Prognostic Value Of The Pretherapeutic Eus Staging In Rectal Cancer Treated By Radio-(Chemo)Therapy Followed By Surgery. Long Term Results Of The Ffcd 9203 Randomized Study

Introduction: Few studies have evaluated the prognostic value of endorectal ultrasound ERUS) in patients treated by radiotherapy and surgery. Methods : in the FFCD 9203 trial (Gérard et al., JCO, 2005), 742 patients with rectal cancer, at least T3, received a preoperative radiotherapy. Delivery of chemotherapy was randomly allocated and surgery was planned 3-10 weeks after completion of radiotherapy. ERUS was optional as part of the pretherapeutic staging; data were available in 394 patients. Median duration of follow-up was 6.75 years. The statistical analysis was performed with a log-rank test and a Cox model. Results: Six factors had a significant prognostic value in the univariate analysis : WHO performance status, histological type and tumor differentiation, clinical stage, date of randomization, stage T4 (p = 0.004) and number of lymph nodes (p < 0.05) on ERUS. In the multivariate analysis, only tumor differentiation kept a significant prognostic value (p < 0.05). The presence of perirectal lymph nodes had a nearly significant prognostic value (p = 0.10). Conclusion: ERUS may predict the long term prognosis of rectal cancer treated by radiotherapy and surgery, but its prognostic value disappears in front of the weight of histological analysis. This might be due to the fact that ERUS may have been used to select the patients to be included in the study.