Aspirin use and the risk of cholangiocarcinoma

Whether aspirin use is protective against cholangiocarcinoma (CCA) remains unclear. We determined the association between aspirin use and other risk factors for each CCA subtype individually. In a hospital-based case-control study, 2395 CCA cases (1169 intrahepatic, 995 perihilar, and 231 distal) seen at the Mayo Clinic, Rochester, MN, from 2000 through 2014 were enrolled. Controls selected from the Mayo Clinic Biobank were matched two to one with cases by age, sex, race, and residence (n = 4769). Associations between aspirin use, other risk factors, and CCA risk were determined. Aspirin was used by 591 (24.7%) CCA cases and 2129 (44.6%) controls. There was a significant inverse association of aspirin use with all CCA subtypes, with adjusted odds ratios (AORs) of 0.35 (95% confidence interval [CI], 0.29-0.42), 0.34 (95% CI 0.27-0.42), and 0.29 (95% CI 0.19-0.44) for intrahepatic, perihilar, and distal CCA, respectively (P < 0.001 for all). Primary sclerosing cholangitis was more strongly associated with perihilar (AOR = 453, 95% CI 104-999) than intrahepatic (AOR = 93.4, 95% CI 27.1-322) or distal (AOR = 34.0, 95% CI 3.6-323) CCA, whereas diabetes was more associated with distal (AOR = 4.2, 95% CI 2.5-7.0) than perihilar (AOR = 2.9, 95% CI 2.2-3.8) or intrahepatic (AOR = 2.5, 95% CI 2.0-3.2) CCA. Cirrhosis not related to primary sclerosing cholangitis was associated with both intrahepatic and perihilar CCA, with similar AORs of 14. Isolated inflammatory bowel disease without primary sclerosing cholangitis was not associated with any CCA subtype.

CONCLUSIONS

Aspirin use was significantly associated with a 2.7-fold to 3.6-fold decreased risk for the three CCA subtypes; our study demonstrates that individual risk factors confer risk of different CCA subtypes to different extents. (Hepatology 2016;64:785-796).

Association between variants in inflammation and cancer-associated genes and risk and survival of cholangiocarcinoma

Genetic risk factors for cholangiocarcinoma (CCA) remain poorly understood. We assessed the effect of single-nucleotide polymorphisms (SNPs) of genes modulating inflammation or carcinogenesis on CCA risk and survival. We conducted a case-control, candidate gene association study of 370 CCA patients and 740 age-, sex-, and residential area-matched healthy controls. Eighteen functional or putatively functional SNPs in nine genes were genotyped. The log-additive genotype effects of SNPs on CCA risk and survival were determined using logistic regression and the log-rank test, respectively. Initial analysis identified significant associations between SNP rs2143417 and rs689466 in cyclooxygenase 2 (COX-2) and CCA risk, after adjusting for multiple comparisons (cutoff of P = 0.0028). However, these findings were not replicated in another independent cohort of 212 CCA cases and 424 matched controls. No significant association was found between any SNP and survival of CCA patients. Although COX-2 has been shown to contribute to cholangiocarcinogenesis, the COX-2 SNPs tested were not associated with risk of CCA. This study shows a lack of association between variants of genes related to inflammation and carcinogenesis and CCA risk and survival. Other factors than these genetic variants may play more important roles in CCA risk and survival.

Pancreatic polypeptide response to a mixed meal is blunted in pancreatic head cancer associated with diabetes mellitus

INTRODUCTION

Pancreatic polypeptide (PP) is a hormone secreted by islet cells of the ventral pancreas. It has been proposed that a blunted PP response to a mixed meal can distinguish diabetes mellitus (DM) secondary to pancreatic disease from other types of DM. We performed a proof of concept study to determine if PP response to a mixed meal discriminates DM secondary to pancreatic cancer (PaCDM) from type 2 DM (T2DM).

METHODS

We studied 18 subjects with new onset DM (PaCDM (n = 9) and T2DM (n = 9); matched for age and gender). Serum PP levels were measured at 0, 30, and 60 min following a mixed meal. Increases in PP levels from baseline were compared using the Wilcoxon test.

RESULTS

In PaCDM the PP increase following a mixed meal was less than T2DM at 30 min (median 60.0%, IQR, 33.0-119.8 vs. 134.5%, IQR, 117.5-265.9; p = 0.03), but statistically similar at 60 min (median 55.8%, interquartile range (IQR) 23.7-121.5 vs. 100.0%, IQR, 47.7-202.5; p = 0.17). In PaCDM subjects, the PP increase over baseline was smaller in those with a tumor located in the pancreatic head (n = 6) compared to the body/tail (n = 3) at 30 min (41.3% vs. 158.7%, p = 0.02) and at 60 min (37.4% vs. 167.4%,p = 0.04).

CONCLUSIONS

Subjects with PaCDM have a blunted PP response to a mixed meal compared to T2DM. However, the blunted PP response is only observed in those PaC subjects with a tumor located in the head of the pancreas. Confirmation in larger studies may suggest this could be used to aid screening for sporadic PaC.

Toward a molecular classification of colorectal cancer: the role of telomere length

Telomere biology is central to the maintenance of genomic stability and telomeric dysfunction is thought to be an early stage in carcinogenesis. Reports of telomere lengths and their ascribed colorectal cancer (CRC) risks have been discordant, with both very short and very long telomeres implicated. Nevertheless, telomeres appear to play a very central role in cancer initiation. Telomere length changes also appear to impact disease burden, progression, and overall survival. This review covers contemporary views on telomere biology and CRC risk, with a brief overview of analytical methods employed in telomere measurement. We conclude with arguments in favor of including telomere assessment in the molecular profiling of CRCs.

Fibroblast growth factor signaling in liver carcinogenesis

Fibroblast growth factors, or FGFs, are a large family of polypeptide cytokines exhibiting a pleiotropy of functions, from cell growth to angiogenesis, wound healing, and tissue repair. This review broadly covers the genetics and protein expression of the FGF family members and the signaling pathways involved in FGF-mediated growth regulation. We emphasize the role of FGFs in the pathogenesis of hepatocellular carcinoma (HCC), including their effects on regulation of the tumor microenvironment and angiogenesis. Finally, we present current views on FGF's potential role as a prognostic marker in clinical practice, as well as its potential as a therapeutic target in HCC.

Telomeres and telomere dynamics: relevance to cancers of the GI tract

Aberrations in telomere length and telomere maintenance contribute to cancer development. In this article, we review the basic principles of telomere length in normal and tumor tissue and the presence of the two main telomere maintenance pathways as they pertain to gastrointestinal tract cancer. Peripheral blood telomeres are shorter in patients with many types of gastrointestinal tract cancers. Telomere length in tumor DNA also appears to shorten early in cancer development. Tumor telomere shortening is often accompanied by telomerase activation to protect genetically damaged DNA from normal cell senescence or apoptosis, allowing immortalized but damaged DNA to persist. Alternative lengthening of telomeres is another mechanism used by cancer to maintain telomere length in cancer cells. Telomerase and alternative lengthening of telomeres activators and inhibitors may become important chemopreventive or chemotherapeutic agents as our understanding of telomere biology, specific telomere-related phenotypes and its relationship to carcinogenesis increases.