The following article features coverage from the 2020 Gastrointestinal Cancers Symposium meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.

Results of a prospective evaluation of the risks and benefits of surgical resection of a primary tumor prior to chemotherapy in patients diagnosed with stage IV colorectal cancer characterized by synchronous, unresectable metastases were presented at the 2020 Gastrointestinal Cancers Symposium in San Francisco, California.

Although findings of several retrospective studies have suggested that primary tumor resection prior to treatment with chemotherapy improves overall survival (OS) in patients with unresectable metastases at the time of colorectal cancer diagnosis, no prospective studies have previously investigated this approach.

This question was evaluated in a clinical trial in which patients with asymptomatic, unresectable stage IV colorectal cancer at diagnosis were randomly assigned to receive primary tumor resection followed by chemotherapy (eg, mFOLFOX6 plus bevacizumab and CapeOX plus bevacizumab were options) or chemotherapy alone (UMIN Clinical Trials Registry: UMIN000008147). The primary study endpoint was OS.

Between June 2012 and April 2019, 160 patients were randomly assigned to 1 of 2 treatment arms (78 individuals received surgery plus chemotherapy, and 82 individuals received chemotherapy alone, respectively).

At first interim analysis, which took place once 50% of the expected events occurred, early study termination was recommended by the Data and Safety Monitoring Committee of the Japan Clinical Oncology Group (JCOG) as a result of futility.

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At a median follow-up of 22.0 months, median OS was 25.9 months and 26.7 months for those treated with surgery plus chemotherapy and chemotherapy alone, respectively (hazard ratio [HR], 1.10; 95% CI, 0.76-1.59; one-sided P =.69).

Three deaths occurred in the postoperative period due to surgical complications in patients assigned to the study arm that included primary tumor resection.

The study authors concluded that “primary tumor resection followed by chemotherapy has no survival benefit over chemotherapy alone” and that “primary tumor resection is not recommended for colorectal cancer patients with asymptomatic primary tumor and synchronous unresectable metastases.”

Disclosure: Some of the study authors reported financial relationships with pharmaceutical and medical device companies. For a full list of disclosures, please refer to the study abstract.

Read more of Cancer Therapy Advisor‘s coverage of the ASCO GI annual meeting by visiting the conference page.

Reference

Kanemitsu Y, Shitara K, Mizusawa J, et al. A randomized phase III trial comparing primary tumor resection plus chemotherapy with chemotherapy alone in incurable stage IV colorectal cancer: JCOG1007 study (iPACS). J Clin Oncol. 2020;38(suppl 4):Abstract 7.