No Long-Term Advantage for Complete Response to Neoadjuvant Chemo/RT

WASHINGTON—Stage II and III rectal cancer patients who achieve a complete response (CR) to neoadjuvant chemoradiation do not enjoy any long-term survival advantage over patients who do not, Mark Onaitis, MD, of Duke University Medical Center, said at the 54th Annual Cancer Symposium of the Society of Surgical Oncology.

Neoadjuvant chemoradiation for rectal cancer has been observed to cause clinical downstaging, he said. Whether response affects survival and whether downstaging makes responders candidates for later local excision have been unclear, however. The present study of complete responders aimed to explore these questions.

A database of 131 rectal cancer patients who had received fluorouracil (5-FU)-based chemotherapy plus radiation therapy (45 Gy) yielded 30 complete T-stage responders, according to pathologic analysis performed postoperatively.

Begun in 1987, the database also provided information on patient demography, pre- and postoperative tumor staging, the type of surgery performed, number and nature of complications, and survival. Complete responders resembled the other 100 patients in their tumor characteristics before surgery.

Neoadjuvant chemoradiation "made no long-term difference in terms of local recurrence and survival rates," Dr. Onaitis said. Although the complete responders enjoyed an "early survival advantage," this did not persist in the long term, he reported.

Complete pathologic tumor sterilization, therefore, "confers no long-term advantage," he observed, noting that clinical response proved unreliable as a predictor of long-term survival.

Only lymph node status proved a significant prognostic factor in this study, he said. He noted that 4 of the complete T-stage responders had positive lymph nodes. "This is also part of the rationale for recommending against local excision (in which no lymph nodes are resected)," he said.

Based on these results, Dr. Onaitis stated that local excision alone "should be undertaken with caution" in complete responders to neoadjuvant therapy, since these patients may need further therapy.

He stressed that the findings are retrospective in nature, the follow-up period is relatively short, and the number of patients is relatively small. "Therefore, the conclusions are preliminary and await further study," he said.