Is Primary Tumor Resection Beneficial in Stage IV CRC?

TOPLINE:

Resecting the primary colon tumor before chemotherapy does not improve overall survival compared with chemotherapy alone in patients with metastatic colon cancer not amenable to curative therapy, new data showed.

METHODOLOGY:

Chemotherapy is the primary treatment in patients with stage IV colorectal cancer (CRC) and unresectable metastases. It’s unclear whether primary tumor resection before chemotherapy prolongs survival.Among 393 patients with stage IV colon cancer and unresectable metastases enrolled in the SYNCHRONOUS and CCRe-IV trials, 187 were randomly allocated to undergo primary tumor resection and 206 to upfront chemotherapy.The chemotherapy regimen was left up to the treating physician. Overall survival was the primary endpoint. Median follow-up time was 36.7 months.

TAKEAWAY:

Median overall survival was 16.7 months with primary tumor resection and 18.6 months with upfront chemotherapy (P=.191).Comparable overall survival between the study groups was further confirmed on multivariate analysis (hazard ratio, 0.944; P=.65) and across all subgroups.Serious adverse events were more common with upfront chemo than surgery (18% vs 10%; P=.027), due mainly to a significantly higher incidence of GI-related events (11% vs 5%; P=.031).Overall, 24% of the primary tumor resection group did not receive any chemotherapy.

IN PRACTICE:

“The results of our study provide compelling data that upfront primary tumor resection in treatment-naive stage IV CRC not amenable for curative treatment does not prolong [overall survival]. A relatively low incidence of serious adverse events in patients with an intact primary tumor together with a considerable number of patients who did not receive any chemotherapy in the primary tumor resection group provides further arguments against resection of the primary tumor in this group of patients,” the authors of the combined analysis concluded.

SOURCE:

The study, with first author Nuh N. Rahbari, MD, University of Ulm, Ulm, Germany, was published online on February 27 in the Journal of Clinical Oncology.

LIMITATIONS:

Neither study completed their planned patient accrual. Although both trials are nearly identical, differences in the individual study cohorts and trial implementation could have introduced bias. Tumor molecular profiling was not performed.