Depth of tumor invasion in locally advanced rectal cancer correlates with patients' prognosis: the usefulness of elastic stain for its measurement.
OBJECTIVE
The relationship between the prognosis and the extent of colorectal carcinoma (CRC) is still unclear. As a simple parameter of the local invasion of CRC, we assessed the extent of tumor invasion beyond the outer border of the muscularis propria (MP).


METHODS
We examined 147 cases of CRC using a slight modification of the procedure established by the Japanese Society for Cancer of the Colon and Rectum. For the statistical analysis, the patients were divided into two groups, namely, a "shallow" group and a "deep" group, using a specific cut-off value (COV). A multivariate analysis to identify independent prognostic factors was performed.


RESULTS
Significant differences in the 5-year survival rate were observed between the "shallow" and "deep" groups in 39 cases of rectal carcinoma (COV 4 mm; 72.4% vs. 30.0%, hazard ratio = 3.204), but not observed in 147 cases of CRC. In addition, the outcome for patients with "deep" cancer in the lower rectum was markedly worse than that for patients with "shallow" cancer (COV 4 mm; 81.8% vs. 12.5%, hazard ratio = 5.371).


CONCLUSIONS
The depth of tumor invasion beyond the MP is thus considered to be an important prognostic factor for patients with T3/T4 rectal carcinoma, especially in the lower rectum. A careful follow-up is required for the patients with rectal carcinoma that has invaded more than 4 mm beyond the MP.
Katsumata
Daisuke
D
Department of Surgical and Molecular Pathology, Dokkyo University School of Medicine, 880 Kitakobayashi, Mibu, Shimotsuga, Tochigi, 321-0293, Japan.
Fukui
Hirokazu
H
Ono
Yuko
Y
Ichikawa
Kazuhito
K
Tomita
Shigeki
S
Imura
Johji
J
Abe
Akihito
A
Fujita
Masanori
M
Watanabe
Osamu
O
Tsubaki
Masahiro
M
Sunagawa
Masakatsu
M
Fujimori
Takahiro
T
D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000473:pathology* / Q000601:surgery; D004396:Coloring Agents; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery; D016019:Survival Analysis
D004396:Coloring Agents