What can 27 years of Niger cancer registry tell us about breast cancer epidemiology? Incidence of breast cancer from 1992 to 2018 in Niger

Abstract

Breast cancer (BC) is a leading cause of cancer morbidity and mortality within the female population in sub-Saharan Africa. Growing cancer incidence and mortality are multidimensional, and often associated with the so-called ‘’westernization’’ of lifestyle in African countries, including Niger, where there is no recent update of the cancer registry. The intent of this paper was to analyze 27 years of Niger cancer registry data and produce updated cancer trends and figures. The Niger cancer registry was established in 1992 and compiled on Canreg4. It is a member of African cancer registry network. The total number of cases included in this study was 12,340 patients and the study was conducted in 2020. Incidence trends (joint point) and survival (Kaplan Meier and Cox proportional hazards model) were used to analyze the data. Breast cancer showed high frequency among women, 18.9% (18.3-19.6) followed by gynecological cancers, with cervical and ovarian cancers accounting for 11.0% (10-12.1) and 5.4% (5.0-5.8) of total cases, respectively. Followed by liver cancer, at 13% (12.4-13.6), skin 7.1% (5.5-7.8) and colon/rectum cancer at 4.2% (3.4-5.1). The average cancer patient age was 44.7 (44.4-45.0) years. Despite a slow startup, cancer case registration in Niger showed a significant increase, with an annual percentage change (APC) of 3.7 (1.5-6.0), from 1992 to 2018. Overall, 14.1% (13.5-14.7) of cancer patients reportedly died. Breast cancer survival was found to be associated with sex, age and diagnostic method. Cancer incidence in Niger is growing significantly; breast and gynecological cancers are the most frequent and reported mortality data suggest low survival in Niger. Multicentric cancer screening centers and systematic reporting are necessary for a wider coverage of the cancer registry. Key words: Niger, cancer registry, breast cancer, survival.