Breast radiotherapy for occult breast cancer with axillary nodal metastases--does it reduce the local recurrence rate and increase overall survival?

Abstract

Aims: The optimal management of axillary lymph node metastases from occult breast cancer (TXN1-2M0) is uncertain and practice varies in the use of primary breast radiotherapy. We conducted a retrospective review to examine clinical outcomes for patients managed with or without primary breast radiotherapy.

Materials and methods: Case records from the clinical oncology database were reviewed to identify patients presenting with axillary nodal metastases but no detectable primary tumour between 1974 and 2003. Fifty-three patients with TXN1-2M0 breast cancer were identified, representing 0.4% of patients managed for breast cancer during this period. Of those tested, 59% had oestrogen receptor-positive tumours. Seventy-seven per cent received ipsilateral breast radiotherapy.

Results: There was a trend towards reduced ipsilateral breast tumour recurrence in patients who received radiotherapy (16% at 5 years, 23% at 10 years) compared with those who did not (36% at 5 years, 52% at 10 years). Similarly, the locoregional recurrence rate was 28% at 5 years for patients who received radiotherapy compared with 53.7% at 5 years for non-irradiated patients. Breast cancer-specific survival was higher (P=0.0073; Log-rank test) in patients who received ipsilateral breast radiotherapy (72% at 5 years, 66% at 10 years) compared with those who did not (58% at 5 years, 15% at 10 years).

Conclusion: Primary breast radiotherapy may reduce ipsilateral breast tumour recurrence and may increase survival in patients presenting with axillary lymph node metastases and occult breast primary (TXN1-2M0). Larger studies or prospective registration studies are needed to validate these findings.