A national evaluation of the use and survival impact of adjuvant chemotherapy in Stage II colon cancer from the national cancer database

Elevated postoperative carcinoembryonic antigen guides adjuvant chemotherapy for stage II colon cancer: a multicentre cohort retrospective study

Most clinical doctors rely on high-risk factors recommended by guidelines to decide whether to undergo adjuvant chemotherapy for stage II colon cancer. However, these high-risk factors do not include postoperative carcinoembryonic antigen (CEA). This study aims to explore the elevation of postoperative CEA as a risk factor, in addition to other high-risk factors, to guide adjuvant chemotherapy for patients with stage II colon cancer. A retrospective analysis was conducted on stage II colon cancer patients who underwent curative surgery at Yunnan Cancer Hospital and The Sixth Affiliated Hospital of Sun Yat-Sen University from April 2008 to January 2019. Patients were classified into three groups based on high-risk factors recommended by guidelines and postoperative CEA levels: low-risk with normal postoperative CEA, low-risk with elevated postoperative CEA and high-risk. COX regression analysis was used to identify independent prognostic factors affecting patients' recurrence free survival (RFS). The Kaplan-Meier method was used to create the patients' RFS curve. The restricted cubic spline (RCS) curve was used to assess the correlation between postoperative CEA and RFS on a continuous scale. Among 761 patients, there were 444 males (62.01%), with a median [IQR] age of 58.0 (18.0-88.0) years. A group of 425 high-risk patients had a 3-year RFS of 82.2% (95% CI 78.5-86.1%), while a group of 291 low-risk patients had a 3-year RFS of 89.7% (95% CI 86.1-93.5%). There was a statistically significant difference between the two groups (HR 1.83; 95% CI 1.22-2.74; P = 0.0067). Among them, the 3-year RFS of 261 low-risk patients with normal postoperative CEA was 93.6% (95% CI 90.5-96.8%), while the 3-year RFS of 30 low-risk patients with elevated postoperative CEA was 57.3% (95% CI 41.8-71.4%). There was a significant difference compared to the 3-year RFS of 425 high-risk patients (overall log-rank P < 0.0001). The multivariate analysis adjusted by the COX proportional hazards model showed that low-risk patients with elevated postoperative CEA patients (HR 14.95, 95% CI 4.51-49.63, P < 0.0001) was independently associated with a 3-year RFS. The restricted cubic spline model showed that in stage II colon cancer patients with tumor diameter > 1.955 ng/mL, the risk of postoperative recurrence increased with increasing postoperative CEA levels. Patients with elevated postoperative CEA levels have a significantly increased risk of recurrence. They should be included as high-risk factors to guide adjuvant chemotherapy for stage II colon cancer.

Adjuvant chemotherapy is associated with improved overall survival in select patients with Stage II colon cancer: A National Cancer Database analysis

BACKGROUND AND OBJECTIVES

Guidelines for Stage II colon cancer recommend adjuvant chemotherapy (AC) only for tumors with high-risk features, but long-term outcomes data are mixed. We aimed to determine if AC was associated with a survival benefit in this population.

METHODS

Patients were identified from the National Cancer Database and included if they met the following criteria: diagnosis of Stage II colon cancer, surgery, survival data, and complete data on six high-risk features. The cohort of 57 335 patients was stratified by receipt of AC. Subgroup analysis was performed on patients under the age of 65 years with no comorbidities. Overall survival (OS) was the primary endpoint.

RESULTS

An increasing number of high-risk features was associated with significantly decreased median OS. AC was associated with significantly increased OS for patients with 0, 1, 2, and ≥3 high-risk features. On subgroup analysis, receipt of AC was associated with a reduced risk of death (hazard ratio: 0.66; confidence interval: 0.59-0.74). For patients in the subgroup who had a T4 tumor, AC was associated with increased OS (92.7 vs. 83.6 months).

CONCLUSIONS

AC should be considered for all younger, healthy patients with Stage II colon cancer and may be associated with a survival benefit for patients with T4 disease.