High-risk Stage II Colorectal Cancers Carry an Equivalent Risk of Peritoneal Recurrence to Stage III.

BACKGROUND/AIM: Several risk factors for recurrence have been identified in stage II colorectal cancer. However, in contrast to stage III, the benefits of adjuvant chemotherapy for these patients remain controversial. We hypothesized that the different impacts of chemotherapy may be due to different patterns of recurrence between these stages. The aim of this study was to characterize recurrence in high-risk stage II colorectal cancer (CRC) in comparison with stage III.

PATIENTS AND METHODS: A total of 442 patients with curatively resected stage III and high-risk stage II CRCs were evaluated. The recurrence site and frequency were compared between these stages. The risk factors of recurrence by site were identified using multivariate analyses.

RESULTS: During the follow-up (median: 6.4 years), 31% of stage III and 13% of high-risk stage II patients manifested recurrence. Recurrence in the liver, lung, and distant lymph nodes was significantly more frequent in stage III (18%, 12%, 11%) than in high-risk stage II (7%, 6%, 3%). Stage III was independently associated with recurrence in these organs. In contrast, the rate of peritoneal recurrence was 5% in both stages.

CONCLUSION: Clinicians should be aware that high-risk stage II CRC has a similar risk of postoperative recurrence in the peritoneum to Stage III CRC.