title: Distal intramural and tumor spread in the mesorectum after neoadjuvant radiochemotherapy in rectal cancer: about 124 consecutive patients.
abstract: This observational prospective study aimed to assess the distribution of intramural and mesorectal tumor spread in mid/low rectal cancer after neoadjuvant radiochemotherapy. Distribution of mesorectal metastatic lymph nodes (MLNs) and mesorectal extranodal cancer tissue (EX), according to the tumor location, were analyzed. Distal intramural tumor spread was also performed. A total of 1676 LNs, 135 MLNs, and 69 EX were detected on 124 consecutive surgical specimens. Forty-two patients (34%) had MLNs. Six patients (4.8%) were classified as ypN1c. Distal viable cancer spread was observed in 3 patients (2.4%), all with mid rectal carcinoma. Two patients (1.6%) presented distal direct intramural extension less than 1 cm; and 1 (0.8%), with EX localized no more than 2 cm from the lower edge of the tumor. MLNs (76%) and EX (94%) were preferentially localized in the peritumoral area and in the first 3 cm just above the tumor. No viable distal intramural or mesorectal spread was observed in low rectal carcinoma. Distal intramural and mesorectal cancer spread is a rare event after neoadjuvant RCT. These results suggest that the 1-cm distal margin recommended in patients with low rectal carcinoma could be reduced with insurance to obtain a negative distal margin. The knowledge of preferential localization of MLNs and EX would help the pathologist to improve patient's lymph node staging.
authors.affiliation: Department of Pathology, Beaujon Hospital, 92110 Clichy, France. Electronic address: nathalie.guedj@bjn.aphp.fr.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Guedj
authors.affiliation: Department of Colo-rectal Surgery, Beaujon Hospital, 92110 Clichy, France.
authors.forename: Léon
authors.initials: L
authors.lastname: Maggiori
authors.affiliation: Department of Pathology, Beaujon Hospital, 92110 Clichy, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Poté
authors.affiliation: Department of Pathology, Beaujon Hospital, 92110 Clichy, France.
authors.forename: Emma
authors.initials: E
authors.lastname: Norkowski
authors.affiliation: Department of Pathology, Beaujon Hospital, 92110 Clichy, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Cros
authors.affiliation: Department of Pathology, Beaujon Hospital, 92110 Clichy, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bedossa
authors.affiliation: Department of Colo-rectal Surgery, Beaujon Hospital, 92110 Clichy, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Panis
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary / Q000601:surgery / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D059186:Chemoradiotherapy, Adjuvant; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D000072662:Margins of Excision; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D012007:Rectum / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects* / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome
keywords: Lymph nodes metastases; Mesorectum; Radiochemotherapy; Rectal cancer; Tumor deposits