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Malte Braitmaier,1 Bianca Kollhorst,1 Miriam Heinig,2 Ingo Langner,2 Jonas Czwikla,3 Franziska Heinze,3 Laura Buschmann,4 Heike Minnerup,4 Xabiér García-Albéniz,5,6 Hans-Werner Hense,4 André Karch,4 Hajo Zeeb,7,8 Ulrike Haug,2,8 Vanessa Didelez1,9 1Department of Biometry and Data Management, Leibniz Institute for Prevention Research and Epidemiology – BIPS, Bremen, Germany; 2Department of Clinical Epidemiology, Leibniz Institute for Prevention Research and Epidemiology – BIPS, Bremen, Germany; 3SOCIUM Research Center on Inequality and Social Policy, University of Bremen, Bremen, Germany; 4Institute for Epidemiology and Social Medicine, Faculty of Medicine, Westfälische Wilhelms University of Münster, Münster, Germany; 5Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA; 6RTI Health Solutions, Barcelona, Spain; 7Department of Prevention and Evaluation, Leibniz Institute for Prevention Research and Epidemiology – BIPS, Bremen, Germany; 8Faculty of Human and Health Sciences, University of Bremen, Bremen, Germany; 9Faculty of Mathematics and Computer Science, University of Bremen, Bremen, GermanyCorrespondence: Vanessa Didelez, Leibniz Institute for Prevention Research and Epidemiology – BIPS, Department of Biometry and Data Management, Achterstraße 30, Bremen, 28359, Germany, Tel +49-421-56939, Fax +49-421-56941, Email didelez@leibniz-bips.deBackground: The efficacy of mammography screening in reducing breast cancer mortality has been demonstrated in randomized trials. However, treatment options - and hence prognosis – for advanced tumor stages as well as mammography techniques have considerably improved since completion of these trials. Consequently, the effectiveness of mammography screening under current conditions is unclear and controversial. The German mammography screening program (MSP), an organized population-based screening program, was gradually introduced between 2005 and 2008 and achieved nation-wide coverage in 2009.Objective: We describe in detail a study protocol for investigating the effectiveness of the German MSP in reducing breast cancer mortality in women aged 50 to 69 years based on health claims data. Specifically, the proposed study aims at estimating per-protocol effects of several screening strategies on cumulative breast cancer mortality. The first analysis will be conducted once 10-year follow-up data are available.Methods and Analysis: We will use claims data from five statutory health insurance providers in Germany, covering approximately 37.6 million individuals. To estimate the effectiveness of the MSP, hypothetical target trials will be emulated across time, an approach that has been demonstrated to minimize design-related biases. Specifically, the primary contrast will be in terms of the cumulative breast cancer mortality comparing the screening strategies of “never screen” versus “regular screening as intended by the MSP”.Ethics and Dissemination: In Germany, the utilization of data from health insurances for scientific research is regulated by the Code of Social Law. All involved health insurance providers as well as the responsible authorities approved the use of the health claims data for this study. The Ethics Committee of the University of Bremen determined that studies based on claims data are exempt from institutional review. The findings of the proposed study will be published in peer-reviewed journals.Keywords: emulated target trial, cancer screening, effectiveness, claims data, mammography

Studying the effect of duration of treatment on prognostic outcomes using real-world data is challenging because only people who survive for a long time can receive a treatment for a long time. Specifying a target trial helps overcome such challenge. We aimed to estimate the effect of different durations of treatment with antihypertensive drugs with anticholinergic properties (AC AHT) on the risk of vascular dementia and Alzheimer's disease by emulating a target trial using the UK CPRD GOLD database (2001-2017). Comparing treatment for 3-6 years versus ≤3 years yielded null results for both types of dementia. Comparing a longer duration of treatment, >6 years versus ≤3 years, yielded a 10-year risk ratio of 0.69 (95% CI, 0.54-0.90) for vascular dementia and 0.91 (95% CI, 0.77-1.10) for Alzheimer's disease. For illustration, we performed an analysis that failed to emulate a target trial by assigning exposure categories using post-baseline information, obtaining implausible beneficial estimates. Our findings indicate a modest benefit of longer duration of treatment with AC AHT on vascular dementia and highlight the value of the target trial emulation to avoid selection bias in the evaluation of the effect of different durations of treatment., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: No consensus about the effectiveness of prostate-specific antigen (PSA) screening exists among clinical guidelines, especially for the elderly. Randomized trials of PSA screening have yielded different results, partly because of variations in adherence, and it is unlikely that new trials will be conducted. Our objective was to estimate the effect of annual PSA screening on prostate cancer (PC) mortality in Medicare beneficiaries age 67-84 years., Methods: This is a large-scale, population-based, observational study of two screening strategies: annual PSA screening and no screening. We used data from 537,599 US Medicare (2001-2008) beneficiaries age 67-84 years who had a good life expectancy, no previous PC, and no PSA test in the 2 years before baseline. We estimated the 8-year PC mortality and incidence, treatments for PC, and treatment complications of PSA screening., Results: In men age 67-74 years, the estimated difference in 8-year risk of PC death between PSA screening and no screening was -2.3 (95% CI, -4.1 to -1.1) deaths per 1,000 men (a negative risk difference favors screening). Treatment complications were more frequent under PSA screening than under no screening. In men age 75-84 years, risk difference estimates were closer to zero., Conclusion: Our estimates suggest that under conventional statistical criteria, annual PSA screening for 8 years is highly compatible with reductions of PC mortality from four to one fewer PC deaths per 1,000 screened men age 67-74 years. As with any study using real-world data, the estimates could be affected by residual confounding.

