The usefulness of immunohistochemical evaluation of dihydropyrimidine dehydrogenase for rectal cancer treated with preoperative radiotherapy.
OBJECTIVE
DPD (dihydropyrimidine dehydrogenase) activity shows a correlation with 5-fluorouracil chemosensitivity. To quantify DPD activity is important for selection of chemosensitive cases of not only sporadic colorectal cancer but also rectal cancer with preoperative radiotherapy. However, it is not cost-effective. We investigated the relation between the immunohistochemical expression pattern of DPD and its activity in rectal cancer treated with radiotherapy, and compared the immunohistochemical DPD expression pattern of preradiation biopsy specimens with that of resected tissues.


METHODS
DPD expression pattern of preradiation biopsy specimens were compared with that of resected tissues. Eighteen colorectal cancer tissue samples were obtained after surgery from October 2000 to January 2001. DPD activity was quantified by sandwich enzyme-linked immunosorbent assay. The streptoavidin-biotin peroxidase complex technique was used for the immunohistochemical expression pattern.


RESULTS
DPD was stained in the cytoplasm of cancer cells. There was a significant correlation between the immunohistochemical expression pattern of DPD and its activity in tumor tissue treated with or without radiotherapy. The immunohistochemical expression pattern of preradiation biopsy specimens was almost the same as that of resected tissues.


CONCLUSIONS
The immunohistochemical expression pattern of DPD correlated with its activity in tumor tissue treated with preoperative radiotherapy. Immunohistochemical evaluation is considered to be an effective method of predicting the sensitivity to 5-fluorouracil of rectal cancer treated with preoperative radiotherapy.
Komuro
Yasuhiro
Y
Department of Surgical Oncology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. komuro@kt.rim.or.jp
Watanabe
Toshiaki
T
Tsuno
Nelson
N
Kitayama
Joji
J
Inagaki
Naohito
N
Nishida
Miwa
M
Nagawa
Hirokazu
H
D000911:Antibodies, Monoclonal; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D015153:Blotting, Western; D003131:Combined Modality Therapy; D042943:Dihydrouracil Dehydrogenase (NADP); D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D007150:Immunohistochemistry; D010088:Oxidoreductases / Q000378:metabolism*; D012004:Rectal Neoplasms / Q000201:enzymology* / Q000532:radiotherapy / Q000601:surgery / Q000628:therapy*
D000911:Antibodies, Monoclonal; D000964:Antimetabolites, Antineoplastic; D010088:Oxidoreductases; D042943:Dihydrouracil Dehydrogenase (NADP); D005472:Fluorouracil