New scoring system to distinguish deep invasive submucosal and muscularis propria colorectal cancer during colonoscopy: a development and global multicenter external validation study (e-T2 Score)

Expert assessment of infiltration depth and recommendation of endoscopic resection technique in early Barrett cancer

BACKGROUND

Early Barrett cancer can be curatively treated by endoscopic resection. The choice of the resection technique, however-endoscopic mucosal resection (EMR) or submucosal dissection (ESD)-largely depends on the assumed infiltration depth as judged by the endoscopist. However, the accuracy of endoscopic diagnosis of the degree of cancer infiltration is not known.

METHODS

Three to four high-quality images (both in overview and close-up) from 202 of early Barrett esophagus cancer cases (82% men, mean age 66.9 years) were selected from our endoscopy database (73.3% stage T1a and 26.7% in stage T1b). Images were shown to 9 Barrett esophagus experts, with patients' clinical data (age, sex, Barrett esophagus length) and biopsy results. The experts were asked to predict infiltration depth (T1b vs. T1a), and to suggest the appropriate endoscopic resection technique (EMR or ESD, or surgery). Interobserver variability (kappa values) was also determined for these parameters.

RESULTS

Overall positive (PPV) and negative predictive values (NPV) to diagnose T1b versus T1a infiltration were 40.7% (95% CI: 36.7, 44.8) and 79.8% (95% CI: 77.5, 81.9), respectively; kappa value was 0.41. Paris classification (kappa 0.51) and suggested treatment also varied between experts. In a post hoc analysis, only the correlation between lesions classified as invisible or flat according to the Paris classification (IIB; 25% of all cases) and the suggested resection technique was better: In this subgroup, EMR was recommended in >80% of cases, with a high complete (basal R0) resection rate (mean of 88.1%).

CONCLUSIONS

Precise endoscopic distinction between mucosal and submucosal involvement of Barrett esophagus cancer by experts as a basis for choosing the resection technique has limited predictive values and high interobserver variability. It seems that mainly invisible/flat lesions may result in good resection outcomes when treated by EMR, but this stratification strategy has to be assessed in further studies.

Challenges in Implementing Endoscopic Resection for T2 Colorectal Cancer

The current standard treatment for muscularis propria-invasive (T2) colorectal cancer is surgical colectomy with lymph node dissection. With the advent of new endoscopic resection techniques, such as endoscopic full-thickness resection or endoscopic intermuscular dissection, T2 colorectal cancer, with metastasis to 20%-25% of the dissected lymph nodes, may be the next candidate for endoscopic resection following submucosal-invasive (T1) colorectal cancer. We present a novel endoscopic treatment strategy for T2 colorectal cancer and suggest further study to establish evidence on oncologic and endoscopic technical safety for its clinical implementation.

Limited wedge resection for T1 colon cancer (LIMERIC-II trial) - rationale and study protocol of a prospective multicenter clinical trial

BACKGROUND

The sole presence of deep submucosal invasion is shown to be associated with a limited risk of lymph node metastasis. This justifies a local excision of suspected deep submucosal invasive colon carcinomas (T1 CCs) as a first step treatment strategy. Recently Colonoscopy-Assisted Laparoscopic Wedge Resection (CAL-WR) has been shown to be able to resect pT1 CRCs with a high R0 resection rate, but the long term outcomes are lacking. The aim of this study is to evaluate the safety, effectiveness and long-term oncological outcomes of CAL-WR as primary treatment for patients with suspected superficial and also deeply-invasive T1 CCs.

METHODS

In this prospective multicenter clinical trial, patients with a macroscopic and/or histologically suspected T1 CCs will receive CAL-WR as primary treatment in order to prevent unnecessary major surgery for low-risk T1 CCs. To make a CAL-WR technically feasible, the tumor may not include > 50% of the circumference and has to be localized at least 25 cm proximal from the anus. Also, there should be sufficient distance to the ileocecal valve to place a linear stapler. Before inclusion, all eligible patients will be assessed by an expert panel to confirm suspicion of T1 CC, estimate invasion depth and subsequent advise which local resection techniques are possible for removal of the lesion. The primary outcome of this study is the proportion of patients with pT1 CC that is curatively treated with CAL-WR only and in whom thus organ-preservation could be achieved. Secondary outcomes are 1) CAL-WR's technical success and R0 resection rate for T1 CC, 2) procedure-related morbidity and mortality, 3) 5-year overall and disease free survival, 4) 3-year metastasis free survival, 5) procedure-related costs and 6) impact on quality of life. A sample size of 143 patients was calculated.

