miR‑106b‑5p in stage II left‑sided and right‑sided colon cancer and its association with the prognostic characteristics of patients

MicroRNA (miR)-106b-5p is highly expressed in colon cancer; however, data on its expression levels in left-sided colon cancer (LCC) vs. right-sided colon cancer (RCC) is lacking. The present study aimed to assess the differences in miR-106b-5p expression in stage II LCC and RCC, as well as its relationship with patient prognosis. From August 2018 to February 2020, 40 specimens of primary stage II colon cancer were collected from Huizhou First Hospital (Huizhou, China), which included 20 cases of LCC and 20 cases of RCC. The miR-106b-5p expression levels in cancer tissues were compared with normal adjacent tissues, as well as between LCC and RCC tissues, and survival outcomes were assessed. miR-106b-5p expression was significantly higher in stage II LCC tissues compared with RCC tissues. However, no significant difference in 5-year survival was observed between the two groups. Notably, 5-year survival was significantly lower in the high miR-106b-5p expression group compared with the low expression group among patients with RCC. By contrast, there were no survival differences between the high and low miR-106b-5p expression groups in LCC. Multivariate analysis indicated that miR-106b-5p expression was an independent prognostic factor for patients with RCC. In conclusion, miR-106b-5p expression was significantly upregulated in colon cancer tissues, with higher expression levels demonstrated in LCC compared with RCC. High miR-106b-5p expression in RCC was identified as an independent prognostic factor, whilst its expression in LCC did not show a significant association with prognosis.