title: Clinical significance of perineural invasion diagnosed by immunohistochemistry with anti-S100 antibody in Stage I-III colorectal cancer.
abstract: OBJECTIVE
  Perineural invasion (PN) diagnosed by hematoxylin-eosin (HE) staining is an important prognostic factor after curative-intent surgery in patients with colorectal cancer. However, the clinical significance of PN diagnosed by immunohistochemistry (IHC) has not been investigated. The present study assessed the clinical significance of PN diagnosed by IHC with an anti-S100 antibody in patients with colorectal cancer.
  
  
  METHODS
  We retrospectively enrolled 184 consecutive patients with stage I-III colorectal cancer who had undergone curative-intent surgery. We analyzed the absence/presence of PN diagnosed by HE staining (HE-PN) compared to that diagnosed by IHC with the anti-S100 antibody (S100-PN). Potential prognostic factors were identified by univariate and multivariate analyses of the overall and relapse-free survival. The [Formula: see text] statistics were used to assess the inter-observer reproducibility.
  
  
  RESULTS
  The incidence of HE-PN and S100-PN among the 184 patients was 60 patients (32.6%) and 113 patients (61.4%), respectively (P < 0.001). A multivariate Cox proportional hazards regression model analysis indicated that S100-PN was an independent prognostic factor for both the overall and relapse-free survival. The [Formula: see text] value was 0.77 for S100-PN and 0.47 for HE-PN.
  
  
  CONCLUSIONS
  PN diagnosed by IHC is an important prognostic factor in patients with colorectal cancer. An inter-observer assessment showed superior judgment reproducibility for S100-PN compared with HE-PN.
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan. shimaday@med.niigata-u.ac.jp.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Shimada
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Kido
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kameyama
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Mae
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Ryoma
authors.initials: R
authors.lastname: Yagi
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Tajima
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Okamura
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nagahashi
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Minagawa
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Kosugi
authors.affiliation: Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Wakai
authors.affiliation: Division of Molecular and Diagnostic Pathology, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Niigata, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ajioka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000912:Antibodies, Neoplasm / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D009418:S100 Proteins / Q000276:immunology*
chemical_list: D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; D009418:S100 Proteins
keywords: Colorectal cancer; Immunohistochemistry; Perineural invasion; S100