Background: The results of the Grupo Español Multidisciplinar en Cáncer Digestivo (GEMCAD)-1402 phase II randomized trial suggested that adding aflibercept to modified fluorouracil, oxaliplatin, and leucovorin (mFOLFOX6) induction, followed by chemoradiation and surgery, could increase the pathological complete response (pCR) rate in patients with high-risk, locally advanced rectal cancer. Here we update results up to 3 years of follow-up and evaluate the predictive value of consensus molecular subtypes identified with immunohistochemistry (IHC)., Methods: Patients with magnetic resonance imaging-defined T3c-d and/or T4 and/or N2 rectal adenocarcinoma in the middle or distal third were randomly assigned to mFOLFOX6 induction, with aflibercept (mF+A; n = 115) or without aflibercept (mF; n = 65), followed by capecitabine plus radiotherapy and surgery. The risk local relapse, distant metastases, disease-free survival (DFS), and overall survival (OS) were estimated at 3 years. Selected samples were classified via IHC into immune-infiltrate, epithelial, or mesenchymal subtypes., Results: mF+A and mF had 3-year DFS of 75.2% (95% confidence interval [CI] = 66.1% to 82.2%) and 81.5% (95% CI = 69.8% to 89.1%), respectively; 3-year OS of 89.3% (95% CI = 82.0% to 93.8%) and 90.7% (95% CI = 80.6% to 95.7%), respectively; 3-year cumulative local relapse incidences of 5.2% (95% CI = 1.9% to 11.0%) and 6.1% (95% CI = 1.7% to 15.0%), respectively; and 3-year cumulative distant metastases rates of 17.3% (95% CI = 10.9% to 25.5%) and 16.9% (95% CI = 8.7% to 28.2%), respectively. pCRs were achieved in 27.5% (n = 22 of 80) and 0% (n = 0 of 10) of patients with epithelial and mesenchymal subtypes, respectively., Conclusion: Adding aflibercept to mFOLFOX6 induction was not associated with improved DFS or OS. Our findings suggested that consensus molecular subtypes identified with IHC subtypes could be predictive of pCR with this treatment., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Metformin users appear to have a substantially lower risk of cancer than nonusers in many observational studies. These inverse associations may be explained by common flaws in observational analyses that can be avoided by explicitly emulating a target trial., Methods: We emulated target trials of metformin therapy and cancer risk using population-based linked electronic health records from the UK (2009-2016). We included individuals with diabetes, no history of cancer, no recent prescription for metformin or other glucose-lowering medication, and hemoglobin A1c (HbA1c) <64 mmol/mol (<8.0%). Outcomes included total cancer and 4 site-specific cancers (breast, colorectal, lung, and prostate). We estimated risks using pooled logistic regression with adjustment for risk factors via inverse-probability weighting. We emulated a second target trial among individuals regardless of diabetes status. We compared our estimates with those obtained using previously applied analytic approaches., Results: Among individuals with diabetes, the estimated 6-year risk differences (metformin - no metformin) were -0.2% (95% CI = -1.6%, 1.3%) in the intention-to-treat analysis and 0.0% (95% CI = -2.1%, 2.3%) in the per-protocol analysis. The corresponding estimates for all site-specific cancers were close to zero. Among individuals regardless of diabetes status, these estimates were also close to zero and more precise. By contrast, previous analytic approaches yielded estimates that appeared strongly protective., Conclusions: Our findings are consistent with the hypothesis that metformin therapy does not meaningfully influence cancer incidence. The findings highlight the importance of explicitly emulating a target trial to reduce bias in the effect estimates derived from observational analyses., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: To assess the effect of hydroxychloroquine (HCQ) and Tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) as pre-exposure prophylaxis on COVID-19 risk., Methods: EPICOS is a double-blind, placebo-controlled randomized trial conducted in Spain, Bolivia, and Venezuela. Healthcare workers with negative SARS-CoV-2 IgM/IgG test were randomly assigned to the following: daily TDF/FTC plus HCQ for 12 weeks, TDF/FTC plus HCQ placebo, HCQ plus TDF/FTC placebo, and TDF/FTC placebo plus HCQ placebo. Randomization was performed in groups of four. Primary outcome was laboratory-confirmed, symptomatic COVID-19. We also studied any (symptomatic or asymptomatic) COVID-19. We compared group-specific 14-week risks via differences and ratios with 95% CIs., Results: Of 1002 individuals screened, 926 (92.4%) were eligible and there were 14 cases of symptomatic COVID-19: 220 were assigned to the TDF/FTC plus HCQ group (3 cases), 231 to the TDF/FTC placebo plus HCQ group (3 cases), 233 to the TDF/FTC plus HCQ placebo group (3 cases), and 223 to the double placebo group (5 cases). Compared with the double placebo group, 14-week risk ratios (95% CI) of symptomatic COVID-19 were 0.39 (0.00-1.98) for TDF + HCQ, 0.34 (0.00-2.06) for TDF, and 0.49 (0.00-2.29) for HCQ. Corresponding risk ratios of any COVID-19 were 0.51 (0.21-1.00) for TDF + HCQ, 0.81 (0.44-1.49) for TDF, and 0.73 (0.41-1.38) for HCQ. Adverse events were generally mild., Discussion: The target sample size was not met. Our findings are compatible with both benefit and harm of pre-exposure prophylaxis with TDF/FTC and HCQ, alone or in combination, compared with placebo., (Copyright © 2022 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

