Adjuvant treatment of stage II colon cancer: is there a true no-chemotherapy group?

Elevated preoperative carcinoembryonic antigen (CEA) and Ki67 is predictor of decreased survival in IIA stage colon cancer

BACKGROUND

The present study was designed to investigate the prognostic factors of stage IIA (pT3N0M0) colon cancer.

METHODS

We retrospectively reviewed consecutive patients with stage IIA colon cancer treated with curative surgery alone from January 2004 to June 2008 in Peking University Cancer Hospital. Patient demographics, and clinical, histopathologic, and laboratory data were analyzed. Univariate and multivariate analyses were carried out to identify prognostic factors associated with 3-year disease-free survival (DFS).

RESULTS

For the 84 valid cases reviewed in this study, the 3-year DFS was 88.1 %. That for a group with elevated CEA was 77.1 % and for a group with a normal CEA level, it was 95.9 %, with statistical difference (p = 0.007). Multivariate analysis demonstrated that CEA level (p = 0.012, OR = 8.013, 1.573-40.817), expression of Ki67 (p = 0.099, OR = 3.298, 0.799-3.610), male gender (p = 0.024, OR = 7.212, 1.293-40.237), and anemia (p = 0.011, OR = 6.461, 1.537-27.151) were the independent prognostic factors for 3-year DFS. Stratified analysis revealed that an elevated CEA level combined with high expression of Ki67 was associated with poorer prognosis (3-year DFS 70 %).

CONCLUSIONS

An elevated preoperative serum level of CEA and high expression of Ki67 in tumor tissue were predictors of poor prognosis for patients with stage IIA colon cancer. These patients should therefore be considered candidates for receiving intensive surveillance. Future clinical trials using multicenter patient cohorts should be prospectively performed to evaluate whether these high-risk patients could benefit from adjuvant chemotherapy to improve prognosis.