Statin use and survival after colorectal cancer: the importance of comprehensive confounder adjustment

Association of metformin and statin uses with the prognosis of colon cancer: a meta-analysis

BACKGROUND

Metformin and statins are commonly used globally for the treatment of type 2 diabetes mellitus and dyslipidemia, respectively. Recently, multiple novel pathways have been discovered, which may contribute to the treatment of various types of cancer. Several meta-analysis studies have reported that the use of metformin or statins is associated with a lower risk of colon cancer compared to nonusers. In this study, our aim was to perform a meta-analysis and investigate the prognostic roles of these two medications in colon cancer.

METHODS

To identify relevant articles, literature searches were performed in the PubMed and Web of Science databases using a combination of keywords related to metformin, statins and colon cancer prognosis until August 2023. The study utilized STATA 12.0 software (Stata Corporation, College Station, Texas, USA) to compute all the hazard ratios (HRs) and 95% confidence intervals (CIs) regarding the association between metformin or statin uses and prognostic-related outcomes.

RESULTS

Our analysis revealed that the use of metformin was associated with a significantly lower overall mortality of colon cancer (HR = 0.63; 95% CI = 0.51-0.77; I2  = 94.9%; P  < 0.001), as well as lower cancer-specific mortality of colon cancer (HR = 0.68; 95% CI = 0.50-0.94; I2  = 91.9%; P  < 0.001). Similarly, the use of statins was also associated with a lower overall mortality of colon cancer (HR = 0.68; 95% CI = 0.60-0.78; I2  = 93.8%; P  < 0.001), as well as a lower cancer-specific mortality of colon cancer (HR = 0.74; 95% CI = 0.67-0.81; I2  = 82.2%; P  < 0.001).

CONCLUSION

Our meta-analysis study suggests that statins and metformin may have potential as adjuvant agents with significant benefits in the prognosis of colon cancer.

Large-scale external validation and meta-analysis of gene methylation biomarkers in tumor tissue for colorectal cancer prognosis

BACKGROUND

DNA methylation biomarkers in colorectal cancer (CRC) tissue hold potential as prognostic indicators. However, individual studies have yielded heterogeneous results, and external validation is largely absent. We conducted a comprehensive external validation and meta-analysis of previously suggested gene methylation biomarkers for CRC prognosis.

METHODS

We performed a systematic search to identify relevant studies investigating gene methylation biomarkers for CRC prognosis until March 2024. Our external validation cohort with long-term follow-up included 2303 patients with CRC from 22 hospitals in southwest Germany. We used Cox regression analyses to assess associations between previously suggested gene methylation biomarkers and prognosis, adjusting for clinical variables. We calculated pooled hazard ratios (HRs) and their 95% confidence intervals (CIs) using random-effects models.

FINDINGS

Of 151 single gene and 29 multiple gene methylation biomarkers identified from 121 studies, 37 single gene and seven multiple gene biomarkers were significantly associated with CRC prognosis after adjustment for clinical variables. Moreover, the directions of these associations with prognosis remained consistent between the original studies and our validation analyses. Seven single biomarkers and two multi-biomarker signatures were significantly associated with CRC prognosis in the meta-analysis, with a relatively strong level of evidence for CDKN2A, WNT5A, MLH1, and EVL.

INTERPRETATION

In a comprehensive evaluation of the so far identified gene methylation biomarkers for CRC prognosis, we identified candidates with potential clinical relevance for further investigation.

FUNDING

The German Research Council, the Interdisciplinary Research Program of the National Center for Tumor Diseases (NCT), Germany, the German Federal Ministry of Education and Research.

Deep learning for dual detection of microsatellite instability and POLE mutations in colorectal cancer histopathology

In the spectrum of colorectal tumors, microsatellite-stable (MSS) tumors with DNA polymerase ε (POLE) mutations exhibit a hypermutated profile, holding the potential to respond to immunotherapy similarly to their microsatellite-instable (MSI) counterparts. Yet, due to their rarity and the associated testing costs, systematic screening for these mutations is not commonly pursued. Notably, the histopathological phenotype resulting from POLE mutations is theorized to resemble that of MSI. This resemblance not only could facilitate their detection by a transformer-based Deep Learning (DL) system trained on MSI pathology slides, but also indicates the possibility for MSS patients with POLE mutations to access enhanced treatment options, which might otherwise be overlooked. To harness this potential, we trained a Deep Learning classifier on a large dataset with the ground truth for microsatellite status and subsequently validated its capabilities for MSI and POLE detection across three external cohorts. Our model accurately identified MSI status in both the internal and external resection cohorts using pathology images alone. Notably, with a classification threshold of 0.5, over 75% of POLE driver mutant patients in the external resection cohorts were flagged as "positive" by a DL system trained on MSI status. In a clinical setting, deploying this DL model as a preliminary screening tool could facilitate the efficient identification of clinically relevant MSI and POLE mutations in colorectal tumors, in one go.

Bovine meat and milk factor protein expression in tumor-free mucosa of colorectal cancer patients coincides with macrophages and might interfere with patient survival

Bovine milk and meat factors (BMMFs) are plasmid-like DNA molecules isolated from bovine milk and serum, as well as the peritumor of colorectal cancer (CRC) patients. BMMFs have been proposed as zoonotic infectious agents and drivers of indirect carcinogenesis of CRC, inducing chronic tissue inflammation, radical formation and increased levels of DNA damage. Data on expression of BMMFs in large clinical cohorts to test an association with co-markers and clinical parameters were not previously available and were therefore assessed in this study. Tissue sections with paired tumor-adjacent mucosa and tumor tissues of CRC patients [individual cohorts and tissue microarrays (TMAs) (n = 246)], low-/high-grade dysplasia (LGD/HGD) and mucosa of healthy donors were used for immunohistochemical quantification of the expression of BMMF replication protein (Rep) and CD68/CD163 (macrophages) by co-immunofluorescence microscopy and immunohistochemical scoring (TMA). Rep was expressed in the tumor-adjacent mucosa of 99% of CRC patients (TMA), was histologically associated with CD68+/CD163+ macrophages and was increased in CRC patients when compared to healthy controls. Tumor tissues showed only low stromal Rep expression. Rep was expressed in LGD and less in HGD but was strongly expressed in LGD/HGD-adjacent tissues. Albeit not reaching statistical significance, incidence curves for CRC-specific death were increased for higher Rep expression (TMA), with high tumor-adjacent Rep expression being linked to the highest incidence of death. BMMF Rep expression might represent a marker and early risk factor for CRC. The correlation between Rep and CD68 expression supports a previous hypothesis that BMMF-specific inflammatory regulations, including macrophages, are involved in the pathogenesis of CRC.

Regression-based Deep-Learning predicts molecular biomarkers from pathology slides

Deep Learning (DL) can predict biomarkers from cancer histopathology. Several clinically approved applications use this technology. Most approaches, however, predict categorical labels, whereas biomarkers are often continuous measurements. We hypothesize that regression-based DL outperforms classification-based DL. Therefore, we develop and evaluate a self-supervised attention-based weakly supervised regression method that predicts continuous biomarkers directly from 11,671 images of patients across nine cancer types. We test our method for multiple clinically and biologically relevant biomarkers: homologous recombination deficiency score, a clinically used pan-cancer biomarker, as well as markers of key biological processes in the tumor microenvironment. Using regression significantly enhances the accuracy of biomarker prediction, while also improving the predictions' correspondence to regions of known clinical relevance over classification. In a large cohort of colorectal cancer patients, regression-based prediction scores provide a higher prognostic value than classification-based scores. Our open-source regression approach offers a promising alternative for continuous biomarker analysis in computational pathology.

End-to-end prognostication in colorectal cancer by deep learning: a retrospective, multicentre study

BACKGROUND

Precise prognosis prediction in patients with colorectal cancer (ie, forecasting survival) is pivotal for individualised treatment and care. Histopathological tissue slides of colorectal cancer specimens contain rich prognostically relevant information. However, existing studies do not have multicentre external validation with real-world sample processing protocols, and algorithms are not yet widely used in clinical routine.

METHODS

In this retrospective, multicentre study, we collected tissue samples from four groups of patients with resected colorectal cancer from Australia, Germany, and the USA. We developed and externally validated a deep learning-based prognostic-stratification system for automatic prediction of overall and cancer-specific survival in patients with resected colorectal cancer. We used the model-predicted risk scores to stratify patients into different risk groups and compared survival outcomes between these groups. Additionally, we evaluated the prognostic value of these risk groups after adjusting for established prognostic variables.

FINDINGS

We trained and validated our model on a total of 4428 patients. We found that patients could be divided into high-risk and low-risk groups on the basis of the deep learning-based risk score. On the internal test set, the group with a high-risk score had a worse prognosis than the group with a low-risk score, as reflected by a hazard ratio (HR) of 4·50 (95% CI 3·33-6·09) for overall survival and 8·35 (5·06-13·78) for disease-specific survival (DSS). We found consistent performance across three large external test sets. In a test set of 1395 patients, the high-risk group had a lower DSS than the low-risk group, with an HR of 3·08 (2·44-3·89). In two additional test sets, the HRs for DSS were 2·23 (1·23-4·04) and 3·07 (1·78-5·3). We showed that the prognostic value of the deep learning-based risk score is independent of established clinical risk factors.

