Synchronous colorectal carcinoma: a risk factor in colorectal cancer surgery.

Background: Synchronous colorectal carcinoma occurs in 1% to 8% of cases. There are little data on the impact of synchronous colorectal cancer on surgical treatment and short-term postoperative outcomes.

Objective: The purpose of this work was to evaluate clinical characteristics and treatment patterns of synchronous colorectal carcinoma and their influence on short-term postoperative outcomes in comparison with solitary colorectal carcinoma.

Design: This was a population-based observational study. Patient and tumor characteristics, treatment patterns, and postoperative outcomes are described for patients with a solitary and synchronous colorectal carcinoma separately. Multivariable logistic regression analysis was used to analyze the association between synchronous colorectal carcinoma and postoperative complications in comparison with a solitary colorectal carcinoma.

Settings: The study included in-hospital registration for the Dutch Surgical Colorectal Audit.

Patients: Patients were those with primary colorectal carcinoma from 2009 to 2011.

Main Outcome Measures: Severe postoperative complications, reinterventions, and 30-day mortality were measured.

Results: Of 25,413 patients with colorectal cancer, 884 (3.5%) had synchronous colorectal tumors. Patients with synchronous colorectal carcinoma were older and more often of male sex compared with patients with solitary colorectal carcinoma. In ≥ 35% of cases, an extended surgical procedure was conducted (n = 310). In multivariable logistic regression analysis, synchronous colorectal carcinoma was associated with a higher risk of severe postoperative complications (OR, 1.40; 95% CI, 1.20-1.63) and reinterventions (OR, 1.37; 95% CI, 1.14-1.65) compared with solitary colorectal carcinoma but not with higher 30-day mortality (OR, 1.34; 95% CI, 0.96-1.88).

Limitations: This study was limited by the data being self-reported. Case-mix adjustment was limited to information available in the data set, and no long-term outcome data were available.

Conclusions: Synchronous colorectal carcinomas are prevalent in 3.5% of patients and require a different treatment strategy in comparison with solitary colorectal carcinoma. Postoperative outcomes are unfavorable, most likely because of extensive surgery.