Search

Background & Aims Human studies examining associations between circulating levels of insulin-like growth factor 1 (IGF1) and insulin-like growth factor binding protein 3 (IGFBP3) and colorectal cancer risk have reported inconsistent results. We conducted complementary serologic and Mendelian randomization (MR) analyses to determine whether alterations in circulating levels of IGF1 or IGFBP3 are associated with colorectal cancer development. Methods Serum levels of IGF1 were measured in blood samples collected from 397,380 participants from the UK Biobank, from 2006 through 2010. Incident cancer cases and cancer cases recorded first in death certificates were identified through linkage to national cancer and death registries. Complete follow-up was available through March 31, 2016. For the MR analyses, we identified genetic variants associated with circulating levels of IGF1 and IGFBP3. The association of these genetic variants with colorectal cancer was examined with 2-sample MR methods using genome-wide association study consortia data (52,865 cases with colorectal cancer and 46,287 individuals without [controls]) Results After a median follow-up period of 7.1 years, 2665 cases of colorectal cancer were recorded. In a multivariable-adjusted model, circulating level of IGF1 associated with colorectal cancer risk (hazard ratio per 1 standard deviation increment of IGF1, 1.11; 95% confidence interval [CI] 1.05–1.17). Similar associations were found by sex, follow-up time, and tumor subsite. In the MR analyses, a 1 standard deviation increment in IGF1 level, predicted based on genetic factors, was associated with a higher risk of colorectal cancer risk (odds ratio 1.08; 95% CI 1.03–1.12; P = 3.3 × 10–4). Level of IGFBP3, predicted based on genetic factors, was associated with colorectal cancer risk (odds ratio per 1 standard deviation increment, 1.12; 95% CI 1.06–1.18; P = 4.2 × 10–5). Colorectal cancer risk was associated with only 1 variant in the IGFBP3 gene region (rs11977526), which also associated with anthropometric traits and circulating level of IGF2. Conclusions In an analysis of blood samples from almost 400,000 participants in the UK Biobank, we found an association between circulating level of IGF1 and colorectal cancer. Using genetic data from 52,865 cases with colorectal cancer and 46,287 controls, a higher level of IGF1, determined by genetic factors, was associated with colorectal cancer. Further studies are needed to determine how this signaling pathway might contribute to colorectal carcinogenesis., Graphical abstract

Previous in vitro and case–control studies have found an association between the insulin‐like growth factor (IGF)‐axis and bladder cancer risk. Circulating concentrations of IGF‐I have also been found to be associated with an increased risk of several cancer types; however, the relationship between pre‐diagnostic circulating IGF‐I concentrations and bladder cancer has never been studied prospectively. We investigated the association of pre‐diagnostic plasma concentrations of IGF‐I with risk of overall bladder cancer and urothelial cell carcinoma (UCC) in a case–control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. A total of 843 men and women diagnosed with bladder cancer between 1992 and 2005 were matched with 843 controls by recruitment centre, sex, age at recruitment, date of blood collection, duration of follow‐up, time of day and fasting status at blood collection using an incidence density sampling protocol. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression with adjustment for smoking status. No association was found between pre‐diagnostic circulating IGF‐I concentration and overall bladder cancer risk (adjusted OR for highest versus lowest fourth: 0.91, 95% CI: 0.66–1.24, p trend = 0.40) or UCC (n of cases = 776; 0.91, 0.65–1.26, p trend = 0.40). There was no significant evidence of heterogeneity in the association of IGF‐I with bladder cancer risk by tumour aggressiveness, sex, smoking status, or by time between blood collection and diagnosis (p heterogeneity > 0.05 for all). This first prospective study indicates no evidence of an association between plasma IGF‐I concentrations and bladder cancer risk., What's new? Past prospective studies have shown a positive association between circulating insulin‐like growth factor I (IGF‐I) concentration and colorectal, prostate, and breast cancer risk. However, the association between circulating IGF‐I concentrations and bladder cancer risk remains uncertain. Using a nested‐case control study with 843 bladder cancer cases across 9 European countries, for the first time here the authors examined prospectively the association between pre‐diagnostic circulating IGF‐I concentrations and bladder cancer risk. IGF‐I was not associated with overall risk of bladder cancer or urothelial cell carcinoma. Further prospective data, including on tumour aggressiveness, are required to examine the association in greater detail.