INTERPRETATION

Our findings indicate that attention-based self-supervised deep learning can robustly offer a prognosis on clinical outcomes in patients with colorectal cancer, generalising across different populations and serving as a potentially new prognostic tool in clinical decision making for colorectal cancer management. We release all source codes and trained models under an open-source licence, allowing other researchers to reuse and build upon our work.

FUNDING

The German Federal Ministry of Health, the Max-Eder-Programme of German Cancer Aid, the German Federal Ministry of Education and Research, the German Academic Exchange Service, and the EU.

CpG-biomarkers in tumor tissue and prediction models for the survival of colorectal cancer: A systematic review and external validation study

The research aimed to identify previously published CpG-methylation-based prognostic biomarkers and prediction models for colorectal cancer (CRC) prognosis and validate them in a large external cohort. A systematic search was conducted, analyzing 298 unique CpGs and 12 CpG-based prognostic models from 28 studies. After adjustment for clinical variables, 48 CpGs and five prognostic models were confirmed to be associated with survival. However, the discrimination ability of the models was insufficient, with area under the receiver operating characteristic curves ranging from 0.53 to 0.62. Calibration accuracy was mostly poor, and no significant added prognostic value beyond traditional clinical variables was observed. All prognostic models were rated at high risk of bias. While a fraction of CpGs showed potential clinical utility and generalizability, the CpG-based prognostic models performed poorly and lacked clinical relevance.

Colorectal cancer risk stratification on histological slides based on survival curves predicted by deep learning

Studies have shown that colorectal cancer prognosis can be predicted by deep learning-based analysis of histological tissue sections of the primary tumor. So far, this has been achieved using a binary prediction. Survival curves might contain more detailed information and thus enable a more fine-grained risk prediction. Therefore, we established survival curve-based CRC survival predictors and benchmarked them against standard binary survival predictors, comparing their performance extensively on the clinical high and low risk subsets of one internal and three external cohorts. Survival curve-based risk prediction achieved a very similar risk stratification to binary risk prediction for this task. Exchanging other components of the pipeline, namely input tissue and feature extractor, had largely identical effects on model performance independently of the type of risk prediction. An ensemble of all survival curve-based models exhibited a more robust performance, as did a similar ensemble based on binary risk prediction. Patients could be further stratified within clinical risk groups. However, performance still varied across cohorts, indicating limited generalization of all investigated image analysis pipelines, whereas models using clinical data performed robustly on all cohorts.

Transformer-based biomarker prediction from colorectal cancer histology: A large-scale multicentric study

Deep learning (DL) can accelerate the prediction of prognostic biomarkers from routine pathology slides in colorectal cancer (CRC). However, current approaches rely on convolutional neural networks (CNNs) and have mostly been validated on small patient cohorts. Here, we develop a new transformer-based pipeline for end-to-end biomarker prediction from pathology slides by combining a pre-trained transformer encoder with a transformer network for patch aggregation. Our transformer-based approach substantially improves the performance, generalizability, data efficiency, and interpretability as compared with current state-of-the-art algorithms. After training and evaluating on a large multicenter cohort of over 13,000 patients from 16 colorectal cancer cohorts, we achieve a sensitivity of 0.99 with a negative predictive value of over 0.99 for prediction of microsatellite instability (MSI) on surgical resection specimens. We demonstrate that resection specimen-only training reaches clinical-grade performance on endoscopic biopsy tissue, solving a long-standing diagnostic problem.

Generalizable biomarker prediction from cancer pathology slides with self-supervised deep learning: A retrospective multi-centric study

Deep learning (DL) can predict microsatellite instability (MSI) from routine histopathology slides of colorectal cancer (CRC). However, it is unclear whether DL can also predict other biomarkers with high performance and whether DL predictions generalize to external patient populations. Here, we acquire CRC tissue samples from two large multi-centric studies. We systematically compare six different state-of-the-art DL architectures to predict biomarkers from pathology slides, including MSI and mutations in BRAF, KRAS, NRAS, and PIK3CA. Using a large external validation cohort to provide a realistic evaluation setting, we show that models using self-supervised, attention-based multiple-instance learning consistently outperform previous approaches while offering explainable visualizations of the indicative regions and morphologies. While the prediction of MSI and BRAF mutations reaches a clinical-grade performance, mutation prediction of PIK3CA, KRAS, and NRAS was clinically insufficient.

Artificial intelligence in gastric cancer: applications and challenges

Gastric cancer (GC) is one of the most common malignant tumors with high mortality. Accurate diagnosis and treatment decisions for GC rely heavily on human experts' careful judgments on medical images. However, the improvement of the accuracy is hindered by imaging conditions, limited experience, objective criteria, and inter-observer discrepancies. Recently, the developments of machine learning, especially deep-learning algorithms, have been facilitating computers to extract more information from data automatically. Researchers are exploring the far-reaching applications of artificial intelligence (AI) in various clinical practices, including GC. Herein, we aim to provide a broad framework to summarize current research on AI in GC. In the screening of GC, AI can identify precancerous diseases and assist in early cancer detection with endoscopic examination and pathological confirmation. In the diagnosis of GC, AI can support tumor-node-metastasis (TNM) staging and subtype classification. For treatment decisions, AI can help with surgical margin determination and prognosis prediction. Meanwhile, current approaches are challenged by data scarcity and poor interpretability. To tackle these problems, more regulated data, unified processing procedures, and advanced algorithms are urgently needed to build more accurate and robust AI models for GC.

Simvastatin Inhibits Tumor Growth and Migration by Mediating Caspase-1-Dependent Pyroptosis in Glioblastoma Multiforme

OBJECTIVES

Glioblastoma multiforme (GBM) is the most common and lethal central nervous system cancer and is associated with a poor prognosis. Simvastatin, a kind of widely used hypolipidemic agent, has been investigated for its beneficial effects on various types of cancers. The main purpose of this paper is to investigate the potential inhibitory effects of simvastatin on GBM and the underlying mechanism.

METHODS

Cell viability and cell cycle of simvastatin-treated U87 and U251 cells were determined by CCK8 assay and flow cytometry, respectively. Additionally, we assessed cell migration and invasion abilities using a wound-healing assay and transwell assay. mRNA and protein expression patterns of caspase-1 and its markers nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) and IL-1β in different conditions were detected by real-time polymerase chain reaction, immunofluorescence staining, and Western blot.

RESULTS

Simvastatin decreased the viability of GBM cells and inhibited cell migration and invasion in a dose-dependent manner. Moreover, suppression of pyroptosis, as characterized by decreased expression of caspase-1, NLRP3, and IL-1β, was observed. However, use of an miR-214 inhibitor reversed the simvastatin suppressive effect on GBM cells.

CONCLUSIONS

Simvastatin inhibits GBM progression by suppressing caspase-1-dependent pyroptosis, regulated by miR-214.

Incorporation of functional status, frailty, comorbidities, and co-medication in prediction models for colorectal cancer survival

Limitations in functional status, frailty, multiple comorbidities, and co-medications are common among older colorectal cancer (CRC) patients. We investigated whether adding these factors could improve the predictive value of a reference model containing age, sex, tumor stage and location for prediction of 5-year overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), recurrence-free survival (RFS), and non-disease-specific survival (nDSS) for all CRC patients as well as for younger (<65 years) and older patients (≥65 years). Overall, 3,410 CRC patients from the DACHS study were analyzed and area under receiver operating characteristic curves (AUC) and net reclassification improvements (NRI) were assessed. In prediction of OS, the reference model plus functional status was identified as the best model among all CRC patients (AUC: 0.762) and younger CRC patients (AUC: 0.820). In older CRC patients, comorbidity should additionally be added (AUC: 0.747). For nDSS, the reference model plus comorbidity and frailty had the best predictive performance in all CRC patients (AUC: 0.776). For the outcomes DFS (AUC: 0. 727), DSS (AUC: 0. 838), and RFS (AUC: 0. 784), the reference model was already the best model in all CRC patients because no significant NRIs were observed. The pattern "The less CRC-specific the survival outcome and the older the CRC patients, the more relevant the inclusion of functional status, comorbidity, and frailty in CRC prognostic scores is" was observed. Thus, different nomograms for younger and older CRC patients for 1-, 3-, and 5-year OS prognosis estimation are being suggested.

Artificial intelligence for detection of microsatellite instability in colorectal cancer-a multicentric analysis of a pre-screening tool for clinical application

BACKGROUND

Microsatellite instability (MSI)/mismatch repair deficiency (dMMR) is a key genetic feature which should be tested in every patient with colorectal cancer (CRC) according to medical guidelines. Artificial intelligence (AI) methods can detect MSI/dMMR directly in routine pathology slides, but the test performance has not been systematically investigated with predefined test thresholds.

METHOD

We trained and validated AI-based MSI/dMMR detectors and evaluated predefined performance metrics using nine patient cohorts of 8343 patients across different countries and ethnicities.

RESULTS

Classifiers achieved clinical-grade performance, yielding an area under the receiver operating curve (AUROC) of up to 0.96 without using any manual annotations. Subsequently, we show that the AI system can be applied as a rule-out test: by using cohort-specific thresholds, on average 52.73% of tumors in each surgical cohort [total number of MSI/dMMR = 1020, microsatellite stable (MSS)/ proficient mismatch repair (pMMR) = 7323 patients] could be identified as MSS/pMMR with a fixed sensitivity at 95%. In an additional cohort of N = 1530 (MSI/dMMR = 211, MSS/pMMR = 1319) endoscopy biopsy samples, the system achieved an AUROC of 0.89, and the cohort-specific threshold ruled out 44.12% of tumors with a fixed sensitivity at 95%. As a more robust alternative to cohort-specific thresholds, we showed that with a fixed threshold of 0.25 for all the cohorts, we can rule-out 25.51% in surgical specimens and 6.10% in biopsies.

