Alcohol consumption can increase the risk of certain cancer types, including cancers of the head and neck. A meta-analysis, published in Alcoholism: Clinical and Experimental Research, focussed solely on nasopharyngeal cancer and found that alcohol consumption is indeed associated with increased risk. However, it also found that consuming less than 7 drinks a week might decrease the risk. Nevertheless, these results should be handled very carefully, because many factors could have influenced this association.
What is already known? With heavy alcohol consumption, especially in combination with smoking, the risk of cancers of the head and neck increases.2 A previous meta-analysis3 that looked at multiple cancer types in China, found a borderline increased risk of 21% of nasopharyngeal cancer for drinkers versus non-drinkers. However, no dose-response was performed.
What does this study add? This meta-analysis looks beyond China, only includes studies with relative high quality, and starts an attempt at a dose-response analysis.
The authors included 25 studies, of which 23 case-control studies and two cohort studies. Most of these studies (15) are conducted in China, but also in other countries such as the United States (4).
That the included studies are mostly studies from China can be explained by the fact that this type of cancer is rare in most areas (<1/100.000), but is more prevalent in China (25/100.000 in South China). In 2002, it even became the fourth most common cancer in Hong Kong.
Alcohol increases risk
When the authors look at ever-drinkers they appear to have a 10% increased risk to develop nasopharyngeal cancer (NPC) compared to non-drinkers.
Decreased risk with moderate consumption
When looking at the amount of alcohol consumed data show that people drinking more than 7 drinks a week (grams of alcohol not mentioned) have a 29% increased risk to develop NPC.However, people drinking less than 7 drinks a week have a 23% decreased risk of NPC.
Unfortunately, the study did not look well into the consumption pattern, as it did not make a distinction between binge drinking and spreading the drinks evenly across the week.
Smoking and Epstein-Barr virus
As already mentioned, smoking can be a big confounding factor with cancer types in the head and neck. Unfortunately only 13 of the 25 studies that were included took smoking into account as a confounder. But apart from that, there is something special with the development of NPC: it can also be caused by an Epstein-Barr virus infection. A previous study found that 95% of the NPC cases were seropositive4. Because of this high percentage, case-control studies cannot account for this virus. Thus the authors suggest performing more prospective cohort studies with a better study design.
- No heterogeneity between studies
- dose-response analysis performed
- Almost solely case-control studies
- Most studies conducted in Asia
- Epstein-Barr virus is not accounted for
- Only half of the studies took smoking as confounder into account
- No differentiation between wine, beer and spirits
- Consumption pattern not clearly defined
1 Du, T., Chen, K., Zheng, S., Bao, M., Huang, Y., & Wu, K. (2019). Association Between Alcohol Consumption and Risk of Nasopharyngeal Carcinoma: A Comprehensive Meta‐Analysis of Epidemiological Studies. Alcoholism: Clinical and Experimental Research.
2 Hashibe M, Brennan P, Chuang SC et al. (2009). Interaction between tobacco and alcohol use and the risk of head and neck cancer: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium. Cancer Epidemiol Biomarkers Prev, 18(2):541-550.
3 Li Y, Yang H, Cao J (2011) Association between alcohol consumption and cancers in the Chinese population—a systematic review and meta‐analysis. PLoS ONE
4 Raabtraub N (2002) Epstein‐Barr virus in the pathogenesis of NPC. Semin Cancer Biol 12:431–441.
Fotocredits: ‘stress’ from JESHOOTS-com