Background and Aims

The recent description of “invasive” forms of intramucosal carcinoma (IMC) has rekindled interest in studying the characteristics, management, and prognosis of IMCs and comparing them with T1 colorectal cancers (CRCs).

Methods

This population-based study included 282 cases of IMC and 207 cases of T1 CRC diagnosed by colonoscopy after a positive fecal blood test through a screening program.

Results

IMC presented mainly in the form of pedunculated polyps (68.4%) located in the distal colon (69.9%) ≥20 mm in size (60.6%). IMCs were resected endoscopically in 227 (80.5%) patients and surgically resected in 55 (19.5%) patients. Surgical patients had more right-sided, more sessile, and larger lesions. There was no sign of lymphovascular invasion. Compared with T1 CRCs, IMCs demonstrated lower rates of sessile polyps (31.6% vs 49.8%, P < .0001), primary and ultimate surgical treatment (19.5% vs 39.1% and 19.9% vs 78.7%, P < .0001, respectively), lymph node metastasis in surgical patients (0% vs 9.5%, P = .041), cancer recurrence and cancer-related mortality (0% vs 5.6% and 0% vs 2.5%, respectively), and bleeding after endoscopic resection (1.8% vs 8.7%, P = .001). By multivariate analysis of the pooled cohort (IMC + T1 CRC, n = 489), the factors significantly associated with first-line surgery were shown to be polyp characteristics and the gastroenterologist who performed the colonoscopy.

Conclusions

IMCs account for a quarter of all screening-detected CRCs. They have an excellent prognosis regardless of whether endoscopic or surgical treatment is performed. IMCs differ significantly from T1 carcinomas in terms of management and prognosis.

中文翻译：

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重新评估粘膜内结直肠癌的特征，治疗和预后以及与T1癌的比较。

背景和目标

对黏膜内癌（IMC）的“侵入性”形式的最新描述引起了人们对研究IMC的特征，治疗和预后并将其与T1大肠癌（CRC）进行比较的兴趣。

方法

这项基于人群的研究包括282例IMC和207例T1 CRC，这些患者是通过筛查程序在粪便血液检查呈阳性后通过结肠镜检查诊断的。

结果

IMC主要表现为位于远端结肠（69.9％）≥20 mm（60.6％）的带蒂息肉（68.4％）。在227例（80.5％）内镜下切除IMC，在55例（19.5％）内通过手术切除。手术患者的右侧较多，无梗且病变较大。没有淋巴管浸润的迹象。与T1 CRC相比，IMC的无蒂息肉发生率（分别为31.6％和49.8％，P  <.0001），初次和终极手术治疗的发生率更低（分别为19.5％，39.1％和19.9％vs 78.7％，P  <.0001） ，外科手术患者的淋巴结转移（0％比9.5％，P  = .041），癌症复发和与癌症相关的死亡率（分别为0％比5.6％和0％比2.5％）以及内窥镜切除术后出血（1.8） ％对8.7％，P  = 0.001）。通过对合并队列的多变量分析（IMC + T1 CRC，n = 489），与一线手术显着相关的因素显示为息肉特征和进行结肠镜检查的肠胃病学家。

结论

IMC占所有筛查检测到的CRC的四分之一。无论是否进行内镜或外科治疗，它们的预后都很好。在管理和预后方面，IMC与T1癌有显着差异。