Purpose

Studies suggest that patients with type two diabetes mellitus (T2D) may be at increased risk of post-colonoscopy colorectal cancer (PCCRC). We investigated clinical and molecular characteristics and survival of T2D patients with PCCRC to elucidate how T2D-related PCCRC may arise.

Methods

We identified T2D patients with colorectal cancer (CRC) from 1995 to 2015 and computed prevalence ratios (PRs) comparing clinical and molecular characteristics of CRC in T2D patients with PCCRC vs. in T2D patients with colonoscopy-detected CRC (dCRC). We also followed T2D patients from the diagnosis of PCCRC/dCRC until death, emigration, or study end and compared mortality using Cox-proportional hazards regression models adjusted for sex, age, year of CRC diagnosis, and CRC stage.

Results

Compared with dCRC, PCCRC was associated with a higher prevalence of proximal CRCs (54% vs. 40%; PR: 1.43, 95% confidence interval [CI] 1.27–1.62) in T2D patients. We found no difference between PCCRC vs. dCRC for CRC stage, histology, and mismatch repair status. The proportion of CRCs that could be categorized as PCCRC decreased over time. Within one year after CRC, 63% of PCCRC vs. 78% of dCRC patients were alive (hazard ratio [HR] 1.85 [95% CI 1.47–2.31]). Within five years after CRC, 44% of PCCRC vs. 54% of dCRC patients were still alive (HR 1.44 [95% CI 1.11–1.87]).

Conclusion

The increased prevalence of proximally located PCCRCs and the poorer survival may suggest overlooked colorectal lesions as a predominant explanation for T2D-related PCCRC, although altered tumor progression cannot be ruled out.

中文翻译：

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2 型糖尿病和结肠镜检查后结直肠癌：临床和分子特征以及生存

目的

研究表明，二型糖尿病 (T2D) 患者患结肠镜检查后结直肠癌 (PCCRC) 的风险可能增加。我们调查了患有 PCCRC 的 T2D 患者的临床和分子特征以及生存情况，以阐明 T2D 相关的 PCCRC 是如何发生的。

方法

我们确定了 1995 年至 2015 年间患有结直肠癌 (CRC) 的 T2D 患者，并计算了患病率 (PR)，比较了患有 PCCRC 的 T2D 患者与患有结肠镜检查检测到的CRC (dCRC) 的 T2D 患者的 CRC 临床和分子特征。我们还跟踪 T2D 患者从 PCCRC/dCRC 诊断到死亡、移民或研究结束，并使用根据性别、年龄、CRC 诊断年份和 CRC 分期进行调整的 Cox 比例风险回归模型比较死亡率。

结果

与 dCRC 相比，T2D 患者中 PCCRC 与近端 CRC 的患病率较高相关（54% vs. 40 %；PR：1.43，95% 置信区间 [CI] 1.27–1.62）。我们发现 PCCRC与dCRC 在 CRC 分期、组织学和错配修复状态方面没有差异。随着时间的推移，可归类为 PCCRC 的 CRC 比例逐渐下降。CRC 发生后一年内，63% 的 PCCRC 患者存活，而 78% 的 dCRC 患者存活（风险比 [HR] 1.85 [95% CI 1.47–2.31]）。CRC 发生后五年内，44% 的 PCCRC 患者仍存活，而 54% 的 dCRC 患者仍存活（HR 1.44 [95% CI 1.11–1.87]）。

结论

尽管不能排除肿瘤进展的改变，但近端 PCCRC 患病率的增加和较差的生存率可能表明被忽视的结直肠病变是 T2D 相关 PCCRC 的主要解释。