Higher Tumor-Infiltrating Lymphocyte Level Associated With Better Outcomes in HER2-Positive Early Breast Cancer Independent of Neoadjuvant Treatment

“In an analysis of the NeoALTTO trial reported in JAMA Oncology, Salgado et al found that a higher level of tumor-infiltrating lymphocytes was associated with improved pathologic compete response rate and event-free survival independent of neoadjuvant treatment received in patients with HER2-positive early breast cancer.

“In NeoALTTO, 455 patients were randomly assigned to receive neoadjuvant trastuzumab (Herceptin), lapatinib (Tykerb), or the combination for 6 weeks followed by the addition of weekly paclitaxel for 12 weeks and three cycles of fluorouracil, epirubicin, and cyclophosphamide after surgery. Percentage of tumor-infiltrating lymphocytes were measured by hematoxylin-eosin stained core biopsy sections taken at diagnosis.”


High TIL Levels Predict Positive Outcomes in HER-2–Positive Breast Cancer

“High levels of tumor-infiltrating lymphocytes served as an independent positive predictive marker for EFS and pathological complete response in HER-2–positive early breast cancer treated with chemotherapy and anti-HER–2 agents, according a secondary analysis of the NeoALTTO trial.

“ ‘Increasingly, oncogenic addiction, in which tumors become dependent on a sole oncogenic pathway for growth, is thought to promote a tumor microenvironment conducive to immune escape,’ Sherene Loi, MD, PhD, of the Peter MacCallum Cancer Centre at the University of Melbourne, and colleagues wrote. ‘Although this had not been shown yet for HER-2 oncogenic signaling, one could speculate that anti-HER–2 therapy may not only work in a cell-intrinsic manner but may also reserve HER-2–induced immunosuppression as a mechanism for action.’

“The NeoALTTO trial included 455 women with HER-2–positive early-stage breast cancer between 2008 and 2010. The researchers randomly assigned patients to neoadjuvant treatment with trastuzumab (Herceptin, Genentech), lapatinib (Tykerb, GlaxoSmithKline) or both.

“Patients received the initial treatment for 6 weeks, followed by weekly paclitaxel for 12 weeks and three treatment cycles of fluorouracil, epirubicin and cyclophosphamide after surgery.”