Low levels of BRCA1 protein expression predict a worse prognosis in stage I-II colon cancer.

Background: and have been well studied for their roles in tumorigeneis, plus cancer diagnosis and treatment, but their prognostic value in colon cancer, especially for early-stage cancer, has not been fully illuminated. This study examined the expression levels of BRCA1 and BRCA2 proteins in sporadic colon cancer cases and investigated their value in prognosis.

Methods: The expression levels of and in 275 colon cancer patients who underwent radical surgeries were assayed by immunohistochemical staining in dissected tumor samples. Also, its correlation with clinicopathological characteristics, disease-free survival, and overall survival was investigated.

Results: Tumors with low expression levels of , and both were 19.6%, 17.8%, and 6.5%, respectively. The levels of expression were not associated with clinicopathological parameters (gender, age, histological differentiation, and tumor node metastasis stage). Patients with low-levels of BRCA1 protein in their tumors demonstrated a lower chance of 5-year disease-free survival (55.6% vs. 69.7%, =0.046), which was more obvious in the patients with stage I-II tumors without chemotherapy (52.6% vs. 82.6%, =0.006). Neither BRCA1 nor BRCA2 affected overall survival in this cohort. Multivariate analysis revealed that pathologic stage and the level of BRCA1 protein were independent factors of long-term disease-free survival.

Conclusion: This study highlights BRCA1 as an independent prognosticator of early-stage colon cancer.