According to the study, among patients with locally advanced rectal cancer treated with a combination of chemotherapy and radiotherapy and subsequent surgery, the complete disappearance of detectable cancer cells (called pathologic complete response) after the treatment is related to better long-term outcome than do those without pathological complete response. These patients survive more years without disease and have less risk of metastasis.

This fact seems obvious, but could not be clearly demonstrated so far, and opens the door to personalized treatments.

Studies review

In the study, researchers reviewed data from 17 studies published in scientific journals. Among the 3,105 patients who had participated in these investigations, 484 had a complete pathological response after preoperative radiation therapy. Five years later, 83.3% of these patients remained disease free compared with 65.6% of patients who did not have complete disappearance of cancer cells after the treatment.

After analyzing the major studies published on the subject (many of them made by the same authors), the researchers conclude that pathological complete response after chemotherapy or radiotherapy seems to be a predictor of good prognosis in patients with locally advanced rectal cancer.

Sebastiano Biondo, IDIBELL’s Gastrointestinal Pathology Group leader and head of the Gastroenterology section of Bellvitge University Hospital, noted that “the study’s findings are clinically relevant because it relates to whether to omit further adjuvant treatment for patients who respond well, or to intensify treatment for those who do not respond”. Additionally, Dr. Biondo explains, “it can affect whether patients who respond very well to chemoradiation would benefit from less invasive strategies such as local excision, or even omit surgery and undertake intensive follow-up.”

Referència de l’article
Monique Maas, Patty J Nelemans, Vincenzo Valentini, Prajnan Das, Claus Rödel, Li-Jen Kuo, Felipe A Calvo, Julio García-Aguilar, Rob Glynne-Jones, Karin Haustermans, Mohammed Mohiuddin, Salvatore Pucciarelli, William Small Jr, Javier Suárez, George Theodoropoulos, Sebastiano Biondo*, Regina G H Beets-Tan, Geerard L Beets. Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data. Lancet Oncol 2010; 11: 835–44.