Lagere overleving bij sociaaleconomisch achtergestelde vrouwen met HER2-negatieve borstkanker na chemotherapie

BACKGROUND: Breast cancer remains the most common oncological condition and the leading cause of cancer-related mortality in the world. In addition to the breast cancer stage at diagnosis, its histology and subtype, the social determinants of health have a substantial role in cancer survivorship. METHODS: Utilizing administrative health databases, a retrospective analysis of stage I-III HER2-negative breast cancer was conducted, examining a cohort of 10,634 women treated with surgery and adjuvant chemotherapy in Ontario, Canada. RESULTS: Our study registered a median follow-up of 5.5 years. The 5-year OS ranging from the lowest to the highest socioeconomic status (SES) was (Q1) 91.3%, (Q2) 92.8%, (Q3) 93.0%, (Q4) 92.9% and (Q5) 94.0%. The 5-year OS rate between the SES groups showed (Q5 vs. Q1) HR 0.65 (95% CI, 0.52-0.81), P = .002), (Q4 vs. Q1) HR 0.79 (95% CI, 0.64-0.97, P = .029) and (Q3 vs. Q1) HR 0.75 (95% CI, 0.60-0.94, P = .013). In the analysis of underlying medical conditions, the mean range of the Charlson comorbidity index was Q1 (2.73 ± 2.96) versus Q5 (2.52 ± 2.63), P < .001. CONCLUSION: Our study shows that there are inequities in the delivery of oncological care amongst women with HER2-negative breast cancer. Those within the lower SES, thereby likely with a socioeconomic disadvantage, exhibited a greater probability of presenting with more advanced cancer staging, were more prone to receive anthracycline-based chemotherapy, while also being confronted with an increased likelihood of significant comorbidities and mortality rates, compared to their wealthier counterparts.