A recent large population-based study of colorectal cancer diagnosed patients shows that lifetime and 1-y pre-diagnostic alcohol abstinence as well as heavy drinking behaviour leads to poorer survival.
Colorectal cancer (CRC) is the development of cancer from the colon or rectum and is due to the abnormal growth of cells that have the ability to spread to other parts of the body. Symptoms may include blood in the stool, a change in bowel movements, weight loss and feeling tired all the time. Most colorectal cancers are due to old age, inflammatory bowel disease and lifestyle factors including diet, obesity, lack of physical activity, smoking and alcohol consumption with only a small number of cases due to underlying genetic disorders. CRC is the third most commonly diagnosed malignancy and the fourth most common cause of cancer-related death worldwide. Approximately half of the patients still die within 5 years from diagnosis, and further efforts to improve prognosis are needed.
The American Journal of Clinical Nutrition recently reported the associations of lifetime and recent pre-diagnostic alcohol consumption with overall, CRC-speciﬁc, recurrence-free, and disease-free survival in CRC patients based on the Cox proportional hazard regression. These subjects with relevant prognostic outcomes were interviewed on sociodemographic and lifestyle factors, medication, and comorbidities.
From the 3146 CRC patients, recruited in 2003–2010, participants with missing endpoints or follow-up times (n = 15) or with missing International Union Against Cancer stage classiﬁcation (n = 10) were excluded; in analyses of recurrence-free and disease-free survival, patients with recurrence before the interview (n = 87) were excluded. The patient cohort included more women alcohol abstainers while the majority of light, moderate, and heavy drinkers were men with a median age of 69 years at the time of diagnosis.
Of the 3121 CRC patients analyzed during the median follow-up period of 4.8 years for overall and 3.9 years for recurrence-free survival, 868 died during the follow-up period, with CRC being the cause of death of the majority (n = 635) of the patients. Lifetime abstainers showed poorer overall and CRC-speciﬁc survival than lifetime light drinkers (women: 0–12 grams/day; men: 0–24 grams/day). Lifetime heavy drinkers (women: >25 grams/day, men: >50 grams/day) showed poorer overall and disease-free survival. Alcohol abstaining in the year before diagnosis was associated with poorer overall (CRC-speciﬁc, and disease-free) survival. Lifetime abstainers with nonmetastatic disease showed poorer CRC-speciﬁc and recurrence-free survival.
The analyses on association of beverage type with survival in CRC patients showed that lifetime and recent ‘wine’ abstaining were signiﬁcantly associated with poorer overall and CRC-speciﬁc survival, while no significant associations with prognosis were observed for beer or liquor consumption. This study also suggested that poorer survival associated with alcohol abstaining might be restricted to diabetes patients and in patients who are 70 years of age or older.
The major limitations of the study included restricted exposure assessment to the amount of alcohol consumed before diagnosis, without paying attention to drinking patterns or changes in alcohol consumption after diagnosis. Moreover, men show a higher overall alcohol consumption than women, in whom further modification in effects are seen due to hormonal differences.
Pre-diagnostic alcohol abstaining and heavy drinking were associated with poorer survival after a CRC diagnosis and hence the study implicates that heavy drinkers might beneﬁt from restricting their alcohol consumption to light/moderate levels. The protective effects of abstaining or light consumption might be restricted to wine, and associations further depend on patients’ overall health status especially presence of diabetes mellitus and age.
Written By: Dr. Pratibha Bharti, PhD Biotechnology