Insulin-like Growth Factor 1 (IGF-1) and its signaling pathway play a primary role in normal growth and ageing, however serum IGF-1 is known to reduce with advancing age. Recent findings suggest IGF-1 is essential for neurogenesis in the adult brain, and this reduction of IGF-1 with ageing may contribute to age-related cognitive decline. Experimental studies have shown manipulation of the GH/GF-1 axis can slow rates of cognitive decline in animals, making IGF-1 a potential biomarker of cognition, and/or its signaling pathway a possible therapeutic target to prevent or slow age-related cognitive decline. A systematic literature review and qualitative narrative summary of current evidence for IGF-1 as a biomarker of cognitive decline in the ageing brain was undertaken. Results indicate IGF-1 concentrations do not confer additional diagnostic information for those with cognitive decline, and routine clinical measurement of IGF-1 is not currently justified. In cases of established cognitive impairment, it remains unclear whether increasing circulating or brain IGF-1 may reverse or slow down the rate of further decline. Advances in neuroimaging, genetics, neuroscience and the availability of large well characterized biobanks will facilitate research exploring the role of IGF-1 in both normal ageing and age-related cognitive decline.

The role of insulin-like growth factors (IGF) in prostate cancer development is not fully understood. To investigate the association between circulating concentrations of IGFs (IGF-I, IGF-II, IGFBP-1, IGFBP-2, and IGFBP-3) and prostate cancer risk, we pooled individual participant data from 17 prospective and two cross-sectional studies, including up to 10,554 prostate cancer cases and 13,618 control participants. Conditional logistic regression was used to estimate the ORs for prostate cancer based on the study-specific fifth of each analyte. Overall, IGF-I, IGF-II, IGFBP-2, and IGFBP-3 concentrations were positively associated with prostate cancer risk (Ptrend all ≤ 0.005), and IGFBP-1 was inversely associated weakly with risk (Ptrend = 0.05). However, heterogeneity between the prospective and cross-sectional studies was evident (Pheterogeneity = 0.03), unless the analyses were restricted to prospective studies (with the exception of IGF-II, Pheterogeneity = 0.02). For prospective studies, the OR for men in the highest versus the lowest fifth of each analyte was 1.29 (95% confidence interval, 1.16-1.43) for IGF-I, 0.81 (0.68-0.96) for IGFBP-1, and 1.25 (1.12-1.40) for IGFBP-3. These associations did not differ significantly by time-to-diagnosis or tumor stage or grade. Aftermutual adjustment for each of the other analytes, only IGF-I remained associated with risk. Our collaborative study represents the largest pooled analysis of the relationship between prostate cancer risk and circulating concentrations of IGF-I, providing strong evidence that IGF-I is highly likely to be involved in prostate cancer development.

Insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) are involved in cell replication, proliferation, differentiation, protein synthesis, carbohydrate homeostasis and bone metabolism. Circulating IGF-I and IGFBP-3 concentrations predict anthropometric traits and risk of cancer and cardiovascular disease. In a genome-wide association study of 10 280 middle-aged and older men and women from four community-based cohort studies, we confirmed a known association of single nucleotide polymorphisms in the IGFBP3 gene region on chromosome 7p12.3 with IGFBP-3 concentrations using a significance threshold of P < 5 × 10(-8) (P = 3.3 × 10(-101)). Furthermore, the same IGFBP3 gene locus (e.g. rs11977526) that was associated with IGFBP-3 concentrations was also associated with the opposite direction of effect, with IGF-I concentration after adjustment for IGFBP-3 concentration (P = 1.9 × 10(-26)). A novel and independent locus on chromosome 7p12.3 (rs700752) had genome-wide significant associations with higher IGFBP-3 (P = 4.4 × 10(-21)) and higher IGF-I (P = 4.9 × 10(-9)) concentrations; when the two measurements were adjusted for one another, the IGF-I association was attenuated but the IGFBP-3 association was not. Two additional loci demonstrated genome-wide significant associations with IGFBP-3 concentration (rs1065656, chromosome 16p13.3, P = 1.2 × 10(-11), IGFALS, a confirmatory finding; and rs4234798, chromosome 4p16.1, P = 4.5 × 10(-10), SORCS2, a novel finding). Together, the four genome-wide significant loci explained 6.5% of the population variation in IGFBP-3 concentration. Furthermore, we observed a borderline statistically significant association between IGF-I concentration and FOXO3 (rs2153960, chromosome 6q21, P = 5.1 × 10(-7)), a locus associated with longevity. These genetic loci deserve further investigation to elucidate the biological basis for the observed associations and clarify their possible role in IGF-mediated regulation of cell growth and metabolism.

