Invasion Of Colorectal Neoplasms Research Articles

Endoscopic Ultrasound Elastography as a Novel Diagnostic Method for the Assessment of Hardness and Depth of Invasion in Colorectal Neoplasms

Introduction: We aimed to compare the efficacy of endoscopic ultrasound elastography (EUS-EG) with that of magnifying chromoendoscopy (MCE) and endoscopic ultrasonography (EUS) for the diagnosis of the depth of invasion in colorectal neoplasms. This is an important clinical issue as the depth of invasion is associated with the risk of metastasis. Methods: Consecutive patients with suspected superficial colorectal neoplasms, evaluated by MCE, EUS, and EUS-EG, for whom endoscopic submucosal dissection was considered, were enrolled in 2018 (derivation study) and in 2019–2020 (validation study). The primary clinical endpoint was the diagnostic yield differentiating intramucosal and shallow submucosal neoplasms from deep submucosal (dSM) and advanced colorectal cancers. In addition, inter- and intra-observer agreements of the elastic score of colorectal neoplasm (ES-CRN) were evaluated by 2 expert and 2 non-expert endoscopists. Results: Thirty-one (33 lesions) and 50 (55 lesions) patients were enrolled in the derivation and validation studies, respectively. Sensitivity, specificity, positive, and negative predictive values, and accuracy of assessment of the depth of submucosal or deeper invasion in the derivation and validation groups were as follows: EUS-EG, 100/88.2/86.7/100/93.3% and 77.8/86.1/73.7/88.6/83.3%; MCE, 66.7/94.4/90.9/77.3/81.8% and 84.2/91.4/84.2/91.4/88.9%; and EUS, 93.3/77.8/77.8/93.3/84.8% and 89.5/65.7/58.6/92.0/74.1%, respectively. For the 2 expert endoscopists, interobserver agreement for the ES-CRN (first and second assessments) in the derivation group was 0.84 and 0.78, respectively; these values were 0.73 and 0.49, respectively, for the 2 non-expert endoscopists. Discussion/Conclusion: All 3 modalities presented similar diagnostic yield. Inter- and intra-observer agreements of the ES-CRN were substantial, even for non-expert endoscopists. Therefore, EUS-EG may be a useful modality in determining the depth of invasion in colorectal neoplasms.

Mo1637 NOVEL METHOD TO DETERMINE THE DEPTH OF INVASION IN COLORECTAL NEOPLASMS WITH ULTRASOUND ELASTOGRAPHY USING A FORWARD-VIEWING RADIAL-ARRAY ECHOENDOSCOPE

With the increasing use of endoscopy for treating colorectal cancer, accurate diagnosis of the depth of invasion in colorectal neoplasms has become an important clinical issue. Our study aimed to compare the diagnostic ability and clinical efficacy of endoscopic ultrasound elastography (EUS-EG) with those of magnifying chromoendoscopy (MCE) and EUS in diagnosing the depth of invasion in colorectal neoplasms. Patients with superficial colorectal neoplasms evaluated by MCE, EUS, and EUS-EG were enrolled. The primary clinical endpoint was the diagnostic yield differentiating intramucosal and shallow submucosal cancers from deep submucosal and advanced colorectal neoplasms, using the elastic score of colorectal neoplasms (ES-CRN). In addition, validation of ES-CRN was performed using inter- and intra-observer agreement from two expert and two non-expert endoscopists. We examined the diagnostic yield of additional patients prospectively due to these results. Thirty-one patients (33 lesions) with colorectal neoplasms were enrolled. The diagnostic yields (sensitivity, specificity, positive predictive value, negative predictive value and accuracy) of deeply submucosal cancers or advanced colorectal neoplasms, respectively, were as follows: EUS-EG:100%/88.2%/86.7%/100%/93.3%, MCE: 66.7%/94.4%/90.9%/77.3%/81.8% and EUS: 93.3%/77.8%/77.8%/93.3%/84.8%. Interobserver agreement for the ES-CRN was 0.70/0.80 and 0.45/0.40 for the first/second assessment, for the two expert endoscopists and two non-expert endoscopists. Furthermore, we examined additional 33 patients (34 lesions) prospectively. The diagnostic yields of prospective study were as follows, respectively: EUS-EG:83.3%/81.5%/50.0%/95.7%/81.8%, MCE: 75.0%/92.0%/75.0%/92.0%/87.9% and EUS: 85.7%/61.5%/37.5%/94.1%/66.7%. The diagnostic yield was from equal to higher for EUS-EG than for MCE and EUS, with moderate inter and intra-observer agreement, even for non-expert endoscopists. Therefore, EUS-EG may be a useful modality to determine the depth of invasion in colorectal neoplasms.

