Breast cancer outcomes and treatment toxicity in geriatric patients compared to other patients at the Cancer Disease Hospital in Zambia.

Abstract

e13773 Background: Breast cancer is the second most common cancer in women in Zambia and the most common cancer in older women. Management of geriatric cancer patients can be challenging due to physiological changes and multiple comorbidities. Methods: Data was extracted from the CDH electronic database of breast cancer patients for November 2005 - November 2022. Geriatric patients were defined as those 65 years old or older. Data was analyzed using descriptive statistics. Clinical-pathologic characteristics and outcomes for geriatric (GP) and younger patients were compared using the Chi Squared Test/Fisher’s exact test for discrete and Student’s T-test for continuous variables. All p-values were two-sided. Results: Of 1981 patients, 493 (24.9%) were geriatric. 374 (18.9%) had Stage I/II cancer, 607 (30.6%) Stage III, 579 (29.2%) de novo Stage IV, with no differences between geriatric and younger patients. 441 (22.2%) had hormone receptor-positive (HR+) disease, 115 (5.8%) had HER2+ by IHC, 195 (9.3%) were triple-negative, 52 (2.6%) HR+HER2+. Geriatric patients were more likely to have invasive lobular carcinoma (4.6% v. 2.4%), less likely to have grade 3 (42.0% v 50.6%) or HER2+ (11.6% v 19.3%) cancer. 1889 (94.8%) received systemic treatment, 1188 (60.0%) surgery, and 844(42.6%) radiation (RT), with no differences in geriatric and younger patients. Geriatric patients were less likely to receive palliative RT (9.6% v 15.7%), to receive a lower total RT dose and had similar rates of RT dermatitis as younger patients. Geriatric patients were less likely to be treated with doxorubicin, docetaxel and more likely with methotrexate. After median follow-up of 1.1 years (st. dev 2.6), 301(15.2%) were alive without disease, 826 (41.7%) alive with cancer, 203 (10.2%) died from cancer, with no difference in local, distal recurrence, or survival for geriatric patients. Geriatric patients were less likely to be in good physical condition (33.9% v 39.4%) and more likely to have a worse ECOG (1.0% v 0.4% for ECOG 4, 4.1% v 2.4% for ECOG 3, 14.0% v 10.9% for ECOG 2, 73.4% v 75.8% for ECOG 1, 7.4% v 10.4% for ECOG 0). Geriatric patients had a lower number of total treatment toxicities (OR 0.95, 95% CI 0.91-0.98) and were less likely to have leukopenia (OR 0.89, 95% CI 0.83-0.94) and neutropenia (OR 0.88, 95% CI 0.82-0.95). (for similar outcomes p-value > 0.05; all where differences are noted p-value < 0.05). Conclusions: GPs were similar to other patients in terms of cancer stage and outcomes and had less aggressive disease. GPs had worse functional status, received less toxic chemotherapy, were less likely to receive surgery and RT. GPs had either a similar amount or less treatment toxicity compared to other patients. Results are limited by short follow-up of about 1.5 years. Results are limited by incomplete non-hematologic toxicity data.