title: Mesorectal Invasion Depth in Rectal Carcinoma Is Associated With Low Survival.
abstract: Most cases of rectal cancer (RC) in our institution are in pathologic stage T3. They are a heterogeneous group but have been classified in a single-stage category. We performed the present study to validate the prognostic significance of the mesorectal extension depth (MED) in T3 RC measured in millimeters beyond the muscularis propria plane.
  
  
  
  We performed a retrospective analysis of 104 patients with T3 RC who had undergone curative surgery after a course of preoperative chemoradiotherapy at a tertiary referral cancer hospital. The patients were grouped by MED (T3a, < 1 mm; T3b, 1-5 mm; T3c > 5-10 mm; and T3d > 10 mm). The clinicopathologic data and disease-free survival were analyzed.
  
  
  
  The 5-year disease-free survival rate according to the T3 subclassification was 87.5% for those with T3a, 57.9% for T3b, 38.7% for T3c, and 40.3% for those with T3d tumors (P = .050). On univariate and multivariate analysis, the prognostic factors affecting survival were overall recurrence (hazard ratio [HR], 3.670; 95% confidence interval [CI], 1.710-7.837; P = .001), histologic grade (HR, 2.204; 95% CI, 1.156-4.199; P = .016), mesorectal invasion depth (HR, 1.885; 95% CI, 1.164-3.052; P = .010), and lymph node metastasis (HR, 1.211; 95% CI, 1.015-1.444; P = .033).
  
  
  
  MED is a significant prognostic factor in patients with T3 RC who have undergone neoadjuvant chemoradiotherapy, especially when the MED is > 5 mm. The MED could be as important as other clinicopathologic factors in predicting disease-specific survival.
authors.affiliation: Department of Gastrointestinal Pathology, Instituto Nacional de Cancerología, Mexico City, Mexico. Electronic address: saul.lino.sil@gmail.com.
authors.forename: Leonardo S
authors.initials: LS
authors.lastname: Lino-Silva
authors.affiliation: Department of Gastrointestinal Pathology, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Reynaldo
authors.initials: R
authors.lastname: Loaeza-Belmont
authors.affiliation: Department of Surgical Oncology, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Gómez Álvarez
authors.affiliation: Department of Surgical Oncology, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Itzel
authors.initials: I
authors.lastname: Vela-Sarmiento
authors.affiliation: Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: José M
authors.initials: JM
authors.lastname: Aguilar-Romero
authors.affiliation: Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Domínguez-Rodríguez
authors.affiliation: Department of Surgical Oncology, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Rosa A
authors.initials: RA
authors.lastname: Salcedo-Hernández
authors.affiliation: Department of Translational Oncology, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Erika B
authors.initials: EB
authors.lastname: Ruiz-García
authors.affiliation: Department of Gastrointestinal Pathology, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Héctor A
authors.initials: HA
authors.lastname: Maldonado-Martínez
authors.affiliation: Department of Surgical Oncology, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Herrera-Gómez
mesh_terms: D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008643:Mesentery / Q000473:pathology*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D016019:Survival Analysis
keywords: Cancer; Colorectal; Mesorectum; Prognosis; Survival