Objectives: Epidemiological studies benefit from unbiased blood specimens collected with minimal cost and effort of blood collection and storage. We evaluated the stability of IGF-1 and IGFBP-3 in whole blood samples stored at room temperature to justify delays in blood processing.Design and methods: Total IGF-1 and IGFBP-3 levels were measured in EDTA plasma (n = 12), heparin plasma (n = 12) and serum (n = 10) samples of healthy volunteers after blood processing delays up till 14 days. Stability of measured IGF-1 and IGFBP-3 levels was tested by paired t-test and a linear mixed effect model.Results: Longitudinal analysis showed that IGF-1 levels were not significantly affected by blood processing delays in EDTA tubes (P = 0.18) and IGFBP-3 levels were marginally stable (p = 0.06). In heparin plasma and serum, however, IGF-1 increased over time of delayed processing and IGFBP-3 levels tended to decrease (pConclusion: Total IGF-1 and IGFBP-3 levels are stable in whole blood collected in EDTA tubes at room temperature up till 7 days, allowing a delay in blood processing to reduce costs in large multi-center studies. (C) 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Item does not contain fulltext We examined consumption of animal foods, protein and calcium in relation to risk of prostate cancer among 142 251 men in the European Prospective Investigation into Cancer and Nutrition. Associations were examined using Cox regression, stratified by recruitment centre and adjusted for height, weight, education, marital status and energy intake. After an average of 8.7 years of follow-up, there were 2727 incident cases of prostate cancer, of which 1131 were known to be localised and 541 advanced-stage disease. A high intake of dairy protein was associated with an increased risk, with a hazard ratio for the top versus the bottom fifth of intake of 1.22 (95% confidence interval (CI): 1.07-1.41, P(trend)=0.02). After calibration to allow for measurement error, we estimated that a 35-g day(-1) increase in consumption of dairy protein was associated with an increase in the risk of prostate cancer of 32% (95% CI: 1-72%, P(trend)=0.04). Calcium from dairy products was also positively associated with risk, but not calcium from other foods. The results support the hypothesis that a high intake of protein or calcium from dairy products may increase the risk for prostate cancer.

Objectives: The risk of some cancers is positively associated with body weight, which may influence circulating levels of sex-steroid hormones, insulin and IGF-I. Interrelationships between these hormones and the associations with adiposity were evaluated in healthy women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC).Methods: A cross-sectional analysis was performed on anthropometric and hormonal data from 743 pre- and 1217 postmenopausal women. Body mass index (BMI) and waist circumference were used as indicators of adiposity. C-peptide, Insulin Growth Factor (IGF)-I, Insulin Growth Factor binding protein (IGFBP)-3, androgens, estrogens and sex hormone binding globulin (SHBG) were measured by immunoassays; free sex steroid concentrations were calculated.Results: BMI and waist circumference were positively correlated with estrogens in postmenopausal women and with C-peptide, free testosterone and inversely with SHBG in all women. C-peptide and IGF-I were inversely correlated with SHBG, and positively with free sex steroids in postmenopausal women. IGF-I was positively associated with postmenopausal estrogens and androgen concentrations in all women.Conclusions: Sex-steroid concentrations appear to be regulated along several axes. Adiposity correlated directly with estrogens in postmenopausal women and with insulin, resulting in lower SHBG and increased levels of free sex steroids. Independent of adiposity and insulin, IGF-I was associated with decreased SHBG levels, and increased concentrations of androgens and postmenopausal estrogens.

The insulin-like growth factor (IGF) system is related to proliferation and tumor growth, and high levels of circulating IGF-I are thought to be a risk factor for several types of cancer. This review summarizes the epidemiologic evidence for an association between circulating IGF-I and cancer risk as well as the experimental evidence for a causal relation between the endocrine IGF system and tumor growth. The potential for dietary intervention to alter the IGF system and thereby cancer risk is supported by several lines of evidence. Postulated mechanisms of action are as follows: (a) reduction of levels of circulating IGF-I, which will decrease activation of the IGF-I receptor and subsequent signaling pathways; (b) increasing local IGF binding proteins, which may have IGF-dependent effects through obstruction of IGF interaction with local IGF-I receptor as well as IGF-independent effects; and (c) interference with estrogens and estrogen receptor action, which may have direct (and possibly synergistic) effects on IGF signaling. An overview is given of the epidemiologic studies on dietary determinants of circulating IGF-I. Examples of dietary factors, such as dairy protein, lycopene, and phytoestrogens, are used to illustrate the potential mode of action of dietary interventions that may act on the IGF system. In conclusion, the IGF system has every potential to serve as an intermediate for cancer (chemo)prevention studies. On the short term, more research initiatives aimed at the effects of specific food components or dietary strategies on the IGF system both in animal models and in humans are warranted.

