Some patients with rectal cancer who experience complete clinical response after neoadjuvant therapy may safely avoid total mesorectal excision. The evidence is still, however, preliminary, according to Julio Garcia-Aguilar, MD, of the Department of Surgery at Memorial Sloan Kettering Cancer Center in New York, New York.
Dr Garcia-Aguilar presented an overview on the latest treatments for locally advanced rectal cancer at the 2016 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, and told clinicians that treatment counseling should convey the risks and benefits by using quantitative estimates expressed in absolute rather than relative terms, to help better empower informed patient decision-making.1
For patients with no evidence of clinical nodal involvement, no high-risk features, and excellent response to chemoradiotherapy, it may be possible to omit postoperative chemotherapy. He said that there is a need, however, for greater evidence to support this option.
Dr Garcia-Aguilar said phased-array MRI can define features associated with a high risk of metastases and a high likelihood of local recurrence. He and his colleagues report that strong scientific evidence to support the use or non-use of adjuvant chemotherapy for patients with rectal cancer is not available. Subsequently, omission of this treatment may be worth considering for some patients. They note that all treatment regimens must be tailored to each individual patient.
“Tumors in the upper rectum which do not threaten the circumferential resection margin may not need radiation,” Dr Garcia-Aguilar told Cancer Therapy Advisor. “Tumors with a clinical and radiological complete response to [chemoradiotherapy] may not need surgery.”
A selective approach to radiotherapy provision is feasible with the use high-quality MRI and optimal total mesorectal excision surgery. Dr Garcia-Aguilar and his team report that it is best to use an infusional approach with 5-fluorouracil (5-FU) instead of a bolus schedule.
They found evidence to support the use of capecitabine as an acceptable alternative to infusional 5-FU. Dr Garcia-Aguilar said when administering FOLFOX, it is paramount to avoid long-term toxicity through dose reductions, or by discontinuing oxaliplatin before peripheral neuropathy becomes severe or persistent.