Impact of COVID-19 Vaccination on Breast Cancer Patients; the Negative Effects of the Pandemic Have Started to Decrease.

Abstract BACKROUND The COVID-19 pandemic has caused delays in diagnosis, and treatment of breast cancer patients. We predicted that the effects of the pandemic on breast cancer patients would decrease during the post-vaccination period. METHODS The data of 131 female patients who were operated on for breast cancer between March 2019, and March 2022, were analyzed into 3 groups: the control group (CG) between March 2019–2020, the pandemic group (PG) between March 2020–2021, and the vaccine group (VG) between March 2021 - March 2022. Patient admission time (PAT), diagnosis time (DT), tumor size, TNM classification and etc data were analyzed. RESULTS Prolonged PAT times in PG compared to CG were observed to be significantly reduced in VG (p = 0.009). In both PG and VG, the DTs were prolonged significantly (p < 0.001 and p < 0.001, respectively). Tumor sizes were found to be larger in PG than in CG and VG (p = 0.003 and p = 0.001, respectively). CONCLUSION After COVID-19 vaccination; delays in diagnosis and treatment caused by the pandemic in breast cancer patients have decreased and the increase in tumor size during the pandemic period has regressed.