title: A phase I trial of high-dose oral tamoxifen and CHOPE.
abstract: Drug resistance is a common phenomenon in clinical oncology. In vitro, tamoxifen has been shown to be an effective inhibitor of P-glycoprotein and a modulator of the multidrug resistance phenotype. We have previously shown that vinblastine can be given safely in combination with tamoxifen at doses that may modulate P-glycoprotein activity. In this phase I trial, tamoxifen (150 mg/m2 twice a day) was given with CHOPE (cyclophosphamide/doxorubicin/vincristine/prednisone/etoposide) in order to assess the toxicities of the combination. Resistance to three of these cytotoxic agents (doxorubicin, vincristine, and etoposide) may be mediated by P-glycoprotein. A total of 13 patients were evaluable on this trial, which showed that the maximum tolerated doses of cyclophosphamide and etoposide were 750 and 80 mg/m2, respectively. The dose-limiting toxicity was myelosuppression with 50% of the patients (3/6) treated at this dose level developing febrile neutropenia and 85% (6/7) developing grade 4 neutropenia. Tamoxifen at a dose of 150 mg/m2 twice a day can be given safely with the lymphoma regimen CHOPE at standard doses, but this combination may result in increased myelosuppression.
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, NC 27707, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Smith
authors.forename: D L
authors.initials: DL
authors.lastname: Trump
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects*; D003520:Cyclophosphamide / Q000009:adverse effects / Q000627:therapeutic use; D004317:Doxorubicin / Q000009:adverse effects / Q000627:therapeutic use; D004334:Drug Administration Schedule; D005047:Etoposide / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy*; D009503:Neutropenia / Q000139:chemically induced; D011241:Prednisone / Q000009:adverse effects / Q000627:therapeutic use; D013629:Tamoxifen / Q000008:administration & dosage*; D014750:Vincristine / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D013629:Tamoxifen; D014750:Vincristine; D005047:Etoposide; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone