 1.03 (95% CI 0.99-1.07), p=0.130]. This increased risk was approximately equally attributable to cardiovascular disease and cancer, though somewhat more apparent for cardiovascular disease mortality in men free from diabetes, hypertension and obesity at baseline [Multivariate HR 1.10 (95% CI 1.01-1.20), p=0.023]. Conclusions. A weak increased all-cause mortality was observed in men with higher traditional Sami diet scores. However, due to the complexity in defining a ‘‘traditional Sami’’ diet, and the limitations of our questionnaire for this purpose, the study should be considered exploratory, a first attempt to relate a ‘‘traditional Sami’’ dietary pattern to health endpoints. Further investigation of cohorts with more detailed information on dietary and lifestyle items relevant for traditional Sami culture is warranted. Keywords: the VIP cohort; Sami, traditional food; traditional lifestyle; mortality (Published: 4 May 2012) Citation: Int J Circumpolar Health 2012, 71 : 18537 - http://dx.doi.org/10.3402/ijch.v71i0.18537

Long-term effects of carbohydrate-restricted diets are unclear. We examined a low-carbohydrate, high-protein (LCHP) score in relation to mortality.This is a population-based cohort study on adults in the northern Swedish county of Västerbotten. In 37,639 men (1460 deaths) and 39,680 women (923 deaths) from the population-based Västerbotten Intervention Program, deciles of energy-adjusted carbohydrate (descending) and protein (ascending) intake were added to create an LCHP score (2-20 points). Sex-specific hazard ratios (HR) were calculated by Cox regression.Median intakes of carbohydrates, protein and fat in subjects with LCHP scores 2-20 ranged from 61.0% to 38.6%, 11.3% to 19.2% and 26.6% to 41.5% of total energy intake, respectively. High LCHP score (14-20 points) did not predict all-cause mortality compared with low LCHP score (2-8 points), after accounting for saturated fat intake and established risk factors (men: HR for high vs low 1.03 (95% confidence interval (CI) 0.88-1.20), P for continuous = 0.721; women: HR for high vs low 1.10 (95% CI 0.91-1.32), P for continuous = 0.229). For cancer and cardiovascular disease, no clear associations were found. Carbohydrate intake was inversely associated with all-cause mortality, though only statistically significant in women (multivariate HR per decile increase 0.95 (95% CI 0.91-0.99), P = 0.010).Our results do not support a clear, general association between LCHP score and mortality. Studies encompassing a wider range of macronutrient consumption may be necessary to detect such an association.

Early pregnancy and multiparity are known to reduce the risk of women to develop breast cancer at menopause. Based on the knowledge that the differentiation of the breast induced by the hormones of pregnancy plays a major role in this protection, this work was performed with the purpose of identifying what differentiation-associated molecular changes persist in the breast until menopause. Core needle biopsies (CNB) obtained from the breast of 42 nulliparous (NP) and 71 parous (P) postmenopausal women were analyzed in morphology, immunocytochemistry and gene expression. Whereas in the NP breast, nuclei of epithelial cells were large and euchromatic, in the P breast they were small and hyperchromatic, showing strong methylation of histone 3 at lysine 9 and 27. Transcriptomic analysis performed using Affymetrix HG_U133 oligonucleotide arrays revealed that in CNB of the P breast, there were 267 upregulated probesets that comprised genes controlling chromatin organization, transcription regulation, splicing machinery, mRNA processing and noncoding elements including XIST. We concluded that the differentiation process induced by pregnancy is centered in chromatin remodeling and in the mRNA processing reactome, both of which emerge as important regulatory pathways. These are indicative of a safeguard step that maintains the fidelity of the transcription process, becoming the ultimate mechanism mediating the protection of the breast conferred by full-term pregnancy.

Background: It has been suggested that the relative importance of oestrogen-metabolising pathways may affect the risk of oestrogen-dependent tumours including endometrial cancer. One hypothesis is that the 2-hydroxy pathway is protective, whereas the 16α-hydroxy pathway is harmful. Methods: We conducted a case–control study nested within three prospective cohorts to assess whether the circulating 2-hydroxyestrone : 16α-hydroxyestrone (2-OHE1 : 16α-OHE1) ratio is inversely associated with endometrial cancer risk in postmenopausal women. A total of 179 cases and 336 controls, matching cases on cohort, age and date of blood donation, were included. Levels of 2-OHE1 and 16α-OHE1 were measured using a monoclonal antibody-based enzyme assay. Results: Endometrial cancer risk increased with increasing levels of both metabolites, with odds ratios in the top tertiles of 2.4 (95% CI=1.3, 4.6; Ptrend=0.007) for 2-OHE1 and 1.9 (95% CI=1.1, 3.5; Ptrend=0.03) for 16α-OHE1 in analyses adjusting for endometrial cancer risk factors. These associations were attenuated and no longer statistically significant after further adjustment for oestrone or oestradiol levels. No significant association was observed for the 2-OHE1 : 16α-OHE1 ratio. Conclusion: Our results do not support the hypothesis that greater metabolism of oestrogen via the 2-OH pathway, relative to the 16α-OH pathway, protects against endometrial cancer.

