Endorectal ultrasound in the follow-up of rectal cancer patients treated by local excision or radical surgery

PURPOSE: This study was designed to investigate the role of a scheduled follow-up protocol using endorectal ultrasonography for the diagnosis of local recurrence after local excision and radical surgery for rectal cancer. METHODS: A selected group of 275 patients with invasive rectal cancer followed prospectively by endorectal ultrasonography after curative-intent local excision (n = 108) or radical surgery (n = 167) was reviewed. For the radical-surgery group, results were compared with a group of 176 rectal cancer patients who had similar operations during the same period of time and were not entered in follow-up protocol. Excluded were patients with invasive cancers removed by snare excision, male patients treated by abdominoperineal resection, and patients treated by endocavitary radiation. Student's unpaired t-test was used to compare tumor and patient characteristics. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test. RESULTS: In the local-excision group, 32 patients developed local recurrence, 26 (81 percent) were asymptomatic, and 10 of them (31 percent) were diagnosed only by endorectal ultrasound. We found no difference in the rates of salvage surgery or survival between patients diagnosed of recurrence by ultrasound or other methods. In the radical-surgery group, 12 patients developed local recurrence, 5 (42 percent) were asymptomatic, and 4 of them (33 percent) were diagnosed only by endorectal ultrasound. More patients with isolated local recurrence in the follow-up group underwent salvage surgery (4/9 patients; 44 percent) compared with patients without follow-up (3/13 patients; 23 percent), but the differences were not significant. CONCLUSIONS: Endorectal ultrasound identifies one-third of asymptomatic local recurrences that were missed by digital examination or proctoscopic examination. However, the impact of the earlier diagnosis in patient survival can only be determined by a larger, prospective, randomized trial.