[Clinical significance of P53-immunohistochemistry in large slice in evaluating distal intramural spread extent in rectal cancer].
OBJECTIVE
The optimal distal molecular clearance margin of rectal cancer hasn't been confirmed. This study was designed to explore the molecular margin of distal intramural spread (DIS)in rectal cancer, and its prognostic value, and to further clarify the required distal margin of radical surgery for rectal cancer.


METHODS
Sixty-one P53 positive specimens,resected from patients with rectal cancer from Aug.1996 to Oct. 1997, were collected. Microscopic DIS was examined by P53-immunohistochemistry (P53-IHC),comparing with conventional hematoxylineosin (HE)staining in consecutive large slice. Tissue shrinkage ratio,comparing the distal clearance margin measured in fresh specimens to that measured in large slice after fixed in each case,was used to convert macroscopically measured extent of distal spread to its actual extent. After long-term follow-up, the survival curves of 4 DIS groups were estimated by Life-table method.


RESULTS
With P53-IHC,DIS was observed in 50 cases (82.0%), DIS extents were 0.11-3.50 cm with the mean of 0.59 cm, DIS extent of > 3.00 cm was detected in 1 case only. Meanwhile,DIS was observed in 29 cases (47.5%)by HE staining, DIS extents were 0.10-1.39 cm with the mean of 0.13 cm. There was significant difference between the 2 means (P< 0.0001). The long-term result indicated that the survival rate of DIS extent of >1.00 cm group was lower than those of non-DIS group,and DIS extent of < 0.50 cm group (P< 0.05).


CONCLUSIONS
DIS was more exactly detected by P53-IHC than by HE. Most of DIS extents were less than 1 cm in rectal cancer. For over 95% cases, 3 cm distal to the rectal cancers was relatively safe in radical operations. The poor prognosis can be predicted in cases with DIS extent of >1 cm.
Pan
Zhi-Zhong
ZZ
Department of Abdominal Surgery, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, P.R.China. panzhizhong@medmail.com.cn
Wan
De-Sen
DS
Zhang
Chang-Qing
CQ
Shao
Jian-Yong
JY
Li
Li-Ren
LR
Chen
Gong
G
Zhou
Zhi-Wei
ZW
Lu
Zhen-Hai
ZH
Wang
Fu-Long
FL
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D000231:Adenocarcinoma, Papillary / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D012007:Rectum / Q000378:metabolism / Q000473:pathology*; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D016159:Tumor Suppressor Protein p53