To identify cancer-linked genes, Sjöblom et al. and Wood et al. performed a genome-wide mutation screening in human breast and colorectal cancers. 140 CAN-genes were found in breast cancer, which in turn contained overall 334 mutations. These mutations could prove useful for diagnostic and therapeutic purposes.We used a MALDI-TOF MS 40-plex assay for testing 40 loci within 21 high-ranking breast cancer CAN-genes. To confirm mutations, we performed single-plex assays and sequencing.In general, the mutation rate of the analyzed loci in our sample cohort was very low. No mutation from the 40 loci analyzed could be found in the 6 cell lines. In tissue samples, a single breast cancer tissue sample showed heterozygosity at locus c.5834GA within the ZFYVE26 gene (Zinc finger FYVE domain-containing gene 26).Sjöblom et al./Wood et al. already showed that the vast majority of CAN-genes are mutated at very low frequency. Due to the fact that we only found one mutation in our cohort, we therefore assume that at the selected loci, mutations might be low-frequency events and therefore, more rarely detectable. However, further evaluation of the CAN-gene mutations in larger cohorts should be the aim of further studies.

Chromosomal instability is a known hallmark of many cancers. DNA polymerases represent a group of enzymes that are involved in the mechanism of chromosomal instability as they have a central function in DNA metabolism. We hypothesized that genetic variation in the polymerase genes may affect gene expression or protein configuration and by that cancer risk and clinical outcome. We selected four genes encoding for the catalytic subunits of the polymerases β, δ, θ and ζ (POLB, POLD1, POLQ and REV3L, respectively) and two associated proteins (MAD2L2 and REV1) because of their previously reported association with chromosomal instability and/or tumorigenesis. We selected potentially functional and most informative tagging single nucleotide polymorphisms (SNPs) for genotyping in a population-based series of 783 Swedish breast cancer (BC) cases and 1562 controls. SNPs that showed a significant association in the Swedish population were additionally genotyped in a Polish population consisting of 506 familial/early onset BC cases and 568 controls. SNPs in all three polymerase ζ subunit genes associated either with BC risk or prognosis. Two SNPs in REV3L and one SNP in MAD2L2 associated with BC risk: rs462779 (multiplicative model: OR 0.79, 95% CI 0.68-0.92), rs3204953 (dominant model: OR 1.28, 95% CI 1.05-1.56) and rs2233004 (recessive model: OR 0.49, 95% CI 0.28-0.86). Homozygous carriers of the minor allele C of the third SNP in REV3L, rs11153292, had significantly worse survival compared to the TT genotype carriers (HR 2.93, 95% CI 1.34-6.44). Minor allele carriers of two REV1 SNPs (rs6761391 and rs3792142) had significantly more often large tumours and tumours with high histological grade and stage. No association was observed for SNPs in POLB, POLQ and POLD1. Altogether, our data suggest a significant role of genetic variation in the polymerase ζ subunit genes regarding the development and progression of BC.

Altered DNA methylation is often seen in malignant cells, potentially contributing to carcinogenesis by suppressing gene expression. We hypothesized that heritable methylation potential might be a risk factor for breast cancer and evaluated possible association with breast cancer for single nucleotide polymorphisms (SNPs) either involving CpG sequences in extended 5'-regulatory regions of candidate genes (ESR1, ESR2, PGR, and SHBG) or CpG and missense coding SNPs in genes involved in methylation (MBD1, MECP2, DNMT1, MGMT, MTHFR, MTR, MTRR, MTHFD1, MTHFD2, BHMT, DCTD, and SLC19A1). Genome-wide searches for genetic risk factors for breast cancers have in general not investigated these SNPs, because of low minor allele frequency or weak haplotype associations. Genotyping was performed using Mass spectrometry-Maldi-Tof in a screening panel of 538 cases and 1,067 controls. Potential association to breast cancer was identified for 15 SNPs and one of these SNPs (rs7766585 in ESR1) was found to associate strongly with breast cancer, OR 1.30 (95% CI 1.17-1.45; p-value 2.1 × 10(-6)), when tested in a verification panel consisting of 3,211 unique breast cancer cases and 4,223 unique controls from five European biobank cohorts. In conclusion, a candidate gene search strategy focusing on methylation-related SNPs did identify a SNP that associated with breast cancer at high significance.

Studies on survival between familial and sporadic cancers have been inconclusive and only recent data on a limited number of cancers are available on the concordance of survival between family members. In this review, we address these questions by evaluating the published and unpublished data from the nation-wide Swedish Family-Cancer Database and a total of 13 cancer sites were assessed. Using sporadic cancer as reference, HRs were close to 1.0 for most of the familial cancers in both the offspring and parental generations, which suggested that survival in patients with familial and sporadic cancers was equal, with an exception for ovarian cancer with a worse prognosis. Compared to offspring whose parents had a poor survival, those with a good parental survival had a decreased risk of death for most cancers and HR was significantly decreased for cancers in the breast, prostate, bladder, and kidney. For colorectal and nervous system cancers, favorable survival between the generations showed a borderline significance. These data are consistent in showing that both good and poor survival in certain cancers aggregate in families. Genetic factors are likely to contribute to the results. These observations call for intensified efforts to consider heritability in survival as one mechanism regulating prognosis in cancer patients.

