The researchers conducted a case-control study of 1,279 people with oesophageal cancer and 1,346 people without oesophageal cancer in Kenya, Tanzania, and Malawi.
The study analysed data on the population’s drinking habits including whether someone had ever consumed alcohol, their daily number of drinks, the estimated ethanol intake and whether they typically drank high alcohol content drinks like spirits or preferred lower alcohol content drinks like beer.
Study leaders Dr Diana Menya in Kenya, Blandina Mmbaga in Tanzania and Charles Dzamalala in Malawi noted that a specific effort to ascertain a wide variety of traditional alcohols including chang’aa, gongo and kachasu – distilled spirits that can reach over 40% or 50% alcohol-by-volume – was made.
Historically it has been difficult to assess alcohol as a potential risk factor of oesophageal cancer, because of the complex alcohol consumption patterns in the region. As such, previous studies have been inconsistent in their findings. However, this ground-breaking study shows a clear contribution of alcohol consumption to oesophageal cancer risk in East Africa, particularly in men in Kenya and Tanzania.
Lead IARC researchers, Dr Valerie McCormack and Dr Daniel Middleton said:
In Africa, higher numbers of people develop oesophageal cancer than in most other parts of the world; 28,000 people in Africa developed oesophageal cancer in 2020 and they have high mortality. There is still more research to do because there is a complex mix of patients affected by this cancer in East Africa, but the study indicates that if action is taken immediately to reduce alcohol consumption in the region, we could see a substantial reduction in the burden of oesophageal cancer.
Anna Diaz Font, Head of Research Funding at World Cancer Research Fund International said:
Oesophageal cancer is often diagnosed late, leading to a low recovery rate. This makes it crucial to uncover the causes of oesophageal cancer and prevent it from developing in the first place. This is particularly important in Africa, where the rates are extremely high. This new study, in an understudied population, supports findings from our Third Expert Report2 that alcohol is a risk factor for many cancers including oesophageal, and that more public health policies to reduce intake will reduce incidence of this disease.
Risks associated with oesophageal cancer
Oesophageal cancer is the seventh most common type of cancer worldwide and causes the sixth highest number of cancer deaths. There are two types of oesophageal cancer: squamous cell carcinoma (the type common in East Africa) and adenocarcinoma, with the former responsible for 88% of cases globally.
Survival rates are poor mainly because cancer of the oesophagus is usually diagnosed at a late stage when a patient’s ability to swallow food and drink is severely affected by their tumour which obstructs the food pipe. At this stage, the patient is often already very weak and dehydrated and the cancer has spread to other organs.
