Subset Analysis of a Multicenter, Randomized Controlled Trial to Compare Magnifying Chromoendoscopy with Endoscopic Ultrasonography for Stage Diagnosis of Early Stage Colorectal Cancer.
BACKGROUND
Our recent prospective study found equivalent accuracy of magnifying chromoendoscopy (MC) and endoscopic ultrasonography (EUS) for diagnosing the invasion depth of colorectal cancer (CRC); however, whether these tools show diagnostic differences in categories such as tumor size and morphology remains unclear. Hence, we conducted detailed subset analysis of the prospective data.


METHODS
In this multicenter, prospective, comparative trial, a total of 70 patients with early, flat CRC were enrolled from February 2011 to December 2012, and the results of 66 lesions were finally analyzed. Patients were randomly allocated to primary MC followed by EUS or to primary EUS followed by MC. Diagnoses of invasion depth by each tool were divided into intramucosal to slight submucosal invasion (invasion depth <1000 μm) and deep submucosal invasion (invasion depth ≥1000 μm), and then compared with the final pathological diagnosis by an independent pathologist blinded to clinical data. To standardize diagnoses among examiners, this trial was started after achievement of a mean κ value of ≥0.6 which was calculated from the average of κ values between each pair of participating endoscopists.


RESULTS
Both MC and EUS showed similar diagnostic outcomes, with no significant differences in prediction of invasion depth in subset analyses according to tumor size, location, and morphology. Lesions that were consistently diagnosed as Tis/T1-SMS or ≥T1-SMD with both tools revealed accuracy of 76-78%. Accuracy was low in borderline lesions with irregular pit pattern in MC and distorted findings of the third layer in EUS (MC, 58.5%; EUS, 50.0%).


CONCLUSIONS
MC and EUS showed the same limited accuracy for predicting invasion depth in all categories of early CRC. Since the irregular pit pattern in MC, distorted findings to the third layer in EUS and inconsistent diagnosis between both tools were associated with low accuracy, further refinements or even novel methods are still needed for such lesions.


BACKGROUND
University hospital Medical Information Network Clinical Trials Registry UMIN 000005085.
Department of Gastroenterology, Japanese Red Cross Nagoya Daini Hospital, Nagoya, Aichi, Japan.
Tomonori
T
Yamada
Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan; Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Boston, Massachusetts, United States of America; Department of Surgery, Harvard Medical School, Boston, Massachusetts, United States of America.
Takaya
T
Shimura
Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan.
Masahide
M
Ebi
Department of Gastroenterology, Kasugai Municipal Hospital, Kasugai, Aichi, Japan.
Yoshikazu
Y
Hirata
Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan.
Hirotaka
H
Nishiwaki
Department of Gastroenterology, Gifu Prefectural Tajimi Hospital, Tajimi, Gifu, Japan.
Takashi
T
Mizushima
Department of Gastroenterology, Chukyo Hospital, Nagoya, Aichi, Japan.
Koki
K
Asukai
Department of Gastroenterology, Chukyo Hospital, Nagoya, Aichi, Japan.
Shozo
S
Togawa
Department of Experimental Pathology and Tumor Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan.
Satoru
S
Takahashi
Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan.
Takashi
T
Joh
D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009361:Neoplasm Invasiveness; D012680:Sensitivity and Specificity