Despite potentially relevant chemical differences between filtered and boiled coffee, this study is the first to investigate consumption in relation to the risk of incident cancer.Subjects were from the Västerbotten Intervention Project (64,603 participants, including 3,034 cases), with up to 15 years of follow-up. Hazard ratios (HR) were calculated by multivariate Cox regression.No associations were found for all cancer sites combined, or for prostate or colorectal cancer. For breast cancer, boiled coffee ≥4 versus1 occasions/day was associated with a reduced risk (HR = 0.52, CI = 0.30-0.88, p (trend) = 0.247). An increased risk of premenopausal and a reduced risk of postmenopausal breast cancer were found for both total (HR(premenopausal) = 1.69, CI = 0.96-2.98, p (trend) = 0.015, HR(postmenopausal) = 0.60, CI = 0.39-0.93, p (trend) = 0.006) and filtered coffee (HR(premenopausal) = 1.76, CI = 1.04-3.00, p (trend) = 0.045, HR(postmenopausal) = 0.52, CI = 0.30-0.88, p (trend) = 0.045). Boiled coffee was positively associated with the risk of respiratory tract cancer (HR = 1.81, CI = 1.06-3.08, p (trend) = 0.084), a finding limited to men. Main results for less common cancer types included total coffee in renal cell cancer (HR = 0.30, CI = 0.11-0.79, p (trend) = 0.009) and boiled coffee in pancreas cancer (HR = 2.51 CI = 1.15-5.50, p (trend) = 0.006).These findings demonstrate, for the first time, the potential relevance of brewing method in investigations of coffee consumption and cancer risk, but they must be confirmed in future studies.

International audience; Previously, we reported that insulin-like growth factor (IGF)-I during early pregnancy is positively associated with maternal risk of breast cancer. To further explore this association, we designed a new study limited to women who donated a blood sample during their first pregnancy ending with childbirth. A case–control study was nested within the Northern Sweden Maternity Cohort in which repository since 1975, serum specimens remaining after early pregnancy screening for infectious diseases had been preserved. Study subjects were selected among women who donated a blood sample during the full-term pregnancy that led to the birth of their first child. Two hundred and forty-four women with invasive breast cancer were eligible. Two controls, matching the index case for age and date at blood donation were selected ( = 453). IGF-I was measured in serum samples on an Immulite 2000 analyzer. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals. A significant positive association of breast cancer with IGF-I was observed, with OR of 1.73 (95% CI: 1.14–2.63) for the top tertile

PURPOSE: Although survival has been studied for various subtypes of non-Hodgkin's lymphoma (NHL), there have been few comprehensive studies to quantify the prognosis, including all specific histologies. The effect of family history on survival in NHL has not been examined. METHODS: We used the Swedish Family-Cancer Database to estimate hazard ratios in NHL by histology and family history. RESULTS: Using diffuse centroblastic lymphoma as reference (HR 1.0), patients with Waldenstrom's macroglobulinemia and hairy-cell leukemia had the best survival. Survival advantage was also noted among patients with lymphoplasmacytic lymphoma and different kinds of follicular lymphomas. For T-cell lymphoma, mycosis fungoides showed a favorable prognosis. As for survival by family history, a total of 98 familial cases were noted in our Database with a similar prognosis compared to sporadic cases in both parental and offspring generations. A non-significant familial concordance of either good or poor survival was noted among family members when probands' prognosis was stratified by survival time. CONCLUSIONS: Our results provide quantitative prognosis data for patients with NHL according to specific histologies. Patients with a familial NHL had a similar prognosis compared to patients with sporadic disease. The data suggest familial concordance in either good or poor survival among family members.

Isozymes of amino acid naphthylamidase were investigated in 11 patients with chronic myeloid leukaemia (CML) and 1 patient with erythroleukaemia. Two isozymes were found in all cases (isozymes A and C) which also occur in normal granulocytes. An isozyme with intermediate mobility appeared in all the patients in two main forms (isozymes BF and BS), which both differed from the isozyme B found in normal granulocytes. This may therefore support the diagnosis. In 3 patients a shift occurred between isozymes BF and BS, the possible significance of which is discussed.

During the period 1978-1982 in the three northernmost countries of Sweden all 143 patients with a registered diagnosis of chronic lymphocytic leukemia (CLL) were retrospectively analyzed. After re-evaluation, 122 cases remained in the study. The mean age was 71 years and the male/female ratio was 2.2:1. Sixty-one patients were Binet stage A, 29 stage B and 32 stage C. The diagnosis CLL was made after routine check-up for other diseases in most of the patients and they had no symptoms from the CLL. The median survival was 51 months and there were no differences in crude survival according to stage or other prognostic factors such as hemoglobin, lymphocytes or thrombocytes in peripheral blood. Analysis of CLL as a cause of specific mortality showed the stage of CLL to have a slight prognostic significance. This could be due to the fact that many of the patients suffered from other serious diseases, allowing the detection of early stage or advanced CLL with no symptoms.

