Synchronous Advanced Colorectal Neoplasia: Clinicopathologic Features and Prognostic Significance.

Objective: This study aimed to compare the clinico-pathologic features, recurrence rate and disease-free survival between colorectal cancers (CRCs) with synchronous advanced colorectal neoplasia (SCN) and solitary CRCs to determine the prognostic significance of SCN.

Methods: A retrospective review of prospectively collected data of patients with CRCs was conducted in Phramongkutklao Hospital from January 2009 to December 2014. Patients were categorized in 3 groups: 1) solitary CRCs, 2) CRCs with advanced colorectal adenomas (ACAs) but having no another cancer and 3) synchronous colorectal cancers (S-CRCs) with or without ACAs. Patients undergoing curative resection and complete standard adjuvant treatment were recruited to evaluate the prognostic significance of SCN.  Clinicopathologic features, recurrence rate and disease-free survival were analyzed to compare among different groups.  Result: Among 328 recruited patients, 282 were classified as solitary CRCs (86%), 23 as CRCs with ACAs (7%) and 23 as S-CRCs (7%). Patients with CRCs with SCN (groups 2 and 3) were significantly older than patients with solitary CRCs (p <0.01), and SCN was found more commonly among males (15.2%) than females (12.3%) (p=0.045). In all, 288 patients achieved a curative resection and accomplished complete standard postoperative adjuvant treatment. Of these, the accumulative number of patients experiencing tumor recurrence was 11.8, 21.2, 24.6, 26.4 and 26.7% at the 1-, 3-, 5-, 7- and 10-year surveillance period, respectively. The disease-free survival of the groups with SCN was marginally higher than that of solitary CRCs groups (p=0.72) (solitary CRCs, 120.7±4.4 months; CRCs/ACAs, 127.4±13.9 months and S-CRCs: 126.2±13.6 months).

Conclusion: CRCs with SCN were found at a more advanced age than those with solitary CRCs. SCN was found more often among males than females. After achieving curative resection and complete adjuvant treatment, the recurrence rate and disease-free survival of CRCs with SCN did not significantly differ from those of solitary CRCs.