Abstract P1-13-15: Risk of late recurrence of hormone receptor positive breast cancer in cases with no recurrent disease at five years after surgery

Abstract

Abstract Background: Among women who take 2-5 years of adjuvant endocrine therapy, more than half of all recurrences of hormone receptor (HR) positive breast cancer occur after the first 5 years. Data from large clinical trials including ATLAS, aTTom,MA17 and NSABP B-30 support extending tamoxifen or aromatase inhibitor beyond 5 year for women with HR positive breast cancer. For decision making according to extending endocrine therapy, the information of the risk of late recurrence is quietly important. Patients and methods: In order to determine ten year disease free survival (DFS) rates, we reviewed medical records and database of patients who were treated at National Kyushu Cancer Center between 1990 and 2001. Among seven hundred fifty seven patients with HR positive breast cancer, 550 received tamoxifen for 2-5 years. Eighty eight patients had recurrence within five years after surgery, and 13 were not followed, with 83.5% of 5-year DFS after surgery. Remaining four hundred twenty six had no recurrence at the time of 5 years after surgery. To evaluate the risk of late recurrence, we analyzed the long-term results in association with clinicopathological factors for these 426 patients. Results: Four hundred twenty six patients had 87.1% of 10-year DFS rate. According to lymph node metastasis (N), ten year DFS rates were 91.4% for 275 N-negative and 80.0% for 155 N-positive cases (P = 0.0037). As for the number of lymph node metastasis, 10-year DFS rates were 82.5%, 74.2%, and 79.1% for N1-3, N4-9, N>9, respectively. Tumor size was correlated with the prognosis, and 10-year DFS rates were 91.5% for 167 T1 (≤2 cm), 86.9% for T2 (2-5 cm), and 67.9% for T3 (>5cm) (P = 0.0334). There were no significant differences between grade and prognosis, and 10-year DFS rates of grade 1, 2 and 3 were 88.9%, 89.8%, and 96.8%, respectively (p = 0.3914). Considering the age at 5 years after surgery, no significant differences were observed as for late recurrence. Ten-year DFS rates of 96 cases of age under 50, 227 between 50 and 65, 113 over 65 was 89.4%, 85.1%, and 86.0%, respectively. Ten-year DFS rates of N-negative and N-positive were 94.3% and 81.2%, 88.1% and 80.1%, and 90.4% and 76.7% for these age criteria, respectively. Conclusion: Patients with HR positive breast cancer require optimal information for decision making whether to receive extending endocrine therapy or not. Our data demonstrated the risk of late recurrence in relation to clinic-pathological factors, which may support the consideration about extending endocrine therapy. Relatively high risks of late recurrence with over 10% of 10 year DFS rates are there in cases with N-positive or T2-3 HR positive breast cancer. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-13-15.