Prospective cohort of real-world, curative-intent breast cancer treatment patterns in Malawi.

Abstract

e18736 Background: Despite increasing availability of curative-intent breast cancer treatment in concordance with the National Comprehensive Cancer Network (NCCN) Harmonized Guidelines for Sub-Saharan Africa (SSA), few descriptions of their application in SSA are available. Our aim was to describe patterns of curative-intent treatment including neoadjuvant (NAC) and/or adjuvant chemotherapy (AdC) and surgery (S) by stage and HIV status, and the association between guideline-concordant treatment completion and overall survival (OS). Methods: We enrolled newly diagnosed breast cancer patients in a prospective cohort study at Kamuzu Central Hospital in Malawi from Dec 2016 – Oct 2018. Unadjusted odds ratios (OR) with 95% CI were calculated to identify factors associated with completion of guideline-concordant treatment, defined as S and at least 4 cycles of NAC or AdC. A logistic regression model was performed using variables with p<0.1. Survival analysis was performed with Kaplan Meier methods and log-rank test. Results: 67 non-metastatic patients were included. 12 (18%) were HIV+; 13 (19%) were Stage II and 54 (81%) Stage III. 46 (69%) began treatment with NAC, of which 39 (85%) were Stage III and 7 (15%) Stage II. 12 (18%) began treatment with S+AdC, of which 5 (42%) were Stage II and 7 (58%) were Stage III. 2 (3%) Stage III patients were treated with palliative chemotherapy (PC). 7 (10%) never received treatment. Overall, 41 (61%) underwent S. In bivariate analysis, factors associated with failure to complete treatment were HIV+ (OR 0.25 CI (0.06-0.99), Stage III (OR 0.10 CI (0.01-0.89) and ER/PR-/HER2+ (OR 0.07 CI (0.01-0.49). In adjusted analysis, ER/PR-/HER2+ (OR 0.12 (0.01-0.97) was associated with failure to complete treatment. HIV+ patients received less NAC than HIV- (2.5 vs 4 cycles; p=0.07) and similar AdC as HIV- (6 vs 6 cycles; p=0.7). Median OS for those who began treatment with NAC was shorter than with S+AdC (28.5 vs 40 months; p=0.01). Median OS for HIV+ vs HIV- who received NAC was 19.7 vs 32.7 months (p=0.10) and received S+AdC was unreached vs 37.1 months (p=0.27). Conclusions: When applying NCCN Harmonized Guidelines for SSA to Malawi, most patients received NAC for curative breast cancer treatment and had significantly shorter OS compared to those receiving upfront S+AdC. Stage III, HIV+, and ER/PR-/HER2+ patients were less likely to complete guideline-concordant treatment which may reflect advanced disease or poor treatment tolerability. Further study is needed to identify barriers to guideline-concordant treatment and inform interventions to improve breast cancer treatment outcomes in Malawi and SSA.[Table: see text]