Preoperative radiotherapy for rectal adenocarcinoma: Which are strong prognostic factors?

This retrospective 12-year study evaluated the prognostic value of initial and postoperative staging of rectal tumors.Between 1985 and 1996, 297 patients were treated with preoperative radiotherapy (39 Gy in 13 fractions) and surgery for Stage T2-T4N0-N1M0 rectal adenocarcinoma. Pretreatment staging included a clinical examination and endorectal ultrasonography (EUS) since 1988. Clinical staging was performed by digital rectal examination and rigid proctoscopy. EUS was performed in 236 patients. Postoperative staging was performed by examination of the pathologic specimen.The median follow-up was 49 months. The overall 5-year survival rate was 67%, with a local failure rate of 9%. The rate of sphincter preservation was 65%. The clinical examination findings were strong prognostic factor for both cT stage (p0.001) and cN stage (p0.006) but had poor specificity for cN stage (only 25 lymph nodes detected). In both univariate and multivariate analyses, EUS had a statistically significant prognostic value for uT (p0.014) but not for uN (p0.47) stage. In contrast, pT and pN stages were strong prognostic factors (p0.001 and p0.001, respectively).Pretreatment staging, including clinical examination and EUS, seemed accurate enough to present a high prognostic value for the T stage. EUS was insufficient to stage lymph node involvement. Owing to its lack of specificity, uN stage was not a reliable prognostic factor. An improvement in N staging is necessary and essential. Despite downstaging, postoperative staging remained a very strong prognostic factor for both T and N stages.