Sarah Rayne1, Kathryn Schnippel2, Surbhi Grover3, Kirstin Fearnhead4, Deirdre Kruger5, Carol Benn5, Cynthia Firnhaber6. 1. Department of Surgery, Helen Joseph Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. Electronic address: rayne.sarah@gmail.com. 2. Health Economics Unit, School of Public Health and Family Medicine, Faculty of Health Sciences, University of Cape Town, South Africa. 3. Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Princess Marina Hospital, Gaborone, Botswana, Botswana-UPENN Partnership, Gaborone, Botswana. 4. Department of Anatomical Pathology, National Health Laboratory Services, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. 5. Department of Surgery, Helen Joseph Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. 6. Clinical HIV Research Unit, Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Abstract
BACKGROUND: Adverse outcomes from breast cancer disproportionately affect women in sub-Saharan Africa, with delay the most studied contribution to advanced stage at presentation. However, tumor molecular biology and its contribution to advanced stage are yet to be explored. MATERIALS AND METHODS: Patients newly diagnosed with breast cancer in a South African tertiary breast center completed a questionnaire and file review concerning socioeconomics, delay to care, stage at presentation, and molecular characteristics. Logistic regression was done to determine the relative risk of advanced stage presentation. RESULTS: Advanced stage was present in 70.1% (n = 162) of the 231 participants, with 55.8% stage III (n = 129) and 32% (n = 72) having a T4 tumor. The median age was 56 y with 21.6% (n = 47) aged <45 y. Most common subtype was luminal B (57.7%, n = 128) followed by luminal A (21.6%, n = 48), triple negative (13.9%, n = 31), and HER2 positive (6.7%, n = 15). Lobular cancer (incidence risk ratio [IRR], 1.29; 95% confidence interval [CI], 1.03-1.62), high grade and intermediate grade tumors (IRR, 1.90; 95% CI, 1.15-3.13 and IRR, 1.95; 95% CI, 1.18-3.22, respectively), high Ki67 proliferation index (IRR, 1.30; 95% CI, 1.02-1.66), and HER2 overexpression (IRR, 1.32; 95% CI, 1.12-1.55) were more likely to present with advanced disease, as were luminal B (HER2+) cancers (adjusted IRR [aIRR], 1.46; 95% CI, 1.10-1.95). Although on univariate analysis Black and young participants were both more likely to have advanced stage (IRR, 1.23; 95% CI, 1.01-1.49 and IRR, 1.25; 95% CI, 1.04-1.51, respectively), in multivariate analysis controlling for tumor biology and delay, these were no longer significant (aIRR, 1.12; 95% CI, 0.91-1.37 and aIRR, 1.17; 95% CI, 0.94-1.48, respectively). CONCLUSIONS: Tumor biology has a compelling role in the etiology of advanced-stage disease irrespective of socioeconomic factors. Accurate pathologic assessment is important in planning breast cancer care in Africa.
BACKGROUND: Adverse outcomes from breast cancer disproportionately affect women in sub-Saharan Africa, with delay the most studied contribution to advanced stage at presentation. However, tumor molecular biology and its contribution to advanced stage are yet to be explored. MATERIALS AND METHODS:Patients newly diagnosed with breast cancer in a South African tertiary breast center completed a questionnaire and file review concerning socioeconomics, delay to care, stage at presentation, and molecular characteristics. Logistic regression was done to determine the relative risk of advanced stage presentation. RESULTS: Advanced stage was present in 70.1% (n = 162) of the 231 participants, with 55.8% stage III (n = 129) and 32% (n = 72) having a T4 tumor. The median age was 56 y with 21.6% (n = 47) aged <45 y. Most common subtype was luminal B (57.7%, n = 128) followed by luminal A (21.6%, n = 48), triple negative (13.9%, n = 31), and HER2 positive (6.7%, n = 15). Lobular cancer (incidence risk ratio [IRR], 1.29; 95% confidence interval [CI], 1.03-1.62), high grade and intermediate grade tumors (IRR, 1.90; 95% CI, 1.15-3.13 and IRR, 1.95; 95% CI, 1.18-3.22, respectively), high Ki67 proliferation index (IRR, 1.30; 95% CI, 1.02-1.66), and HER2 overexpression (IRR, 1.32; 95% CI, 1.12-1.55) were more likely to present with advanced disease, as were luminal B (HER2+) cancers (adjusted IRR [aIRR], 1.46; 95% CI, 1.10-1.95). Although on univariate analysis Black and young participants were both more likely to have advanced stage (IRR, 1.23; 95% CI, 1.01-1.49 and IRR, 1.25; 95% CI, 1.04-1.51, respectively), in multivariate analysis controlling for tumor biology and delay, these were no longer significant (aIRR, 1.12; 95% CI, 0.91-1.37 and aIRR, 1.17; 95% CI, 0.94-1.48, respectively). CONCLUSIONS:Tumor biology has a compelling role in the etiology of advanced-stage disease irrespective of socioeconomic factors. Accurate pathologic assessment is important in planning breast cancer care in Africa.