[Pathologic study of circumferential margin involvement in middle and lower rectal cancer].
OBJECTIVE
To study the rule of circumferential margin involvement (CMI) in middle and low rectal cancer and improve its detection rate.


METHODS
Pathological large slices stained by HE method was combined with immunohistochemistry to study the CMI of 41 patients with middle and low rectal cancer. There were 20 female and 21 male patients, with an average age of 59.5 years (range, 33 to 77 years).


RESULTS
The positive rate of CMI by HE staining was 21.9%. The CMI positive rates of CK20, CDX2 and MMP7 by immunohistochemistry staining was 29.3%, 31.7% and 26.8%, respectively. The positive rate of CMI was 36.6% when combined both HE and immunohistochemistry test, which was significantly higher than those in single methods (all P < 0.05). The positive rate of CMI in poorly differentiated tumor was significantly higher than that in moderately and well-differentiated tumor. The positive rate of CMI in the tumors with a distance of less than 5 cm between the anal verge and the lower tumor margin was significantly higher than that in tumors with the above-mentioned distances of greater than or equal to 5 cm (P < 0.05). According to MMP7 detection, the positive rate of CMI in the group without lymphatic metastasis was significantly lower than that in N1 and N2 group (all P < 0.05). There was no significant correlation between CMI and gender, age, tumor infiltration, lymphatic metastasis, general pathological types and operation methods (P > 0.05).


CONCLUSIONS
The positive detection rate of CMI can be improved when combined large slices HE staining and immunohistochemistry. There is significant association between CMI and poorly differentiated tumor, lower location and positive lymphatic metastasis.
Yu
Bin
B
The Second Department of Surgery, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China. yubinli_68@163.com
Yu
Yue-ming
YM
Chen
Yan-ning
YN
Li
Yong-tao
YT
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012004:Rectal Neoplasms / Q000473:pathology*