A diagnostic biopsy-adapted immunoscore predicts response to neoadjuvant treatment and selects patients with rectal cancer eligible for a watch-and-wait strategy

VACCARO, CARLOS A

CLINICAL CANCER RESEARCH

AMER ASSOC CANCER RESEARCH

Año: 2020

1078-0432

Purpose: No biomarker to personalize treatment in locally advanced rectal cancer (LARC) is currently available. We assessed in LARC whether a diagnostic biopsy-adapted Immunoscore (ISB) could predict response to neoadjuvant treatment (nT) and better define patients eligible to an organ preservation strategy ("Watch-and-Wait").Experimental design: Biopsies from two independent cohorts (n1=131, n2=118) of patients with LARC treated with nT followed by radical surgery, were immunostained for CD3+ and CD8+ T cells and quantified by digital pathology to determine ISB. The expression of immune-related genes post-nT was investigated (n=64 patients). Results were correlated with response to nT and disease-free survival (DFS). The ISB prognostic performance was further assessed in a multicentric cohort (n=73 patients) treated by Watch-and-Wait.Results: ISB positively correlated with the degree of histologic response (P