A Swedish national care programme has provided guidelines for staging, treatment and follow-up of all patients with Hodgkin's disease (HD) since 1985. Between January 1985 and December 1992, 920 patients were reported and followed prospectively. Of a total of 533 patients with stage I and II disease, 484 presented with supradiaphragmatic HD and 49 (9%) with infradiaphragmatic HD. The median follow-up time was 4.3 yr (3.3-10 yr). Significant differences in average age (45 +/- 21 yr and 55 +/- 19 yr), male:female ratio (1.1:1 and 2.8:1) and B-symptoms (25% and 47%) were observed in patients with supra- and infradiaphragmatic HD, respectively. Forty-six patients with infradiaphragmatic HD were treated with a curative intention and 40 (87%) achieved a complete response. Eleven (28%) of the 40 patients have recurred and 8 patients have died of HD. Complete response rates and recurrence frequencies did not differ from those observed in patients with supradiaphragmatic HD. Mortality was, however, significantly higher (p = 0.001) in the infradiaphragmatic group; this was due mainly to poorer effects of salvage treatment in a elderly population. In this population-based study, patients with peripheral disease in stage IA respond well to inverted Y irradiation alone, whereas it appears to be important to give stage II patients chemotherapy or a combined modality treatment in order to avoid unacceptably high recurrence rates.

Peripheral blood from 69 patients with non-Hodgkin's lymphoma was examined with respect to B and T cell markers. Evidence for monoclonal B cell was found in 29 cases, 8 of 'high grade' and 21 of 'low grade' malignancy according to the Kiel classification. 17 out of the 29 patients had a normal lymphocyte count. Using conventional staging methods 4 cases of the 29 were in stages II and III, all others in stage IV. The proportion of S-phase cells in peripheral blood, determined by flow cytometry, was found to be elevated in cases with a monoclonal cell population. It is concluded that surface marker analysis of blood cells may be valuable as a diagnostic tool, as an indicator of prognosis and perhaps for the staging procedure of malignant lymphomas.

ObjectivesTo estimate the interval cancer incidence, its determinants and the episode sensitivity in the Norrbotten Mammography Screening Programme (NMSP).SettingSince 1989, women aged 40–74 years (n = 55,000) have been invited to biennial screening by the NMSP, Norrbotten county, Sweden.MethodsData on 1047 invasive breast cancers from six screening rounds of the NMSP (1989–2002) were collected. We estimated the invasive interval cancer rates, rate ratios and the episode sensitivity using the detection and incidence methods. A linear Poisson-model was used to analyse association between interval cancer incidence and sensitivity.Results768 screen-detected and 279 interval cancer cases were identified. The rate ratio of interval cancer decreased with age. The 50–59 year age group showed the highest rate ratio (RR = 0.52, 95% CI 0.41–0.65) and the 70–74 year age group the lowest (RR = 0.23, 95% CI 0.15–0.36). The rate ratios for the early (0–12 months) and late (13–24 months) interval cancers were similar (RR = 0.18, 95% CI 0.15–0.22 and 0.20, 95% CI 0.17–0.24). There was a significantly lower interval cancer incidence in the prevalence round as compared with the incidence rounds. According to the detection method the episode sensitivity increased with age from 57% in the age group 40–49 years to 84% in the age group 70–74 years. The corresponding figures for the incidence method were 50% and 77%, respectively.ConclusionOur study showed an interval cancer incidence of 38% and the episode sensitivity of 62–73%, depending on the method of calculation. Our results are of clinically acceptable level and concert with the reference values of the European guidelines.

Chromosomal instability (CIN) is a major characteristic of many cancers. We investigated whether putatively functional single nucleotide polymorphisms (SNPs) in genes related to CIN (CENPF, ESPL1, NEK2, PTTG1, ZWILCH, ZWINT) affect breast cancer (BC) risk and clinical outcome in a Swedish cohort of 749 incident BC cases with detailed clinical data and up to 15 years of follow-up and 1493 matched controls. As a main observation, carriers of the A allele of the CENPF SNP rs438034 had a worse BC-specific survival compared to the wild type genotype GG carriers (hazard ratio (HR) 2.65, 95% confidence interval (CI) 1.19-5.90), although they were less likely to have regional lymph node metastases (odds ratio (OR) 0.71, 95% CI 0.51-1.01) and tumours of stage II-IV (OR 0.73, 95% CI 0.54-0.99). As there is increasing evidence that CENPF is associated with poor prognosis in patients with primary BC, further independent studies are needed to clarify the importance of genetic variation in the CENPF gene in the clinic.

Both adjuvant therapy and mammography screening can decrease breast cancer mortality and there is a need of knowing to what extent those two modalities are used in the population. Screening coverage is well documented but there is a scarcity of population-based data on use of systemic adjuvant treatment.To describe the introduction, and trends in the use of adjuvant systemic therapy for breast cancer in two of six public health regions in Sweden.Population-based data on use of adjuvant therapy were available from databases with documented high quality and high coverage data for Stockholm (1976-2005) and North Sweden (1980-2003, and 2005).The use of systemic treatment was infrequent before the late 1980s in both regions, but increased during the 1990s. In 2005, the proportion of operable breast cancer patients treated with adjuvant endocrine therapy in the ages 40-59 was around 60 to 80%. The proportion adjuvant chemotherapy was less than 15% for the ages 70-74. For the north region the use of endocrine therapy increased successively over time, with an exception for age group 40-49 were a more rapidly increase occurred in the late 1990s. In Stockholm the increment was higher and more rapidly. There was no clear difference in chemotherapy use between the regions, and the use increased from the mid 1980s in age group 40-49, and in the early 1990s for women aged 50-59. In age group's 60-69 and 70-74 the use was relatively infrequent.Trends in, and levels of the use of adjuvant systemic therapy for breast cancer varied over time in the two study regions, particularly for endocrine therapy. We consider that the differences between the regions mainly reflect different interpretations of new scientific evidence. We stress the importance of a good documentation of all new treatment protocols.

