Journal of Clinical Oncology, Vol 10, 433-437, Copyright © 1992 by American Society of Clinical Oncology
Carboplatin: an active drug in metastatic breast cancer
M Martin, E Diaz-Rubio, A Casado, P Santabarbara, JM Lopez Vega, E Adrover and L Lenaz
Servicio de Oncologia Medica, Hospital Universitario San Carlos, Madrid, Spain.
PURPOSE: The study was undertaken to assess the antitumor activity of
carboplatin 400 mg/m2 intravenously every 4 weeks in metastatic breast
cancer (MBC). PATIENTS AND METHODS: Thirty-four MBC patients without any
prior exposure to chemotherapy entered the study. All patients had
measurable disease in at least one site and were assessable for response
and toxicity. RESULTS: Of 34 assessable patients, 12 obtained a complete
(one) or partial (11) response to carboplatin, resulting in an overall
response rate of 35% (95% confidence interval, 19.8% to 53.5%). The median
duration of response was 8 months (range, 2+ to 12 months). Responses were
seen in lymph nodes (four of six), lung (five of nine), skin and soft
tissues (four of nine), breast (two of eight), and liver (three of 11), but
not in measurable lytic lesions of the bone. Toxicity was mild, mainly
consisting of emesis (81% of the patients; 66% of the courses), leukopenia
of World Health Organization (WHO) grade 1 to 2 (47% of the patients; 18%
of the courses), and thrombocytopenia (12% of the patients; 3% of the
courses). There were no cases of life-threatening toxicity, although one
patient developed grade 4 thrombocytopenia without bleeding. Of 22 patients
who did not respond to carboplatin, 18 received salvage therapy with
cyclophosphamide, doxorubicin, and fluorouracil (CAF; 15 patients);
cyclophosphamide, methotrexate, and fluorouracil (CMF; one patient); or
hormones (two patients). Objective responses to CAF and hormonal therapy
were seen in 11 of 15 and two of two patients, respectively. The remaining
patient did not respond to CMF salvage chemotherapy. Overall, the response
rate to either first-line carboplatin or second- line salvage therapy was
73.5% (25 of 34 patients). After a median follow-up time of 22 months, the
median survival was 19 months. CONCLUSIONS: Carboplatin is an active drug
in MBC patients without previous exposure to chemotherapy. In our study,
the use of an experimental drug as first-line single-agent treatment in MBC
did not have a negative influence on patient survival, as the majority of
the carboplatin nonresponding patients could be salvaged with a
conventional therapeutic regimen.
