The expression of THOX2 in colorectal mucinous adenocarcinoma and its relationship with prognosis.

e15529 Background: The role of THOX2 in the occurrence and development of tumors has gradually attracted attention, but there is no study on the expression and function of THOX2 in colorectal mucinous adenocarcinoma (MC). The purpose of this study was to investigate the expression of thyroid oxidase 2 (THOX2) in colorectal MC and its relationship with prognosis. Methods: 30 patients with colorectal adenocarcinoma (AC) and 15 patients with MC were selected from The Fourth hospital of Hebei Medical University from October 1, 2018 to July 1, 2019. They were selected to detect the mRNA and protein levels of THOX2 in the colorectal cancer tissues of the two different pathological types using qRT-PCR and immunohistochemistry (IHC) methods. A total of 109 patients with MC who received surgical treatment between January 1, 2015 and January 1, 2015 were selected. The clinicopathological parameters of the patients were collected and survival follow-up was performed. The expression of THOX2 protein in MC tissues was detected by IHC test, and the differences in the expression of THOX2 protein in different tissues were analyzed by χ2 test. Cox univariate and multivariate analyses were used to investigate the relationship between clinicopathological characteristics, THOX2 protein expression level and DFS and OS in patients with MC. Results: The levels of THOX2 mRNA and protein in 15 cases of MC were significantly higher than those in 30 cases of AC. The high expression of THOX2 protein in MC tissues was closely correlated with tumor site, whether mixed with other pathological types, TNM stage, lymph node metastasis, M stage, and liver metastasis, peritoneal metastasis and other site metastasis occurred in patients after initial treatment. Cox regression analysis of 95 patients' survival data showed that high expression of THOX2, right colon and lymph node metastasis were influential factors for DFS in MC patients, and were independent prognostic factors for predicting DFS in MC patients. The expression of THOX2, lymph node metastasis, liver metastasis after adjuvant therapy and peritoneal metastasis are the influencing factors of OS in MC patients. Lymph node metastasis is an independent prognostic factor for OS in MC patients. Conclusions: The expression of THOX2 in MC was significantly higher than that of AC, and it was related to the malignant biological manifestations of tumor. At the same time, the high expression of THOX2 is associated with short DFS and OS in patients with MC, and may be used as a potential biomarker and efficacy predictor for MC patients.

Surgical Resection for Liver Metastases Developing 10 and 21 Years After Primary Surgery for Mucinous Colon Adenocarcinoma: A Case Report

Optimal management for liver metastases from colorectal mucinous adenocarcinoma is still controversial. Here, we report such a case of liver metastases that developed twice with 10-year intervals after curative resection. An 84-year-old man had undergone a radical left hemicolectomy for descending colon cancer at age 63 years. The histopathologic diagnosis was mucinous adenocarcinoma. Ten years later, he was found to have a cystic tumor in liver and underwent partial hepatectomy of segment 5. Moreover, 10 years after that hepatic resection, computed tomography showed a low-density tumor with calcification in remnant liver, and partial hepatectomy of segment 8 was performed. Histopathologic and immunohistochemical findings of each liver tumor indicated metastasis from primary colon mucinous adenocarcinoma. It is rare for colorectal mucinous adenocarcinoma to recur twice after long intervals of 10 years. However, in a patient with a history of colorectal mucinous adenocarcinoma, possibility of recurrence more than 10 years after curative surgery also must be kept in mind. Long-term clinical follow-up after curative surgery for primary colon cancer or liver metastases may be necessary to detect early signs of recurrence of colorectal mucinous adenocarcinoma.