Significance of CEA and CA19-9 combination as a prognostic indicator and for recurrence monitoring in patients with stage II colorectal cancer

BACKGROUND

The purpose of this study was to evaluate the significance of the combination of the carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels as a prognostic indicator and for monitoring for recurrence and metastasis after potentially curative surgery for patients with stage II colorectal cancer.

PATIENTS AND METHODS

A total of 238 patients with stage II colorectal cancer who underwent potentially curative surgery were enrolled in the study. A high CEA level was defined as a level exceeding 5 ng/ml and a high CA19-9 level was defined as a level exceeding 37 U/ml.

RESULTS

Out of these 238 patients, 92 (38.7%) patients had high CEA levels, 23 (9.7%) patients had high CA19-9 levels and 15 (6.3%) patients had both high CEA and CA19-9 levels. The disease-free and overall survival rates were significantly worse in patients with both a high CEA level and high CA19-9 level. Tumor marker(s) elevated before the operation tended to be elevated again at the time of relapse.

CONCLUSION

The combination of preoperative CEA and CA19-9 levels was useful for predicting the prognosis and for monitoring recurrence and metastasis after potentially curative surgery in patents with stage II colorectal cancer.

EMVI-positive stage II rectal cancer has similar clinical outcomes as stage III disease following pre-operative chemoradiotherapy

BACKGROUND

Stage II rectal cancers comprise a heterogeneous group, and there is significant variability in practise with regards to adjuvant chemotherapy; the survival benefit of chemotherapy is perceived to be <4% in these patients. However, in recent years, the emergence of additional prognostic factors such as extramural venous invasion (EMVI) suggests that there may be sub-stratification of stage II tumours and, further, we may be under-estimating the benefit adjuvant chemotherapy provides in high-risk patients. This study examined the outcomes of patients with stage II and III rectal cancer to determine whether EMVI status influences disease-free survival (DFS).

PATIENTS AND METHODS

An analysis of a prospectively maintained database was conducted of patients presenting with rectal cancer between 2006 and 2012. All patients underwent curative surgery and had no evidence of metastases at presentation. Clinicopathological factors were compared between stage II and III disease. The primary end point was 3-year DFS; univariate and multivariate analysis was carried out using Cox proportional hazards regression models; hazard ratios (HR) with 95% confidence intervals (CIs) were calculated.

RESULTS

Four hundred and seventy-eight patients were included: 233 stage II; 245 stage III. The prevalence of EMVI was 34.9%; 57 stage II patients (24.5%) and 110 stage III patients (44.9%). On multivariate analysis, only EMVI status was a significant factor for DFS. The adjusted HR for EMVI either alone or in combination with nodal involvement was 2.08 (95% CI 1.10-2.95) and 2.74 (95% CI 1.66-4.52), respectively.

CONCLUSION

EMVI is an independently poor prognostic factor for DFS for both stage II and stage III rectal cancer. These results demonstrate that there is risk-stratification within stage II tumours which affects prognosis. When discussing the use of adjuvant chemotherapy with patients that have EMVI-positive stage II tumours, these results provide evidence for a similarly increased risk of distant failure as stage III disease without venous invasion.

Cost-effectiveness of adjuvant FOLFOX and 5FU/LV chemotherapy for patients with stage II colon cancer

PURPOSE

We evaluated the cost-effectiveness of adjuvant chemotherapy using 5-fluorouracil, leucovorin (5FU/LV), and oxaliplatin (FOLFOX) compared with 5FU/LV alone and 5FU/LV compared with observation alone for patients who had resected stage II colon cancer.

METHODS

We developed 2 Markov models to represent the adjuvant chemotherapy and follow-up periods and a single Markov model to represent the observation group. We used calibration to estimate the transition probabilities among different toxicity levels. The base case considered 60-year-old patients who had undergone an uncomplicated hemicolectomy for stage II colon cancer and were medically fit to receive 6 months of adjuvant chemotherapy. We measured health outcomes in quality-adjusted life-years (QALYs) and estimated costs using 2007 US dollars.

RESULTS

In the base case, adjuvant chemotherapy of the FOLFOX regimen had an incremental cost-effectiveness ratio (ICER) of $54,359/QALY compared with the 5FU/LV regimen, and the 5FU/LV regimen had an ICER of $14,584/QALY compared with the observation group from the third-party payer perspective. The ICER values were most sensitive to 5-year relapse probability, cost of adjuvant chemotherapy, and the discount rate for the FOLFOX arm, whereas the ICER value of 5FU/LV was most sensitive to the 5-year relapse probability, 5-year survival probability, and the relapse cost. The probabilistic sensitivity analysis indicates that the ICER of 5FU/LV is less than $50,000/QALY with a probability of 99.62%, and the ICER of FOLFOX as compared with 5FU/LV is less than $50,000/QALY and $100,000/QALY with a probability of 44.48% and 97.24%, respectively.

CONCLUSION

Although adjuvant chemotherapy with 5FU/LV is cost-effective at all ages for patients who have undergone an uncomplicated hemicolectomy for stage II colon cancer, FOLFOX is not likely to be cost-effective as compared with 5FU/LV.