Trends in gastrointestinal cancer burden in Zimbabwe: 10-year retrospective study 2009-2018

As one of the non-communicable diseases, cancer will overtake communicable, maternal, neonatal and nutritional diseases combined as the leading cause of mortality by 2040. Gastrointestinal (GI) cancers are predicted to increase by over 50% in the next 20 years, with a higher incidence in developing countries. In this study, we describe the national GI cancer trends in Zimbabwe using the annual reports from the Zimbabwe National Cancer Registry (ZNCR) from 2009 to 2018.

Demographic data and incidence of GI cancer subtypes were collected and analysed from the ZNCR annual reports from 2009 to 2018. Age standardised rates (ASRs) for each GI cancer subtype were calculated and simple trend analysis was performed over the 10-year study period.

In total, 10,859 new GI cancer cases were reported during the study period, accounting for 17.2% of all cancers in Zimbabwe and 55% of these were males. The most prevalent GI cancers were oesophageal, liver, gastric, colon and rectal malignancies. In males, on average the incidence of ASR of oesophageal, liver and gastric cancer increased annually by 14.7%, 17% and 16%, respectively. In females, on average the ASR of oesophageal, liver and gastric cancer increased annually by 27.2%; 18% and 13%, respectively. Overall, one in ten new cases of oesophageal cancer were diagnosed in patients under 45 years of age and for liver cancer, one in four new male cases were diagnosed below the age of 45 years.

Zimbabwe faces an increasing trend in all GI cancer subtype incidence over the decade reviewed. The rate of increase in oesophageal and gastric cancers in females was particularly high and the male-to-female ratio observed requires further etiological studies. The increasing rate of young GI cancer patients requires both education regarding risk factors and national screening policies that are tailored to the Zimbabwean population's characteristics and context.