As with many chronic illnesses, recurrent prostate cancer generally requires sustained treatment to prolong survival. However, initiating treatment immediately after recurrence may negatively impact quality of life without any survival gains. Therefore, we consider sustained strategies for initiating treatment based on specific characteristics of prostate-specific antigen (PSA), which can indicate disease progression. We define the protocol for a target trial comparing treatment strategies based on PSA doubling time, in which androgen deprivation therapy is initiated only after doubling time decreases below a certain threshold. Such a treatment strategy means the timing of treatment initiation (if ever) is not known at baseline, and the target trial protocol must explicitly specify the frequency of PSA monitoring until the threshold is met, as well as the duration of treatment. We describe these and other components of a target trial that need to be specified in order for such a trial to be emulated in observational data. We then use the parametric g-formula and inverse-probability weighted dynamic marginal structural models to emulate our target trial in a cohort of prostate cancer patients from clinics across the United States., (© 2022. Springer Nature B.V.)

Background: Recruitment into randomized trials of hydroxychloroquine (HCQ) for prevention of COVID-19 has been adversely affected by a widespread conviction that HCQ is not effective for prevention. In the absence of an updated systematic review, we conducted a meta-analysis of randomized trials that study the effectiveness of HCQ to prevent COVID-19., Methods: A search of PubMed, medRxiv, and clinicaltrials.gov combined with expert consultation found 11 completed randomized trials: 7 pre-exposure prophylaxis trials and 4 post-exposure prophylaxis trials. We obtained or calculated the risk ratio of COVID-19 diagnosis for assignment to HCQ versus no HCQ (either placebo or usual care) for each trial, and then pooled the risk ratio estimates., Results: The pooled risk ratio estimate of the pre-exposure prophylaxis trials was 0.72 (95% CI: 0.58-0.90) when using either a fixed effect or a standard random effects approach, and 0.72 (95% CI: 0.55-0.95) when using a conservative modification of the Hartung-Knapp random effects approach. The corresponding estimates for the post-exposure prophylaxis trials were 0.91 (95% CI: 0.72-1.16) and 0.91 (95% CI: 0.62-1.35). All trials found a similar rate of serious adverse effects in the HCQ and no HCQ groups., Discussion: A benefit of HCQ as prophylaxis for COVID-19 cannot be ruled out based on the available evidence from randomized trials. However, the "not statistically significant" findings from early prophylaxis trials were widely interpreted as definite evidence of lack of effectiveness of HCQ. This interpretation disrupted the timely completion of the remaining trials and thus the generation of precise estimates for pandemic management before the development of vaccines., (© 2022. Springer Nature B.V.)

Background: Previous case-control studies have reported a strong association between statin use and lower cancer risk. It is unclear whether this association reflects a benefit of statins or is the result of design decisions that cannot be mapped to a (hypothetical) target trial (that would answer the question of interest)., Methods: We outlined the protocol of a target trial to estimate the effect of statins on colorectal cancer incidence among adults with low-density lipoprotein (LDL) cholesterol below 5 mmol/L. We then emulated the target trial using linked electronic health records of 752 469 eligible UK adults (CALIBER 1999-2016) under both a cohort design and a case-control sampling of the cohort. We used pooled logistic regression to estimate intention-to-treat and per-protocol effects of statins on colorectal cancer, with adjustment for baseline and time-varying risk factors via inverse-probability weighting. Finally, we compared our case-control effect estimates with those obtained using previous case-control procedures., Results: Over the 6-year follow-up, 3596 individuals developed colorectal cancer. Estimated intention-to-treat and per-protocol hazard ratios were 1.00 (95% confidence interval [CI]: 0.87, 1.16) and 0.90 (95% CI: 0.71, 1.12), respectively. As expected, adequate case-control sampling yielded the same estimates. By contrast, previous case-control analytical approaches yielded estimates that appeared strongly protective (odds ratio 0.57, 95% CI: 0.36, 0.91, for ≥5 vs. <5 years of statin use)., Conclusions: Our study demonstrates how to explicitly emulate a target trial using case-control data to reduce discrepancies between observational and randomized trial evidence. This approach may inform future case-control analyses for comparative effectiveness research., (© The Author(s) 2020; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.)

Importance: The Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database may provide insights into the comparative effectiveness of oncological treatments for elderly individuals who are underrepresented in clinical trials., Objective: To evaluate the suitability of SEER-Medicare data for assessing the effectiveness of adding a drug to an existing treatment regimen on the overall survival of elderly patients with cancer., Design, Setting, and Participants: This comparative effectiveness study analyzed SEER-Medicare data from 9549 individuals who received a new diagnosis of stage II colorectal cancer (2008-2012) and 940 patients who received a new diagnosis of advanced pancreatic adenocarcinoma (2007-2012), with follow-up to December 31, 2013 (SEER-Medicare data released in 2015). Two (hypothetical) target trials were designed and emulated based on 2 existing randomized clinical trials: (1) adjuvant fluorouracil after curative surgery for individuals with stage II colorectal cancer and (2) erlotinib added to gemcitabine for individuals with advanced pancreatic adenocarcinoma. Data were analyzed January 2018 to March 2019., Exposures: The following treatment strategies were compared: (1) fluorouracil initiation vs no initiation within 3 months of tumor resection and (2) erlotinib initiation vs no initiation within 12 weeks of gemcitabine initiation., Main Outcomes and Measures: All-cause mortality within 60 months of baseline for the fluorouracil trial and within 72 weeks for the erlotinib trial., Results: Compared with 3293 individuals in the existing fluorouracil trial, 9549 eligible individuals included in the present analyses were more likely to have colon cancer (8565 [90%] vs 2291 [71%]) and were older (median [interquartile range], 79 [73-84] vs 63 [56-68] years). The 5-year risk difference for initiation vs noninitiation of fluorouracil after surgery was -3.8% (95% CI, -14.8% to 12.6%), and the mortality hazard ratio (HR) was 0.95 (95% CI, 0.85-1.04). Compared with 569 individuals in the existing erlotinib trial, 940 eligible patients included in the present analysis were older (median [range], 74 [66-93] vs 64 [36-92] years) and more likely to be male (547 [58%] vs 298 [52%]). The 1-year risk difference for initiation vs noninitiation of erlotinib was 4.7% (95% CI, -9.4% to 18.0%), and the corresponding mortality HR was 1.04 (95% CI, 0.86-1.42). In naive analyses, the mortality HR estimate was 1.14 (95% CI, 0.95-1.36) for the fluorouracil emulation and 0.68 (95% CI, 0.54-0.87) for the erlotinib emulation., Conclusions and Relevance: The present estimates were similar to those from randomized clinical trials that studied adding the same cancer drugs to existing regimens. The published HR was 1.02 (95% CI, 0.70-1.48) in the fluorouracil trial for individuals aged 70 or older and 0.96 (95% CI, 0.74-1.24) in the erlotinib trial for individuals aged 65 years or older. The SEER-Medicare database may be adequate for studying the real-world effectiveness of adding a drug to treatment regimens used for elderly individuals with cancer.

