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Quantitation of intratumoral thymidylate synthase expression predicts for disseminated colorectal cancer response and resistance to protracted-infusion fluorouracil and weekly leucovorin.

Leichman, C G, Lenz, H J, Leichman, L, Danenberg, K, Baranda, J, Groshen, S, Boswell, W, Metzger, R, Tan, M, Danenberg, P V·1997·Journal of Clinical Oncology

Abstract

PURPOSE: Response rates to fluorouracil (5-FU)-based therapy remain low. As new, active agents are being tested, information regarding specific intratumoral genetic determinants of chemotherapy sensitivity or resistance can be used to plan therapy rationally. Intratumoral thymidylate synthase (TS) quantitation may be among the most important determinants of sensitivity or resistance to 5-FU. MATERIALS AND METHODS: Forty-six disseminated colorectal cancer patients had measurable tumor biopsies for polymerase chain reaction (PCR)-based determination of TS mRNA pretreatment. Protracted infusion of 5-FU 200 mg/m2/d for 21 days with weekly intravenous leucovorin 20 mg/m2 each cycle was given. After two cycles, responses were evaluated. Response data were correlated with independently determined intratumoral ratios of TS/beta-actin mRNA for each patient. RESULTS: TS/beta-actin ratios were successfully obtained for 42 patients (91%). TS/beta-actin ratios ranged from 0.3 x 10(-3) to 18.2 x 10(-3) (median, 3.5 x 10[-3]). Twelve patients (26%) responded to treatment (median TS/beta-actin ratio, 1.7 x 10[+3]). Thirty-four patients did not respond (median TS/beta-actin ratio, 5.6 x 10[-3]). No patient with a TS mRNA level greater than 4.1 x 10(-3) responded. The median TS/beta-actin ratio (3.5 x 10[-3]) significantly segregated responders from nonresponders (P = .001). Median survival for patients with TS/beta-actin ratios < or = 3.5 x 10(-3) was 13.6 months; for patients with TS/beta-actin ratios greater than 3.5 x 10(-3), it was 8.2 months (P = .02). CONCLUSION: For this cohort, the intratumoral TS/beta-actin ratio had a statistically significant association with response and survival. This relationship for other 5-FU schedules remains unknown. Confirmation of these data in a larger patient population could lead to determination of therapy for disseminated colorectal cancer based on a specific intratumoral molecular parameter.

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Metadata

Authors
Leichman, C. G., Lenz, H. J., Leichman, L., Danenberg, K., Baranda, J., Groshen, S., Boswell, W., Metzger, R., Tan, M., & Danenberg, P. V.
Venue
Journal of Clinical Oncology
Published
1997-10
Volume
15
Issue
10
Pages
3223-3229
ISSN
  • 0732-183X (ISSN-L)
  • 1527-7755
OpenAlex
W1797303364
Cited by
475
References
0
FWCI
7.30
Type
journal article
Language
en
Open access
closed

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CoChat. (2026). Citation check: Quantitation of intratumoral thymidylate synthase expression predicts for disseminated colorectal cancer response and resistance to protracted-infusion fluorouracil and weekly leucovorin. https://app.cochat.ai/papers/10.1200/jco.1997.15.10.3223
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Leichman, C. G., Lenz, H. J., Leichman, L., Danenberg, K., Baranda, J., Groshen, S., Boswell, W., Metzger, R., Tan, M., & Danenberg, P. V. (1997). Quantitation of intratumoral thymidylate synthase expression predicts for disseminated colorectal cancer response and resistance to protracted-infusion fluorouracil and weekly leucovorin. Journal of Clinical Oncology. https://doi.org/10.1200/jco.1997.15.10.3223

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