Patterns of breast relapse after local excision +/- radiotherapy for early stage breast cancer

One hundred patients with breast recurrence have been identified from patients at the Royal Marsden Hospital, treated by local excision +/- radiotherapy for early stage primary invasive breast cancer between 1961 and 1985. The mean follow-up was 58 months (range 1 month - 19 years). In 74/100 patients, breast recurrence occurred within the breast parenchyma, was not associated with systemic relapse and carried a relatively good prognosis with a median survival of 77 months from the time of breast relapse. In 67 patients with parenchymal relapse in whom the site of relapse could be reliably compared with that of the original tumour, 60 (90%) patients developed recurrent tumours at or close to the primary site. In 24/100 patients, breast recurrence occurred in the overlying skin and in only two of these patients (2% of total) did recurrence actually occur within the scar tissue. Skin relapse was associated with systemic relapse and carried a relatively poor prognosis with a median survival of 36 months from the time of recurrence. The pattern of breast relapse was similar in irradiated and unirradiated patients. Skin relapse appears to be a manifestation of metastatic disease while parenchymal relapse may represent regrowth of primary tumour. This pattern of breast relapse questions the requirement for radiotherapy to the whole breast after local excision for early stage breast cancer.