Purpose: RAS and BRAF mutations can be detected as a mechanism of acquired resistance in circulating tumor (ct) DNA in patients with metastatic colorectal cancer treated with anti-epidermal growth factor receptor therapy., Methods: RAS and BRAF mutational status was assessed in ctDNA in a baseline plasma sample and a serum sample collected at the time of the last available determination (named secondary extraction) from patients with KRAS exon 2 wild-type metastatic colorectal cancer treated in two first-line prospective biomarker-designed clinical trials (PULSE, ClinicalTrials.gov identifier: NCT01288339; and POSIBA, ClincialTrials.gov identifier: NCT01276379)., Results: Analysis of extended RAS and BRAF in tissue and plasma from 178 patients with KRAS exon 2 wild-type metastatic colorectal cancer showed a sensitivity of 64.1% and a specificity of 90%. The median overall survival (OS) of baseline patients with RAS and BRAF mutations in ctDNA was 22.3 months (95% CI, 15.6 to 29 months) and 8.9 months (95% CI, 6.3 to 11.4 months), respectively, which was significantly inferior to the median OS of 40.4 months (95% CI, 35.9 to 44.9 months) in two patients with wild-type disease ( P < .001). Acquisition of RAS/BRAF mutations occurred in nine of 63 patients (14%) with progressive disease (PD; ie, blood draw within 1 month before PD or after PD) compared with six of 73 patients (8%) with no PD or blood extraction for ctDNA analysis before 1 month of PD ( P = .47). Median OS in patients with RAS/BRAF acquisition was 23.9 months (95% CI, 19.7 to 27.9 months) compared with 40.6 months (95% CI, not reached to not reached) in patients who remained free of mutations ( P = .016)., Conclusion: Our results confirm that baseline RAS and BRAF testing in ctDNA discriminates survival. The emergence of RAS/BRAF mutations has limited relevance for the time to progression to anti-epidermal growth factor receptor therapy.

The increasing availability of large healthcare databases is fueling an intense debate on whether real-world data should play a role in the assessment of the benefit-risk of medical treatments. In many observational studies, for example, statin users were found to have a substantially lower risk of cancer than in meta-analyses of randomized trials. Although such discrepancies are often attributed to a lack of randomization in the observational studies, they might be explained by flaws that can be avoided by explicitly emulating a target trial (the randomized trial that would answer the question of interest). Using the electronic health records of 733,804 UK adults, we emulated a target trial of statins and cancer and compared our estimates with those obtained using previously applied analytic approaches. Over the 10-yr follow-up, 28,408 individuals developed cancer. Under the target trial approach, estimated observational analogs of intention-to-treat and per-protocol 10-yr cancer-free survival differences were -0.5% (95% confidence interval (CI) -1.0%, 0.0%) and -0.3% (95% CI -1.5%, 0.5%), respectively. By contrast, previous analytic approaches yielded estimates that appeared to be strongly protective. Our findings highlight the importance of explicitly emulating a target trial to reduce bias in the effect estimates derived from observational analyses.

Background: Neoadjuvant therapy (NAT) for pancreatic adenocarcinoma (PDAC) patients has shown promising results in non-randomized trials. This is a multi-institutional phase II trial of NAT in resectable PDAC patients., Methods: Patients with confirmed resectable PDAC after agreement by two expert radiologists were eligible. Patients received three cycles of GEM (1000 mg/m 2 /week) plus daily erlotinib (ERL) (100 mg/day). After re-staging, patients without progressive disease underwent 5 weeks of therapy with GEM (300 mg/m 2 /week), ERL 100 mg/day and concomitant radiotherapy (45 Gy). Efficacy was assessed using tumor regression grade (TRG) and resection margin status. Using a single-arm Simon's design, considering the therapy not useful if R0 < 40% and useful if the R0 > 70% (alpha 5%, beta 10%), 24 patients needed to be recruited. This trial was registered at ClinicalTrials.gov, number NCT01389440., Results: Twenty-five patients were enrolled. Adverse effects of NAT were mainly mild gastrointestinal disorders. Resectability rate was 76%, with a R0 rate of 63.1% among the resected patients. Median overall survival (OS) and disease-free survival (DFS) were 23.8 (95% CI 11.4-36.2) and 12.8 months (95% CI 8.6-17.1), respectively. R0 resection patients had better median OS, compared with patients with R1 resection or not resected (65.5 months vs. 15.5 months, p = 0.01). N0 rate among the resected patients was 63.1%, and showed a longer median OS (65.5 vs. 15.2 months, p = 0.009)., Conclusion: The results of this study confirm promising oncologic results with NAT for patients with resectable PDAC. Therefore, the present trial supports the development of phase II randomized trials comparing NAT vs. upfront surgery in resectable pancreatic cancer.

