Author: By Lynda Williams, Senior medwireNews Reporter
medwireNews: Adopting a systematic approach of second-look surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) does not extend disease-free survival (DFS) for patients at high risk of colorectal peritoneal metastases compared with conventional surveillance, indicate phase III trial results.
The PROPHYLOCHIP–PRODIGE 15 investigators now believe that “essential surveillance of patients at high risk of developing colorectal peritoneal metastases appears to be adequate and effective in terms of survival outcomes.”
The open-label study included 150 patients who had undergone resection of a primary colorectal cancer and had resection of synchronous and localised peritoneal or ovarian metastases, or had a perforated tumour.
After a median 50.8 months of follow-up, 3-year DFS was achieved by 44% of the 75 patients who underwent laparotomy with complete exploration of the abdominal cavity, with intravenous fluorouracil 400 mg/m2 plus leucovorin 20 mg/m² and HIPEC consisting of oxaliplatin 460 mg/m2 or oxaliplatin 300 mg/m2 plus irinotecan 200 mg/m2.
These patients then underwent systematic surveillance consisting of a physical examination, CT scan and blood tumour marker analysis every 3 months for the 3 first years of follow-up, and then at 6-month intervals for the subsequent 2 years.
Three-year DFS was also achieved by a comparable 53% of the 75 patients randomly assigned to receive only the standard surveillance after their initial surgery.
Overall survival was also similar between the second-look surgery plus HIPEC and surveillance only groups after 3 years (79 vs 80%) or 5 years (68 vs 72%) of follow-up, report Diane Goéré, from University Hospital Saint-Louis in Paris, France, and co-workers.
Second-look surgery resulted in 16 colonic, 13 small bowel, nine rectal and two wedge liver resections, as well as eight oophorectomies, four hysterectomies, and single cases of splenectomy and atypical gastrectomy. A further 34 patients required colorectal, ileocolic or ileo-ileal reconstructions, and five patients had ureteral anastomoses.
But while 37 of the 71 surgical patients were diagnosed with macroscopic peritoneal metastases, definitive histology confirmed this diagnosis in just 26 patients.
Major postoperative complications occurred in 41% of the second-look surgery patients, with the most common grade 3–4 adverse events being intra-abdominal complications (17%), including further surgery in eight cases, and haematological toxicity (18%).
“The main point highlighted by this study for the clinical setting lies in identifying the patients at risk of colorectal peritoneal metastases in order to properly monitor them and to diagnose peritoneal recurrence at an early enough stage to propose a complete surgical resection”, Diane Goéré and co-authors write in The Lancet Oncology.
They suggest: “New and alternative strategies—which could include early second-look surgery, other protocols of HIPEC, or reinforced surveillance including new imaging—should now be evaluated.”
Reference
Goéré D, Glehen O, Quenet F, et al. Second-look surgery plus hyperthermic intraperitoneal chemotherapy versus surveillance in patients at high risk of developing colorectal peritoneal metastases (PROPHYLOCHIP–PRODIGE 15): a randomised, phase 3 study. Lancet Oncol; Advance online publication 24 July 2020. DOI: 10.1016/S1470-2045(20)30322-3
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