Breast Conservation Therapy Versus Mastectomy - Preliminary Results of Pattern of Failure and Survival Rate in Early Breast Cancer

Kim, Yeon Sil; Yoon, Sei Chul; Chung, Su Mi; Ryu, Mi Ryeong; Jung, Sang Sul; Choi, Ihl Bohng

Abstract

PURPOSE: This retrospective study was conducted to compare early preliminary results of breast conservation therapy (BCT) with mastectomy in early breast cancer. MATERIALS AND MEHTODS: We evaluated 171 women with AJCC stage I and II breast cancer who had been treated at Kangnam St. Mary's Hospital from March 1989 to August 1996. Eighty-eight patients underwent mastectomy and 85 patients did conservative surgery with breast irradiation. In the BCT group, all patients received whole breast irradiation to a total dose of 45~50 Gy/5~6 wks, followed by a boost to the original tumor site at least 60 Gy. Chemotherapy was administered to 29 (34.1%) patients in BCT and 40 (45.5%) in mastectomy, with various sequencing of surgery and/or radiation. We compared survival rate, patterns of failure in each treatment group and the prognostic factors that had a significant effect on treatment failure. The median follow-up time was 63 months (19~111 months). Log rank test was used to estimate the prognostic factors for treatment failure.
RESULTS
Overall survival, disease free survival, locoregional recurrence and distant metastasis rates were not significantly different between the two treatment groups. During the follow-up period, 11 patients (12.5%) in the mastectomy group and 10 patients (11.8%) in the BCT group were failed. Six local recurrences occurred after mastectomy and 5 after BCT. Five patients failed at distant site in mastectomy and 4 in BCT. Of the local recurrence cases, five of 6 mastectomy patients and 3 of 5 BCT patients were alive with no evidence of disease after salvage surgery and/or chemoirradiation. Our results indicated that the major influence on survival was distant metastasis. Unfortunately, control of distant metastasisis was not frequently achieved. Even with salvage systemic therapy or radiotherapy, most of distant metastasis patients died or had uncontrolled disease in both treatment groups: only one of 4 BCT patients and none of mastectomy patients were alive without disease. There was no apparent difference in the incidence rate of contralateral breast cancer and non-breast 2nd primary tumor between the two treatment groups. Univariate Log-rank test identified the N stage and the involved axillary LN number as distinct prognostic factors that were highly predictive of treatment failure in both treatment groups. Additionally, marginal status in BCT and histologic nuclear grade in the mastectomy group were risk factors for treatment failure (p<0.05).
CONCLUSION
Although further careful follow-up is necessary to confirm the trends evident in this series, it would appear that patterns of failure and survival rate following conservative surgery and radiotherapy in early breast cancer are similar to those following mastectomy. The great majority of patients with local recurrence had an exellent salvage rate in both treatment groups. Therefore, these preliminary short term results support BCT as an equally effective management for early breast cancer as an alternative to mastectomy.