Introduction: This study evaluated allogenic packed red blood cell (aPRBC) transfusion rates in patients undergoing resection for gastric cancer and the implementation of blood-saving protocols (BSP)., Methods: Retrospective study of all gastric cancer patients operated on with curative intent in Catalonia and Navarra (2011-2013) and included in the Spanish subset of the EURECCA Oesophago-Gastric Cancer Registry. Hospitals with BSP were defined as those with a preoperative haemoglobin (Hb) optimisation circuit associated with restrictive transfusion strategies. Predictors of aPRBC transfusion were identified by multinomial logistic regression analysis., Results: A total of 652 patients were included, 274 (42.0%) of which received aPRBC transfusion. Six of the 19 participating hospitals had BSP and treated 145 (22.2%) patients. Low Hb level at diagnosis (10 vs 12.4g/dL), ASA score III/IV, pT3-4, open surgery, associated visceral resection, and having being operated on in a hospital without BSP were predictors of aPRBC transfusion, while low Hb level, associated visceral resection, and non-BSP hospital remained predictors in the multivariate analysis. In case of comparable risk factors for aPRBC transfusion, there was a higher use of preoperative intravenous iron treatment (26.2% vs 13.2%) and a lower percentage of transfusions (31.7% vs 45%) in hospitals with BSP., Conclusions: The perioperative transfusion rate in gastric cancer was 42%. Hospitals with BSP showed a significant reduction of blood transfusions but treated only 22% of patients. Main predictors of aPRBC were low Hb level, associated visceral resection, and undergoing surgery at a hospital without BSP., (Copyright © 2018 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.)

Introduction: The coexpression of pIGF-1R and MMP-7 (double-positive phenotype, DP) correlates with poor overall survival (OS) in KRAS wild-type (WT) (exon 2) metastatic colorectal cancer (mCRC) patients treated with irinotecan-cetuximab in second/third line., Methods: We analyzed two prospective biomarker design trials of newly diagnosed RAS-WT mCRC patients treated with panitumumab-FOLFOX6 (PULSE trial; NCT01288339) or cetuximab plus either FOLFOX6/FOLFIRI (POSIBA trial; NCT01276379). The main exposure was DP phenotype (DP/non-DP), as assessed by two independent pathologists. DP cases were defined by immunohistochemistry as >70% expression of moderate or strong intensity for both MMP-7 and pIGF-1R. Primary endpoint: progression-free survival (PFS); secondary endpoints: OS and response rate. PFS and OS were adjusted by baseline characteristics using multivariate Cox models., Results: We analyzed 67 patients (30 non-DP, 37 DP) in the PULSE trial and 181 patients in the POSIBA trial (158 non-DP, 23 DP). Response rates and PFS were similar between groups in both studies. DP was associated with prolonged OS in PULSE (adjusted HR: 0.23; 95%CI: 0.11-0.52; P=.0004) and with shorter OS in POSIBA (adjusted HR: 1.67; 95%CI: 0.96-2.90; P=.07)., Conclusion: A differential effect of anti-EGFRs on survival by DP phenotype was observed. Panitumumab might be more beneficial for RAS-WT mCRC patients with DP phenotype, whereas cetuximab might improve OS in non-DP., (Copyright © 2018. Published by Elsevier Inc.)

The study of nonindicated medications on cancer outcomes is challenged by potential time-related biases. The literature has strongly advocated for treating the exposure as time-varying and summarizing the outcomes through a dose-response model (an etiologic-focused analysis). An alternative is to refashion the data to resemble a hypothetical randomized trial of drug use (an action-focused analysis). To our knowledge, their relative treatment of time-related bias and aspects of interpretation have not been compared. In this commentary, using the study of metformin use on colorectal cancer risk by Bradley and colleagues (2018) as motivation, we compare the etiologic versus action-focused analysis of epidemiologic data. We examine their treatment of immortal person-time, time-varying confounding, selection bias, and the biological and clinical relevance of their results. In doing so, we aim to establish areas of common ground and points of departure that can guide future observational studies of medications on cancer risk, recurrence, and survival. Cancer Epidemiol Biomarkers Prev; 27(5); 520-4. ©2018 AACR See related article by Bradley et al., p. 525 ., (©2018 American Association for Cancer Research.)

