Locoregional recurrences following radical external beam irradiation and interstitial implantation for operable breast cancer--a twenty three year experience.

Locoregional recurrences are reported in 493 consecutive with T1 T2 N0 N1 breast cancer patients who were treated with radical external beam irradiation and interstitial 192 Ir. implant between 1961 and 1979. Follow-up ranges from 5-23 years (mean 10 years) with 195 patients having 10-23 years follow up (mean 12 years). Tumorectomy was performed in 130/158 (88%) T1 and 73/335 (22%) T2 patients. There were 51 (10%) locoregional recurrences with 34 mammary, 14 combined mammary/axillary and 3 isolated axillary recurrences. The 10 year relapse rate was 20/195 (10%). The risk, timing and site of relapse varied according to TNM stage and tumorectomy. The risk was higher for T2 (42/335, 12.5%) than T1 (9/158, 5.5%) due to a larger number of recurrences occurring in the first 5 years (T2 32/335, 9.5% vs T1 4/158, 2.5%). Between 5-10 years, risk of relapse equalized to around 3% for both groups and only 1 relapse was seen after 10 years. Of the 48 mammary recurrences, 25 (52%) occurred in the implant volume, 7 (14%) occurred on the margin of the implant, 12 (25%) occurred at sites remote from the primary and in 4 (9%), the exact site could not be defined. 14/48 mammary recurrences were accompanied by axillary relapse, there were 3 isolated axillary recurrences and supraclavicular metastases accompanied axillary relapse in 3 cases. The overall risk, of axillary relapse was 3% (17/493) and there was significant correlation with initial N stage. Salvage surgery generally mastectomy and axillary dissection, was possible in 45/51 (90%) recurrences. 23/45 (50%) survive NED 0.2-9 years (mean 3 years) after salvage. 8/23 (35%) followed longer than 5 years after salvage survive NED. Our results have been compared with other series in the literature and changes in our current protocol are described.