Considerations and restrictions for non-operative treatment of rectal cancer in selected patients.

摘要

Surgery is the corner stone of curative treatment for rectal cancer and the reference for new treatments. Proper treatment consists of complete surgical removal of the tumour, with clear circumferential resection margins, checked with adequate pathological examination, the results of which can be used as a reference for adjuvant treatment. In the past decade, preoperative chemoradiotherapy (CRT) has been introduced for rectal cancer to downstage and downsize the tumour. A pathological complete response (pCR), defined as no tumour detectable during pathological examination of the resection specimen, has been reported in 10-30% of patients treated with preoperative CRT. These findings raise the question of whether these patients were already curatively treated with CRT before surgery. Despite this question, pCR as a surrogate endpoint is still under debate. In several trials involving preoperative CRT, pCRs were recorded, but none of the treatment schedules used in these trials resulted in improved overall survival. However, patients with a pCR have a better prognosis than those without a complete response. Habr-Gama and co-workers have attempted to find evidence for omitting surgery in the treatment of such patients, a subject extensively discussed by O'Neill and colleagues in this issue of The Lancet Oncology. Adequate patient selection is crucial for non-surgical treatment. Nevertheless, no data from large trials, in which standardised preoperative staging with MRI is mandatory, are currently available.