Importance: Patients with cancer who use statins appear to have a substantially better survival than nonusers in observational studies. However, this inverse association between statin use and mortality may be due to selection bias and immortal-time bias., Objective: To emulate a randomized trial of statin therapy initiation that is free of selection bias and immortal-time bias., Design, Setting, and Participants: We used observational data on 17 372 patients with cancer from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database (2007-2009) with complete follow-up until 2011. The SEER-Medicare database links 17 US cancer registries and claims files from Medicare and Medicaid in 12 US states. We included individuals with a new diagnosis of colorectal, breast, prostate, or bladder cancer who had not been prescribed statins for at least 6 months before the cancer diagnosis. Individuals were duplicated, and each replicate was assigned to either the strategy "statin therapy initiation within 6 months after diagnosis" or "no statin therapy initiation." Replicates were censored when they stopped following their assigned strategy, and the potential selection bias was adjusted for via inverse-probability weighting. Hazard ratios (HRs), cumulative incidences, and risk differences were calculated for all-cause mortality and cancer-specific mortality. We then compared our estimates with those obtained using the same analytic approaches used in previous observational studies., Exposures: Statin therapy initiation within 6 months after cancer diagnosis., Main Outcomes and Measures: Cancer-specific and all-cause mortality using SEER-Medicare data and data from previous studies., Results: Of the 17 372 patients whose data were analyzed, 8440 (49%) were men, and 8932 (51%) were women (mean [SD] age, 76.4 [7.4] years; range, 66-115 years). The adjusted HR (95% CI) comparing statin therapy initiation vs no initiation was 1.00 (0.88-1.15) for cancer-specific mortality and 1.07 (0.93-1.21) for overall mortality. Cumulative incidence curves for both groups were almost overlapping (the risk difference never exceeded 0.8%). In contrast, the methods used by prior studies resulted in an inverse association between statin use and mortality (pooled hazard ratio 0.69)., Conclusion and Relevance: After using methods that are not susceptible to selection bias from prevalent users and to immortal time bias, we found that initiation of therapy with statins within 6 months after cancer diagnosis did not appear to improve 3-year cancer-specific or overall survival.

Background: Although chemotherapy is the cornerstone treatment for patients with metastatic colorectal cancer (mCRC), acquired chemoresistance is common and constitutes the main reason for treatment failure. Monoclonal antibodies against insulin-like growth factor-1 receptor (IGF-1R) have been tested in pre-treated mCRC patients, but results have been largely deceiving., Methods: We analysed time to progression, overall survival, and the mutational status of RAS, BRAF and nuclear p-IGF-1R expression by immunohistochemistry, in 470 metastatic CRC patients. The effect of IGF-1R activation and distribution was also assessed using cellular models of CRC and RNAi for functional validation., Results: Nuclear IGF-1R increased in metastatic tumours compared to paired untreated primary tumours, and significantly correlated with poor overall survival in mCRC patients. In vitro, chemo-resistant cell lines presented significantly higher levels of IGF-1R expression within the nuclear compartment, and PIAS3, a protein implicated also in the sumoylation process of intranuclear proteins, contributed to IGF-1R nuclear sequestration, highlighting the essential role of PIAS3 in this process. Intriguingly, we observed that ganitumab, an IGF-1R blocking-antibody used in several clinical trials, and dasatinib, an SRC inhibitor, increased the nuclear localisation of IGF-1R., Conclusions: Our study demonstrates that IGF-1R nuclear location might lead to chemotherapy and targeted agent resistance.

Observational analyses for causal inference often rely on real world data collected for purposes other than research. A frequent goal of these observational analyses is to use the data to emulate a hypothetical randomized experiment, i.e., the target trial, that mimics the design features of a true experiment, including a clear definition of time zero with synchronization of treatment assignment and determination of eligibility. We review a recent observational analysis that explicitly emulated a target trial of screening colonoscopy using insurance claims from U.S. Medicare. We then compare this explicit emulation with alternative, simpler observational analyses that do not synchronize treatment assignment and eligibility determination at time zero and/or do not allow for repeated eligibility. This empirical comparison suggests that lack of an explicit emulation of the target trial leads to biased estimates, and shows that allowing for repeated eligibility increases the statistical efficiency of the estimates.

Background: No randomized, controlled trials of screening colonoscopy have been completed, and ongoing trials exclude persons aged 75 years or older. The Medicare program, however, reimburses screening colonoscopy without an upper age limit., Objective: To evaluate the effectiveness and safety of screening colonoscopy to prevent colorectal cancer (CRC) in persons aged 70 to 74 and those aged 75 to 79 years., Design: Large-scale, population-based, prospective study. The observational data were used to emulate a target trial with 2 groups: colonoscopy screening and no screening., Setting: United States., Participants: 1 355 692 Medicare beneficiaries (2004 to 2012) aged 70 to 79 years at average risk for CRC who used Medicare preventive services and had no previous diagnostic or surveillance colonoscopies in the past 5 years., Measurements: 8-year risk for CRC and 30-day risk for adverse events., Results: In beneficiaries aged 70 to 74 years, the 8-year risk for CRC was 2.19% (95% CI, 2.00% to 2.37%) in the screening colonoscopy group and 2.62% (CI, 2.56% to 2.67%) in the no-screening group (absolute risk difference, -0.42% [CI, -0.24% to -0.63%]). Among those aged 75 to 79 years, the 8-year risk for CRC was 2.84% (CI, 2.54% to 3.13%) in the screening colonoscopy group and 2.97% (CI, 2.92% to 3.03%) in the no-screening group (risk difference, -0.14% [CI, -0.41 to 0.16]). The excess 30-day risk for any adverse event in the colonoscopy group was 5.6 events per 1000 individuals (CI, 4.4 to 6.8) in the 70- to 74-year age group and 10.3 per 1000 (CI, 8.6 to 11.1) in the 75- to 79-year age group., Limitation: CRC-specific mortality was not available, but CRC incidence and stage were studied at diagnosis., Conclusion: Screening colonoscopy may have had a modest benefit in preventing CRC in beneficiaries aged 70 to 74 years and a smaller benefit in older beneficiaries. The risk for adverse events was low but greater among older persons., Primary Funding Source: National Institutes of Health.

