The regional cancer spectrum in Uganda: a population-based cancer survey by sub-regions (2017-2020).

Background: Accurate estimation of the burden of cancer in developing countries is a major public health concern for cancer prevention and control because of the limited coverage of population-based cancer registries (PBCRs). The cancer registration coverage status of Uganda was 11.90% and was not uniformly distributed in all regions of Uganda. This population-based survey was conducted to assess the burden of cancer in all the sub-regions of Uganda by site, sex and age group to accurately determine the cancer profile of Uganda by sub-region for a tailored intervention to mitigate cancer risk factors and burden.

Methods: This study used existing administrative units of Uganda from which 55 districts emerged, forming 10 sub-regions as satellite population-based cancer registry study sites. Data on newly diagnosed cancer cases were retrospectively collected for the period 2017-2020 using a cancer notification form, entered into CanReg5 Software, exported to spreadsheets and univariate analysis was performed to determine the cancer spectrum, their proportions and crude rates by site, sex, age group and geographical location.

Results: A total of 25,576 cancer cases were registered, up to 14,322 (56%) were in females and, male cancers were 11,254 (44%). The top five female cancers in all the sub-regions included cervical cancer (43%, n = 6,190), breast (22%, n = 3,200), esophagus (5.6%, n = 800), ovary (5.2%, n = 746), Kaposi Sarcoma (KS) (4.7%, n = 666) and other less common cancers (18.5%, n = 2,720). In males, the top five cancers included prostate cancer 25.1 % (n = 2,820), esophagus 15.1% (n = 1,704), KS 12.4% (n = 1,395), liver 8.8% (n = 989) and stomach 4.8% (n = 539), with other less common male cancers accounting for 33.8% (n = 3,807).In all the sub-regions of Uganda, cancers of the esophagus, liver and KS are common in both males and females, but the number of males with these cancers is twice that of their female counterparts. In Rwenzori, Kigezi and Bugishu sub-Regions, there seems to be an increased risk of developing other skin cancers in females, while stomach cancers have been reported in both males and females. Most of the other sub-regions register emerging cases of only ovarian cancer in females. In children, the top three cancers included lymphoma, 33.9% (n = 653); soft tissue sarcomas, 20.8% (n = 400); malignant bone tumors, 15.8% (n = 305); myeloid-type leukemia, 13.8% (n = 265); and the other less common childhood cancers combined, 15.7% (n = 303). The proportion of childhood cancers is higher in the male child compared to the female at a ratio of 1.3:1.

Conclusions: The sub-regional cancer spectrum in Uganda ranges from cervical cancer to breast, esophageal, ovarian and KS in females. Male cancers include prostate, esophageal, KS, liver and stomach cancers. Although the cancer profile is similar in most sub-regions of Uganda, except Ankole subregions with mountainous topography (Rwenzori, Kigezi, Bugisu), there has been significant variation in cancer profile, especially for males, where Non-Hodgkins Lymphomas is one of the cancers reported for Uganda by PBCRs in Gulu, and Kampala has been replaced by stomach cancers as one of the common male cancers in the sub-regions. These findings emphasize the need for the establishment and support of additional regional PBCRs and periodic population-based cancer surveys to accurately determine the burden of cancer, inform the establishment of regional cancer centers and guide national and sub-national cancer control programs in Uganda. Cancer surveillance systems using PBCRs should be part of the national cancer control program. Periodic population-based cancer surveys should also be conducted as part of Uganda's demographic and health surveys in areas without PBCRs to inform the country comprehensively and accurately on the cancer burden to design robust cancer mitigation measures.