Prognostic value of B-cell linker protein in colorectal cancer

Abstract

This study aimed to investigate the clinicopathological and prognostic impact of B-cell linker (BLNK) protein expression in colorectal cancer (CRC) as its function in CRC remains unexplored. We performed immunohistochemical staining for BLNK using tissue microarrays of 418 consecutive CRC samples; of these 10 were excluded due to inappropriate staining. The expression intensity and staining level was scored as 0–3 and 0–4, respectively, based on the percentage of positive cells. The immunoreactivity score (IRS) was calculated by multiplying these two scores. BLNK expression was observed in 222 patients (54.4 %). Lymph node metastasis (p = 0.031), right colon cancer (p = 0.026), mucinous adenocarcinoma (p < 0.001), and perineural invasion (p = 0.049) were more frequently observed in the IRS 4–12 group than in the IRS 0–3 group. At the same cutoff point, the 5-year recurrence-free survival rate of the patients with stage III was significantly lower than that observed in IRS 4–12 group (74.8 % ± 4.2 % vs. 54.2 % ± 8.5 %, p = 0.003). Multivariate analysis revealed IRS 4–12 to be an independent risk factor for recurrence (Hazard ratio 2.346, 95 % confidence interval 1.348–4.085, p = 0.003). In conclusion, overexpression of BLNK protein is an independent risk factor for CRC recurrence.