INTERPRETATION

When applied in a clinical setting, this means that the AI system can rule out MSI/dMMR in a quarter (with global thresholds) or half of all CRC patients (with local fine-tuning), thereby reducing cost and turnaround time for molecular profiling.

Quality of life, distress, and posttraumatic growth 5 years after colorectal cancer diagnosis according to history of inpatient rehabilitation

Purpose

In Germany, almost every other colorectal cancer (CRC) patient undergoes inpatient cancer rehabilitation (ICR), but research on long-term outcomes is sparse. We aimed to assess health-related quality of life (HRQOL), distress, and posttraumatic growth among former rehabilitants and non-rehabilitants as well as respective differences and to estimate disease-related quality of life deficits in both groups.

Methods

HRQOL (EORTC-QLQ-C30/CR29), distress (QSC-R10), and posttraumatic growth (PTGI) were assessed according to past ICR in patients 5-year post-CRC-diagnosis in the German DACHS study. Least square mean differences in HRQOL scores and elevated distress levels (QSC-R10 > 14 points) by ICR were estimated by confounder-adjusted linear and logistic regression, respectively. Differences in PTGI scales were tested for statistical significance. EORTC-QLQ-C30 reference scores from population controls were accessed from the LinDE study to estimate disease-related deficits in both treatment groups.

Results

49% of the included 1906 CRC survivors had undergone ICR. Rehabilitants reported lower HRQOL scores than non-rehabilitants in several dimensions of the EORTC-QLQ-C30/CR29. Differences were pronounced among younger survivors (< 70 years). In younger survivors, past ICR also predicted elevated distress. However, rehabilitants showed higher posttraumatic growth. When compared to 934 population controls, non-rehabilitants and older rehabilitants reported HRQOL scores (EORTC-QLQ-C30) similar to controls except higher levels of bowel dysfunctions, whereas younger rehabilitants experienced deficits regarding most scales (13/15).

Conclusion

Our findings suggest a high disease burden 5 years after diagnosis in particular among younger CRC survivors who had undergone ICR. Observed HRQOL deficits are possibly linked to the initial indication for ICR and rehabilitants may benefit from effective follow-up concepts after ICR.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03865-3.

Smoking Behavior and Prognosis After Colorectal Cancer Diagnosis: A Pooled Analysis of 11 Studies

Background

Smoking has been associated with colorectal cancer (CRC) incidence and mortality in previous studies, but current evidence on smoking in association with survival after CRC diagnosis is limited.

Methods

We pooled data from 12 345 patients with stage I-IV CRC from 11 epidemiologic studies in the International Survival Analysis in Colorectal Cancer Consortium. Cox proportional hazards regression models were used to evaluate the associations of prediagnostic smoking behavior with overall, CRC-specific, and non-CRC-specific survival.

Results

Among 12 345 patients with CRC, 4379 (35.5%) died (2515 from CRC) over a median follow-up time of 7.5 years. Smoking was strongly associated with worse survival in stage I-III patients, whereas no association was observed among stage IV patients. Among stage I-III patients, clear dose-response relationships with all survival outcomes were seen for current smokers. For example, current smokers with 40 or more pack-years had statistically significantly worse overall, CRC-specific, and non-CRC-specific survival compared with never smokers (hazard ratio [HR] =1.94, 95% confidence interval [CI] =1.68 to 2.25; HR = 1.41, 95% CI = 1.12 to 1.78; and HR = 2.67, 95% CI = 2.19 to 3.26, respectively). Similar associations with all survival outcomes were observed for former smokers who had quit for less than 10 years, but only a weak association with non-CRC-specific survival was seen among former smokers who had quit for more than 10 years.

Conclusions

This large consortium of CRC patient studies provides compelling evidence that smoking is strongly associated with worse survival of stage I-III CRC patients in a clear dose-response manner. The detrimental effect of smoking was primarily related to noncolorectal cancer events, but current heavy smoking also showed an association with CRC-specific survival.

Association of Polypharmacy with Colorectal Cancer Survival Among Older Patients

Background

In geriatric oncology, polypharmacy is often assessed during a comprehensive geriatric assessment. Previous studies about its association with survival among patients with colorectal cancer (CRC) were inconclusive and had high risk for indication bias.

Patients and Methods

A cohort study was conducted with 3,239 patients with CRC, aged ≥65 years, who were recruited in Germany between 2003 and 2016, while being hospitalized for CRC surgery. We defined polypharmacy as the concurrent use of five or more drugs, and excessive polypharmacy (EPP) as concurrent use of eight or more drugs. Cox proportional hazards regression models were performed to assess the associations of polypharmacy with 5‐year overall (OS), CRC‐specific (CSS), and non‐cancer‐specific survival (NCS) with rigorous adjustment for morbidity to minimize indication bias (e.g., for cancer stage, functional status, and 13 common diseases/conditions).

Results

The prevalence of polypharmacy was 54.7% and that of EPP was 24.2%. During up to 5 years of follow‐up, 1,070 participants died, among whom 615 died of CRC and 296 died of other causes than cancer. EPP was statistically significantly associated with poorer up‐to‐5‐year OS (hazard ratio [HR], 1.23; 95% confidence interval [CI], 1.02–1.47) and CSS (HR, 1.31; 95% CI, 1.03–1.68). HR point estimate for NCS was higher than 1 (1.22) but not statistically significant.

Conclusion

Polypharmacy was very common and EPP was a weak risk factor for mortality in this large cohort of older patients with CRC. Clinical trials are needed to address the causality of this relationship because older patients with CRC might benefit from deprescribing drugs without an indication.

Implications for Practice

The results of this study support the hypothesis that excessive polypharmacy, defined as use of eight or more concurrently used active substances, has a negative impact on the prognosis of older patients with colorectal cancer (CRC). This study suggests to oncologists that performing a medication review for older patients with CRC with eight drugs or more is indicated (especially when a broader comprehensive geriatric assessment is being performed). Such a medication review should not only focus on reducing the number of medications (by deprescribing drugs without an indication) but also check the appropriateness of indicated drugs for older patients with cancer.

Excessive polypharmacy, defined as the concurrent use of eight or more drugs, is becoming more common, especially in the older population. This article evaluates the association of polypharmacy with overall survival in large cohort patients with colorectal cancer.

Statins use and the prognosis of colorectal cancer: a meta-analysis

BACKGROUND

Previous observational studies regarding the prognostic value of statin on colorectal cancer (CRC) patients showed various results.

METHODS

Articles regarding the prognostic value of statin on CRC and published in English and before October 2020 were searched in the following databases: PubMed, Web of Science, EMBASE, Medline and Google Scholar. The multivariate hazard ratios (HRs) and their 95% confidence intervals (CI) were computed to explore associations between statins use and overall mortality or cancer-specific mortality of CRC.

RESULTS

The study included 5 retrospective case-control studies (including 475 statins users and 1925 no-statin users) and 11 prospective cohort studies (including 40659 statins users and 344459 no-statin users). The present study showed that statins use might be significantly associated with lower overall mortality in CRC with a random effects model (HR = 0.81, 95% CI 0.76 to 0.86, I² = 61.9%, p value for Q test <0.001). In addition, statins use might be significantly associated with lower cancer-specific mortality in CRC with a random effects model (HR = 0.78, 95% CI 0.72 to 0.85, I² = 57.3%, p value for Q test = 0.007).

CONCLUSIONS

In conclusion, the present study indicated that that statin use was a protective factor for CRC prognosis. However, the relationship between statins use and CRC prognosis requires repeated and large prospective studies to be verified.

An overview on the biological activity and anti-cancer mechanism of lovastatin

Lovastatin, a secondary metabolite isolated from fungi, is often used as a representative drug to reduce blood lipid concentration and treat hypercholesterolemia. Its structure is similar to that of HMG-CoA. Lovastatin inhibits the binding of the substrate to HMG-CoA reductase, and strongly competes with HMG-CoA reductase (HMGR), thereby exerting a hypolipidemic effect. Further, its safety has been confirmed in vivo and in vitro. Lovastatin also has anti-inflammatory, anti-cancer, and neuroprotective effects. Therefore, the biological activity of lovastatin, especially its anti-cancer effect, has garnered research attention. Several in vitro studies have confirmed that lovastatin has a significant inhibitory effect on cancer cell viability in a variety of cancers (such as breast, liver, cervical, lung, and colon cancer). At the same time, lovastatin can also increase the sensitivity of some types of cancer cells to chemotherapeutic drugs and strengthen their therapeutic effect. Lovastatin inhibits cell proliferation and regulates cancer cell signaling pathways, thereby inducing apoptosis and cell cycle arrest. This article reviews the structure, biosynthetic pathways, and applications of lovastatin, focusing on the anti-cancer effects and mechanisms of action.

Inpatient rehabilitation therapy among colorectal cancer patients - utilization and association with prognosis: a cohort study

BACKGROUND

Inpatient rehabilitation therapy (IRT) is commonly offered to cancer patients during or after cancer treatment in Germany. However, little is known about utilization and long-term effects of this offer in colorectal cancer (CRC) patients. We aimed to assess IRT utilization, determinants of utilization and the association between IRT and survival in CRC patients.