Final height in girls with turner syndrome after long-term growth hormone treatment in three dosages and low dose estrogens.van Pareren YK, de Muinck Keizer-Schrama SM, Stijnen T, Sas TC, Jansen M, Otten BJ, Hoorweg-Nijman JJ, Vulsma T, Stokvis-Brantsma WH, Rouwe CW, Reeser HM, Gerver WJ, Gosen JJ, Rongen-Westerlaken C, Drop SL.Department of Pediatrics, Division of Endocrinology, Erasmus University MC/Sophia Children's Hospital, 3015 GJ Rotterdam, The Netherlands. vanpareren@zonnet.nlAlthough GH treatment for short stature in Turner syndrome is an accepted treatment in many countries, which GH dosage to use and which age to start puberty induction are issues of debate. This study shows final height (FH) in 60 girls with Turner syndrome treated in a randomized dose-response trial, combining GH treatment with low dose estrogens at a relatively young age. Girls were randomly assigned to group A (4 IU/m(2).d; approximately 0.045 mg/kg/d), group B (first year, 4 IU/m(2).d; thereafter 6 IU/m(2).d), or group C (first year, 4 IU/m(2).d; second year, 6 IU/m(2).d; thereafter, 8 IU/m(2).d). After a minimum of 4 yr of GH treatment, at a mean age of 12.7 +/- 0.7 yr, low dose micronized 17beta-estradiol was given orally. After a mean duration of GH treatment of 8.6 +/- 1.9 yr, FH was reached at a mean age of 15.8 +/- 0.9 yr. FH, expressed in centimeters or SD score, was 157.6 +/- 6.5 or -1.6 +/- 1.0 in group A, 162.9 +/- 6.1 or -0.7 +/- 1.0 in group B, and 163.6 +/- 6.0 or -0.6 +/- 1.0 in group C. The difference in FH in centimeters, corrected for height SD score and age at start of treatment, was significant between groups A and B [regression coefficient, 4.1; 95% confidence interval (CI), 1.4, 6.9; P < 0.01], and groups A and C (coefficient, 5.0; 95% CI, 2.3, 7.7; P < 0.001), but not between groups B and C (coefficient, 0.9; 95% CI, -1.8, 3.6). Fifty of the 60 girls (83%) had reached a normal FH (FH SD score, more than -2). After starting estrogen treatment, the decrease in height velocity (HV) changed significantly to a stable HV, without affecting bone maturation (change in bone age/change in chronological age). The following variables contributed significantly to predicting FH SD score: GH dose, height SD score (ref. normal girls), chronological age at start of treatment, and HV in the first year of GH treatment. GH treatment was well tolerated. In conclusion, GH treatment leads to a normalization of FH in most girls, even when puberty is induced at a normal pubertal age. The optimal GH dosage depends on height and age at the start of treatment and first year HV

The insulin-like growth factor axis, which has been shown to protect cells from apoptosis, plays an essential role in normal cell physiology and in cancer development. The family of insulin-like growth factor binding proteins (IGFBPs) has been shown to have a diverse spectrum of functions in cell growth, death, motility, and tissue remodeling. Among the six IGFBP family members, IGFBP-5 has recently been shown to play an important role in the biology of breast cancer, especially in breast cancer metastasis however, the exact mechanisms of action remain obscure and sometimes paradoxical. An in-depth understanding of IGFBP-5 would shed light on its potential role as a target for breast cancer therapeutics.

