Intratumoral pyrimidine nucleoside phosphorylase (PyNPase) activity predicts a selective effect of adjuvant 5'-deoxy-5-fluorouridine (5'DFUR) on breast cancer.

Abstract

BACKGROUND:

Pyrimidine nucleoside phosphorylase (PyNPase) is the enzyme that converts 5'-deoxy-5-fluorouracil (5'DFUR) to 5-fluorouracil (5FU). Its activity in cancer tissue may correlate with the selective antitumor activity of 5'DFUR in breast cancer.

METHODS:

Two hundred and sixteen T2 breast cancer patients were treated consecutively with surgery followed by 5'DFUR (600 mg/body/day) + tamoxifen (20 mg/body/day) for 2 years. PyNPase activity in breast cancer tissue, determined by high-performance liquid chromatography, ranged from 4.2-626.0 micrograms FU/mg protein/hr (mean +/- SD, 203.5 +/- 122.4), and the examined patients were divided into two groups: group A (high PyNPase group), cases with the PyNPase activity equal to or more than the mean value of 203.5 micrograms FU/mg protein/hr, and group B (low PyNPase group), cases with activity less than the mean value.

RESULTS:

Although there was no difference in relapse-free survival (RFS) between groups A and B, among node-positive patients (n = 83) those in group A tended to have a longer RFS. When divided into subgroups according to estrogen receptor (ER) status, among node-positive and ER-positive tumors (n = 49), the RFS was significantly better in group A than in group B (p < 0.05).

CONCLUSION:

Intratumoral PyNPase activity might be of use as a predictor of the effect of adjuvant 5'DFUR on breast cancer.

• Authors: Y Hata, H Takahashi, F Sasaki, M Ogita, J Uchino, M Yoshimoto, Y Akasaka, Y Nakanishi, Y Sawada
• Journal: Breast cancer (Tokyo, Japan) (Breast Cancer) Vol. 7 Issue 1 Pg. 37-41 (Jan 2000) ISSN: 1340-6868 [Print] Japan
• PMID: 11029769 (Publication Type: Journal Article)

Chemical References

• Antimetabolites, Antineoplastic
• Antineoplastic Agents, Hormonal
• Neoplasm Proteins
• Prodrugs
• Floxuridine
• Tamoxifen
• Mitomycin
• Pentosyltransferases
• Pyrimidine Phosphorylases
• Thymidine Phosphorylase
• Fluorouracil
• doxifluridine

Topics

• Adult
• Aged
• Antimetabolites, Antineoplastic (administration & dosage, pharmacokinetics, therapeutic use)
• Antineoplastic Agents, Hormonal (administration & dosage)
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Biotransformation
• Breast Neoplasms (drug therapy, enzymology, mortality, surgery)
• Carcinoma, Ductal, Breast (drug therapy, enzymology, mortality, surgery)
• Chemotherapy, Adjuvant
• Chromatography, High Pressure Liquid
• Disease-Free Survival
• Female
• Floxuridine (administration & dosage, pharmacokinetics, therapeutic use)
• Fluorouracil (metabolism)
• Follow-Up Studies
• Humans
• Lymphatic Metastasis
• Mastectomy, Radical
• Menopause
• Middle Aged
• Mitomycin (administration & dosage)
• Neoplasm Proteins (analysis, metabolism)
• Pentosyltransferases (analysis, metabolism)
• Prodrugs (administration & dosage, pharmacokinetics, therapeutic use)
• Pyrimidine Phosphorylases
• Tamoxifen (administration & dosage)
• Thymidine Phosphorylase (analysis, metabolism)
• Treatment Outcome