MATERIALS AND METHODS

CRC patients diagnosed in 2005-2014 recruited in the population-based DACHS study in South West Germany were included. Determinants of IRT utilization were assessed by multivariable logistic regression. Hazard ratios (HRs) of the association of IRT with overall and disease-specific survival were estimated by adjusted Cox proportional hazards models. Modified landmark approach was applied to avoid immortal time biased results.

RESULTS

Among the included CRC patients (n = 3704), 43.6% underwent IRT. Patients who did not live in a relationship with a partner, worked as employee and who reported higher levels of physical activity were more likely to undergo IRT. Patients were less likely to undergo IRT if they had private health insurance, were diagnosed with cancer stage IV, received no or laparoscopic cancer surgery or were treated in a hospital with medium vs. high surgical volume. The median follow-up time was 4.4 years (post-landmark). Utilization of IRT was associated with better overall (HR 0.81, 95% confidence interval 0.72-0.92) and disease-specific survival (HR 0.72, 95% confidence interval 0.61-0.85).

CONCLUSION

Almost every other CRC patient underwent IRT. Next to clinical characteristics, identified social and lifestyle characteristics seemed to play an essential role in the decision-making. Use of IRT was associated with better overall and disease-specific survival.

Association of co-medication quality with chemotherapy-related adverse drug reactions and survival in older colorectal cancer patients

BACKGROUND

Evidence about the clinical relevance of appropriate co-medication among older colorectal cancer (CRC) patients is sparse.

METHODS

A cohort study was conducted with 3,239 CRC patients aged 65 years and older. To assess co-medication quality, we calculated the total Fit fOR The Aged (FORTA) score and its sub-scores for medication overuse, underuse, and potentially inappropriate medication use. Multivariable Cox proportional hazards or logistic regression models were performed to evaluate the association of co-medication quality with up to 5-year overall survival, CRC-specific survival, and chemotherapy-related adverse drug reactions (ADRs).

RESULTS

Overall, 3,239 and 1,209 participants were included in analyses on survival and ADRs, respectively. The hazard ratios [95%-confidence intervals] for the total FORTA score ≥ 7 vs. 0-1 points were 1.83 [1.40-2.40] and 1.76 [1.22-2.52] for up to 5-year overall and CRC-specific survival, respectively. Worse up to 5-year OS and CSS was also evident for FORTA sub-scores for PIM use and overuse whereas no association was observed for underuse. Although results for the total FORTA and potentially inappropriate medication score were much stronger among patients receiving chemotherapy, no significant associations with chemotherapy-related ADRs were observed. Moreover, associations were particularly strong among men and rectal cancer patients as compared to women and colon cancer patients.

CONCLUSIONS

Poor total co-medication quality was significantly associated with worse up to 5-year overall and CRC-specific survival. Randomized controlled trials are needed to test whether improved cancer co-medication management in older CRC patients prolongs survival.

DNA Methylation-Based Estimates of Circulating Leukocyte Composition for Predicting Colorectal Cancer Survival: A Prospective Cohort Study

Simple Summary

Inflammation is involved in the evolution of cancer. Leukocytes, of which the proportion can be estimated using epigenome-wide methylation data, may serve as a prognostic marker in colorectal cancer (CRC). Our aim was to investigate whether DNA methylation-based estimates of circulating leukocytes is associated with all-cause and disease-specific mortality in a prospective CRC patients’ cohort. Significant associations with CRC prognosis were observed for CD4+ T cells, CD8+ T cells, B cells, NK cells, and lymphocytes, independent of age, sex, tumor stage, tumor subsite, and therapy. CD4+ T cells outperformed other leukocytes and provided added predictive value in comparison to age, sex, and tumor stage. Although cell counting is commonly used in clinical practice, DNA methylation-estimated cell proportions could be a promising tool in understanding the role of leukocytes as CRC prognostic biomarkers when using stored blood samples.

Abstract

Leukocytes are involved in the progression of colorectal cancer (CRC). The proportion of six major leukocyte subtypes can be estimated using epigenome-wide DNA methylation (DNAm) data from stored blood samples. Whether the composition of circulating leukocytes can be used as a prognostic factor is unclear. DNAm-based leukocyte proportions were obtained from a prospective cohort of 2206 CRC patients. Multivariate Cox regression models and survival curves were applied to assess associations between leukocyte composition and survival outcomes. A higher proportion of lymphocytes, including CD4+ T cells, CD8+ T cells, B cells, and NK cells, was associated with better survival, while a higher proportion of neutrophils was associated with poorer survival. CD4+ T cells outperformed other leukocytes in estimating the patients’ prognosis. Comparing the highest quantile to the lowest quantile of CD4+ T cells, hazard ratios (95% confidence intervals) of all-cause and CRC-specific mortality were 0.59 (0.48, 0.72) and 0.59 (0.45, 0.77), respectively. Furthermore, the association of CD4+ T cells and prognosis was stronger among patients with early or intermediate CRC or patients with colon cancer. In conclusion, the composition of circulating leukocytes estimated from DNAm, particularly the proportions of CD4+ T cells, could be used as promising independent predictors of CRC survival.

The association of vitamin D with survival in colorectal cancer patients depends on antioxidant capacity

BACKGROUND

Vitamin D plays a role in detoxifying free radicals, which might explain the previously reported lower mortality in colorectal cancer (CRC) patients with higher vitamin D concentrations.

OBJECTIVES

We aimed to assess whether the associations of 25-hydroxyvitamin D [25(OH)D] with prognosis in CRC patients differ by total thiol concentration (TTC), a biomarker of antioxidant capacity.

METHODS

CRC patients who were diagnosed from 2003 to 2010 and recruited into a population-based study in southern Germany (n = 2,592) were followed over a period of 6 y. 25(OH)D and TTC were evaluated from blood samples collected shortly after CRC diagnosis. Associations of 25(OH)D with all-cause and CRC mortality according to TTC were estimated using multivariable Cox proportional hazards regression.

RESULTS

There was a weak positive correlation between 25(OH)D and TTC (r = 0.26, P < 0.001). 25(OH)D was inversely associated with mortality among patients in the lowest and middle TTC tertiles, but no associations were found among patients in the highest TTC tertile (P-interaction = 0.01). Among patients in the lowest/middle TTC tertiles, those in the middle and highest (compared with lowest) 25(OH)D tertiles had 31% and 44% lower all-cause mortality (P < 0.001) and 25% and 45% lower CRC mortality (P < 0.001), respectively. However, in the highest TTC tertile, 25(OH)D was not associated with all-cause (P = 0.638) or CRC mortality (P = 0.395).

CONCLUSIONS

The survival advantages in CRC patients with adequate vitamin D strongly depend on antioxidant capacity and are most pronounced in cases of low antioxidant capacity. These findings suggest that TTC and other biomarkers of antioxidant status may be useful as the basis for enhanced selection criteria of patients for vitamin D supplementation, in addition to the conventional judgment based on blood 25(OH)D concentrations, and also for refining selection of patients for clinical trials aiming to estimate the effect of vitamin D supplementation.

Early discontinuation and dose reduction of adjuvant chemotherapy in stage III colon cancer patients

Background

The benefit of chemotherapy in colon cancer patients is well documented but depends largely on whether patients complete the planned treatment regimen. We evaluated predictors of early discontinuation (EDChemo) and dose reduction of chemotherapy, especially the role of adverse treatment effects, in stage III patients who received adjuvant chemotherapy.

Methods

Stage III colon cancer patients who were diagnosed in 2003-2014 and recruited into a population-based study in Germany and received FOLFOX [5-fluorouracil (5-FU), leucovorin (LV), and oxaliplatin], capecitabine monotherapy (CapMono), or 5-FU/LV were included. We assessed determinants of EDChemo and dose reduction using multivariable logistic regression. Also, we estimated proportions of EDChemo and dose reduction that are attributable to adverse effects using attributable fractions.

Results

EDChemo and dose reduction rates were 52% and 17% for FOLFOX, 28% and 9% for CapMono, and 45% and 6% for 5-FU/LV, respectively. Predictors of EDChemo were low-grade tumor and treatment in a medium-volume hospital (for FOLFOX), obesity (for CapMono), and increasing age, T4 stage, and treatment in a medium-volume hospital (for 5-FU/LV). Adverse effects were particularly strongly associated with EDChemo and contributed to about 63%, 51%, and 32% of EDChemo of FOLFOX, CapMono, and 5-FU/LV, respectively. Of the various adverse effects, gastrointestinal events showed the strongest associations with EDChemo and accounted for about 7%, 26%, and 20% of EDChemo of FOLFOX, CapMono, and 5-FU/LV, respectively. Adverse effects were, moreover, a strong determinant of dose reduction and accounted for about 82% of all cases.

Conclusions

EDChemo is common in stage III colon cancer patients receiving chemotherapy and more than half of the cases of EDChemo and dose reduction are due to adverse treatment effects. Further research should address the potential for reducing EDChemo and dose reduction rates by close monitoring of patients for early signs and enhanced management of adverse effects, especially gastrointestinal events.

Magnitude of the Age-Advancement Effect of Comorbidities in Colorectal Cancer Prognosis

BACKGROUND

Comorbidities and old age independently compromise prognosis of patients with colorectal cancer (CRC). The impact of comorbidities could thus be considered as conveying worse prognosis already at younger ages, but evidence is lacking on how much worsening of prognosis with age is advanced to younger ages in comorbid versus noncomorbid patients. We aimed to quantify, for the first time, the impact of comorbidities on CRC prognosis in "age advancement" of worse prognosis.

