Abstract:

Objective

To investigate the correlation of stromal tumor-infiltrating lymphocytes（sTILs） with axillary pathological complete response （apCR） in clinically node-positive （cN+） young breast cancer patients treated with neoadjuvant therapy （NAT）.

Methods

Data of cN+ young breast cancer patients treated with NAT at the Department of Breast in Sichuan Cancer Hospital from January 2017 to June 2024 were reviewed. sTILs were evaluated according to the recommendations by the International TILs Working Group. The expression of sTILs was defined as low （sTILs＜10%）， moderate （10%≤sTILs＜50%）， or high （sTILs≥50%）. The associations between clinicopathological characteristics and apCR were analyzed.Univariate analysis was conducted by the chi-square test or Fisher's exact test， while multivariate analysis was performed using binary logistic regression.

Results

A total of 101 young breast cancer patients were included， and the overall apCR rate was 45.5% （46/101）. Univariate analysis suggested statistically significant associations of apCR with clinical tumor stage， human epidermal growth factor receptor 2 status， breast pathological complete response （bpCR）， and sTILs. Multivariate analysis showed that bpCR （yes vs no；odds ratio=3.14； 95% confidence interval 1.15～8.52； P=0.025） and sTILs （P=0.038； high vs low， OR=9.28，95%CI： 1.59～54.09， P=0.013； moderate vs low， OR=2.04， 95%CI： 0.78～5.30， P=0.144） were independent predictive factors for apCR in cN+ young breast cancer patients undergoing NAT. The apCR rate of patients with bpCR and high sTILs was 100% （6/6）， whereas only 26.9% （7/26） of patients with non-bpCR and low sTILs achieved an apCR.

Conclusion

bpCR and sTILs are independent predictive factors for apCR in cN+young breast cancer patients undergoing NAT.

Key words: Young breast cancer patients, Stromal tumor-infiltrating lymphocytes, Neoadjuvant therapy, Axillary pathological complete response, Predictive factor