Depth of mesorectal invasion has prognostic significance in T3N0 low rectal cancer.
OBJECTIVE
To investigate mesorectal fat invasion as a prognostic factor for T3N0 low rectal adenocarcinoma following sharp mesorectal excision.


METHODS
Subjects consisted of 26 patients who had a potential curative excision of a T3N0 low rectal adenocarcinoma without neoadjuvant therapy between August 1988 and April 2003. Histological preparations were used to measure depth of mesorectal invasion, which was analyzed for associations with disease-free survival and recurrence.


RESULTS
Five-year overall survival and disease-free survival were 64.8% and 57.1%, respectively. Ten patients developed recurrent disease; 3 had local recurrence, 3 had distant metastasis, and 4 had both local and distant recurrence. Rectal cancers were stratified by depth of mesorectal invasion using 4 cutoff values (2, 3, 4, 5 mm), and examined by Cox proportional hazard model. At a cutoff of 3 mm, multivariate analyses confirmed depth of mesorectal invasion to be an independent prognostic factor for 5-year disease-free survival (< 3mm, 90.9%; > or = 3mm, 32.0%; p = 0.023). Distant metastasis differed significantly (< 3mm, 0%; > or = 3mm, 46.7%; p = 0.01), but local recurrence did not (< 3 mm, 9.1%; > or = 3mm, 40%; p = 0.17).


CONCLUSIONS
Patients with advanced low T3N0 rectal cancer are at high risk of distant metastases. Depth of mesorectal invasion may be valuable in decisions regarding intensive adjuvant therapy.
Tokoro
Tadao
T
Department of Surgery, Kinki University School of Medicine, 377-2 Oohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan. tokoro@surg.med.kindai.ac.jp
Okuno
Kiyotaka
K
Hida
Jin-ichi
J
Ishimaru
Eizaburo
E
Ueda
Kazuki
K
Yoshifuji
Takehito
T
D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery; D012007:Rectum / Q000473:pathology / Q000601:surgery; D015996:Survival Rate