METHODS

A total of 4,602 patients aged ≥30 years who were diagnosed with CRC in 2003 through 2014 were recruited into a population-based study in the Rhine-Neckar region of Germany and observed over a median period of 5.1 years. Overall comorbidity was quantified using the Charlson comorbidity index (CCI). Hazard ratios and age advancement periods (AAPs) for comorbidities were calculated from multivariable Cox proportional hazards models for relevant survival outcomes.

RESULTS

Hazard ratios for CCI scores 1, 2, and ≥3 compared with CCI 0 were 1.25, 1.53, and 2.30 (P<.001) for overall survival and 1.20, 1.48, and 2.03 (P<.001) for disease-free survival, respectively. Corresponding AAP estimates for CCI scores 1, 2, and ≥3 were 5.0 (95% CI, 1.9-8.1), 9.7 (95% CI, 6.1-13.3), and 18.9 years (95% CI, 14.4-23.3) for overall survival and 5.5 (95% CI, 1.5-9.5), 11.7 (95% CI, 7.0-16.4), and 21.0 years (95% CI, 15.1-26.9) for disease-free survival. Particularly pronounced effects of comorbidity on CRC prognosis were observed in patients with stage I-III CRC.

CONCLUSIONS

Comorbidities advance the commonly observed deterioration of prognosis with age by many years, meaning that at substantially younger ages, comorbid patients with CRC experience survival rates comparable to those of older patients without comorbidity. This first derivation of AAPs may enhance the empirical basis for treatment decisions in patients with comorbidities and highlight the need to incorporate comorbidities into prognostic nomograms for CRC.

Targeting cancer-promoting inflammation - have anti-inflammatory therapies come of age?

The immune system has crucial roles in cancer development and treatment. Whereas adaptive immunity can prevent or constrain cancer through immunosurveillance, innate immunity and inflammation often promote tumorigenesis and malignant progression of nascent cancer. The past decade has witnessed the translation of knowledge derived from preclinical studies of antitumour immunity into clinically effective, approved immunotherapies for cancer. By contrast, the successful implementation of treatments that target cancer-associated inflammation is still awaited. Anti-inflammatory agents have the potential to not only prevent or delay cancer onset but also to improve the efficacy of conventional therapeutics and next-generation immunotherapies. Herein, we review the current clinical advances and experimental findings supporting the utility of an anti-inflammatory approach to the treatment of solid malignancies. Gaining a better mechanistic understanding of the mode of action of anti-inflammatory agents and designing more effective treatment combinations would advance the clinical application of this therapeutic approach.

Whole blood DNA methylation aging markers predict colorectal cancer survival: a prospective cohort study

Background

Blood DNA methylation-based aging algorithms predict mortality in the general population. We investigated the prognostic value of five established DNA methylation aging algorithms for patients with colorectal cancer (CRC).

Methods

AgeAccelHorvath, AgeAccelHannum, DNAmMRscore, AgeAccelPheno and AgeAccelGrim were constructed using whole blood epi-genomic data from 2206 CRC patients. After a median follow-up of 6.2 years, 1079 deaths were documented, including 596 from CRC. Associations of the aging algorithms with survival outcomes were evaluated using the Cox regression and survival curves. Harrell’s C-statistics were computed to investigate predictive performance.

Results

Adjusted hazard ratios (95% confidence intervals) of all-cause mortality for patients in the third compared to the first tertile were 1.66 (1.32, 2.09) for the DNAmMRscore, 1.35 (1.14, 1.59) for AgeAccelPheno and 1.65 (1.37, 2.00) for AgeAccelGrim, even after adjustment for age, sex and stage. AgeAccelHorvath and AgeAccelHannum were not associated with all-cause or CRC-specific mortality. In stage-specific analyses, associations were much stronger for patients with early or intermediate stage cancers (stages I, II and III) than for patients with metastatic (stage IV) cancers. Associations were weaker and less often statistically significant for CRC-specific mortality. Adding DNAmMRscore, AgeAccelPheno or AgeAccelGrim to models including age, sex and tumor stage improved predictive performance moderately.

Conclusions

DNAmMRscore, AgeAccelPheno and AgeAccelGrim could serve as non-invasive CRC prognostic biomarkers independent of other commonly used markers. Further research should aim for tailoring and refining such algorithms for CRC patients and to explore their value for enhanced prediction of treatment success and treatment decisions.

Statins decrease the expression of c-Myc protein in cancer cell lines

Statins are potent inhibitors of the mevalonate/cholesterol biosynthetic pathway and are widely prescribed for the prevention of cardiovascular diseases. Here, we carried out a comprehensive analysis of the effects of three statins, simvastatin, atorvastatin, and lovastatin, on six different cancer cell lines that include a P-glycoprotein-expressing, multidrug resistant variant of an ovarian cancer cell line. Incubation of all cancer cell lines with statins resulted in suppression of cell proliferation without inducing apoptotic cell death. The cell proliferation arrest could be reversed upon transfer of cells to statin-free growth media as well as by the supplementation of the growth media with mevalonate. Further analysis suggested that statins induced cell cycle arrest at G0/G1 phase in four cancer cell lines and the loss of c-Myc protein in three cancer cell lines. The c-Myc expression and the progression of cell division cycle were restored upon the addition of mevalonate to the culture media containing statins. Finally, cells incubated with statins contained an increased level of phosphorylated histone H2AX, an observation previously correlated to cellular senescence. Together, these data demonstrate that statins inhibit the mevalonate pathway which is tightly coupled to oxidative branch of the pentose phosphate pathway, c-Myc expression, cell division cycle progression, and cellular senescence. Implications of these observations in the application of statins as cancer therapeutics are discussed.

Impact of Polypharmacy for Chronic Ailments in Colon Cancer Patients: A Review Focused on Drug Repurposing

Colorectal cancer is characterized by high incidence worldwide. Despite increased awareness and early diagnosis thanks to screening programmes, mortality remains high, particularly for patients with metastatic involvement. Immune checkpoint inhibitors or poly (ADP-ribose) polymerase (PARP)-inhibitors have met with disappointing results when used in this setting, opposed to other malignancies. New drugs with different mechanisms of action are needed in this disease. Drug repurposing might offer new therapeutic options, as patients with metastatic colorectal cancer often share risk factors for other chronic diseases and thus frequently are on incidental therapy with these drugs. The aim of this review is to summarise the published results of the activity of drugs used to treat chronic medications in patients affected by colorectal cancer. We focused on antihypertensive drugs, Non-Steroid Anti-inflammatory Drugs (NSAIDs), metformin, antidepressants, statins and antibacterial antibiotics. Our review shows that there are promising results with beta blockers, statins and metformin, whereas data concerning antidepressants and antibacterial antibiotics seem to show a potentially harmful effect. It is hoped that further prospective trials that take into account the role of these drugs as anticancer medications are conducted.

Age-dependent performance of BRAF mutation testing in Lynch syndrome diagnostics

BRAF V600E mutations have been reported as a marker of sporadic microsatellite instability (MSI) colorectal cancer (CRC). Current international diagnostic guidelines recommend BRAF mutation testing in MSI CRC patients to predict low risk of Lynch syndrome (LS). We evaluated the age-specific performance of BRAF testing in LS diagnostics. We systematically compared the prevalence of BRAF mutations in LS-associated CRCs and unselected MSI CRCs in different age groups as available from published studies, databases and population-based patient cohorts. Sensitivity/specificity analysis of BRAF testing for exclusion of LS and cost calculations were performed. Among 969 MSI CRCs from LS carriers in the literature and German HNPCC Consortium, 15 (1.6%) harbored BRAF mutations. Six of seven LS patients with BRAF-mutant CRC and reported age were <50 years. Among 339 of 756 (44.8%) of BRAF mutations detected in unselected MSI CRC, only 2 of 339 (0.6%) BRAF mutations were detected in patients <50 years. The inclusion of BRAF testing led to high risk of missing LS patients and increased costs at age <50 years. BRAF testing in patients <50 years carries a high risk of missing a hereditary cancer predisposition and is cost-inefficient. We suggest direct referral of MSI CRC patients <50 years to genetic counseling without BRAF testing.

Which patients to sample in clinical cohort studies when the number of events is high and measurement of additional markers is constrained by limited resources

PURPOSE

We consider an existing clinical cohort with events but limited resources for the investigation of a further potentially expensive marker. Biological material of the patients is stored in a biobank, but only a limited number of samples can be analyzed with respect to the marker. The question arises as to which patients to sample, if the number of events preclude standard sampling designs.

METHODS

Modifications of the nested case-control and the case-cohort design for the proportional hazards model are applied, that allow efficient sampling in situations where standard nested case-control and case-cohort are not feasible. These sampling designs are compared to simple random sampling and extreme group sampling, the latter including only patients with extreme outcomes, ie either with an event early in time or without an event until at least a point later in time.

RESULTS

The modified nested case-control design and the modified case-cohort design provide powerful methods for sampling in a clinical cohort with many events. The simple random sampling usually is less efficient. If focus is on precise estimation of a potential effect in terms of a hazard ratio, extreme group sampling is not competitive. If focus is on screening for important biomarkers, extreme group sampling markedly outperforms the other sampling designs.