The strong correlation between smoking and exposure to oncogenic human papillomaviruses (HPVs) has made it difficult to verify the independent role of smoking in cervical carcinogenesis. Thus, the authors evaluated this role. Five large Nordic serum banks containing samples from more than 1,000,000 subjects were linked with nationwide cancer registries (1973-2003). Serum samples were retrieved from 588 women who developed invasive cervical cancer and 2,861 matched controls. The samples were analyzed for cotinine (a biomarker of tobacco exposure) and antibodies to HPV types 16 and 18, herpes simplex virus type 2, and Chlamydia trachomatis. Smoking was associated with the risk of squamous cell carcinoma (SCC) among HPV16- and/or HPV18-seropositive heavy smokers (odds ratio=2.7, 95% confidence interval: 1.7, 4.3). A similar risk of SCC (odds ratio=3.2, 95% confidence interval: 2.6, 4.0) was found in heavy smokers after adjustment for HPV16/18 antibodies. The point estimates increased with increasing age at diagnosis and increasing cotinine level. This study confirms that smoking is an independent risk factor for cervical cancer/SCC in women infected with oncogenic HPVs. These findings emphasize the importance of cervical cancer prevention among women exposed to tobacco smoke.

Pregnancy hormones are believed to be involved in the protection against breast cancer conferred by pregnancy. The authors explored the association of maternal breast cancer with human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP). In 2001, a case-control study was nested within the Northern Sweden Maternity Cohort, an ongoing study in which blood samples have been collected from first-trimester pregnant women since 1975. Cases (n = 210) and controls (n = 357) were matched for age, parity, and date of blood donation. Concentrations of hCG and AFP were measured by immunoassay. No overall significant association of breast cancer with either hCG or AFP was observed. However, women with hCG levels in the top tertile tended to be at lower risk of breast cancer than women with hCG levels in the lowest tertile in the whole study population and in subgroups of age at sampling, parity, and age at cancer diagnosis. A borderline-significant decrease in risk with high hCG levels was observed in women who developed breast cancer after the median lag time to cancer diagnosis (> or =14 years; odds ratio = 0.53, 95% confidence interval: 0.27, 1.03; P = 0.06). These findings, though very preliminary, are consistent with a possible long-term protective association of breast cancer risk with elevated levels of circulating hCG in the early stages of pregnancy.

Background: Family history has been reported to be associated with an increased risk of pancreatic cancer. However, its possible influence on pancreatic cancer survival has rarely been studied, probably because of the rareness of cases in the same family. Methods: We used the nationwide Swedish Family-Cancer Database to examine the survival differences between familial and sporadic pancreatic cancers. Hazard ratios (HRs) for cause-specific and overall survival in pancreatic cancer were examined. HRs show the probability of death in the study group compared to the reference group. Results: A total of 75 familial pancreatic cancers were noted. HRs were significantly higher among offspring with an affected parent compared to those without an affected parent; for cause-specific and overall survival, the HRs were 1.44 and 1.37, respectively. Reversing the analysis and deriving HRs for parents (offspring as probands) showed that familial pancreatic cancer had a worse prognosis than sporadic cases (HR 1.37 for cause-specific and 1.28 for overall survival). The HRs were close to unity among spouses with concordant pancreatic cancer. Conclusion: The data show that survival in familial pancreatic cancer is worse than that in sporadic disease, which could be explained by genetic factors, if other confounding factors can be excluded.

Purpose Quantitative data on subsequent cancers after primary cancers provide information on treatment-related risks on second cancers, with implications for therapeutic adverse effects and human susceptibility in general. Quantitative data on solid tumors are limited. We focus on survivors of non-Hodgkin's lymphoma (NHL) because the disease is diagnosed at a wide range of ages and treated uniformly primarily with chemotherapy. Patients and Methods The nationwide Swedish Family-Cancer Database included 11.5 million individuals whose cancers were retrieved from the Swedish Cancer Registry. Standardized incidence ratios (SIRs) were calculated for subsequent neoplasms among 28,131 patients with NHL. Results The SIR for solid tumors after NHL was 1.65 (2,290 patients) and that for lymphohematopoietic neoplasms was 5.36 (369 patients). Among the 25 most common solid tumors, the SIRs were increased for all but nine sites; the highest SIR (40.8) was observed for spinal meningioma. The SIRs for solid tumors declined in an age-dependent manner from 4.52 in diagnostic age younger than 20 years to 1.12 in diagnostic age 70+ years. In the most common patient groups, the SIRs for solid tumors increased up to 30 years after NHL diagnosis. Because of the high incidence of solid tumors in these age groups, they contributed the largest numbers of therapy-related cases. Conclusion These data indicate that age at treatment determines both the magnitude of the initial relative risk and the time-dependent modulation of the response. Therapy-related damage persists at least 30 years and its toll of solid tumors is largest 21 to 30 years after diagnosis.

