Background and objective: For early stage breast cancer with less than four metastatic axillary lymph nodes (ALN), indications for adjuvant radiotherapy are not well defined. This study was to investigate the risk factors for postmastectomy locoregional recurrence and survival in those patients.
Methods: In total 217 patients undergoing mastectomy in Sun Yat-sen University Cancer Center between March 1998 and March 2002 were retrospectively reviewed. Seventy-one patients were at pT1 stage, and 146 cases at pT2 stage. Two hundred and two patients received adjuvant chemotherapy, 51 received radiotherapy (RT), and 116 received endocrine therapy whose estrogen receptors (ER) or progesterone receptors (PR) were positive.
Results: The median follow-up time for these patients was 69 months. The 5-year actuarial locoregional recurrence-free survival (LRFS), disease-free survival (DFS), and overall survival (OS) were 85.2%, 81.8%, and 90.2%, respectively. Treatment failure was found in 44 patients, among whom 21 cases were diagnosed as locoregional recurrence. The 5-year actuarial OS was significantly lowered in patients with locoregional recurrence than in those without (61.9% vs. 93.6%, P<0.0001). Age younger than 35 years, pT2 tumor, and the rate of metastatic ALN>or=30% were risk factors for poor LRFS, DFS, and OS. When a scoring system was established consisting of these three prognostic factors, the 5-year actuarial LRFS in patients with varied scores were significantly different (P=0.0072). In the subgroup of 159 patients who received adjuvant chemotherapy of not less than five cycles, 35 patients who received adjuvant RT achieved significantly better survival rates than those who did not.
Conclusion: Age younger than 35 years, pT2 tumor, and the rate of metastatic ALN>or=30% are risk factors for locoregional recurrence and survival in patients with early stage breast cancer who have one to three positive ALN. Adjuvant RT is recommended for those patients.