DISCUSSION

CAL-WR is a full-thickness local resection technique that could also be effective in removing pT1 colon cancer. With the lack of current endoscopic local resection techniques for > 15 mm pT1 CCs with deep submucosal invasion, CAL-WR could fill the gap between endoscopy and major oncologic surgery. The present study is the first to provide insight in the long-term oncological outcomes of CAL-WR.

TRIAL REGISTRATION

CCMO register (ToetsingOnline), NL81497.075.22, protocol version 2.3 (October 2022).

Colonoscopy-Assisted Laparoscopic Wedge Resection for the Treatment of Suspected T1 Colon Cancer

BACKGROUND

Local en bloc resection of pT1 colon cancer has been gaining acceptance during the last few years. In the absence of histological risk factors, the risk of lymph-node metastases (LNM) is negligible and does not outweigh the morbidity and mortality of an oncologic resection. Colonoscopy-assisted laparoscopic wedge resection (CAL-WR) has proved to be an effective and safe technique for removing complex benign polyps. The role of CAL-WR for the primary resection of suspected T1 colon cancer has to be established.

METHODS

This retrospective study aimed to determine the radicality and safety of CAL-WR as a local en bloc resection technique for a suspected T1 colon cancer. Therefore, the study identified patients in whom high-grade dysplasia or a T1 colon carcinoma was suspected based on histology and/or macroscopic assessment, requiring an en bloc resection.

RESULTS

The study analyzed 57 patients who underwent CAL-WR for a suspected macroscopic polyp or polyps with biopsy-proven high-grade dysplasia or T1 colon carcinoma. For 27 of these 57 patients, a pT1 colon carcinoma was diagnosed at pathologic examination after CAL-WR. Histological risk factors for LNM were present in three cases, and 70% showed deep submucosal invasion (Sm2/Sm3). For patients with pT1 colon carcinoma, an overall R0-resection rate of 88.9% was achieved. A minor complication was noted in one patient (1.8%).

CONCLUSIONS

The CAL-WR procedure is an effective and safe technique for suspected high-grade dysplasia or T1-colon carcinoma. It may fill the gap for tumors that are macroscopic suspected for deep submucosal invasion, providing more patients an organ-preserving treatment option.

D3 lymph node dissection improves the survival outcome in patients with pT2 colorectal cancer

BACKGROUND

The extent of lymphadenectomy in patients with pT2 colorectal cancer (CRC) remains controversial. This study aimed to elucidate the effects of D3 and D2 lymph node dissection (LND) on survival in patients diagnosed with pT2 CRC.

METHODS

This was a retrospective cohort study from a high-volume cancer center in Japan. From April 2007 to December 2020, 6273 patients with primary CRC were included in the study; among these, 616 patients diagnosed with pT2 CRC underwent radical colorectal resection. Propensity score matching (PSM) was applied to balance potential confounding factors, and a total of 104 matched pairs were extracted from the entire cohort. Independent risk factors associated with prognosis were determined by Cox regression analysis. The main outcome measures were overall survival (OS) and cancer-specific survival (CSS).

RESULTS

Before PSM, there was a statistically significant difference across the cohort in OS and CSS (p = 0.000 and 0.013) between D3 and D2 LND groups; the estimated hazard ratio (HR) was 2.2 (95% confidence interval (CI), 1.1-4.4, p = 0.031) for OS in the D3 LND and 4.4 (95% CI, 1.7 to 11, p = 0.0027) for CSS (p = 0.013). There was also a significant difference (p = 0.024) in OS between the D3 and D2 LND groups in the matched cohort, with an estimated HR for OS of 3.3 (95% CI, 1.2 to 9.1, p = 0.024) and an estimated HR for CSS of 7.2 (95% CI, 1.6 to 33, p = 0.011).

CONCLUSIONS

D3 LND had a significant survival advantage in the treatment of pT2 CRC. The results of this study provide a theoretical basis for the application of D3 LND in radical surgery for preoperative T2 CRC.