Purpose Several earlier studies have assessed survival in prostate cancer based on familial risk of this disease. As a novel concept, we posit that factors governing survival in prostate cancer are likely to be different from those governing risk of prostate cancer. To prove this, we searched for familial clustering of survival (ie, concordance of survival among family members). Patients and Methods We used the nationwide Swedish Family-Cancer Database to estimate hazard rates (HRs) for cause-specific and overall survival in invasive prostate cancer. HRs show the probability of death in the study group compared with the reference group. The study covered 610 sons of affected fathers with median follow-up times for survival ranging from 34 to 76 months. Results When the survival in sons was analyzed according to the fathers' length of survival, there was a concordance of prognosis; the HR was 0.62 for sons whose fathers had survived longer than 59 months, compared with sons whose fathers had survived fewer than 24 months (P for trend, .02). On a continuous scale, the sons' survival increased almost linearly with the fathers' survival time. When the analysis was reversed and HRs were derived for fathers, the concordance of good and poor survival remained. Conclusion The results are consistent in showing that both good and poor survival in prostate cancer aggregate in families. Genetic factors are likely to contribute to the results, which provide the first challenging population-level evidence on heritability in prognosis of prostate cancer.

While cancer survival at several sites has historically been shown to vary by education level, a current comprehensive assessment of survival following a cancer diagnosis in Sweden, a country with universal health care and cancer screening, has yet to be carried out.Using the 2006 update of the Swedish Family-Cancer Database and Cox's proportional hazards regression methods, we calculate the adjusted hazard ratio (HR) and 95% confidence interval to estimate the influence of education level on site-specific cancer survival.Significant positive associations between education level and cancer survival were observed following a diagnosis of upper aerodigestive track cancer, colon cancer, pancreatic cancer, lung cancer, kidney cancer, urinary bladder cancer, melanoma, non-Hodgkin's lymphoma, breast cancer, endometrial cancer, cervical cancer, prostate cancer, and testicular cancer. Although the HRs differed between cancer sites, compared with women and men completing9 years of education, university graduates were associated with a significant 40% improved survival for all cancer sites combined.Survival differences by education level were observed for both indolent and aggressive malignancies.

Extracellular matrix degradation, mediated by the urokinase plasminogen activation (uPA) system, is a critical step in tumor invasion and metastasis. High tumor levels of uPA and its inhibitor PAI-1 have been correlated with poor prognosis in breast cancer. We examined whether genetic variation in the genes of the uPA system affect breast cancer susceptibility and prognosis. We genotyped eight potentially functional single nucleotide polymorphisms (SNPs) in six genes of the uPA system in 959 Swedish breast cancer patients with detailed clinical data and up to 15 years of follow-up together with 952 matched controls. We used the unconditional logistic regression models to evaluate the associations between genotypes and breast cancer risk and tumor characteristics. The Kaplan-Meier method was used to estimate the survival probabilities; the log-rank test was used to test differences between subgroups. None of the SNPs conferred an increased breast cancer risk, but correlation with some traditional prognostic factors was observed for several SNPs. Most importantly, we identified the -675 4G/5G SNP in the PAI-1 gene as a promising prognostic biomarker for breast cancer. Compared to the 4G/4G and 4G/5G genotypes 5G/5G homozygosity correlated significantly with worse survival (RR 2.04, 95% CI 1.45–2.86, P < 0.001), especially in patients with more aggressive tumors. 5G/5G homozygotes were also the group with worse survival among lymph node negative cases. Our finding suggests that genotyping PAI-1 -675 4G/5G may help in clinical prognosis of breast cancer.

Objectives: To study the effectiveness of service screening with mammography in Northern Sweden. Setting: Two counties which invited women aged 40–74 years to service screening with mammography were compared with two counties where service screening started 5–7 years later. There were 109,000 and 77,000 women in the study and control counties, respectively. Methods: Cohorts in the study group were defined to include only breast cancer cases diagnosed after their first invitation to screening. Two outcome measures for breast cancer mortality were used; excess mortality and underlying cause of death (UCD). Detection mode was used to estimate the efficacy of screening for those women who actually attended screening. The cohorts were followed for 11 years. Results: The relative rate (RR) of breast cancer death as excess mortality and UCD for women aged 40–74 years invited to screening, compared with women not yet invited, was 0.70 (95% confidence interval [CI] 0.56–0.87) and 0.74 (95% CI 0.62–0.88), respectively. The largest effect was seen in women aged 40–49 years (RR = 0.64 and RR = 0.62 for excess mortality and UCD, respectively). RR in age 40–74 years for women actually screened was 0.65 (95% CI 0.51–0.84) and 0.70 (95% CI 0.57–0.86) for excess mortality and UCD, respectively. The number of women needed to screen to save one life was 912 after 11 years of follow-up. Conclusions: This study confirms previous findings in the earlier follow-up and indicates a long-term reduction of breast cancer mortality by 26–30%. The efficacy among those who actually attended screening was about 5% larger.

The aim of this study was to estimate breast cancer survival according to detection mode for 5120 women with invasive breast cancer, in particular for those detected in the screening intervals. We found a significant survival difference in favour of women with cancer detected in the screening intervals (n=729) compared with those uninvited (n=1879) during the 13-year follow-up. Detection mode was proven to modify the prognostic effect of stage. Women with stage I interval cancer had shorter survival and those with stage II had longer survival than expected. It is suggested that interval cancers might consist of two subgroups with different behaviour: one of fast-growing tumours presenting as stage I cases and another of slow-growing tumours presenting as stage II+ cases. A hypothesis related to this observation is discussed.

