New and evolving research in locally advanced rectal cancer suggests that selective use of treatments in some patients can achieve outcomes similar to those of standard regimens, according to the chair of the Department of Radiation Oncology at Duke University School of Medicine, Durham, North Carolina.
Total neoadjuvant therapy (TNT) is the standard treatment that involves systemic chemotherapy and radiation therapy before surgery for patients with locally advanced rectal cancer, Christopher G. Willett, MD, explained, in an interview. However, recent clinical trials support several strategies for “deintensification” of TNT for patients with locally advanced rectal cancer, he said.
Some patients may not require surgery or radiation therapy, or they may not require any treatment modalities including radiation therapy, chemotherapy, and surgery, Dr. Willett continued.
However, “these patients require close surveillance post treatment to identify any recurrence that may require salvage treatment,” he added.
During a presentation at the 2024 National Comprehensive Cancer Network Annual Conference, Dr. Willett primarily discussed the following three strategies for deintensifying overall therapy for locally advanced rectal cancer:
- Selective surgical omission for patients with rectal cancer having a complete clinical response after TNT with close surveillance following treatment.
- Selective omission of radiation therapy for patients with surgery such as sphincter-sparing surgery.
- Selective omission of all treatment modalities (radiation therapy, chemotherapy and surgery).
Does Watch and Wait Work?
Selective surgical omission, also known as a “watch and wait” or nonoperative management (NOM), involves treating patients with chemotherapy or a combination of chemo and radiation therapy but without surgery, Dr. Willett said during his presentation at the meeting.
Data from the OPRA trial published in the Journal of Clinical Oncology showed that 36% of patients who started on NOM developed tumor regrowth, most of which occurred in the first 2-3 years. Five-year disease-free survival rates were similar in patients who had total mesorectal excision (TME) upfront and those who had salvage TME procedures after tumor regrowth (61% and 62%, respectively). An update to the OPRA trial showed that the clinical outcomes persisted, and the results suggest no significant differences in disease-free survival between upfront surgery vs. watch and wait, Dr. Willett said.
Does Selective Omission of Radiotherapy Work?
Selective omission of radiotherapy is another option for reducing the overall treatment burden in patients with locally advanced rectal cancer, Dr. Willett. For these patients, who are at relatively low risk for recurrence, radiation along with surgery may not be needed.
Data from the FOWARC trial, published in the Journal of Clinical Oncology in 2016 and 2019, included 495 patients from 15 centers in China. In the randomized trial, the researchers found no significant difference in the primary outcome of disease-free survival between patients assigned in a 1:1:1 ratio to three arms:
- FOLFOX chemotherapy alone (a combination of chemotherapy drugs including folinic acid, fluorouracil, and oxaliplatin).
- FOLFOX plus chemoradiation.
- FU (fluorouracil)/LV (leucovorin calcium) plus chemoradiation.