早期 HER2 阳性乳腺癌中 TIL（肿瘤浸润淋巴细胞）与 BMI 的相互作用：ShortHER 试验分析

We demonstrated the prognostic role of tumor-infiltrating lymphocytes (TILs) in patients with early human epidermal growth factor receptor 2 (HER2)-positive breast cancer (eBC) enrolled in the ShortHER trial. Here, we analyze how body mass index (BMI) modulates the prognostic role of TILs.

The ShortHER study randomized 1253 patients with HER2-positive eBC to 9 weeks versus 1 year of adjuvant trastuzumab + chemotherapy. We assessed BMI at diagnosis (available for n = 1213, n = 34 underweight were excluded). Survival endpoints were disease-free survival (DFS), recurrence-free survival (RFS), distant DFS (DDFS) and overall survival (OS). We calculated the cumulative incidence of first event types by competing risk analysis.

A total of 583 (48%) patients were lean, 360 (29.7%) overweight and 236 (19.5%) obese. Lean patients versus those with overweight or obesity had similar DFS, RFS, DDFS and OS. Within the TIL + BMI cohort (n = 819), TILs (5% increase) were independently associated with DFS (P = 0.003), RFS (P = 0.001) and DDFS (P = 0.018) in lean patients. In patients with overweight or obesity, TILs were independently associated only with DDFS (P = 0.044). In lean patients, TILs 20% were associated with improved DFS (P = 0.007), RFS (P = 0.002) and DDFS (P = 0.027) compared with TILs <20%. In patients with overweight or obesity, DFS, RFS, DDFS and OS did not significantly differ between TILs 20% and TILs <20%. In lean patients, there was a higher cumulative incidence of locoregional relapse (P = 0.001) and distant relapse (P = 0.07) in patients with TILs <20% versus TILs 20%. In patients with overweight or obesity, there was a higher cumulative incidence of distant relapse (P = 0.005) in patients with TILs <20% versus TILs 20%.

We suggest that BMI may impair the local, but not distant, protective effect of TILs in patients with overweight or obesity with HER2-positive eBC treated with adjuvant chemotherapy + trastuzumab.