Genome-wide association studies (GWASs) help to understand the effects of single nucleotide polymorphisms (SNPs) on breast cancer (BC) progression and survival. We performed multiple analyses on data from a previously conducted GWAS for the influence of individual SNPs, runs of homozygosity (ROHs) and inbreeding on BC survival. (I.) The association of individual SNPs indicated no differences in the proportions of homozygous individuals among short-time survivors (STSs) and long-time survivors (LTSs). (II.) The analysis revealed differences among the populations for the number of ROHs per person and the total and average length of ROHs per person and among LTSs and STSs for the number of ROHs per person. (III.) Common ROHs at particular genomic positions were nominally more frequent among LTSs than in STSs. Common ROHs showed significant evidence for natural selection (iHS, Tajima’s D, Fay-Wu’s H). Most regions could be linked to genes related to BC progression or treatment. (IV.) Results were supported by a higher level of inbreeding among LTSs. Our results showed that an increased level of homozygosity may result in a preference of individuals during BC treatment. Although common ROHs were short, variants within ROHs might favor survival of BC and may function in a recessive manner.

Germline mutations in tumour suppressor genes cause various cancers. These genes are also somatically mutated in sporadic tumours. We hypothesized that there may also be cancer-related germline variants in the genes commonly mutated in sporadic breast tumours. After excluding the well-characterized breast cancer (BC) genes, we screened 15 novel genes consistently classified as BC driver genes in next-generation sequencing approaches for single nucleotide polymorphisms (SNPs). Altogether 40 SNPs located in the core promoter, 5′- and 3′-UTR or which were nonsynonymous SNPs were genotyped in 782 Swedish incident BC cases and 1,559 matched controls. After statistical analyses, further evaluations related to functional prediction and signatures of selection were performed. TBX3 was associated with BC risk (rs2242442: OR = 0.76, 95% CI 0.64–0.92, dominant model) and with less aggressive tumour characteristics. An association with BC survival and aggressive tumour characteristics was detected for the genes ATR (rs2227928: HR = 1.63; 95% CI 1.00–2.64, dominant model), RUNX1 (rs17227210: HR = 3.50, 95% CI 1.42–8.61, recessive model) and TTN (rs2303838: HR = 2.36; 95% CI 1.04–5.39; rs2042996: HR = 2.28; 95% CI 1.19–4.37, recessive model). According to the experimental ENCODE data all these SNPs themselves or SNPs in high linkage disequilibrium with them (r 2 ≥ 0.80) were located in regulatory regions. RUNX1 and TTN showed also several signatures of positive selection. The study gave evidence that germline variants in BC driver genes may have impact on BC risk and/or survival. Future studies could discover further germline variants in known or so far unknown driver genes which contribute to cancer development.

Genetic polymorphisms in vitamin D metabolism and signaling genes have been inconsistently associated with risk of breast cancer, though few studies have examined SNPs in vitamin D-related genes other than the vitamin D receptor (VDR) gene and particularly have not examined the association with the retinoid X receptor alpha (RXRA) gene which may be a key vitamin D pathway gene. We conducted a nested case-control study of 734 cases and 1435 individually matched controls from a population-based prospective cohort study, the Northern Sweden Mammary Screening Cohort. Tag and functional SNPs were genotyped for the VDR, cytochrome p450 24A1 (CYP24A1), and RXRA genes. We also genotyped specific SNPs in four other genes related to vitamin D metabolism and signaling (GC/VDBP, CYP2R1, DHCR7, and CYP27B1). SNPs in the CYP2R1, DHCR7, and VDBP gene regions that were associated with circulating 25(OH) D concentration in GWAS were also associated with plasma 25(OH) D in our study (p-trend < 0.005). After taking into account the false discovery rate, these SNPs were not significantly associated with breast cancer risk, nor were any of the other SNPs or haplotypes in VDR, RXRA, and CYP24A1. We observed no statistically significant associations between polymorphisms or haplotypes in key vitamin D-related genes and risk of breast cancer. These results, combined with the observation in this cohort and most other prospective studies of no association of circulating 25(OH) D with breast cancer risk, do not support an association between vitamin D and breast cancer risk.

Background: The role of insulin-like growth factor (IGF)-I in breast cancer remains controversial, despite numerous reports on the association of the hormone with breast cancer or high-risk mammographic densities. We hypothesized that exposure to elevated IGF-I during early pregnancy, a period characterized by intense cell proliferation in the breasts and in the presence of high concentrations of sex steroids, will be associated with increased maternal risk to develop a breast malignancy. Methods: The Northern Sweden Maternity Cohort is an ongoing prospective study, collecting blood samples from first-trimester-pregnant women since 1975 as part of screening for infectious diseases. A case-control study (212 cases and 369 controls) was nested among Northern Sweden Maternity Cohort members who delivered singleton babies. RIA was used to measure IGF-I and IGF-II levels. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). Results: Breast cancer risk increased with increasing IGF-I (top tertile OR, 1.7; 95% CI, 1.1-2.7). The association was stronger among the primiparous (OR, 2.2; 95% CI, 1.1-4.4) than in the nonprimiparous women (OR, 1.4; 95% CI, 0.7-2.8). Upper-tertile risks seemed to decrease within the 33-year groups of age at sampling, from 2.5 (0.9-7.6) to 2.1 (0.9-5.0) and 1.2 (0.5-2.5), respectively. There was no association of breast cancer with first-trimester-pregnancy IGF-II. Conclusions: The study offers further evidence that IGF-I is important in breast cancer. Our findings suggest that the adverse effect of IGF-I on the breast may be stronger before the remodeling of the gland induced by a first pregnancy. (Cancer Epidemiol Biomarkers Prev 2006;15(12):2489–93)

