Multinational validation study of the Immunoscore biopsy in patients with rectal cancer managed by a watch-and-wait strategy

Watch-and wait is a preservative strategy for rectal cancer patients with clinical complete response after neoadjuvant chemoradiotherapy. A multinational retrospective study was carried out to validate the utility of the Immunoscore biopsy (IS_B) performed on pretreatment biopsies to predict time to recurrence (TTR). IS_B categories were significantly associated with a gradual scaling of the risk of both local regrowth and distant metastasis. IS_B
was the strongest predictor of TTR (ISB High versus Low HR 6.93; p=0.0017). Addition of IS_B to a clinical-based model significantly improved the prediction of recurrence. The authors conclude that these findings validate IS_B
as a prognostic tool in patients with rectal cancer managed by watch-and-wait strategy.