Surveillance Could Be a Viable Option for Certain Patients With Rectal Cancer

A “watch and wait” surveillance approach may allow certain patients with rectal cancer to achieve excellent outcomes without immediate surgery, according to a retrospective review of clinical data presented at the 2015 Gastrointestinal Cancers Symposium.

The review found that patients with stage 1-3 rectal cancer whose tumors completely disappeared after treatment had similar four-year survival rates regardless of whether they had immediate rectal surgery or took a surveillance approach. Avoiding rectal surgery can significantly improve quality of life, reducing risks like impaired bowels and sexual function.

Non-operative management (NOM) for rectal cancer is becoming increasingly accepted as an option worldwide, although it is currently not a standard approach. The findings from this study build on prior evidence from research conducted in Brazil and the Netherlands, and may impact treatment decisions going forward, says senior study author Philip Paty, a surgical oncologist at Memorial Sloan Kettering Cancer Center in New York.

“We believe that our results will encourage more doctors to consider this watch and wait approach in patients with clinical complete response as an alternative to immediate rectal surgery, at least for some patients,” says Paty. “From my experience, most patients are willing to accept some risk to defer rectal surgery in hope of avoiding major surgery and preserving rectal function.”

The review analyzed 442 patients beginning in 2006, when NOM was first used for the treatment of select rectal cancers at Memorial Sloan Kettering, and ending in 2013. Of these patients, rectal surgery was deferred in 73 who experienced a clinical complete response (cCR) after radiation and chemotherapy. A comparison group was formed from 72 patients that underwent standard rectal surgery and experienced a pathologic complete response (pCR).

Patients in both groups were treated concurrently along the same time frame with a median follow-up of 3.5 years.

Among the 73 NOM patients, 54 experienced durable tumor regression and avoided rectal surgery, while 19 later underwent rectal surgery to treat tumor regrowth. However, this regrowth proved to be manageable and was successfully resected. Of the 19 NOM patients with tumor regrowth, two were salvaged successfully with local excision resulting in rectal preservation. The remaining 17 patients underwent rectal resections.

The four-year overall survival rate was 91 percent in the NOM group compared with 95 percent in the standard-surgery group. There were six deaths due to cancer in the NOM group and four in the standard-surgery group. The differences in these results were not statistically significant.

The number of distant recurrences between the two groups was also similar. This data suggests that NOM does not compromise outcomes, and that preservation of the rectum is achieved in a majority of patients. A statistical different was not seen for disease-specific survival between the two arms.

A prospective phase 2 study has recently begun enrolling patients at 20 institutions across the United States, and non-surgical management will be offered to patients whose tumors fully disappear after initial chemotherapy and radiation. Candidates for NOM include the about 40 percent to 50 percent of patients with stage 1 rectal cancer and 30 percent to 40 percent of patients with stage 2-3 cancer, whose tumors disappear clinically after initial treatment with chemo-radiation and systemic chemotherapy.

Patients undergoing the “watch and wait” approach are followed at three- to four-month intervals by digital rectal and endoscopic exams and at six-month intervals by cross-sectional imaging.

“Avoiding surgery has the potential to significantly improve quality of life for patients, for example by avoiding a colostomy," says Smitha Krishnamurthi, the moderator of the press conference and a medical oncologist and associate professor of medicine at University Hospitals Case Medical Center and Case Western Reserve University. "Longer follow-up is needed, however, to be sure that this approach does not result in higher cancer recurrences. A prospective study in the United States evaluating this important issue is now enrolling patients."