66P - The TILs near solid structures is a potential prognostic factor of distant metastases in the luminal HER2-negative breast cancer

Background

The phenomenon of intratumoral morphological heterogeneity is associated with both the progression of the disease and chemosensitivity and chemoresistance. However, there are very few data about the microenvironment heterogeneity near morphological structures in breast cancer patients of various molecular subtypes. This phenomenon may underlie the failure of tumor-infiltration lymphocytes as a prognostic factor in luminal forms of breast cancer.

Methods

152 patients with IC NST (T1–3N0–2M0) aged 29 to 75 years were enrolled in the study. The molecular subtype was determined using immunohistochemical analysis of the expression of estrogen and progesterone receptors, Ki-67 and Her2/neu. TILs were assessed in accordance with the recommendations of the International TILs Working Group

Results

It was shown that TILs near the various morphological structures is heterogeneous only in luminal Her2-negative patients. In addition, was found that the development of distant metastases and worse metastatic-free survival in this cohort of patients is associated with a high (more than 5%) TILs near solid structures and also depended on Ki-67 level.

Conclusions

TILs near solid structures is a potential prognostic factor for the development of distant metastasis in the luminal Her2-negative and Ki-67 level less 20% subtype of IC NST. The study was supported by the Russian Science Foundation (grant #20-75-10033).

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

the Russian Science Foundation.

Disclosure

All authors have declared no conflicts of interest.