Objective. We evaluated the acute effects of low-dose oral estradiol and sequential progesterone on the insulin-like growth factor (IGF)/growth hormone (GH) axis, IGF-binding proteins (IGFBPs) 1 and 3, and plasma levels of sex hormone-binding globulin (SHBG) in postmenopausal subjects. Study design. Thirty healthy normal-weight women (mean age: 54.2+5.7 years) spontaneously postmenopausal for at least 6 months were enrolled. None had used hormone replacement therapy (HRT). Appropriate investigations excluded renal, glucose, lipid and coagulation abnormalities. Breast X-ray and endometrial ultrasound examinations excluded organic pathologies. They received oral cyclical HRT for 1 year, based on the administration of oral estradiol (1 mg/day) for 28 consecutive days plus progesterone (200 mg/day) from day 15 to day 28; out of the whole group, 15 subjects received progesterone orally (group A), while in 15 progesterone was administered transvaginally (group B). On the day before treatment (T0), on day 14 (T14) and on day 28 (T28) of the first cycle, plasma levels of estradiol, progesterone, SHBG, GH, IGF-I and -II, IGFBP-1 and -3, insulin and C-peptide were assayed in all patients. The same parameters were evaluated at T14 and T28 during the 12th month of treatment. Results. At T14, we observed significant increases in the levels of estradiol (from 20+16 to 115+71 pg/ml, p50.001), SHBG (from 132+42 to 182+55 nmol/l, p50.001) and IGFBP-1 (from 92+57 to 127+87 ng/ml, p50.004), while the level of IGF-I decreased (from 197+138 to 129+85 ng/ml, p50.003). At T28, progesterone levels were significantly higher in the women receiving it orally than transvaginally (8.4+6.1 vs. 3.7+3.2 ng/ml, p50.025). However, while oral progesterone did not affect the estrogen-induced variations, transvaginal progesterone abrogated the increase in the levels of IGFBP-1. The levels of IGF-II, IGFBP-3, GH, glucose, C-peptide and insulin did not change at any time. At 1 year, the values maintained the same trends. The estrogen-induced variations of SHBG were correlated directly with those of estradiol (r ¼0.48) and inversely with those of IGF-I (r ¼70.424). Conclusions. Low-dose oral estradiol reduces plasma levels of IGF-I and increases IGFBP-1 and SHBG concentrations, while GH is unchanged. These effects, significant and immediate, lead us to hypothesize a direct action of estradiol on hepatocytes.

Item does not contain fulltext BACKGROUND: Higher circulating insulin-like growth factor I (IGF-I) concentrations have been related to a greater risk of cancer. Lycopene intake is inversely associated with cancer risk, and experimental studies have shown that it may affect the IGF system, possibly through an effect on IGF-binding proteins (IGFBPs). OBJECTIVE: The objective of our study was to investigate the effect of an 8-wk supplementation with tomato-derived lycopene (30 mg/d) on serum concentrations of total IGF-I, IGF-II, IGFBP-1, IGFBP-2, and IGFBP-3. DESIGN: We conducted a randomized, placebo-controlled, double-blinded crossover study in 40 men and 31 postmenopausal women with a family history of colorectal cancer, a personal history of colorectal adenoma, or both. RESULTS: Lycopene supplementation significantly (P = 0.01) increased serum IGFBP-1 concentrations in women (median relative difference between serum IGFBP-1 concentrations after lycopene supplementation and after placebo, 21.7%). Serum IGFBP-2 concentrations were higher in both men and women after lycopene supplementation than after placebo, but to a lesser extent (mean relative difference 8.2%; 95% CI: 0.7%, 15.6% in men and 7.8%; 95% CI: -5.0%, 20.6% in women). Total IGF-I, IGF-II, and IGFBP-3 concentrations were not significantly altered by lycopene supplementation. CONCLUSIONS: This is the first study known to show that lycopene supplementation may increase circulating IGFBP-1 and IGFBP-2 concentrations. Because of high interindividual variations in IGFBP-1 and IGFBP-2 effects, these results should be confirmed in larger randomized intervention studies.

