Clinical significance of survivin mRNA expression (<i>BIRC5</i>) in colorectal cancer

Abstract

Aim. To evaluate the clinical significance of survivin (BIRC5) mRnA expression in circulating tumor cells (CTCs) and tumor material from colorectal cancer (CRC).Materials and methods. The study was organized according to the principle of a continuous prospective non-randomized study. The expression of survivin (BIRC5) mRnA in CTCs and tumor material was determined using RT-pCR.Results. The study included 130 patients (study group – 109 patients with colorectal cancer and observation group – 21 patients with colon adenomas). All patients underwent complete tumor removal (radical surgery – 93.6 %), cytoreductive – 6.4 %).A high level of survivin (BIRC5) mRnA expression was detected in colorectal adenocarcinoma in comparison with adenomas (pMann–whitney < 0.001) M ± SD (1.678 ± 2.45 and 0.023 ± 0.07). In the study and observation group, the expression of survivin mRnA (BIRC5) in CTCs both before surgery M ± SD (1.175 ± 1.33 and 0.052 ± 0.11) and after 3 months M ± SD (1.015 ± 0.93 and 0.018 ± 0.002) was significantly different (pMann–whitney <0.001).During adjuvant chemotherapy, a decrease in the level of survivin expression in CTCs was observed (p 9 months after surgery, CTCs remain in the bloodstream even despite adjuvant chemotherapy (p = 0.015 and p = 0.012). Overexpression of survivin in CTCs before surgery correlates with damage to regional lymph nodes (p = 0.03, r = 0.21), stage of the tumor process (p = 0.01, r = 0.25), degree of tumor differentiation (p = 0.03, r = 0.21). Overexpression of survivin in CTCs 9 months after surgery significantly affects relapse-free survival HR (95 % CI HR) = 3.1 (95 % CI 1.56–6,08, p = 0.0012) and overall survival of patients HR (95 % CI HR) =6.8 (95 % CI 2.65–17.33, p = 0.0001).Conclusions. Overexpression of survivin mRnA in colorectal cancer is a negative prognosis factor for the disease and directly depends on the tumor involvement of regional lymph nodes, the stage of the disease, degree of tumor differentiation, promoting the development of disease relapse, and can be used to diagnose minimal residual disease (MRD) and assess the prognosis of overall patient survival.