Colorectal cancer (CRC) is characterized by alteration of critical pathways such TP53 inactivation, BRAF, PI3CA mutations, APC inactivation, KRAS, TGF-β, CTNNB mutations, disregulation of Epithelial to mesnechymal transition (EMT) genes, WNT signaling activation, MYC amplification, and others. Differences in these molecular events results in differences in phenotypic characteristics of CRC, that have been studied and classified by different models of molecular subtypes. It could have potential applications to prognosis, but also to therapeutical approaches of the CRC patients. We review and summarized the different molecular classifications and try to clarify their clinical and therapeutical relevance., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: Autologous tumour lysate dendritic cell vaccine (ADC) has T-cell stimulatory capacity and, therefore, potential antitumour activity. We designed a phase II randomised trial of ADC + best supportive care (BSC) (experimental arm [EA]) compared with BSC (control arm [CA]), in pre-treated metastatic colorectal cancer (mCRC) patients., Patients and Methods: Patients with progressive mCRC, at least to two chemotherapy regimens and Eastern Cooperative Oncology Group performance status (ECOG PS) 0-2, were randomised to EA versus CA. Stratification criteria: ECOG PS (0-1 versus 2) and lactate dehydrogenase (ULN). EA was administered subcutaneously till progressive disease. Primary end-point was progression-free survival (PFS) at 4 months., Results: Fifty-two patients were included (28 EA/24 CA). An interim analysis recommended early termination for futility. No objective radiological response was observed in EA. Median PFS in EA was 2.7 months (95% confidence interval [CI], 2.3-3.2 months) versus 2.3 months (95% CI, 2.1-2.5 months) in CA (p = 0.628). Median overall survival (OS) was 6.2 months (95% CI, 4.4-7.9 months) in EA versus 4.7 months (95% CI, 2.3-7 months) in CA (p = 0.41). No ADC-related adverse events were reported. Immunization induces tumour-specific T-cell response in 21 of 25 (84%) patients. Responder patients have an OS of 7.3 months (95% CI, 5.2-9.4 months) versus 3.8 months (95% CI, 0.6-6.9 months) in non-responders; p = 0.026)., Conclusion: Our randomised clinical trial comparing ADC + BSC versus BSC in mCRC demonstrates that ADC generates a tumour-specific immune response but not benefit on PFS and OS. Our results do not support the use of ADC alone, in a phase III trial., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Most GISTs have mutations in KIT or PDGFRA. Patients with advanced GIST with KIT exon 9, PDGFRA mutation or WT for KIT and PDGFRA have a worse progression-free survival (PFS) compared to patients with KIT exon 11 mutated tumors. We evaluated the immunohistochemical (IHC) expression of p-IGF1R (Y1316) and MMP3 as predictors of PFS or overall survival (OS)., Methods: Ninety-two advanced GIST patients included in GEIS-16 study with KIT and PDGFRA mutational information were examined for p-IGF1R (Y1316) and MMP3 expression in a tissue micro-array. To study activation of the IGF1R system, we have used an antibody (anti-pY1316) that specifically recognizes the active phosphorylated form of the IGF1R. DNA was extracted from paraffin-embedded tissues and intronic PCR primers were used to amplify exons 9, 11, 13 and 17 of KIT, 12 and 18 of PDGFRA. Bidirectional sequencing with specific primers was performed on a ABI3100 sequencer using the Big Dye Terminator v3.1 kit. Multivariate model was built using a stepwise automated variable selection approach with criterion to enter the variable in the model of p < 0.10 and criterion to keep the variable in the model of p < 0.05. PFS was computed as the date of imatinib initiation to progression or death. Overall survival was defined as the time from imatinib initiation to death., Results: Phospho-IGF1R was expressed only in 9 % (2/22) of cases without KIT mutation. MMP3 expression was detected in 2/5 patients (40 %) with PDGFRA mutation, 1/16 patients (6 %) with WT genotype and 7/71 patients (10 %) of KIT mutant patients. At univariate analysis KIT exon 11/13 mutation had better PFS than patients with exon 9 mutation, PDGFRA mutation or WT genotype (p = 0.021; HR: 0.46; 95 %CI (0.28-0.76). Less than 24 months disease free-interval (HR 24.2, 95 % CI 10.5-55.8), poor performance status (PS) (HR 6.3, 95 % CI 2.5-15.9), extension of disease; >1 organ (HR 1.89; 95 % CI 1.03-3.4) and genotype analysis (HR 0.57, 95 % CI 0.37-0.97) but not immunophenotype analysis (HR 1.53; 95 % CI 0.76-3.06) were the strongest prognostic factors for PFS in the multivariate analysis., Conclusions: Our results do not support p-IGF-1R and MMP3 evaluation in non-selected GIST patients but evaluation of this immunophenotype in WT and mutant PDGFR mutation in larger group of GIST patients, deserve merits.

Little is known about the magnitude of the association between infective endocarditis and cancer, and about the natural history of cancer patients with concomitant diagnosis of infective endocarditis. We used the SEER-Medicare linked database to identify individuals aged 65 years or more diagnosed with colorectal, lung, breast, or prostate cancer, and without any cancer diagnosis (5% random Medicare sample from SEER areas) between 1992 and 2009. We identified infective endocarditis from the ICD-9 diagnosis of each admission recorded in the Medpar file and its incidence rate 90 days around cancer diagnosis. We also estimated the overall survival and CRC-specific survival after a concomitant diagnosis of infective endocarditis. The peri-diagnostic incidence of infective endocarditis was 19.8 cases per 100,000 person-months for CRC, 5.7 cases per 100,000 person-months for lung cancer, 1.9 cases per 100,000 person-months for breast cancer, 4.1 cases per 100,000 person-months for prostate cancer and 2.4 cases per 100,000 person-months for individuals without cancer. Two-year overall survival was 46.4% (95% CI 39.5, 54.5%) for stage I-III CRC patients with concomitant endocarditis and 73.1% (95 % CI 72.9, 73.3%) for those without it. In this elderly population, the incidence of infective endocarditis around CRC diagnosis was substantially higher than around the diagnosis of lung, breast and prostate cancers. A concomitant diagnosis of infective endocarditis in patients with CRC diagnosis is associated with shorter survival.

