Practical problems of measuring depth of submucosal invasion in T1 colorectal carcinomas.

PURPOSE: Submucosal invasion depth (SID) in colorectal carcinoma (CRC) is an important factor in estimating risk of lymph node metastasis, but can be difficult to measure, leading to inadequate or over-extensive treatment. Here, we aimed to clarify the practical aspects of measuring SID in T1 CRC. METHODS: We investigated 568 T1 CRCs that were resected surgically at our hospital from April 2001 to December 2013, and relationships between SID and clinicopathological factors, including the means of measurement, lesion morphology, and lymph node metastasis. RESULTS: Of these 568 lesions, the SID was ≥1000 µm in 508 lesions. SIDs for lesions measured from the surface layer were all ≥1000 µm. Although lesions with SIDs ≥1000 µm were associated with significantly higher levels of unfavorable histologic types and lymphovascular infiltration than shallower lesions, a depth of ≥1000 µm was not a significant risk factor for lymph node metastasis (LNM) (6.7 vs. 9.8 %; P = 0.64), and no lesions for which the sole pathological factor was SID ≥1000 µm had lymph node metastasis. Protruded lesions showed deeper SIDs than other types. CONCLUSIONS: Although we found several problems of measuring SID in this study, we also found, surprisingly, that SID is not a risk factor for lymph node metastasis, and its measurement is not needed to estimate the risk of lymph node metastasis.

Management of T1 colorectal cancers after endoscopic treatment based on the risk stratification of lymph node metastasis.

BACKGROUND AND AIM: Recent advances in endoscopic technology have allowed many T1 colorectal carcinomas to be resected endoscopically with negative margins. However, the criteria for curative endoscopic resection remain unclear. We aimed to identify risk factors for nodal metastasis in T1 carcinoma patients and hence establish the indication for additional surgery with lymph node dissection. METHODS: Initial or additional surgery with nodal dissection was performed in 653 T1 carcinoma cases. Clinicopathological factors were retrospectively analyzed with respect to nodal metastasis. The status of the muscularis mucosae (MM grade) was defined as grade 1 (maintenance) or grade 2 (fragmentation or disappearance). The lesions were then stratified based on the risk of nodal metastasis. RESULTS: Muscularis mucosae grade was associated with nodal metastasis (P = 0.026), and no patients with MM grade 1 lesions had nodal metastasis. Significant risk factors for nodal metastasis in patients with MM grade 2 lesions were attribution of women (P = 0.006), lymphovascular infiltration (P < 0.001), tumor budding (P = 0.045), and poorly differentiated adenocarcinoma or mucinous carcinoma (P = 0.007). Nodal metastasis occurred in 1.06% of lesions without any of these pathological factors, but in 10.3% and 20.1% of lesions with at least one factor in male and female patients, respectively. There was good inter-observer agreement for MM grade evaluation, with a kappa value of 0.67. CONCLUSIONS: Stratification using MM grade, pathological factors, and patient sex provided more appropriate indication for additional surgery with lymph node dissection after endoscopic treatment for T1 colorectal carcinomas.

'Head Invasion' Is Not a Metastasis-Free Condition in Pedunculated T1 Colorectal Carcinomas Based on the Precise Histopathological Assessment.

BACKGROUND/AIM: Previous reports stated that pedunculated T1 colorectal carcinomas with 'head invasion' showed almost no nodal metastasis, requiring endoscopic treatment alone. However, clinically, some lesions develop nodal metastasis. We aimed to validate the necessity of distinguishing between 'pedunculated' and 'non-pedunculated' lesions, and also between 'head' and 'stalk' invasions. METHODS: Initial or additional surgery with lymph node dissection was performed in 76 pedunculated and 594 non-pedunculated cases. Among pedunculated lesions, the baseline was defined as the junction line between normal and neoplastic epithelium (Haggitt's level 2). The degree of invasion was classified as 'head invasion' (above the baseline) or 'stalk invasion' (beyond the baseline). Clinicopathological factors were analyzed with respect to nodal metastasis. RESULTS: Nine of 76 (11.8%) pedunculated cases and 52/594 (8.8%) non-pedunculated cases developed nodal metastasis (p = 0.40). No significant differences were found in the rate of nodal metastasis between 'head invasion' (4/30, 13.3%) and 'stalk invasion' (5/46, 10.9%). All the 4 cases with 'head invasion' had at least one pathological factor. CONCLUSIONS: 'Head invasion' was not a metastasis-free condition. Even for pedunculated T1 cancers with 'head invasion', additional surgery with lymph node dissection should be considered if these have pathological risk factors.

Endocytoscopic microvasculature evaluation is a reliable new diagnostic method for colorectal lesions (with video).

BACKGROUND: We previously reported on the efficacy of endocytoscopic classification (EC-C). However, the correlation of the endocytoscopic vascular (EC-V) pattern with diagnoses was unclear. OBJECTIVE: To assess the diagnostic accuracy of the EC-V pattern for colorectal lesions. DESIGN: Retrospective. SETTING: A university hospital. PATIENTS: Patients who underwent endocytoscopy between January 2010 and March 2013. INTERVENTION: We evaluated 198 consecutive lesions according to the EC-V pattern (EC-V1, obscure surface microvessels; EC-V2, clearly observed surface microvessels of a uniform caliber and arrangement; and EC-V3, dilated surface microvessels of a nonhomogeneous caliber or arrangement). MAIN OUTCOME MEASUREMENTS: The diagnostic accuracy for predicting hyperplastic polyps and invasive cancer were compared between the EC-V pattern and other modalities (narrow-band imaging, pit pattern, and EC-C). RESULTS: The sensitivity, specificity, and accuracy of the EC-V1 pattern for diagnosing hyperplastic polyps were 95.5%, 99.4%, and 99.0%, respectively. The sensitivity, specificity, and accuracy of the EC-V3 pattern for diagnosing invasive cancer were 74.6%, 97.2%, and 88.6%, respectively. The diagnostic accuracy of the EC-V pattern for predicting hyperplastic polyps was comparable to the other modalities. For predicting invasive cancer, the EC-V pattern was comparable to narrow-band imaging and pit pattern, although EC-C was slightly more accurate (P = .04). In the substudy, the diagnosis time by using the EC-V pattern was shorter than that with the EC-C pattern (P < .001). LIMITATIONS: A single-center, retrospective study. CONCLUSIONS: The EC-V pattern saved more time than the EC-C pattern and had a diagnostic ability comparable to that of other optical biopsy modalities.