CONCLUSIONS

When it is not feasible to sample all events, a modified nested case-control design or case-cohort design leads to efficient effect estimates in the proportional hazards model. If screening for important biomarkers is the primary objective, extreme group sampling is preferable.

Pan-cancer image-based detection of clinically actionable genetic alterations

Molecular alterations in cancer can cause phenotypic changes in tumor cells and their micro-environment. Routine histopathology tissue slides - which are ubiquitously available - can reflect such morphological changes. Here, we show that deep learning can consistently infer a wide range of genetic mutations, molecular tumor subtypes, gene expression signatures and standard pathology biomarkers directly from routine histology. We developed, optimized, validated and publicly released a one-stop-shop workflow and applied it to tissue slides of more than 5000 patients across multiple solid tumors. Our findings show that a single deep learning algorithm can be trained to predict a wide range of molecular alterations from routine, paraffin-embedded histology slides stained with hematoxylin and eosin. These predictions generalize to other populations and are spatially resolved. Our method can be implemented on mobile hardware, potentially enabling point-of-care diagnostics for personalized cancer treatment. More generally, this approach could elucidate and quantify genotype-phenotype links in cancer.

Attempts to use statins in cancer therapy: An update

Although it could be speculated that almost everything has been said concerning the use of statins in cancer therapy, statins as anticancer drugs have both committed supporters and opponents, for whom the dispute about the legitimacy of statin use in cancer treatment seems never to be clearly resolved; every year more than 300 reports which deepen the knowledge about statins and their influence on cancer cells are published. In this mini-review, we focus on the latest (since 2015) outcomes of cohort studies and meta-analyses indicating statin effectiveness in cancer treatment. We discuss attempts to improve the bioavailability of statins using nanocarriers and review the effectiveness of statins in combined therapies. We also summarise the latest results regarding the development of mechanisms of resistance to statins by cancer cells and, on the other hand, give a few examples where statins could potentially be used to overcome resistance to commonly used chemotherapeutics. Finally, special attention is paid to new reports on the effect of statins on epithelial-mesenchymal transition.

Association of Aspirin and Nonsteroidal Anti-Inflammatory Drugs With Colorectal Cancer Risk by Molecular Subtypes

BACKGROUND

Regular use of aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) for a longer period has been inversely associated with colorectal cancer (CRC) risk. However, CRC is a heterogenic disease, and little is known regarding the associations with molecular pathological subtypes.

METHODS

Analyses included 2444 cases with a first diagnosis of CRC and 3130 healthy controls from a German population-based case control study. Tumor tissue samples were analyzed for major molecular pathological features: microsatellite instability (MSI), CpG island methylator phenotype, B-Raf proto-oncogene serine/threonine kinase (BRAF) mutation, and Kirsten rat sarcoma viral oncogene homolog gene (KRAS) mutation. Information on past and current use of NSAIDs, including aspirin, was obtained by standardized interviews. Multinomial logistic regression models were used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). All statistical tests were two-sided.

RESULTS

Regular use of NSAIDs was associated with a reduced CRC risk if tumors were MSS (OR = 0.66, 95% CI = 0.57 to 0.77), BRAF wildtype (OR = 0.67, 95% CI = 0.58 to 0.78), or KRAS wildtype (OR = 0.68, 95% CI = 0.58 to 0.80). Regular NSAID use was less clearly and mostly not statistically significantly associated with CRC risk reduction for MSI-high, BRAF-mutated, or KRAS-mutated CRC. In more specific analyses on MSI-high CRC, regular use of NSAIDs was associated with much stronger risk reduction in the absence of BRAF or KRAS mutations (OR = 0.34, 95% CI = 0.18 to 0.65) but not with KRAS- or BRAF-mutated MSI-high CRC (Pheterogeneity < .001). Results for just aspirin use were similar.

CONCLUSION

Our study suggests variation in risk reduction of CRC subtypes following regular use of NSAIDs and aspirin. Regular use of NSAIDs and aspirin may be more strongly associated with risk reduction of MSI-high CRC without KRAS or BRAF mutation.

Association Between Molecular Subtypes of Colorectal Tumors and Patient Survival, Based on Pooled Analysis of 7 International Studies

BACKGROUND AND AIMS

The heterogeneity among colorectal tumors is probably due to differences in developmental pathways and might associate with patient survival times. We studied the relationship among markers of different subtypes of colorectal tumors and patient survival.

METHODS

We pooled data from 7 observational studies, comprising 5010 patients with colorectal cancer. All the studies collected information on microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and mutations in KRAS and BRAF in tumors. Tumors with complete marker data were classified as type 1 (MSI-high, CIMP-positive, with pathogenic mutations in BRAF but not KRAS), type 2 (not MSI-high, CIMP-positive, with pathogenic mutations in BRAF but not KRAS), type 3 (not MSI-high or CIMP, with pathogenic mutations in KRAS but not BRAF), type 4 (not MSI-high or CIMP, no pathogenic mutations in BRAF or KRAS), or type 5 (MSI-high, no CIMP, no pathogenic mutations in BRAF or KRAS). We used Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CIs) for associations of these subtypes and tumor markers with disease-specific survival (DSS) and overall survival times, adjusting for age, sex, stage at diagnosis, and study population.

RESULTS

Patients with type 2 colorectal tumors had significantly shorter time of DSS than patients with type 4 tumors (HR_DSS 1.66; 95% CI 1.33-2.07), regardless of sex, age, or stage at diagnosis. Patients without MSI-high tumors had significantly shorter time of DSS compared with patients with MSI-high tumors (HR_DSS 0.42; 95% CI 0.27-0.64), regardless of other tumor markers or stage, or patient sex or age.

CONCLUSIONS

In a pooled analysis of data from 7 observational studies of patients with colorectal cancer, we found that tumor subtypes, defined by combinations of 4 common tumor markers, were associated with differences in survival time. Colorectal tumor subtypes might therefore be used in determining patients' prognoses.

Physical activity and long-term fatigue among colorectal cancer survivors - a population-based prospective study

Background

Evidence suggests that physical activity (PA) is beneficial for reducing fatigue in colorectal cancer (CRC) survivors. However, little is known regarding long-term effects of PA on fatigue and whether pre-diagnosis PA is associated with less fatigue in the years after diagnosis. Our study aimed to investigate the association of pre- and post-diagnosis PA with long-term fatigue in CRC survivors.

Methods

This study used a German population-based cohort of 1781 individuals, diagnosed with CRC in 2003–2014, and alive at five-year follow-up (5YFU). Physical activity was assessed at diagnosis and at 5YFU. Fatigue was assessed by the Fatigue Assessment Questionnaire and the EORTC Quality of Life Questionnaire-Core 30 fatigue subscale at 5YFU. Multivariable linear regression was used to explore associations between pre- and post-diagnosis PA and fatigue at 5YFU.

Results

No evidence was found that pre-diagnosis PA was associated with less fatigue in long-term CRC survivors. Pre-diagnosis work-related PA and vigorous PA were even associated with higher levels of physical (Beta (ß) = 2.52, 95% confidence interval (CI) = 1.14–3.90; ß = 2.03, CI = 0.65–3.41), cognitive (ß = 0.17, CI = 0.05–0.28; ß = 0.13, CI = 0.01–0.25), and affective fatigue (ß = 0.26, CI = 0.07–0.46; ß = 0.21, CI = 0.02–0.40). In cross-sectional analyses, post-diagnosis PA was strongly associated with lower fatigue on all scales.

Conclusions

In this study, pre-diagnosis PA does not appear to be associated with less fatigue among long-term CRC survivors. Our results support the importance of ongoing PA in long-term CRC survivors. Our findings might be used as a basis for further research on specific PA interventions to improve the long-term outcome of CRC survivors.

Blood markers of oxidative stress are strongly associated with poorer prognosis in colorectal cancer patients

Oxidative stress has been implicated in the initiation of several cancers, including colorectal cancer (CRC). Whether it also plays a role in CRC prognosis is unclear. We assessed the associations of two oxidative stress biomarkers (Diacron's reactive oxygen metabolites [d-ROMs] and total thiol level [TTL]) with CRC prognosis. CRC patients who were diagnosed in 2003 to 2012 and recruited into a population-based study in Germany (n = 3361) were followed for up to 6 years. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the associations of d-ROMs and TTL (measured from blood samples collected shortly after CRC diagnosis) with overall survival (OS) and disease-specific survival (DSS) were estimated using multivariable Cox regression. Particularly pronounced associations of higher d-ROMs with lower survival were observed in stage IV patients, with patients in the highest (vs lowest) tertile having much lower OS (HR = 1.52, 95% CI = 1.14-2.04) and DSS (HR = 1.61, 95% CI = 1.20-2.17). For TTL, strong inverse associations of TTL with mortality were observed within all stages. In patients of all stages, those in the highest (vs lowest) quintile had substantially higher OS (HR = 0.48, 95% CI = 0.38-0.62) and DSS (HR = 0.52, 95% CI = 0.39-0.69). The addition of these biomarkers to models that included age, sex, tumor stage and subsite significantly improved the prediction of CRC prognosis. The observed strong associations of higher d-ROMs and lower TTL levels with poorer prognosis even in stage IV patients suggest that oxidative stress contributes significantly to premature mortality in CRC patients and demonstrate a large potential of these biomarkers in enhancing the prediction of CRC prognosis beyond tumor stage.