Context: Epidemiological studies have indicated that high serum levels of GH and IGF-I are associated with long-term risks. Objective: The objective of the study was to evaluate the changes in serum levels of GH during overnight profiles, IGF-I, and IGF binding protein 3 (IGFBP-3) in short small for gestational age (SGA) children during GH treatment with two doses. Patients: Thirty-six prepubertal short SGA children were the subjects of this study. Intervention: Subjects received 1 (group A) or 2 (group B) mg GH/m2·d. Main Outcome Measures: At baseline and after 6 months of GH treatment, overnight GH profiles were performed, and serum IGF-I and IGFBP-3 levels were measured. Results: After 6 months, group B had significantly higher GH levels during the profile (mean, maximum, and area under the curve above zero line) than group A (P < 0.009). In group B, maximum GH levels increased from 43.9–161 mU/liter (P < 0.0002), and in group A, from 57.2–104 mU/liter (P = 0.002). During the profile (i.e. 12 h per day), children of group B had mean GH levels of 64.4 vs. 34.8 mU/liter in group A (P = 0.001). The IGF-I and IGF-I to IGFBP-3 ratio sd scores increased significantly in both groups, but were higher in group B than A [1.5 vs. 0.2 (P = 0.002) and 1.4 vs. 0.3 (P = 0.007), respectively]. In group B, 74% of the children had IGF-I levels in the highest quintile during GH treatment compared with 19% in group A. Conclusion: Our study shows that high-dose GH treatment in short SGA children results in high serum GH and IGF-I levels in most children. We recommend monitoring IGF-I levels during GH therapy to ensure that these remain within the normal range.

The insulin-like growth factor (IGF) system is related to proliferation and tumor growth, and high levels of circulating IGF-I are thought to be a risk factor for several types of cancer. This review summarizes the epidemiologic evidence for an association between circulating IGF-I and cancer risk as well as the experimental evidence for a causal relation between the endocrine IGF system and tumor growth. The potential for dietary intervention to alter the IGF system and thereby cancer risk is supported by several lines of evidence. Postulated mechanisms of action are as follows: (a) reduction of levels of circulating IGF-I, which will decrease activation of the IGF-I receptor and subsequent signaling pathways; (b) increasing local IGF binding proteins, which may have IGF-dependent effects through obstruction of IGF interaction with local IGF-I receptor as well as IGF-independent effects; and (c) interference with estrogens and estrogen receptor action, which may have direct (and possibly synergistic) effects on IGF signaling. An overview is given of the epidemiologic studies on dietary determinants of circulating IGF-I. Examples of dietary factors, such as dairy protein, lycopene, and phytoestrogens, are used to illustrate the potential mode of action of dietary interventions that may act on the IGF system. In conclusion, the IGF system has every potential to serve as an intermediate for cancer (chemo)prevention studies. On the short term, more research initiatives aimed at the effects of specific food components or dietary strategies on the IGF system both in animal models and in humans are warranted.

Cholangiocarcinoma cells express and secrete insulin-like growth factor I (IGF-I) and vascular endothelial growth factor (VEGF).To measure IGF-I and VEGF in bile and serum of patients with extrahepatic cholangiocarcinoma and to evaluate their performance as diagnostic markers.Cross-sectional study.Inpatients at the Division of Gastroenterology, University Hospital, Ancona, Italy.73 patients who consecutively had endoscopic retrograde cholangiopancreatography (ERCP), including patients with extrahepatic cholangiocarcinoma (n = 29), pancreatic cancer (n = 19), and benign biliary abnormalities (n = 25; bile duct stones, primary sclerosing cholangitis, and cholangitis).Diagnosis was based on conventional radiology, ERCP, and follow-up. Insulin-like growth factor I and VEGF were measured by using enzyme-linked immunosorbent assay.The biliary IGF-I concentration was 15- to 20-fold higher (P0.001) in extrahepatic cholangiocarcinoma (mean, 84.6 nmol/L [95% CI, 74.0 to 95.2 nmol/L]) than in pancreatic cancer (5.8 nmol/L [CI, 4.0 to 7.5 nmol/L]) or benign biliary abnormalities (4.1 nmol/L [CI, 3.1 to 5.2 nmol/L]). The area under the receiver-operating characteristic curve was 1 when biliary IGF-I values in the extrahepatic cholangiocarcinoma were compared with benign biliary abnormalities or pancreatic cancer. In contrast, biliary VEGF concentration was similar in the 3 groups. Serum IGF-I levels were similar among the groups, whereas serum VEGF levels were higher in the cholangiocarcinoma (0.97 ng/mL [CI, 0.59 to 1.35 ng/mL]; P = 0.0016) and pancreatic cancer groups (0.66 ng/mL [CI, 0.43 to 0.88 ng/mL]; P0.001) compared with patients with benign biliary abnormalities (0.28 ng/mL [CI, 0.17 to 0.37 ng/mL]).Data were obtained in a small sample, the study was performed in a single center, and few patients had a tissue diagnosis.Biliary IGF-I levels in patients undergoing ERCP for biliary obstruction may differentiate extrahepatic cholangiocarcinoma from either pancreatic cancer or benign biliary abnormalities.