294P - Survival outcomes according to tumor-infiltrating lymphocytes and 21-gene recurrence score in ER+HER2- breast cancer

Background

Several lines of evidence suggest that tumor-infiltrating lymphocytes (TILs) and 21-gene recurrence score was associated in ER+/HER2- breast cancer. We investigated survival outcomes according to tumor-infiltrating lymphocytes and 21-gene recurrence score in ER+HER2- breast cancer.

Methods

In 1,883 ER+ breast cancer patients with 21-gene assay, TIL level was evaluated. The cut-off for high recurrence score (RS) was 26. Level of TILs was classified into three groups: low (0-10%), intermediate (11-49%), and high TILs (≥50%). Recurrence-free survival (RFS) was investigated.

Results

A weak positive correlation between TIL level and RS was observed (correlation coefficient=0.283, p<0.001) in all patients. Average RS was significantly increased step-wised manner among the three TIL groups. The RFS of the high RS group was significantly inferior compared to that of the low RS group. When all patients were divided into 4 groups using TIL and RS (high-RS/high- or intermediate-TILs, high-RS/low-TILs, low-RS/high- or intermediate-TILs, and low-RS/low-TIL), the RFS was worst in the high-RS/low-TILs group (p<0.001).

Conclusions

Our findings show that TIL level is correlated with RS in ER+ breast cancer and suggest that poor outcome of the patients with high RS might be compensated if their tumors are enriched with TILs.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.