Cancer Epidemiology in Zimbabwe: Insights from GLOBOCAN 2020 Estimates on Incidence, Mortality, and Risk Modeling

Abstract

Zimbabwe, a landlocked, lower-middle-income country in Southern Africa, faces a significant cancer burden. The present study aims to provide a quantitative analysis of cancer epidemiology in Zimbabwe for 2020 using data from the Global Cancer Observatory (GCO). Focusing on the 10 most frequent cancers, the dataset included new cases (Nc), deaths (Nd), age-standardised rates (ASRi, ASRm), rank (Rk), reciprocal rank (1/Rk), and cumulative risk. Gender-specific trends revealed a disproportionate burden on females, with cervical cancer accounting for 3,043 new cases and 1,976 deaths, while breast cancer followed closely. Among males, prostate cancer was most prevalent, with an ASRi of 70.6 and ASRm of 41.7. A strong linear relationship was observed between incidence and mortality, with Nd approximating 63.2% of Nc. High-lethality cancers such as oesophagus (Nc=781, Nd=718) and liver (Nc=678, Nd=648) were identified as critical for intervention. Logarithmic transformations confirmed power-law behaviour, enhancing predictive accuracy. A novel severity metric (σ) facilitated rank-based prioritisation, highlighting cervical (σ=6) and prostate (σ=5) cancers as high-impact, in contrast to lower-burden types like Kaposi sarcoma (σ=1.4). Cumulative risk assessments estimated the lifetime risk for cervical and breast cancers at 6.7% and 3.9%, respectively. Polynomial and non-linear models revealed inflection points in age-standardised rates and cumulative risks, indicating a plateauing effect in high-incidence cancers. These findings underscore the urgent need for targeted interventions for high-burden cancers and equitable allocation of resources for lower-impact cancers, offering evidence-based insights to guide cancer control policy and resource planning in Zimbabwe.