Objective: To explore the expression of mismatch repair (MMR) proteins in sporadic colorectal cancer (SCRC) patients, and its association with clinicopathological characteristics of SCRC. Methods: Patients with histologically confirmed colorectal cancer were consecutively recruited between December 2011 and June 2015 at Sun Yat-sen University Cancer Center. The exclusion criteria included multiple primary colorectal tumors, hereditary colorectal cancer (including Lynch syndrome, familial adenomatous polyposis), and the patients without the MMR proteins status tested. A total of 2 684 patients were included. Correlations of MMR proteins status and patients' demographics (including gender, age), tumor characteristics (site and differentiation) and TNM staging (excluding 315 SCRC patients receiving neoadjuvant therapy) were investigated. Results: The percentage of deficient MMR (dMMR) in these SCRC patients was 10.2%, and that of proficient MMR (pMMR) was 89.8%. The dMMR was more likely to be detected in younger (≤59 old years) SCRC patients compared to the elderly (>59 years) [12.7%(179/1 406)vs 7.5%(96/1 278), P<0.001]. The dMMR rate in right colon cancer was significantly higher than that in left colon cancer and rectal cancer [22.7%(151/664)vs 7.2%(69/956)vs 5.2%(55/1 064), P<0.001]. Among the various pathological types of SCRC, mucinous adenocarcinoma showed the highest rate of dMMR (24.4%), and neuroendocrine carcinoma the lowest rate of dMMR (0) (P<0.001). In addition, the proportions of dMMR in stage Ⅰ, stage Ⅱ, stage Ⅲ and stage Ⅳ SCRC were 9.7%, 16.5%, 8.5%, and 3.9%, respectively (P<0.001). There is no significant difference in the proportion of dMMR between male and female (11.0% vs 9.1%, P=0.114). Conclusion: dMMR status may be most likely to exist in younger (≤59 years) patients with stage Ⅱ right colon mucinous adenocarcinoma among SCRC.
目的： 分析散发性结直肠癌(SCRC)错配修复(MMR)蛋白表达的流行病学特征，并进一步探讨其与临床病理特征的关系。 方法： 收集中山大学肿瘤防治中心自2011年12月至2015年6月进行手术并经病理确诊的结直肠癌(CRC)患者临床资料进行回顾性分析，排除遗传性肠癌(Lynch综合征、家族性腺瘤性息肉病等)、多原发大肠癌和未检测MMR蛋白表达状态的患者。符合标准的SCRC患者共2 684例，统计其性别、年龄、肿瘤部位、肿瘤分化程度、TNM分期(排除315例接受新辅助放化疗的SCRC患者)和MMR蛋白表达情况，并进一步分析MMR蛋白表达状态与SCRC临床病理特征的关系。 结果： 2 684例SCRC中，MMR蛋白缺失(dMMR)与MMR蛋白表达(pMMR)的比例分别为10.2%和89.8%。老年人(>59岁)和非老年人(≤59岁)SCRC的dMMR比例差异存在统计学意义[7.5%(96/1 278)比12.7%(179/1 406)，P<0.001]。右半结肠癌与左半结肠癌和直肠癌相比，dMMR的比例显著较高，差异有统计学意义[22.7%(151/664)比7.2%(69/956)比5.2%(55/1 064)，P<0.001]；在不同病理类型SCRC中，黏液腺癌的dMMR比例最高(24.4%)，神经内分泌癌dMMR比例最低(0)，差异有统计学意义(P<0.001)；在各分期中，Ⅱ期肠癌dMMR比例最高(16.5%)，Ⅰ期、Ⅲ期、Ⅳ期dMMR比例分别为9.7%、8.5%、3.9%，差异也具有统计学意义(P<0.001)；而男、女SCRC患者间的dMMR比例差异无统计学意义(11.0%比9.1%，P＝0.114)。 结论： dMMR高发于非老年(≤59岁)的Ⅱ期散发性右半结肠黏液腺癌患者。.
Keywords: Clinicopathological characteristics; Colorectal neoplasms; DNA mismatch repair.