Long-term results of breast conservation therapy for breast cancer

This study was done to determine the long-term outcome of breast conservation therapy (BCT) for patients with early-stage breast cancer during a period of treatment evolution at a single institution.

Breast cancer treatment has evolved from extensive surgical extirpation of the breast to treatment options that conserve the breast. Prospective and retrospective studies have confirmed the efficacy of BCT and justify its use for many patients with early breast cancer, but there is no universally accepted consensus as to who benefits from more aggressive application of surgery or radiotherapy in BCT. Prognostic variables for breast cancer and information on factors that contribute to local recurrence help predict BCT results. Continued analysis of BCT still is necessary to improve patient outcome.

Eighty-five patients treated with BCT (lumpectomy with adjuvant radiation therapy) at the Medical College of Virginia from 1980 to 1990 were identified. Clinicopathologic parameters and treatment details were analyzed for relationship to development of local recurrence, distant metastasis, and survival. Fisher's exact test was used for comparisons. Actuarial survival curves were plotted. The earlier treatment period (1980-1985) was compared with the later treatment period (1985-1990).

Median follow-up was 5 years. Actuarial overall survival was 83% at 5 years (69% at 10 years), and 5-year distant metastasis-free survival was 79%. The 5-year actuarial local recurrence rate was 6.6% (crude rate 10.6%, 9/85). Young patients (age < 40 years) were found to be at increased risk for local recurrence (24% < 40 years vs. 6% > or = 40 years, p < 0.05). Tumor margins < or = 3 mm were more frequently found, and lumpectomy site radiation boost was used increasingly from 1986 to 1990. Almost half of all local recurrences occurred after 5 years.

Survival and local recurrence rates were comparable to other series. Young patients were found to be at increased risk for local recurrence. Negative microscopic margins, even when close, can provide low local recurrence rates when adjuvant radiation therapy is administered.