Multicenter study of impact of sTIL level on outcomes of stage I triple-negative breast cancer without chemotherapy

The absolute benefit of chemotherapy for all patients with stage I triple-negative breast cancer (TNBC) is not clear, and biomarkers are not currently available for selecting patients with negligible benefit from neoadjuvant or adjuvant chemotherapy. A cohort study using data from the Netherlands Cancer Registry included 4511 females with stage I TNBC who did not receive neoadjuvant or adjuvant chemotherapy. Stromal tumor-infiltrating lymphocytes (sTILs) were scored in 1041 patients. Patients with pT1c tumors and sTIL levels of 50% or greater had a 10-year breast cancer-specific survival of 95% without chemotherapy, increasing to 98% with an sTIL level of 75% or greater. An association with less magnitude was found between sTILs and outcome in patients with pT1ab tumors. The author conclude that patients with stage I TNBC and high level of sTILs had excellent 10-year breast cancer-specific survival without neoadjuvant or adjuvant chemotherapy.