Can patients with rectal cancer be treated with pre-operative chemoradiation alone?

The present study evaluated the outcomes of patients with rectal cancer who were treated with non-operative management (NOM) after complete clinical response (cRC) to neoadjuvant chemoradiation (nCRT). 

Rectal cancer involves the final part of the large intestine, or rectum. The first choice of treatment for rectal cancer is usually surgery. However, in more advanced stages chemotherapy with radiation is given before surgery to shrink the cancer so it can be completely removed by surgery. Chemotherapy with radiation given before surgery is called neoadjuvant chemoradiation therapy (nCRT). Studies have shown that in some patients with rectal cancer, nCRT can be curative (entirely eradicate the cancer) so surgery may no longer needed. For these patients a nonoperative management (NOM) is warranted. This means that patients are closely monitored and surgery is performed only if a recurrence (return of the cancer) manifests. This way, patients can be spared of the risks and complications of surgery, particularly after the body has been weakened by the nCRT. 

The authors of this study selected a group of 32 patients with rectal cancer who demonstrated a complete clinical response, or cCR (no cancer was palpated at the rectal examination or seen during endoscopic examination) following nCRT. These patients who were treated non-operatively (NOM). Patients were followed up regularly and their outcomes were compared to a second group of 57 rectal cancer patients who undergone surgery to remove the cancer after nCRT and achieved pathological complete response, or pCR (no cancer cells were seen by a pathologist after the cancer was removed). This group served as a control for the NOM group, as patients with pCR are known to have highly favorable prognosis.

In summary, when combined with salvage surgery (surgery to remove cancer recurrence after primary treatment) NOM shows similar survival benefits, compared to standard therapy, in patients with rectal cancer. It may therefore provide a treatment option allowing these patients to delay or avoid surgery. 

The weakness of this study lies in its methodology. The study looks back at patients who have been treated in the past (retrospective study) rather than following the patients throughout their treatment and determining their outcomes (prospective study). Retrospective studies are considered to provide weak statistical evidence. The study group was rather small. Prospective, larger studies are needed to confirm these findings.