Breast conservation in the treatment of early breast cancer a 20‐year follow‐up

Two hundred sixty‐three patients with unilateral primary breast cancer, treated by local excision of the primary tumor and radical radiation therapy between 1954 and 1969, were followed up for a minimum of 10 years and a maximum of 20 years. The treatment plan delivered 4500 rad in fractions of orthovoltage irradiation to five fields: tangential breast fields, axilla with posterior axillary field, parasternal and supraclavicular, with a subsequent boost of 1000 rad to the primary tumor site, axilla, and supraclavicular fossa. Patients were clinically staged using the TNM (UICC) system; 115 patients had tumors less than 2 cm in diameter and a clinically negative axilla (T1N0N1a), 96 had tumors 2 to 5 cm in diameter with a clinically negative axilla (T2N0N1a), and 52 had tumors less than 5 cm in diameter and clinical axillary lymph node metastases (T1T2N1b). The actuarial relapse‐free survival of patients with T1N0N1a tumors was 72% at 5 years, 59% at 10 years, and 47% at both 15 and 20 years. The relapse‐free survival of patients with T2N0N1a tumors was not statistically different (P > 0.05). A significantly worse survival was observed in patients with clinical axillary lymph node metastases (T1T2N1b), with a survival of 37% at 5 years, 29% at 10 years, 23% at 15 years, and 22% at 20 years, when compared with patients with clinically negative lymph nodes (P < 0.01). Locoregional relapse occurred in 22%, at 10 years, of those patients with T1 or T2N0N1a tumors and 52% of the patients with T1T2N1b tumors. The pattern of locoregional relapses indicated that approximately 50% occur at least 5 years after treatment; this contrasts with the pattern of early locoregional relapse after mastectomy. The commonest sites of relapse were in the breast in 19% and axilla in 6% of patients with T1 or T2N0N1a tumors. There was no attenuation of the radiation dose administered at the site of a subsequent relapse. Surgery for radiation failure produced a 42% crude relapse‐free survival at 5 years after salvage mastectomy in those patients originally treated for T1 or T1N0N1a tumors. The results of this study suggest that a significant proportion of patients relapse locally over a prolonged period after breast conservation. The evolution of new radiation techniques may provide better locoregional control and early salvage surgery may result in improved long‐term survival.