Tumor-Infiltrating Lymphocytes Can Predict Response to Neoadjuvant Chemo in Locally Advanced Breast Cancer

A study led by Deepak Kumar and published in Cureus aimed to evaluate tumor-infiltrating lymphocytes (TILs) as predictors of response to neoadjuvant chemotherapy in patients with locally advanced breast cancer (LABC).

Thirty-five patients with LABC were included in the study. Demographics, medical history, and signs and symptoms data were collected for each patient. The cohort underwent a complete clinical evaluation involving physical examination, imaging studies (mammogram/ultrasound imaging) biopsy, and metastatic workup.

The patients consented to core-needle biopsy under local anesthesia followed by a pathologic assessment of breast cancer type before neoadjuvant chemotherapy and after mastectomy.

Patients treated with neoadjuvant chemotherapy were followed up for response using Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and were scheduled for modified radical mastectomy (MRM) after neoadjuvant chemotherapy completion. MRM specimens were sent in for CD3 and CD5 immunohistopathologic analysis; correlations between TILs and grading with NACT response and type of cancer were analyzed.

Twenty-four of the 35 participants were positive for CD3. The researchers also identified a correlation between neoadjuvant chemotherapy for LABC treatment and CD3 TILs: 68.6% of participants were CD3-positive, with 54.3% showing stromal CD3 variants and 14.3% showing intramural CD3 variants. These results indicate that CD3 TILs may have prognostic value for response probability to neoadjuvant chemotherapy.

In this participant sample:

• 17 (48.6%) patients were CD5-positive with stromal predominance.
• 17 (48.6%) patients had a RECIST 1.1 complete response rate to neoadjuvant chemotherapy.
• 16 (45.7%) patients had a RECIST 1.1 partial response to neoadjuvant chemotherapy.
• 1 (2.9%) patient had progressive disease.

The study shows a significant response to neoadjuvant chemotherapy in patients with LABC (P<.0001). These results indicate that tumor size could be effectively evaluated using RECIST 1.1 criteria and that TILs can serve as a promising prognostic marker to evaluate response to neoadjuvant chemotherapy and immunologic response in breast and other types of cancers after chemotherapy treatment.