Comparisons of post-relapse survival (PRS) and post-progression survival have been used to measure efficacy in some cancer clinical trials. These comparisons are an attempt to account for second-line therapies and to identify benefits that do not translate in longer overall survival. However, the use of PRS comparisons can be misleading (either a longer or shorter PRS may indicate a benefit, depending on the circumstances) and can result in biased estimates (because of selection). Here, we describe the problems surrounding PRS comparisons and propose alternative approaches to deal with non-randomized therapies administered after progression to the experimental treatment., (© 2014 UICC.)

Aim: To evaluate the long-term results of conventional chemoradiotherapy and laparoscopic mesorectal excision in rectal adenocarcinoma patients without adjuvant therapy., Methods: Patients with biopsy-proven adenocarcinoma of the rectum staged cT3-T4 by endoscopic ultrasound or magnetic resonance imaging received neoadjuvant continuous infusion of 5-fluorouracil for five weeks and concomitant radiotherapy. Laparoscopic surgery was planned after 5-8 wk. Patients diagnosed with ypT0N0 stage cancer were not treated with adjuvant therapy according to the protocol. Patients with ypT1-2N0 or ypT3-4 or N+ were offered 5-fluorouracil-based adjuvant treatment on an individual basis. An external cohort was used as a reference for the findings., Results: One hundred and seventy six patients were treated with induction chemoradiotherapy and 170 underwent total mesorectal excision. Cancer staging of ypT0N0 was achieved in 26/170 (15.3%) patients. After a median follow-up of 58.3 mo, patients with ypT0N0 had five-year disease-free and overall survival rates of 96% (95%CI: 77-99) and 100%, respectively. We provide evidence about the natural history of patients with localized rectal cancer achieving a complete response after preoperative chemoradiation. The inherent good prognosis of these patients will have implications for clinical trial design and care of patients., Conclusion: Withholding adjuvant chemotherapy after complete response following standard neoadjuvant chemoradiotherapy and laparoscopic mesorectal excision might be safe within an experienced multidisciplinary team.

Background: To quantify and characterize duplicated tests performed during the staging of localized colon cancer in the Medicare population., Methods: We used the SEER-Medicare linked database to select patients diagnosed with localized colon cancer between the years 1996 and 2009. We considered a patient as adequately staged after having received a colonoscopy, an abdominal computed tomography (CT) scan, and a pelvic CT scan. Abdominal and pelvic CT scans performed between complete staging and first cancer-directed treatment, if not ordered due to an acute condition, were considered duplicates. We characterized the institutions providing the tests and evaluated the association with survival using a weighted pooled logistic regression adjusted by baseline and time-varying confounders., Results: Of 36,291 patients with a complete staging, 2680 (7.4%) had at least 1 duplicated test. Patients receiving a duplicate had a higher comorbidity score, were more symptomatic, and had more visits to the emergency department and clinical evaluations. They also were treated with surgery less frequently and had worse survival (hazard ratio 1.22, 95% confidence interval, 1.16-1.28). The type of institution involved in the staging (nonprofit/government centers, proprietary centers, free-standing facilities) was not associated with receiving duplicated tests., Conclusions: We found a low frequency of duplicated abdominal or pelvic CT scans in the staging of colon cancer in the Medicare population.

Objectives: To define predictive parameters of long progression-free survival (PFS) in patients undergoing radioembolisation of neuroendocrine liver metastases., Methods: The following clinical and magnetic resonance imaging (MRI) parameters of 45 radioembolised patients (median age, 62 years; range, 43-75) were reviewed: age, gender, levels of chromogranin A and neuron-specific enolase (NSE), primary tumour site, Ki-67 proliferation index, hepatic tumour load, number of metastases, signal intensity characteristics, vascularisation, haemorrhagic and necrotic transformation and fluid-fluid levels. PFS was assessed according to RECIST 1.0. Statistical analysis included univariate Cox regression, Kaplan-Meier and multivariate regression., Results: Median PFS was 727 days (95 % CI, 378-964). In the univariate regression analysis, hypovascular metastases progressed earlier (111 vs 727 days; P < 0.05). A Ki-67 ≤2 % was associated with a longer PFS than a Ki-67 of 3-20 % or >20 % (911 vs 727 vs 210 days, respectively; P < 0.05). Low NSE predicted longer PFS (911 vs 378 days; P < 0.05). In the adjusted multivariate analysis, vascularisation (hypervascularisation vs. no hypervascularisation; P = 0.0009) and NSE level (low vs high; P = 0.0119) had the strongest influence on PFS., Conclusion: Response to radioembolisation in patients with neuroendocrine liver metastases can be predicted by the metastatic vascularisation pattern, the NSE level and the Ki-67., Key Points: • Radioembolisation is an effective treatment in hepatic metastases of neuroendocrine origin. • Pre-therapeutic vascularisation patterns of metastases on MRI can predict long progression-free survival. • Assessment of pre-therapeutic markers provides better therapy planning.