METHODS
A total of 70 patients aged 70 years and older who were diagnosed with histopathologically T1-2 breast cancer between June 2005 and August 2021 were retrospectively evaluated. All patients underwent breast-conserving surgery. The patient groups who received and did not receive adjuvant radiotherapy were compared. The primary endpoint of the study was ipsilateral breast tumor recurrence-free survival. The study"s secondary endpoints were breast cancer-specific survival and distant metastasis-free survival.

RESULTS
The median age was 73 (70-82). Adjuvant radiotherapy was applied in 53 patients (75.7%). Radiotherapy application decreased with age (70-76 years vs. 77-82 years) (p=0.023). The median follow-up was 42 months (3-169). Five patients had ipsilateral breast recurrence during the follow-up, one patient had regional recurrence (axilla), three patients had distant metastases, and nine died. Two of the patients died of breast cancer, and seven patients died from other causes. There were no differences in recurrence and death rates in patients who received and did not receive radiotherapy. Median overall survival was 119 months (94-145) in the radiotherapy arm and 141 months (136-167) in the non-irradiated arm; the 5-year OS was 81% and 100%, respectively (p=0.078). The 5-year BCSS was 97% in the radiotherapy group and 100% in the non-irradiated group (p=0.222); PFS 83% and 84% (p=0.622); IBTRFS 87% and 100% (p=0.113); and DMFS 93% and 100%, respectively (p=0.275). A statistically significant association was found between hormonal subtypes and DMFS. Five-year DMFS was 67% in triple (?) group, 93% in HR (+) HER2 (?) group, and 100% in HER2 (+) group (p=0.036).

CONCLUSION
Radiotherapy usage decreased with age. There were no differences in recurrence and death rates in patients who received and did not receive radiotherapy. Most of the deaths were due to causes other than breast cancer. Keywords : Breast cancer; elderly; lumpectomy; radiotherapy