Physical Activity and Long-term Quality of Life among Colorectal Cancer Survivors-A Population-based Prospective Study

Evidence suggests that physical activity (PA) is positively associated with (health-related) quality of life (QOL) in colorectal cancer survivors. However, little is known regarding long-term effects of PA on QOL and if prediagnosis PA is associated with QOL in the years after diagnosis. Our study aimed to investigate the association of prediagnosis and postdiagnosis PA with long-term QOL in colorectal cancer survivors.This study is based on a population-based cohort from Germany of 1,781 newly diagnosed colorectal cancer survivors over a 5-year period. PA was assessed at diagnosis and at 5-year follow-up (5YFU). Quality of life was assessed by the European Organisation for Research and Treatment of Cancer C Quality of Life Questionnaire QLQ-C30 at 5YFU. Multivariable linear regression was used to explore associations between prediagnosis and postdiagnosis PA and QOL at 5YFU.No evidence of a positive association between higher levels of prediagnosis PA and better long-term QOL was found. Higher levels of prediagnosis work-related PA and vigorous PA were even associated with decreased QOL in domains such as cognitive [Beta(β) = -2.52, 95% confidence interval (CI) = -3.77, -1.27; β = -1.92, CI = -3.17, -0.67) and emotional functioning (β = -2.52, CI = -3.84, -1.19; β = -2.12, CI = -3.44, -0.80). In cross-sectional analyses, higher postdiagnosis PA was strongly associated with higher QOL. Survivors physically active at both prediagnosis and postdiagnosis as well as survivors who increased their PA between prediagnosis and postdiagnosis reported significantly higher long-term QOL compared with survivors who remained inactive at prediagnosis and postdiagnosis. In this study, higher prediagnosis PA does not appear to be associated with higher QOL among long-term colorectal cancer survivors but our results support the importance of ongoing PA throughout survivorship.

Impact of statin use on cancer-specific mortality and recurrence: A meta-analysis of 60 observational studies

This meta-analysis mainly summarized the studies reporting an association between statin use and cancer-specific mortality and recurrence or progression of cancer patients.We systematically searched for studies about the statin used in cancer patients in electronic databases, including PubMed, Web of Science, Cochrane, Clinical Trials, from inception through the November 2019. A total of 60 studies which included 953,177 participants were eligible with 233,322 cancer patients used statin. Our analysis selected studies presented with outcome based on hazard ratios (HRs) and 95% confidence intervals (CIs) of cancer-specific mortality and cancer recurrence-free survival or progression-free survival. Heterogeneity between the studies was examined using I statistics, and sensitivity analyses were conducted to assess the robustness of the findings. All statistical analyses were performed using RevMan software (version 5.3).The use of statin was potentially associated with a decline in cancer-specific mortality in cancer patients (HR = 0.78; 95% CI: 0.74, 0.84; n = 39; I = 85%). Furthermore, statin use was associated with improved recurrence-free survival (HR = 0.87; 95% CI: 0.78,0.97; n = 23; I = 64%), but not with improvement in progression-free survival (HR = 1.05; 95% CI: 0.95,1.16; n = 14; I2 = 38%).The meta-analysis demonstrated that statin use could exhibit potential survival benefit in the prognosis of cancer patients. But our results are conservative for statins to improve disease recurrence and progression. These findings should be assessed in a prospective randomized cohort.

Smoking, alcohol consumption and colorectal cancer risk by molecular pathological subtypes and pathways

Background

Smoking and alcohol increase risk for colorectal malignancies. However, colorectal cancer (CRC) is a heterogenic disease and associations with the molecular pathological pathways are unclear.

Methods

This population-based case–control study includes 2444 cases with first-diagnosis CRC and 2475 controls. Tumour tissue was analysed for MSI (microsatellite instability), CIMP (CpG island methylator phenotype), BRAF (B-Raf proto-oncogene serine/threonine kinase gene) and KRAS (Kirsten rat sarcoma viral oncogene homologue gene) mutations. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated for associations between alcohol and smoking and CRC molecular subtypes and pathways.

Results

Current smoking showed higher ORs for MSI-high (OR = 2.79, 95% CI: 1.86–4.18) compared to MSS (OR = 1.41, 1.14–1.75, p-heterogeneity (p-het) = 0.001), BRAF-mutated (mut) (OR = 2.40, 1.41–4.07) compared to BRAF-wild type (wt) (OR = 1.52, 1.24–1.88, p-het = 0.074), KRAS-wt (OR = 1.70, 1.36–2.13) compared to KRAS-mut (OR = 1.26, 0.95–1.68, p-het = 0.039) and CIMP-high (OR = 2.01, 1.40–2.88) compared to CIMP-low/negative CRC (OR = 1.50, 1.22–1.85, p-het=0.101). Current smoking seemed more strongly associated with sessile serrated pathway (CIMP-high + BRAF-mut; OR = 2.39, 1.27–4.52) than with traditional pathway CRC (MSS + CIMP-low/negative + BRAF-wt; OR = 1.50, 1.16–1.94) and no association was observed with alternate pathway CRC (MSS + CIMP-low/negative + KRAS-wt; OR = 1.08, 0.77–1.43). No heterogeneity was observed in alcohol consumption association by molecular subtypes.

Conclusions

In this large case–control study, smoking was more strongly associated with MSI-high and KRAS-wt CRC and with cases showing features of the sessile serrated pathway. Association patterns were less clear for alcohol consumption.

Genetic Predictors of Circulating 25-Hydroxyvitamin D and Prognosis after Colorectal Cancer

BACKGROUND

Low serum 25-hydroxyvitamin D [25(OH)D] concentrations in patients with colorectal cancer have been consistently associated with higher mortality in observational studies. It is unclear whether low 25(OH)D levels directly influence colorectal cancer mortality. To minimize bias, we use genetic variants associated with vitamin D levels to evaluate the association with overall and colorectal cancer-specific survival.

METHODS

Six genetic variants have been robustly identified to be associated with 25(OH)D levels in genome-wide association studies. On the basis of data from the International Survival Analysis in Colorectal Cancer Consortium, the individual genetic variants and a weighted genetic risk score were tested for association with overall and colorectal cancer-specific survival using Cox proportional hazards models in 7,657 patients with stage I to IV colorectal cancer, of whom 2,438 died from any cause and 1,648 died from colorectal cancer.

RESULTS

The 25(OH)D decreasing allele of SNP rs2282679 (GC gene, encodes group-specific component/vitamin D-binding protein) was associated with poorer colorectal cancer-specific survival, although not significant after multiple-testing correction. None of the other five SNPs showed an association. The genetic risk score showed nonsignificant associations with increased overall [HR = 1.54; confidence interval (CI), 0.86-2.78] and colorectal cancer-specific mortality (HR = 1.76; 95% CI, 0.86-3.58). A significant increased risk of overall mortality was observed in women (HR = 3.26; 95% CI, 1.45-7.33; P _{heterogeneity} = 0.01) and normal-weight individuals (HR = 4.14; 95% CI, 1.50-11.43, P _{heterogeneity} = 0.02).

CONCLUSIONS

Our results provided little evidence for an association of genetic predisposition of lower vitamin D levels with increased overall or colorectal cancer-specific survival, although power might have been an issue.

IMPACT

Further studies are warranted to investigate the association in specific subgroups.

Postmenopausal hormone replacement therapy and colorectal cancer risk by molecular subtypes and pathways

Postmenopausal hormone replacement therapy (HRT) was found to be associated with lower risk of colorectal cancer (CRC). However, little is known regarding associations with molecular subtypes of CRC. The current study includes female participants of a large German population-based case-control study (922 CRC cases and 1,183 controls). Tumor tissue samples were analyzed for microsatellite instability (MSI), CpG island methylator phenotype (CIMP), BRAF and KRAS mutation status. Multivariable logistic regression models were used to assess the association of HRT use with molecular subtypes and pathways. Postmenopausal HRT use was overall associated with reduced risk of CRC (adjusted odds ratio (aOR) 0.62, 95% confidence interval (CI) 0.50-0.76) and no major differences were observed for molecular subtypes or for tumor marker combinations representing molecular pathways. When stratified by median age (≤/>71 years) potentially stronger risk reductions were observed in the older group for subtypes showing MSI (OR = 0.36, 95% CI 0.17-0.76), BRAF mutation (OR = 0.40, 95% CI 0.30-0.83) and CIMP-high (OR = 0.40, 95% CI 0.21-0.73) and for CRC suggestive of the sessile serrated pathway (OR = 0.45, 95% CI 0.20-1.01). In conclusion, postmenopausal use of HRT was similarly associated with risk reduction of major molecular tumor subtypes and pathways of CRC. Potentially stronger risk reductions with CRC subtypes diagnosed at higher ages require confirmation and clarification from other studies. The current study extends the limited understanding of the mechanisms of HRT in CRC prevention.

Time of Metastasis and Outcome in Colorectal Cancer

OBJECTIVE

The aim of this study was to evaluate outcomes of metastases at various time intervals after colorectal cancer (CRC) diagnosis.

BACKGROUND

Earlier studies have indicated a short time interval between CRC diagnosis and distant metastases to be associated with poor prognosis. The majority of studies assessed outcome from CRC diagnosis or metastasis resection rather than from metastasis diagnosis and might be subject to immortal time bias.

