title: Transanal endoscopic microsurgery for T1 rectal cancer: size matters!
abstract: BACKGROUND
  Transanal endoscopic microsurgery (TEM) is considered a curative option for selected T1 rectal cancer. Although TEM is safe, local recurrence (LR) rates after TEM are unacceptably high. Evidence on selection criteria, however, is not abundant. To expand evidence on low- versus high-risk T1 rectal cancer with respect to LR, this study aimed to identify predictive histopathologic factors in a selected group of T1 rectal cancers treated with TEM only.
  
  
  METHODS
  The study enrolled 62 patients for whom specimens of the primary tumor containing an invasive T1 carcinoma could be reevaluated. Tumors were scored according to predefined criteria, and analysis of predictive factors for locoregional failure was performed.
  
  
  RESULTS
  Local recurrence rates at 3 years for tumors 3 cm in size or smaller were significantly lower than for tumors larger than 3 cm (16 vs. 39%; P < 0.03). Combining smaller tumors with submucosal invasion depth and budding led to identifying tumors that likely will not recur (3-year LR rates, 7 and 10%, respectively).
  
  
  CONCLUSIONS
  The findings showed that low- and high-risk criteria are too robust for identifying tumors at risk for LR. Tumor size alone or in combination with submucosal invasion depth or tumor budding appeared to be a significant predictive factor for locoregional failure after TEM for T1 rectal cancer.
authors: Department of Surgery, IJsselland Hospital, Prins Constantijnweg 2, 2906 ZC, Capelle aan den IJssel, The Netherlands. pdoornebosch@ysl.nl
authors: Pascal G
authors: PG
authors: Doornebosch
authors: Eliane
authors: E
authors: Zeestraten
authors: Eelco J R
authors: EJ
authors: de Graaf
authors: Pleun
authors: P
authors: Hermsen
authors: Imro
authors: I
authors: Dawson
authors: Rob A E M
authors: RA
authors: Tollenaar
authors: Hans
authors: H
authors: Morreau
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal; D005260:Female; D006801:Humans; D008297:Male; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D057605:Natural Orifice Endoscopic Surgery / Q000379:methods*; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000209:etiology; D011351:Proctoscopy / Q000379:methods*; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome; D047368:Tumor Burden