Lower serum CA125 level, negative vascular invasion, and wild BRAF were strongly associated with better 2-year disease-free survival in patients with stage III colorectal cancer who received adjuvant chemotherapy.

BACKGROUND

Adjuvant chemotherapy plays important role in the comprehensive treatment of patients with stage III colorectal cancer. However, there is few molecular markers for predicting the therapeutic effect.

OBJECTIVE

To identify factors that could predict adjuvant chemotherapy benefits in patients with stage III colorectal cancer.

METHODS

The medical records of 294 patients were reviewed and analyzed using the Kaplan-Meier method and Cox analysis.

RESULTS

Lower CA125 (⩽ 35 u/ml, P= 0.0015) serum levels, stage IIIa (P= 0.0027), 1-3 positive lymph nodes (P= 0.0256), negative vascular invasion (P= 0.0215), lower CA199 (⩽ 27 u/ml, P= 0.0038) serum levels, and wild-type BRAF status (P= 0.0125) were significantly associated with a higher 2-year DFS rate in patients with stage III colorectal cancer. However, in multivariate COX analysis, the association remained significant only for CA125 levels (vs. ⩽ 35 u/ml group, HR 3.341; 95% CI, 1.198-9.316; P= 0.0212), vascular invasion (vs. negative vascular invasion, HR, 2.349; 95% CI, 1.227-4.499; P= 0.01), and BRAF (V600E) (vs. wild Braf, HR, 7.794; 95% CI, 1.867-32.531; P= 0.0049).

CONCLUSION

Lower CA125 serum levels, negative vascular invasion, and wild-type BRAF status were significantly associated with improved 2-year DFS rates among patient with stage III disease who received adjuvant chemotherapy.