Clinical features, surgical treatment strategy, and feasibility of minimally invasive surgery for synchronous and metachronous multiple colorectal cancers: A 14-year single-center experience

Background: Patients with a history of colorectal cancer (CRC) are at increased risk of developing secondary synchronous/metachronous CRCs. The role of minimally invasive surgery (MIS) for multiple CRCs remains unclear. This study aimed to evaluate the short-term outcomes of MIS in patients with multiple CRCs and elucidate their clinical characteristics. Methods: This retrospective study reviewed CRC patients who underwent MIS between 2010 and 2023. Multiple CRC cases were categorized into synchronous and metachronous cohorts. Demographics, pathological findings, and perioperative outcomes were analyzed. Propensity score matching (PSM) analysis was performed as appropriate. Results: A total of 1,272 patients met the inclusion criteria, with 99 (7.8%) having multiple CRCs (75 synchronous and 24 metachronous). Multiple CRC patients had a higher prevalence of strong family history (8.1% vs. 1.0%, P < 0.001) and right-sided colon cancer (55.6% vs. 34.4%, P < 0.001) compared to solitary CRC patients. MSI-high/MMR-deficient status, including Lynch syndrome, was frequently observed among patients with multiple CRCs. Synchronous CRCs requiring double-anastomosis were associated with longer operation times (P = 0.03) and increased blood loss (P = 0.03) compared to those with a single-anastomosis. In the metachronous cohort, repeat operation patterns were categorized based on tumor location and sacrificed arteries. Preservation of the left-colic artery avoided extended colectomy in some patients. Patients with multiple CRC involving rectal cancer had a higher anastomotic leakage (AL) rate (17.6% vs. 5.7%, P < 0.01); however, this difference in AL rate disappeared after PSM (8.8% vs. 8.8%, P = 1.0). In patients with multiple CRCs, AL has not been observed ever since the indocyanine green fluorescence imaging was implemented. Conclusions: MIS is feasible for multiple CRCs, with perioperative outcomes comparable to those for solitary CRCs. Preservation of critical arteries may benefit patients at high risk of secondary CRCs, particularly those with a strong family history of CRC, right-sided tumors, or MSI-high/MMR-deficient profiles, including Lynch syndrome. Graphical abstract: (Figure presented.)