Tumor Cellularity and Infiltrating Lymphocytes (CelTIL) as a Survival Surrogate in HER2-Positive Breast Cancer
Menée à partir d'échantillons biopsiques prélevés sur 196 patientes atteintes d'un cancer du sein HER2+ de stade précoce traité par chimiothérapie à base de trastuzumab dans le cadre d'un essai de phase III, cette étude évalue la valeur pronostique de CelTil, un système de score basé sur la cellularité de la tumeur et l'infiltration du stroma tumoral par les lymphocytes
In early-stage HER2-positive breast cancer, biomarkers that guide de-escalation and/or escalation of systemic therapy are needed. CelTIL score is a novel, combined biomarker based on stromal tumor-infiltrating lymphocytes and tumor cellularity and determined in tumor biopsies at week 2 of anti-HER2 therapy only. We evaluated the prognostic value of CelTIL in 196 patients with early-stage HER2-positive disease treated with standard trastuzumab-based chemotherapy in the NeoALTTO phase III trial. Using a pre-specified CelTIL cutoff, a better 5-year event-free survival and overall survival was observed between CelTIL-high and CelTIL-low score with a 76.4% (95% confidence interval [CI] = 68.0%–85.0%) versus 59.7% (95% CI = 50.0%–72.0%) (hazard ratio = 0.40; 95% CI = 0.17 to 0.94), and 86.4% (95% CI = 80.0%–94.0%) vs 73.5% (95% CI = 64.0%–84.0%) (hazard ratio = 0.43; 95% CI = 0.20 to 0.92), respectively. Statistical significance was maintained after adjusting for baseline TILs, hormone receptor status, pre-treatment tumor size and nodal status, type of surgery, treatment arm, and pathological complete response. Further studies to support CelTIL as an early read-out biomarker to help de-escalate/escalate systemic therapy in HER2-positive breast cancer seem warranted.
Journal of the National Cancer Institute , résumé, 2020