A Comparison of Factors Associated with Breast Cancer Stage at Diagnosis and 2-year Overall Survival Pre and During Covid-19 Periods in Johannesburg, South Africa

Purpose: COVID-19 affected care access, treatment options, and cancer outcomes. We assessed stage at diagnosis and 2-year overall survival among South African women with breast cancer (BC) pre- (1 January 2017 to 31 December 2018) and during COVID-19 (01 April 2020 to 31 March 2022). Methods: 1772 participants were enrolled at two Johannesburg academic hospitals, 978 pre- and 794 during COVID-19. Cox proportional hazard models examined risk factors of mortality. Results: Late-stage (III+IV) diagnosis increased by 7% during COVID-19. Two-year crude survival was 72.4% overall. Diagnosis during COVID-19 decreased mortality risk (Hazard ratio (HR)=0.71, 95% Confidence Interval (CI): 0.58-0.87). A family history of BC protected against late-stage diagnosis during both periods. Pre-COVID-19, unemployment (OR=1.47 95%CI 1.07-2.03) and household poverty (OR=1.37 95% CI 1.03-1.82) and being single during COVID-19 increased late-stage odds (OR=1.31 95%CI 1.05-1.62). Being unemployed increased mortality risk (HR=1.36, 95%CI: 1.09-1.69 pre-COVID-19; HR=1.43, 95%CI: 1.06-1.93 COVID-19) as did poor education pre-COVID-19 and tobacco use during COVID-19 (HR=1.60, 95% CI:1.10-2.33). Late-stage BC increased mortality risk (HR = 2.65, 95%CI: 1.95-3.61 pre-COVID; HR = 1.81, 95%CI: 1.31-2.51 COVID) as did high tumor proliferation rates (Ki67 ≥20%) (HR =1.53, 95%CI: 1.22-1.91 pre-COVID; HR = 1.43, 95%CI: 1.03-2.00 COVID). BC subtypes during the pandemic, HR-/HER2+ (HR=1.59, 95%CI: 1.04-2.42) and TNBC (HR=1.60, 95%CI: 1.16-2.19) and positive HIV status pre-COVID (HR=1.61, 95%CI: 1.28-2.02) increased mortality risk. Versus surgery as first treatment, no treatment and neoadjuvant modalities increased mortality risk. Conclusions : Health system and socioeconomic factors negatively impacted access to care; HIV and cancer treatment changes during COVID-19, contributed to improved 2-year survival.