Fragmented pattern of tumor regression and lateral intramural spread may influence margin appropriateness after TEM for rectal cancer following neoadjuvant CRT

Rodrigo O. Perez, Angelita Habr-Gama, Fraser M. Smith, Lauren Kosinski, Guilherme P. São Julião, Esteban Grzona, Viviane Rawet, Maria Regina Vianna, Igor Proscurshim, Patrício Bernardo Lynn, Joaquim Gama-Rodrigues

Research output: Contribution to journalReview articlepeer-review

42 Scopus citations


Background The main tenets of local excision of rectal cancer following neoadjuvant chemoradiation (CRT) are that the mucosal scar represents the main focus of residual disease and a solid conglomerate around this rather than being scattered (fragmented) through the bowel wall. Methods Retrospective review of a prospective cohort of patients with residual rectal ycT1-2N0 adenocarcinoma with small residual tumors (≤3 cm) following CRT who underwent transanal endoscopic microsurgery (TEM) with 1-cm margins around the residual mucosal abnormality was performed. Distribution and morphology (solid vs. fragmented) of tumor spread were studied and correlated to postoperative oncological outcomes. Results Thirty patients were included. Twenty percent (n = 6) were ypT1, 60% (n = 18) were ypT2, and 20% (n = 6) were ypT3 tumors. Fragmentation was present in 37%. The mean distance between foci of residual scattered tumor was 3.6 ± 2.0 mm. Lateral spread under normal mucosa was present in 19 specimens (53%; mean extension 4.8 ± 2.4 mm). With a median follow up of 32 months, none of these findings impacted upon development of recurrence. Conclusions Both occult lateral spread and fragmented tumor patterns are common findings after CRT. Despite the potential of occult spread to mislead surgeon choice of resection margin, its presence did not influence oncological outcome in this series.

Original languageEnglish (US)
Pages (from-to)853-858
Number of pages6
JournalJournal of Surgical Oncology
Issue number8
StatePublished - Jun 2014

All Science Journal Classification (ASJC) codes

  • Surgery
  • Oncology

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