Comparison of prognosis and specific features according to tumor size in small-sized breast cancer with extensive lymph node involvement.

Abstract

81 Background: As known, larger tumor size and more extensive lymph node (LN) involvement have been considered an independent factor for poor prognosis of breast cancer. We evaluated if very small tumor size may be a factor of worse prognosis compared to larger tumor in small sized breast cancer with LN involvement. Methods: A retrospective analysis was made in a single center of all 1400 patients with small (below 2cm, T1) sized and LN involved (N1~N3) breast cancer without metastasis diagnosed between 2004 and 2014. Their ages ranged from 23 to 88 years (mean age 49.1 ± 9.9 years) and mean follow-up was 31 months. All patients were performed with surgery including axillary LN dissection without neo-adjuvant chemotherapy. We subdivided their tumor size to 4 group (T1m, T1a, T1b and T1c) grading by 7th AJCC cancer staging. The number of patients in each group is as follows: T1m = 17, T1a = 63, T1b = 214, T1c = 1106. The specific features related to mortality were analyzed according to the minor groups and they were compared with one another by Chi-square test and Kaplan-Meier analysis. Results: Total expired patients were 39 (2.8%) and the number (the rate in each group) of the minor groups is as follows: T1m = 1 (5.9%), T1a = 1 (1.6%), T1b = 7 (3.3%), T1c = 22 (2.0%). Overall survival of smaller sized tumor groups ( ≤ 1cm, T1m+T1a+T1b) are significantly decreased than the other larger sized group T1c in T1N1 staged patients (p = 0.004). There are significant differences in estrogen receptor, progesterone receptor, nuclear grade, recurrence among the 4 minor groups in whole patients group. In the analysis of nuclear grade, the results show higher grade in T1m than T1a, T1m than T1b, T1b than T1c. Especially, recurrence of T1m is significantly more frequent than T1a (17.6% vs 3.2%, P = 0.03) or T1b (17.6% vs 4.2%, p = 0.016). Conclusions: In conclusion, this study indicates smaller sized tumor with LN involvement can progress worse compared to larger tumor. This result supports very small size can be another predictive factor for prognosis in small sized breast cancer with LN involvement.