Management of T1 colon carcinoma: less is more

Clinicians face dilemmas and challenges in the management of T1 colorectal cancer (CRC), especially for those T1 neoplasms with indeterminate differentiation of submucosal invasion. With the implementation of CRC screening programs across the globe, an increasing number of patients are being diagnosed with early-stage CRC [1]. The strategy selected to achieve curative treatment of T1 colorectal neoplasm depends on the potential for nodal metastasis. The well-defined predictive factors for nodal metastasis include 1) submucosal invasion depth, 2) lymphatic or vascular invasion, 3) poor differentiation, and 4) tumor budding [2]. While numerous studies have reported the correlation of these factors with risk for nodal metastasis, the majority rely on the subsequent pathological analysis.

“… the decision toward a less invasive approach of local resection should not jeopardize the oncological outcomes for patients.”

Endoscopic technologies including image-enhanced endoscopy and endoscopic ultrasound have been applied to differentiate depth of invasion for these early CRCs [3]. Despite the use of these imaging technologies, submucosal invasion remains difficult to predict accurately. Most studies report an accuracy of around 70%–75% in differentiating submucosal invasion using image-enhanced endoscopy. For cases where absolute submucosal invasion cannot be determined, en bloc resection with endoscopic submucosal dissection can be considered as a staging procedure to achieve local resection [4]. Those patients with histopathology after endoscopic submucosal dissection showing high-risk features of incomplete resection should be offered salvage surgery.

Backes et al. reported a cohort study of 877 patients who underwent endoscopic resection for T1 CRC, among whom 40.8% received salvage surgery after incomplete endoscopic resection [5]. After surgery, the histopathology showed that the incomplete resection rate was 0.7% in low-risk T1 CRC compared with 4.4% in high-risk CRC. Moreover, the overall adverse outcome (incomplete resection or metastasis) rate was 2.1% in low-risk T1 CRC vs. 11.7% in high-risk T1 CRC. The study concluded that in the absence of high-risk features, a “wait-and-see” policy can be adopted for those categorized as “incomplete endoscopic resection.”

In this issue of Endoscopy, Hanevelt et al. report on a nationwide cohort study of 9650 patients with T1 CRC from 73 hospital between 2015 and 2022 identified from Netherlands Cancer Registry [6]. The results demonstrate a clear increasing trend toward local resection for treatment of T1 CRC, while no difference was found in the overall and relative survival between hospitals with low or high attitude toward local resection.

National CRC screening was first implemented in the Netherlands in 2014. The target population is men and women aged 55–75 years, who are invited to undergo screening biennially with a fecal immunochemical test. Tose-Zoutendijk et al. reviewed the Netherlands Cancer Registry for all stage 1 CRCs between 2008 and 2020 [7]. Individuals who participated in the screening program had a higher T1 CRC detection rate than those detected in a non-screened group, and the screen-detected T1 CRCs were more likely to be treated with local resection approaches.

One of the important questions is whether local resection for high-risk T1 CRC before surgery could lead to poorer outcomes compared with primary formal surgical resection. In a retrospective cohort study comparing 184 patients treated by endoscopic resection alone and 205 patients with endoscopic resection followed by surgery, those with only deep submucosal invasion as risk factors had a similar recurrence to those treated by endoscopic resection plus surgery [8]. For patients with high-risk factors requiring salvage surgery according to Japanese Society for Cancer of the Colon and Rectum, the cumulative recurrence rate was significantly higher among those treated by endoscopic resection alone (20.1%) compared with those treated with endoscopic resection plus surgery (3.1%).

The trend toward a less invasive approach in the management of CRC can be expected especially with the implementation of CRC screening programs where more cancers can be detected at early stages. The optimal management for those with indeterminate submucosal invasive cancers should be decided in a multi-disciplinary team approach. Meanwhile, the decision toward a less invasive approach of local resection should not jeopardize the oncological outcomes for patients. The ongoing research in early detection and local resection for management of CRC will have a major impact on the recovery as well as the quality of life of our patients.

Publikationsverlauf

Artikel online veröffentlicht:
23. September 2025

• References

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