Staging of rectal cancer by EUS: depth of infiltration in T3 cancers is important Christian Jürgensen, MD, Andreas Teubner, MD, Jörg-Olaf Habeck, MD, Friederike Diener, MD, Hans Scherübl, MD, Ulrich Stölzel, MD Gastrointest Endosc 2011;73:325-8 R4 조경민 / prof. 이창 균

Background Rectal carcinoma : risk of recurrence Modern treatment concepts: based on preoperative tumor staging EUS or MRI

N=42 minimally invasive T3 (invasion < 2 mm beyond MRI by EUS) & advanced T3 disease (invasion > 2 mm) Endosonographic differentiation of superficial & deep infiltration in T3 stage prognostic relevance J Gastroenterol Hepatol 2004;19:750-5 Minimal invasive Advanced rectal cancer Recurrence-free survival rate :P=0.02

Locally advanced tumors (T3, T4) lymph node involvement indication for neoadjuvant therapy Z Gastroenterol 2004;42: Discrimination between T1/2 and T3/4 cancers is crucial for treatment strategies Therefore

Objective- Determine the accuracy of preoperative staging by endorectal US with a focus on endosonographic T3 stage (uT3)

PATIENTS AND METHODS Community and tertiary referral hospital was performed from 1996 to 2004, when uT3 cancers were not considered for neoadjuvant therapy Part retrospective, part prospective study.

PATIENTS AND METHODS Inclusion criteria Between 1996 and 2004 (not considered for neoadjuvant therapy) 83 consecutive patients with de novo rectal carcinoma (confirmed by preoperative- histology) Exclusion criteria Incomplete staging by endorectal US before surgical resection. Data on sex, age, preoperative treatment, and postoperative histology : obtained from patients’ medical records.

Maximum depth of tumor infiltration uT1 : Mucosa (first echo-poor layer in EUS) and/or submucosa (following echo-rich layer) uT2 : Muscularis propria (second echo-poor layer) but not beyond uT3 : Beyond the muscularis propria Minimally invasive uT3: Infiltration up to 2 mm Advanced uT3: infiltration deeper than 2 mm uT4 : Infiltration of adjacent structures and/or peritoneum METHODS retrospectively by evaluation of paper prints and reports.

RESULTS

Results of T staging assessed by endosonography (uT) versus postoperative pathology (pT) Inaccurate staging between T2 and T3 stages Representing 14 of 20 (70%) with incorrect T staging

A substantial proportion of pT2 cancers : overstaged as uT3 cancer by transrectal US  EUS overstaging of patients with pT2 was significantly more frequent in minimally invasive uT3 compared with advanced UT3 (8 of 16 & 1 of 24 P =0.001)  minimally invasive uT3 cancer : the accuracy of the crucial discrimination between T1/2 and T3/4 : 50%  the accuracy of discrimination between T1/2 and T3/4 by EUS ; 88% in this cohort RESULTS Discrimination between T1/2 and T3/4 cancers is crucial for treatment minimally invasive uT3 rectal cancer: higher risk of overstaging of pT2 cancer

Accuracy of endosonographic N staging : 57% (45 of 78) N staging assessed by endosonography (uN0/2) versus pathology (pN0/2) RESULTS

Lymph node involvement assessed by endosonography (uN0/) versus pathology (pN0/) whether lymph nodes involved (N) or not (N0) increasing to 63% (49 of 78)

Locally advanced tumors (T3, T4) lymph node involvement indication for neoadjuvant therapy CONCLUSIONS The high probability of overstaging may be a reason to refer patients with minimally invasive uT3N0 by EUS for surgery without neoadjuvant therapy