Phase I/II study of paclitaxel, carboplatin, and methotrexate in advanced transitional cell carcinoma: a well-tolerated regimen with activity independent of p53 mutation.
OBJECTIVE
To evaluate the feasibility and activity of paclitaxel, carboplatin, and methotrexate in advanced transitional cell carcinoma (TCC) of the urothelium and to relate the activity of this combination to the mutational status of p53.


METHODS
In the Phase I portion, paclitaxel 200 mg/m(2) (3-hour infusion), carboplatin dosed to an area under the curve (AUC) of 6 mg/mL. min, and methotrexate 10 mg/m(2), increasing in 10-mg/m(2) increments, were administered on day 1 and every 21 days thereafter with granulocyte colony-stimulating factor (G-CSF) and leucovorin support. Subsequently, a Phase II study was initiated in which the carboplatin dose was lowered to an AUC of 5 to allow treatment without G-CSF. p53 expression was evaluated using immunohistochemistry.


RESULTS
Thirty-three patients were accrued. Median age was 66 years. No dose-limiting toxicities were seen in the Phase I portion despite escalation of the methotrexate to 60 mg/m(2). Principal toxicities were myelosuppression and neuropathy. The overall response rate (Phase I and II) was 56% (95% confidence interval 38% to 74%). Median survival was 15.5 months; 88% of patients overexpressed p53 at the primary site.


CONCLUSIONS
Paclitaxel, carboplatin, and methotrexate were well tolerated and active in advanced TCC. The high response rate to this regimen despite frequent p53 mutation is consistent with the p53-independent mechanism of paclitaxel. Whether this regimen is superior to methotrexate/vinblastine/doxorubicin/cisplatin, other paclitaxel-based regimens, or to paclitaxel alone will require comparative trials.
Edelman
M J
MJ
Division of Hematology/Oncology, Department of Internal Medicine, UC Davis Medical Center, Sacramento, California, USA.
Meyers
F J
FJ
Miller
T R
TR
Williams
S G
SG
Gandour-Edwards
R
R
deVere White
R W
RW
D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D016190:Carboplatin / Q000008:administration & dosage / Q000009:adverse effects; D002295:Carcinoma, Transitional Cell / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D004252:DNA Mutational Analysis; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005240:Feasibility Studies; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage / Q000009:adverse effects; D008875:Middle Aged; D009367:Neoplasm Staging; D017239:Paclitaxel / Q000008:administration & dosage / Q000009:adverse effects; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality / Q000473:pathology
D016159:Tumor Suppressor Protein p53; D016179:Granulocyte Colony-Stimulating Factor; D016190:Carboplatin; D017239:Paclitaxel; D002955:Leucovorin; D008727:Methotrexate