Predictive factors for distant recurrence of colorectal cancer in patients after curative resection for stage I-III colorectal cancer in Australia.

Purpose: Distant recurrence is a devastating occurrence after colorectal cancer resection. This study aimed to identify the risk factors for distant recurrence following surgery.

Methods: All consecutive colorectal cancer resections with curative intent were included from a prospectively maintained colorectal cancer database. The primary outcome was to identify predictive factors for distant recurrence of colorectal cancer.

Results: A total of 670 eligible cases were identified with 88 (13.1%) developing distant recurrence during the follow-up period. The median time to distant recurrence was 1.2 years with the most common sites of distant recurrence being the lung (44.3%) and liver (44.3%). Predictive factors for distant recurrence in colon cancer included a high tumor, nodal, and overall stage of the primary cancer (p < 0.001 for all). Surgical complications (p = 0.007), including anastomotic leak (p = 0.023), were associated with a higher risk of developing distant recurrence in rectal cancer patients. Independent variables associated with distant recurrence included tumor stage (OR 1.61, p = 0.011), nodal stage (OR 2.18, p < 0.001), and both KRAS (OR 11.04, p < 0.001) and MLH/PMS2 (OR 0.20, p = 0.035) genetic mutations. Among patients with distant recurrence, treatment with surgery conferred the best survival, with patients < 50 years of age having the best overall 5-year survival.

Conclusion: Predictive factors for distant recurrence include advanced tumor and nodal stages, and the presence of KRAS and MLH/PSM2 mutations. Clinicians should be cognizant of these risk factors, and instate close surveillance plans for patients exhibiting these features.