CHICAGO -- A classical form of chemotherapy, used in conjunction with surgery for a rare tumor of the abdomen, does not yield better outcomes than surgery alone, researchers reported.
In a randomized trial, surgery and hyperthermic peritoneal chemotherapy, or HIPEC, offered no survival benefit compared with surgery alone for peritoneal carcinomatosis associated with colorectal cancer, according to François Quenet, MD, of the Regional Cancer Institute in Montpellier, France, and colleagues.
The procedure, using oxaliplatin (Eloxatin) heated to 43°C (about 109°F), also did not extend the time to disease progression, Quenet told reporters here at the (ASCO) annual meeting.
The side effects were similar for the first 30 days after the procedure, he said, but by 60 days patients who got the chemotherapy had significantly more complications, including such things as pulmonary infections.
The study suggests that doctors can "do less for patients with less toxicity," Quenet told ľֱ. But he added that the study really applies only to HIPEC with oxaliplatin, which is the "classical" approach. Other drugs used for the procedure, such as mitomycin C, might still provide a benefit, he said.
The findings "generally argue against the use of HIPEC," Wafik El-Deiry, MD, PhD, of Fox Chase Cancer Center in Philadelphia, who was not involved with the study, told ľֱ.
But he noted that the study leaves some wiggle room: "It remains unclear if subsets of patient might benefit from HIPEC," and the influence of tumor biology and sidedness has not been pinned down.
Finally, he said, other chemotherapy drugs might have a different effect.
The finding should rule out "off-trial" use of HIPEC for peritoneal carcinomatosis associated with colorectal cancer, commented Andrew Epstein, MD, of Memorial Sloan Kettering Cancer Center in New York City, an ASCO-designated expert.
In that disease, he told ľֱ, the procedure should be used only in a clinical trial for a "careful rationally based study" of open questions. Peritoneal carcinomatosis can arise in conjunction with other primary tumors, such as ovarian cancer, where there is other data, he noted, adding that there is no reason to think that outcomes might be different with mitomycin C.
Untreated, peritoneal carcinomatosis associated with colorectal cancer is usually fatal within 6 months, Quenet said.
He explained that the use of surgery when possible and HIPEC with oxaliplatin has for years been considered either the standard of care or an acceptable option in many countries, yielding a survival time of about 40 months and cure for about 16% of patients.
But the procedure had never been tested in a randomized fashion, so Quenet and colleagues enrolled 265 patients from 17 centers in France and randomly assigned them to surgery alone or with HIPEC.
Quenet noted that surgical experience plays a role in outcomes, and most of the patients in the study came from centers with highly experienced surgeons and a high volume of the procedures.
Postoperatively, about 1.5% of patients in each arm of the study died within 30 days, and there was no difference in the rate of other complications early on.
Median survival was 41.7 months for the HIPEC patients and 41.2 months for those who had only surgery, with median 1-year survival rates of 86.9% and 88.3% respectively. Median recurrence-free survival was 13.1 months for HIPEC patients and 11.1 months for those who had surgery only, with 1-year rates of 59% and 46.1%, respectively.
Quenet said an exploratory subgroup analysis suggested that patients with a medium disease burden in the peritoneal cavity might have a benefit from HIPEC with oxaliplatin.
In HIPEC, the chemotherapy drug is heated because early evidence in animal studies suggested it intensified the effect, he explained, adding, however, that "the evidence is not so strong."
The procedure is often used in the U.S. but is not without its detractors, commented Richard Schilsky, MD, ASCO's chief medical officer. "There are surgeons in the U.S. who are fervent believers in HIPEC, and there are others who are true skeptics."
Disclosures
The study had support from UNICANCER, an academic collaboration in France.
Quenet reported relationships with Sanofi/Aventis, Novartis, Ethicon, and Gamida Cell.
Primary Source
ASCO 29018
Quenet F, et al "A UNICANCER phase III trial of hyperthermic intra-peritoneal chemotherapy (HIPEC) for colorectal peritoneal carcinomatosis (PC): PRODIGE 7" ASCO 2018; Abstract LBA3503.