PROGNOSTIC FACTORS INFLUENCING LOCAL CONTROL AND SURVIVAL AFTER BREAST CONSERVING SURGERY AND RADIOTHERAPY IN PATIENTS WITH EARLY STAGE BREAST CANCER

PURPOSE: In the present study treatment results and the prognostic factors influencing survival and local control rates after breast conserving surgery and radiotherapy were evaluated. MATERIALS AND METHODS: Three hundred sixty five patients treated with radiotherapy after breast conserving surgery during 1990-2002 were evaluated retrospectively. Radiotherapy dose was 50 Gy for the whole breast and 10-20 Gy boost for the tumor bed. Median total dose was 60 Gy (range 50-74) with a daily fraction dose of 2 Gy. RESULTS: One hundred sixty-six patients (45.4%) had Stage I, 180 (49.3%) had Stage IIA, 19 (5.2%) had Stage IIB disease. Axillary sampling or dissection was performed in 347 patients with a median of 13 lymph nodes (range 1-44) dissected. Median age was 47 (range: 19-80). The most common histologic type was invasive ductal carcinoma (66%). During a median follow-up duration of 68 months (range: 5-185) 21 patients (5.8%) developed local recurrence and 33 patients (9.0%) developed distant metastasis and 25 patients (6.8%) had died due to breast cancer. Five-year overall, disease-free survival and local control rates were 92.1%, 88.4% and 93.7% respectively. The only prognostic factor influencing overall survival was estrogene receptor (ER) negativity (p=0.05). The factors affecting local control were (+) surgical margins (p=0.01), operation-radiotherapy interval more than 60 days (p=0.02). In multivariate analysis lymph node metastasis (p=0.05) and ER negativity (p=0.03) were the prognostic factors influencing disease-free survival. CONCLUSION: In the present study ER status, surgical margins, lymph node metastasis and starting radiotherapy late were the significant prognostic factors.