title: A three-tier classification system based on the depth of submucosal invasion and budding/sprouting can improve the treatment strategy for T1 colorectal cancer: a retrospective multicenter study.
abstract: More than 85% of patients with T1 colorectal cancer have no lymph node metastasis and can be cured by endoscopic resection. To avoid unnecessary surgery after complete endoscopic resection, accurate histologic methods for evaluating resected specimens are needed to discriminate those at high risk for lymph node metastasis. A retrospective multi-institutional, cross-sectional study of 806 T1 colorectal cancer patients was conducted. A budding/sprouting score was incorporated for predicting lymph node metastasis in addition to other parameters, including the depth of submucosal invasion, histologic grade, and lymphovascular invasion. Lymph node metastasis was detected in 97 patients. Independent predictors of lymph node metastasis by multivariate analysis were depth of submucosal invasion ≥1000 μm (odds ratio (95% confidence interval)=5.56 (2.14-19.10)) and high-grade budding/sprouting (3.14 (1.91-5.21)). Among lesions with a depth of submucosal invasion ≥1000 μm, lymph node metastasis was detected in 59 (29%) of 207 patients with high-grade budding/sprouting, and in 34 (9%) of 396 with low-grade budding/sprouting. Lymph node metastasis was detected in only 4 (2%) of 203 lesions with a depth of submucosal invasion <1000 μm. Of these four tumors, three invaded lymphatic and/or venous vessels. Thus, the risk for lymph node metastasis can be classified into three groups: high risk with a depth of submucosal invasion ≥1000 μm and high-grade budding/sprouting, intermediate-risk with a depth of submucosal invasion ≥1000 μm and low-grade budding/sprouting, and low-risk with a depth of submucosal invasion <1000 μm. These findings revealed that a depth of submucosal invasion ≥1000 μm and high-grade budding/sprouting are powerful predictive parameters for lymph node metastasis in T1 colorectal cancer. This three-tier risk classification system will facilitate the decision for additional major surgery for T1 colorectal cancer patients after successful endoscopic treatment.
authors.affiliation: Department of Human Pathology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawachi
authors.affiliation: Department of Human Pathology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Eishi
authors.affiliation: Department of Surgery, National Defense Medical College, Tokorozawa, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ueno
authors.affiliation: Department of Pathology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nemoto
authors.affiliation: Department of Surgical and Molecular Pathology, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujimori
authors.affiliation: Department of Pathology, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Iwashita
authors.affiliation: Division of Molecular and Diagnostic Pathology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ajioka
authors.affiliation: Pathology Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ochiai
authors.affiliation: PCL Japan, Tokyo, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Ishiguro
authors.affiliation: Clinical Laboratory Division, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Tadakazu
authors.initials: T
authors.lastname: Shimoda
authors.affiliation: Department of Surgery, National Defense Medical College, Tokorozawa, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Mochizuki
authors.affiliation: Department of Pathology, Cancer Institute Hospital, Tokyo, Japan.
authors.forename: Yo
authors.initials: Y
authors.lastname: Kato
authors.affiliation: PCL Japan, Tokyo, Japan.
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Human Pathology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Morio
authors.initials: M
authors.lastname: Koike
authors.affiliation: Department of Surgical Oncology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugihara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000145:classification* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging / Q000379:methods*; D012189:Retrospective Studies; D055815:Young Adult