Comorbidity and polypharmacy in patients with breast cancer

Cancer sufferers are aged ≥ 65 years, but research has focused infrequently on elderly patients with the majority of cancer. We aimed not only to determine the frequency of comorbidity and polypharmacy, but also to present the discrepiancies in elderly versus non-elderly patients with breast cancer. A total of 352 female patients aged over 18 years, 252 non-elderly and 100 elderly, followed-up in the oncology department of a tertiary hospital between January 2016 and September 2019 were retrospectively screened. Demographic data, comorbidity and medications of the patients were recorded hospital data processing system. Polypharmacy was defined as the use of ≥ 5 different medications. The most common four chronic diseases in both non-elderly and elderly groups were muscle-joint-bone disease, gastrointestinal diseases, diabetes mellitus and hypertension. The most common four prescribed drugs were NSAID, adjuvant endocrine therapy, PPI, and vitamin D or/and calcium in non-elderly group while those were ACEI-ARB, PPI, NSAID, and diuretics in elderly one. The frequency of polypharmacy was 50% (n = 126) in the non-elderly patients and 74% (n = 74) in the elderly ones. These were considered statistically significant (p < 0.001). The mean number of prescription medication categories reported was 5.02 (SD = 2.90; range 0–14) in non-elderly group whereas those was 6.83 (SD = 3.18; range 0–15) in elderly one (p < 0.001). The mean of ages were 47.9 years (without polypharmacy) and 51.3 years (with polypharmacy) in non-elderly patients while those are, respectively, 70.9 years and 74.7 years in elderly ones. These were considered statistically significant (respectively; p = 0.006, p = 0.009). We first gained to raise awareness in the literature of comorbidity and polypharmacy in patients with breast cancer and to compare between the elderly and non-elderly participants. For the effectiveness of cancer treatment, importance in geriatric population, attention to drug–drug interaction, such studies should be considered during clinical practice.