No association between alcohol consumption and pancreatic cancer even among individuals genetically susceptible to the carcinogenicity of alcohol

Earlier Diagnosis of Pancreatic Cancer: Is It Possible?

Pancreatic ductal adenocarcinoma has a very high mortality rate which has been only minimally improved in the last 30 years. This high mortality is closely related to late diagnosis, which is usually made when the tumor is large and has extensively infiltrated neighboring tissues or distant metastases are already present. This is a paradoxical situation for a tumor that requires nearly 15 years to develop since the first founding mutation. Response to chemotherapy under such late circumstances is poor, resistance is frequent, and prolongation of survival is almost negligible. Early surgery has been, and still is, the only approach with a slightly better outcome. Unfortunately, the relapse percentage after surgery is still very high. In fact, early surgery clearly requires early diagnosis. Despite all the advances in diagnostic methods, the available tools for improving these results are scarce. Serum tumor markers permit a late diagnosis, but their contribution to an improved therapeutic result is very limited. On the other hand, effective screening methods for high-risk populations have not been fully developed as yet. This paper discusses the difficulties of early diagnosis, evaluates whether the available diagnostic tools are adequate, and proposes some simple and not-so-simple measures to improve it.

Modifiable Pancreatic Ductal Adenocarcinoma (PDAC) Risk Factors

This study aims to summarize the modifiable risk factors for pancreatic ductal adenocarcinoma (PDAC) that have been known for a long time, as well as information from the most recent reports. As a cancer with a late diagnosis and poor prognosis, accurate analysis of PDAC risk factors is warranted. The incidence of this cancer continues to rise, and the five-year survival rate is the lowest with respect to other tumors. The influence of cigarette smoking, alcohol consumption, and chronic pancreatitis in increasing the risk of pancreatic ductal adenocarcinoma is continually being confirmed. There are also newly emerging reports relating to the impact of lifestyle, including physical activity, the gut and oral microbiome, and hepatotropic viruses. A precise understanding of PDAC risk factors can help to identify groups of high-risk patients, and this may contribute to population awareness and education as well as earlier diagnoses with possible better treatment outcomes.

Updated epidemiology of gastrointestinal cancers in East Asia

Globally, gastrointestinal cancers represent more than one-fourth of all cancer incidence and one-third of cancer-related mortality. Although there has been much progress in screening colorectal cancer, the prognosis of other gastrointestinal cancers tends to be poor. The highest burden of gastrointestinal cancers, including stomach, liver, oesophageal and gallbladder cancers, was observed in regions in East Asia. The increasing burden of gastrointestinal cancers in East Asian regions is related to population growth, ageing and the westernization of lifestyle habits in this region. Furthermore, the rising incidence of young-onset colorectal cancer is an emerging trend in East Asia. This Review provides a comprehensive and updated summary of the epidemiology of gastrointestinal cancers in East Asia, with emphasis on comparing their epidemiology in East Asia with that in Western regions, and highlights the major risk factors and implications for prevention. Overall, to optimally reduce the disease burden incurred by gastrointestinal cancers in East Asian regions, a concerted effort will be needed to modify unhealthy lifestyles, promote vaccination against the hepatitis virus, control Helicobacter pylori, liver fluke and hepatitis virus infections, increase the uptake rate of colorectal cancer screening, enhance detection of early cancers and their precursors, and improve cancer survivorship through an organized rehabilitation programme.

Impacts of ADH1B rs1229984 and ALDH2 rs671 polymorphisms on risks of alcohol-related disorder and cancer

BACKGROUND

ADH1B rs1229984 and ALDH2 rs671 are the specifically prevalent functional variants in the East Asians. These variants, which result in a dramatic change in enzyme activity, are highly associated with alcohol-related disorders and cancer. Previous studies focusing on the additive and synergic effects of the variants are few and inconsistent. The aim of the research was to evaluate the associations of ADH1B rs1229984 and ALDH2 rs671 with the risks of alcohol-related disorder and cancer.

METHODS

This cohort study enrolled 42,665 participants from the Taiwan Precision Medicine Initiative database, including 19,522 and 20,534, ADH1B and ALDH2 carriers, respectively. The associations between the two variants and cancer risk were analyzed by univariable and multivariable logistic regression.

RESULTS

Compared with the noncarriers, the ADH1B rs1229984 variant had a stronger effect on alcohol-related disorders and was related to an increased risk of alcohol-related cancers. The CC genotype of ADH1B rs1229984 was significantly associated with cancer of the larynx, pharynx, and nasal cavities [odds ratio (OR) = 1.56, p = 0.0009], cancer of the pancreas (OR = 1.66, p = 0.018), and cancer of the esophagus (OR = 4.10, p < 0.001). Participants who carried the rs1229984 TC/CC and rs671 GG genotypes were at higher risk of esophageal cancer (OR = 3.02, p < 0.001). The risk of esophageal cancer was increased by 381% (OR = 4.81, p < 0.001) in those carrying the rs1229984 TC/CC and rs671 GA/AA genotypes.

CONCLUSION

rs1229984 and rs671 are common and functionally important genetic variants in the Taiwanese population. Our findings provide strong evidence of additive and synergic risks of ADH1B and ALDH2 variants for alcohol-related disorders and cancer. The results suggested that are reduction in alcohol consumption should be advised as a preventive measure for high-risk patients carrying ADH1B rs1229984 C or the ALDH2 rs671 A allele.

New insights into the genetic contribution of ALDH2 rs671 in pancreatic carcinogenesis: evaluation by mediation analysis

A functional variant on ALDH2 rs671 (G>A) confers a protective effect against alcohol‐induced carcinogenesis through an indirect pathway mediated by decreased alcohol consumption. Conversely, this variant also contributes to the accumulation of carcinogenic agents, resulting in a direct carcinogenic effect. This study aimed to separately quantify these two opposing effects of the rs671 A allele on pancreatic cancer risk and explore the impact of the rs671 A allele and alcohol consumption on pancreatic carcinogenesis. We included 426 cases and 1456 age‐ and sex‐matched controls. Odds ratio (OR) and 95% confidence interval (CI) for alcohol consumption were estimated using a conditional logistic regression model. By defining rs671 A allele and alcohol consumption as exposure and mediator, respectively, we used mediation analysis to decompose the total‐effect OR of the rs671 A allele into direct‐ and indirect‐effect ORs. Alcohol consumption (10 g/d) was associated with pancreatic cancer risk (OR, 1.05; 95% CI, 1.01‐1.10), but tests for interaction between the rs671 A allele and alcohol consumption were nonsignificant, indicating that the effect of alcohol consumption did not vary by genotype. Mediation analysis showed that the nonsignificant total effect (OR, 1.15; 95% CI, 0.92‐1.44) can be decomposed into the carcinogenic direct (OR, 1.34; 95% CI, 1.04‐1.72) and protective indirect effect (OR, 0.86; 95% CI, 0.77‐0.95). This study supports the association between alcohol consumption and pancreatic cancer risk and indicates the potential contribution of the rs671 A allele to pancreatic carcinogenesis through impaired metabolism of known or unknown ALDH2 substrates.