SAN ANTONIO--Three different regimens of vinorelbine tartrate
(Navelbine) combined with established chemotherapeutic agents
led to significant responses in up to 60% of patients with advanced
or metastatic breast cancer, including previously treated patients.
In the largest of the three studies, 35 (56.4%) of 62 patients
with metastatic breast cancer responded to the combination of
vinorelbine and doxorubicin as first-line chemotherapy. Seven
patients had complete responses, and 28 had partial responses;
an additional 16 patients remained stable, New York University
oncologist Howard Hochster reported at a general session of the
San Antonio Breast Cancer Symposium.
The dosing regimen consisted of 50 mg/m² of doxorubicin on
day 1, and 25 mg/m² of vinorelbine on days 1 and 8. The regimen
was repeated every 3 weeks for eight cycles, after which patients
continued weekly vinorelbine until progression. The patients completed
a median of six cycles, and 30% completed eight cycles, said Dr.
Hochster, assistant professor of medical oncology/hematology.
The doxorubicin dose was reduced to 40 mg/m² for patients
whose ANC was between 1,000 and 2,000, or whose platelet count
was 75,000 to 100,000. If the ANC fell below 1,000, or platelets
below 75,000, the day 1 doses of doxorubicin and vinorelbine were
delayed for a week. The day 8 vinorelbine dose was delayed 1 week
for grade 4 neutropenia, or if platelets fell below 75,000.
One-year survival for the cohort was 75%, and 44% of the patients
have died. Median survival was 94 weeks, and median time to progression
was 34 weeks.
Grade 4 granulocytopenia occurred in 87% of the patients but,
in most cases, did not require intervention, Dr. Hochster said.
Dose modifications mitigated problems with further episodes of
granulocytopenia, which occurred in only 30% of all chemotherapy
cycles. Eighteen patients required hospitalization for febrile
Thrombocytopenia, nausea, and vomiting were not significant problems.
Three cases of grade 3 cardiotoxicity occurred, and one patient
died of heart failure.