The importance of matrix metalloproteinases and their inhibitors in tumor progression is well documented. We wanted to investigate if single nucleotide polymorphisms (SNPs) in the promoter regions of these genes are associated with susceptibility to or progression of breast cancer. In this, so far largest case-control study, we genotyped eight SNPs in the MMP1, MMP2, MMP3, MMP9, MMP13, RECK and TIMP3 genes in a well-characterized breast cancer series of 959 cases and 952 controls from Sweden. Even though we did not correct for multiple comparisons, only a few associations were noted. We observed a moderately increased risk for the TT homozygotes of the MMP9-1562 C/T SNP (OR 1.88, 95% CI 0.97-3.63) and for the C allele carriers of the TIMP3-1296 T/C SNP (OR 1.25, 95% CI 1.05-1.50). In the survival analysis, only the TC heterozygotes of the RECK-420 T/C SNP showed a better survival compared to the TT homozygotes (P = 0.02 in all cases and P = 0.03 in lymph node negative cases). None of the other SNPs conferred an increased breast cancer risk, nor did they correlate with survival. A combination of the -585 TT homozygosity in the RECK gene and the -1296 TT homozygosity in the TIMP3 gene correlated with estrogen and progesterone receptor status (OR 1.81, 95% CI 1.03-3.21 and OR 2.10, 95% CI 1.18-3.86, respectively), and a combination of the -1306 TT homozygosity in the MMP2 gene and the -1562 CC homozygosity in the MMP9 gene with progesterone receptor status (OR 2.34, 95% CI 1.08-5.08). Although our study suggests some correlations between the studied SNPs and the progression of breast cancer, the rarity of the risk genotypes limits their usefulness in the clinic.

Excess weight has been associated with increased risk of cancer. The effect of body mass index (BMI, kg/m(2)) on overall cancer risk and on risk of developing several common cancer types was examined in a population-based cohort study. Height and weight measurements were available for 35,362 women and 33,424 men recruited in the Northern Sweden Health and Disease Cohort between 1985 and 2003. Among cohort members, 2,691 incident cancer cases were identified. The association of BMI with cancer risk was examined using Poisson regression. Women with BMI27.1 (top quartile) had a 29% higher risk of developing any malignancy compared to women with BMI of 18.5-22.2 (lowest quartile), which increased to 47% in analysis limited to nonsmokers. Analyses according to WHO cut-off points showed that obese women (BMIor = 30) had a 36% higher risk of cancer than women with BMI in the normal range (18.5-25). Individual cancer sites most strongly related to obesity were endometrium (risk for top quartile = 3.53, 95% confidence interval 1.86-7.43), ovary (2.09, 1.13-4.13) and colon (2.05, 1.04-4.41). BMI was inversely related to breast cancer occurring before age 49 (0.58, 0.29-1.11, p(trend)0.04). In men, there was no association of BMI with overall cancer risk. Obese men (BMIor = 30), however, were at increased risk of developing kidney cancer (3.63, 1.23-10.7) and, after exclusion of cases diagnosed within 1 year of recruitment, colon cancer (1.77, 1.04-2.95). Our study provides further evidence that BMI is positively associated with cancer risk. In women from northern Sweden, up to 7% of all cancers were attributable to overweight and obesity and could be avoided by keeping BMI within the recommended range.

Background: In our companion article, incidence-based mortality analysis of data from breast cancer screening programs in 13 areas in Sweden indicated a 40% to 45% reduction in incidence-based breast cancer mortality among women actually screened. In this article, we apply new analytic methods for the evaluation of breast cancer mortality, using all breast cancer deaths in the period under study. Methods: Data were available from 13 areas on breast cancer mortality by year of diagnosis, year of death, and screening exposure. The period of study varied by area, the overall range of year of diagnosis being 1968 to 2001. We had data on 6,231 deaths and an average population of 555,676 women ages 40 to 69 years. Analysis of the effect of being screened was conducted using an alternative statistical analysis applied to all breast cancer deaths in the period of study, in addition to the incidence-based mortality analysis in our companion article. Data were analyzed using Poisson regression and adjusted for self-selection bias, contemporaneous changes in incidence, and changes in mortality independent of screening. Results: Using all deaths in the period of observation, a significant 42% reduction in breast cancer mortality was observed, adjusting for contemporaneous changes independent of screening [relative risk (RR), 0.58; 95% confidence interval (95% CI), 0.53-0.62]. After further adjustment for self-selection bias, the mortality reduction was 39% (RR, 0.61; 95% CI, 0.55-0.68), also highly significant. Conclusions: These results indicate a reduction in breast cancer mortality of 39% in association with screening, after adjustment for contemporaneous changes and self-selection bias. These results confirm previous conclusions arrived at using incidence-based mortality analyses.