Identifying the Most Predictive Post-Chemoradiation TRG System for Rectal Cancer
A partir de données portant sur 563 patients atteints d'un cancer rectal localement avancé traité entre 1998 et 2007 par chimioradiothérapie et excision totale du mésorectum, cette étude évalue plusieurs méthodes visant à prédire le risque de récidive et la survie
The German CAO/ARO/AIO-94 Rectal Cancer Trial revealed that patients with rectal cancer who receive neoadjuvant chemoradiation have a continuous increase of local recurrences up to 10 years following surgery (1). Given the long follow-up required, there is substantial interest in short-term surrogate endpoints following chemoradiation. The two most common immediate postoperative endpoints are pathologic complete response (pCR) and tumor regression grade (TRG). Various factors appear to determine these early endpoints, such as radiotherapy schedule, fractionated and total radiation dose, interval between preoperative chemoradiation and surgical resection, and the combination with chemotherapy. Several studies have suggested that the degree of tumor regression (pCR vs non-pCR; various TRG systems) may be of high clinical relevance because it could be used to both monitor treatment and as a prognostic parameter.
There is a single definition of pCR; no visible microscopic disease in both the primary tumor and lymph nodes (ypT0N0). In contrast, TRG is less well defined. There is no consensus for a universally approved classification. Furthermore, the lack of standard definitions of TRG, heterogeneous diagnostic and treatment strategies, various intervals between the end of chemoradiation and surgery, and the lack of pathology quality control have made the data challenging to interpret.
There are five TRG systems with …
Journal of the National Cancer Institute , éditorial, 2014