Present and future status of flexible spectral imaging color enhancement and blue laser imaging technology

The usefulness of flexible spectral imaging color enhancement (FICE) has been reported for evaluating the esophagus, stomach, and small and large intestine. Higher contrast is shown between cancer and the surrounding mucosa in the esophagus and stomach and may facilitate the detection of gastric cancers missed by white light imaging alone. The surface patterns of gastric mucosa are clearly visualized in non-malignant areas but are irregular and blurred in malignant areas, leading to clear demarcation. Capsule endoscopy with FICE detects angiodysplasia and erosions of the small intestine. The surface and vascular pattern with FICE is useful for the differential diagnosis of colorectal polyps. However, FICE remains somewhat poor at visualizing mucosal microvasculature on a tumor surface. Narrow-band imaging (NBI) is dark in observing whole gastric mucosa and poor at visualizing mucosal microstructure. Blue laser imaging (BLI) has the potential to resolve these limitations. Narrow-band laser light combined with white light shows irregular microvessels on both differentiated and undifferentiated gastric cancer similar to those using NBI. In addition, irregular surface patterns including minute white zones are clearly seen on the uneven surface of differentiated lesions, resulting in exclusion of undifferentiated lesions. Using both distant and close-up views, a high contrast between green intestinal metaplasia and brown gastric cancer may lead to early detection of gastric cancers and determination of a demarcation line. BLI produces high-contrast images in esophageal cancer with clear vision of intrapapillary capillary loops and also predicts the histopathological diagnosis and depth of invasion in colorectal neoplasms.

Evaluation of new subclassification of type VI pit pattern for determining the depth and type of invasion of colorectal neoplasm

Colorectal neoplasms with a type V(I) pit pattern include various lesions, such as adenomas, intramucosal cancers, and submucosal carcinomas. We analyzed 96 colorectal neoplasms with a type V(I) pit pattern and identified six different variants: (1) unclear outline of the pit; (2) irregular margins of the pit; (3) narrowing of the pit; (4) ragged array of the pit; (5) high residual density of the pit; (6) abnormal branching of the pit. We examined the relationship between the appearance of each V(I) pit pattern and histology, including the depth of invasion. In univariate logistic regression analysis the unclear outline, irregular margins, and narrowing of the pit were significantly associated with a submucosal (SM) invasion ≥1000 μm (P < 0.01). In multivariate logistic regression analysis, unclear outline of the pit was shown to be the only significant predictor of highly invasive submucosal cancer (odds ratio = 24.20, P < 0.0001). Regarding tumor morphology, the following were significantly associated with an SM invasion ≥1000 μm: in protruded type, ragged array (P = 0.022), irregular margins of the pit (P = 0.011), and unclear outline of the pit (P < 0.01); in flat type, irregular margins of the pit (P < 0.01) and unclear outline of the pit (P < 0.01); and in the depressed type, narrowing of the pit (P = 0.015) and unclear outline of the pit (P < 0.01). Subclassification of the type V(I) pit pattern is useful for determining the depth of invasion of colorectal neoplasms.