METHODS

Patients in the population-based DACHS study were stratified: metastases at/within 1 month (immediate), 2 to 6 months (early), 7 to 12 months (intermediate), and >12 months (late) after CRC diagnosis. The primary endpoint was overall survival (OS) from metastasis diagnosis. Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CI). HRs were adjusted for important confounders and immortal time.

RESULTS

A total of 1027 patients were included. T4 (P < 0.0001) and node-positive tumors (P < 0.0001) were more frequent in the immediate group. Lung metastases (P < 0.0001) and single-site metastases (P < 0.0001) were more prevalent in the late group. In multivariable analysis, immediate metastases were not associated with poor OS compared to metastases at later time points (late vs immediate: HR 1.21; 95% CI, 0.98-1.48). Subgroup analyses revealed poor OS of late versus immediate metastases for females (1.45; 1.08-1.96), proximal colon cancer (1.54; 1.09-2.16), and N0 (1.46; 1.00-2.12) or N1 disease (1.88; 1.17-3.05).

CONCLUSIONS

Immediate or early metastases are not associated with unfavorable outcome compared to late metastases. These findings challenge the current notion of poor outcome for CRC with immediate or early metastases.

Personalizing the Prediction of Colorectal Cancer Prognosis by Incorporating Comorbidities and Functional Status into Prognostic Nomograms

Despite consistent evidence that comorbidities and functional status (FS) are strong prognostic factors for colorectal cancer (CRC) patients, these important characteristics are not considered in prognostic nomograms. We assessed to what extent incorporating these characteristics into prognostic models enhances prediction of CRC prognosis. CRC patients diagnosed in 2003–2014 who were recruited into a population-based study in Germany and followed over a median time of 4.7 years were randomized into training (n = 1608) and validation sets (n = 1071). In the training set, Cox models with predefined variables (age, sex, stage, tumor location, comorbidity scores, and FS) were used to construct nomograms for relevant survival outcomes. The performance of the nomograms, compared to models without comorbidity and FS, was evaluated in the validation set using concordance index (C-index). The C-indexes of the nomograms for overall and disease-free survival in the validation set were 0.768 and 0.737, which were substantially higher than those of models including tumor stage only (0.707 and 0.701) or models including stage, age, sex, and tumor location (0.749 and 0.718). The nomograms enabled significant risk stratification within all stages including stage IV. Our study suggests that incorporating comorbidities and FS into prognostic nomograms could substantially enhance prediction of CRC prognosis.

Examining Bias in Studies of Statin Treatment and Survival in Patients With Cancer

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.

Treatment selection bias for chemotherapy persists in colorectal cancer patient cohort studies even in comprehensive propensity score analyses

Introduction

Propensity score methods are increasingly used to address confounding related to treatment selection in observational studies. Studies estimating the effect of chemotherapy in colon cancer (CC) patients, however, often lacked information on pertinent comorbidities and functional status (FS). We assessed to what extent comorbidities and FS impact treatment decisions in colorectal cancer patients and explain the benefit of chemotherapy in stage III CC patients.

Methods

Stage II-III colorectal cancer patients diagnosed in 2003-2014 and recruited into a population-based study were included (N=1102). Associations of comorbidity and FS with treatment patterns were examined with multivariable logistic regression. The contribution of lower comorbidity and higher FS to the benefit of chemotherapy was estimated with propensity score weighted Cox models in 430 stage III CC patients who were followed over a median time of 4.7 years.

Results

In stage II (high-risk) and III CC patients, Charlson comorbidity scores 1, 2 and 3+ were associated with 57%, 66% and 70% lower odds of chemotherapy use, respectively. In combination with older age and poor FS, comorbidity was associated with 97% and 83% decreased odds of adjuvant chemotherapy use in CC and rectal cancer patients, respectively. In stage III CC patients, lower comorbidity and higher FS explained 38% and 24% of the overall and disease-specific survival benefits of chemotherapy, respectively. Selection bias was observed even in the comprehensive models, as chemotherapy was still associated with substantially higher non-disease-specific survival (hazard ratio (HR): 0.66; 95% confidence interval (CI): 0.46-0.92), especially in patients <75 years (HR: 0.33; 95% CI: 0.17-0.63).

Conclusion

Lower comorbidity and higher FS of recipients of chemotherapy explain approximately 40% of the benefits of chemotherapy in stage III CC patients. Regardless of how comprehensive propensity score analyses might be in observational studies, treatment selection bias might persist and affect estimates of treatment effects.

A prognostic CpG score derived from epigenome-wide profiling of tumor tissue was independently associated with colorectal cancer survival

Background

Results of previous studies on the association of the CpG island methylator phenotype (CIMP) with colorectal cancer (CRC) prognosis were inconsistent and mostly based on different CIMP definitions. The current study aimed to comprehensively investigate the associations between DNA methylation on genes previously used to define CIMP status with CRC survival.

Results

Patients with CRC followed up for a median of 5.2 years were divided into a study cohort (n = 568) and a validation cohort (n = 308). DNA methylation was measured in tumor tissue using the Illumina Infinium HumanMethylation450 BeadChip and restricted to 43 genes used to define CIMP status in previous studies. Cox proportional hazard regression models were used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) of survival after CRC, including adjustment for tumor stage, microsatellite instability, and BRAF mutation status. In the study cohort, ten CpG sites were identified to be associated with CRC survival. Seven of these ten CpG sites were also associated with CRC survival in the validation cohort and were used to construct a prognostic score. CRC patients with a prognostic score of the lowest methylation level showed poorer disease-specific survival compared with patients with the highest methylation level in both the study cohort and the validation cohort (HR = 3.11 and 95% CI = 1.97–4.91, and HR = 3.06 and 95% CI = 1.71–5.45, respectively).

Conclusions

A CpG panel consisting of seven CpG sites was found to be strongly associated with CRC survival, independent from important clinical factors and mutations associated with CIMP. Further studies are required to confirm these findings.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0703-4) contains supplementary material, which is available to authorized users.

Epidemiologic Analysis Along the Mevalonate Pathway Reveals Improved Cancer Survival in Patients Who Receive Statins Alone and in Combination With Bisphosphonates

PURPOSE

Cohort studies report associations between statin use and improved survival in patients with cancer. We used pharmacoepidemiologic methods to evaluate the survival of patients with cancer who received statins alone or in ostensibly synergistic drug combinations.

MATERIALS AND METHODS

Patients with cancer who were diagnosed from 2010 to 2013 were identified in a large health care claims database. The rate of all-cause death up to 1 year after diagnosis was compared by Cox proportional hazard regression. Sensitivity analyses included age stratification, statin type and intensity, and comparison with or without bisphosphonates and dipyridamole.

RESULTS

Among 312,907 identified patients with cancer, treatment groups included statin users (n = 65,440), nonstatin users who received medications that block cholesterol absorption (n = 9,289), and nonusers (n = 226,007). Statin use before diagnosis was associated with improved overall survival compared with no treatment (hazard ratio [HR], 0.85; 95% CI, 0.80 to 0.91) and specifically in patients with leukemia, lung, or renal cancers. Nonstatin users had increased overall survival compared with no treatment (HR, 0.73; 95% CI, 0.62 to 0.85); when stratified, this difference held true only for pancreatic cancer and leukemia. No differences were observed between statin and nonstatin groups. Bisphosphonate use alone had no effect (n = 4,528), but patients who used both statins and bisphosphonates (n = 4,090) had increased survival compared with no treatment (HR, 0.60; 95% CI, 0.45 to 0.81). The effect of the combination of dipyridamole and statin use (n = 651) was not significant compared with no treatment.

CONCLUSION

This study suggests that the combination of statins with drugs that affect isoprenylation, such as bisphosphonates, improves survival in patients with cancer. Consideration of pathway-specific pharmacology allows for hypotheses testing with the pharmacoepidemiologic approach. Prospective evaluation of these findings warrants clinical investigation and preclinical mechanistic studies.

External validation of molecular subtype classifications of colorectal cancer based on microsatellite instability, CIMP, BRAF and KRAS

Background

Competing molecular classification systems have been proposed to complement the TNM staging system for a better prediction of survival in colorectal cancer (CRC). However, validation studies are so far lacking. The aim of this study was to validate and extend previously published molecular classifications of CRC in a large independent cohort of CRC patients.

Methods

CRC patients were recruited into a population-based cohort study (DACHS). Molecular subtypes were categorized based on three previously published classifications. Cox-proportional hazard models, based on the same set of patients and using the same confounders as reported by the original studies, were used to determine overall, cancer-specific, or relapse-free survival for each subtype. Hazard ratios and confidence intervals, as well as Kaplan-Meier plots were compared to those reported by the original studies.

Results

We observed similar patterns of worse survival for the microsatellite stable (MSS)/BRAF-mutated and MSS/KRAS-mutated subtypes in our validation analyses, which were included in two of the validated classifications. Of the two MSI subtypes, one defined by additional presence of CIMP-high and BRAF-mutation and the other by tumors negative for CIMP, BRAF and KRAS-mutations, we could not confirm associations with better prognosis as suggested by one of the classifications. For two of the published classifications, we were able to provide results for additional subgroups not included in the original studies (men, other disease stages, other locations).

Conclusions

External validation of three previously proposed classifications confirmed findings of worse survival for CRC patients with MSS subtypes and BRAF or KRAS mutations. Regarding MSI subtypes, other patient characteristics such as stage of the tumor, may influence the potential survival benefit. Further integration of methylation, genetic, and immunological information is needed to develop and validate a comprehensive classification that will have relevance for use in clinical practice.