Prevalence of locoregional recurrence and survival post-treatment of head and neck cancers in Africa: a systematic review and meta-analysis

Background Recurrent cancers of the head and neck are associated with poor survival outcome. Yet, their burden in Africa is not reliably known. We therefore aimed to estimate the prevalence of recurrence and the 5-year overall survival among patients treated for head and neck cancers (HNC) in Africa.Method In this systematic review and meta-analysis, we searched four electronic databases (Pubmed, CINAHL, MEDLINE, and Web of Science) and the grey literature for studies reporting the prevalence of HNC recurrence and 5-year overall survival post treatment, published between January 1, 2002, and December 31, 2022. We contacted corresponding authors of relevant studies. Searches were extended to reference lists of review articles and other relevant sources for potentially eligible studies. Each record was assessed for inclusion or exclusion by two independent reviewers. Records with individual-level data on recurrence and survival conducted in Africa were included while exclusion was based on the study design and availability of relevant data. Data were independently extracted by three reviewers from eligible studies, and summary estimates were sought. Our primary outcomes were recurrence and 5-year overall survival of patients who have been treated for HNC, and our secondary outcomes included risk factors, tumor site, squamous cell histology, clinical stage of tumor, and treatment options received. Only records selected for primary outcomes were assessed for secondary outcome data extraction. Random-effects meta-analysis was conducted for each outcome. Meta-regression models were used in addressing sample heterogeneity among the studies. Protocol for this study was registered with PROSPERO, CRD42022372307.Findings This systematic review and meta-analysis returned 3998 records, yielding 28 included studies after exclusion. Eighteen studies reported on the prevalence of HNC recurrence while 24 articles reported on the 5-year overall survival. Of the pooled total study population, 7199 (70.5%) of 10,218 patients were males while 2603 (25.5%) were females. We found that the prevalence of HNC recurrence was 15.4% (I2 = 96.2%; 95% CI: 9.5-22.3; n = 3214; k = 18), and the 5-year overall survival was 54.4% (I2 = 99.5%; 95% CI: 40.1-68.4; n = 9798; k = 24). We also found that the prevalence of smoking and alcohol consumption as risk factors for HNC were 42.6% (I2 = 98.8%; 95% CI: 25.2-61.0; n = 4374; k = 15) and 35.8% (I2 = 98.9%; 95% CI: 21.7-51.4; n = 4110; k = 11) respectively. The pooled current prevalence for advanced HNC (clinical stages III-IV) was 80.0% (I2 = 99.2%; 95% CI: 68.6-89.5; n = 7624; k = 18) compared to 12.2% (I2 = 96.4%; 95% CI: 6.2-19.8; n = 7624; k = 18) in early disease (clinical stages I-II).Interpretation The results showed significantly high prevalence of cancer recurrence, poor 5-year overall survival and very high prevalence of advanced cancers at time of diagnosis. This study provides robust evidence for strategies towards prompt diagnosis and appropriate management of HNC to improve patients' outcome in the African continent. 2023;59: Published 2023 https://doi.org/10. 1016/j.eclinm.2023. 101964