Pathological changes of advanced lower-rectal cancer by preoperative radiotherapy.
OBJECTIVE
In the treatment of lower rectal cancer, we examined the pathological effects of preoperative radiotherapy on intramural spread of tumor and risk factors for local recurrence, including tumor deposit, budding growth of primary tumors, and micrometastasis to lymph nodes.


METHODS
Ninety-four patients who underwent surgery for lower rectal cancer were selected. Forty-seven patients received preoperative radiotherapy, at a total dose of 50 Gy [Rad(+) group], whereas 47 did not [Rad(-) group]. Intramural spread was evaluated between the Rad(+) and Rad(-) groups. For analysis of tumor deposit, budding, and micrometastasis, 25 stage-matched patients were selected in both groups.


RESULTS
Intramural spread was significantly less in the Rad(+) group, compared with the Rad(-) group. The Rad(+) group showed a significant decrease in tumor deposit, budding, and micrometastasis, compared with the Rad(-) group. In patients having overt lymph node metastases or not, the tumor deposit and budding were significantly higher in patients having overt metastases, compared with those not having them, in the Rad(-) group, whereas there was no significant difference in the Rad(+) group.


CONCLUSIONS
Intramural spread and tumor deposit, budding, and micrometastasis were significantly decreased in the Rad(+) group, compared with the Rad(-) group. These results suggested effects of preoperative radiotherapy for sphincter preservation, as well as for decreasing the local recurrence rate.
Kinoshita
Hirokatsu
H
Department of Pathology, Cancer Institute Hospital of the Japanese Foundation for Cancer Research (JFCR) Tokyo 170-8455, Japan.
Watanabe
Toshiaki
T
Yanagisawa
Akio
A
Nagawa
Hirokazu
H
Kato
Yo
Y
Muto
Tetsuichiro
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D010043:Outcome and Process Assessment, Health Care; D012004:Rectal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012007:Rectum / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies
D014408:Biomarkers, Tumor