Despite improvements in detection and management, metastatic
breast cancer remains a leading cause of death among women in industrialized countries.
Chemotherapy is the initial treatment of choice for patients with a negative
estrogen receptor status, as well as for those with a positive
estrogen receptor status who have failed to respond to endocrine treatment. Patients who fail on first-line
chemotherapy become candidates for second-line salvage
chemotherapy; the outlook for these patients is poor, and new active agents continue to be sought.
Docetaxel (
Taxotere; Rhône-Poulenc Rorer, Antony, France) is a semisynthetic
taxoid that is an inhibitor of microtubule depolymerization. This new
anticancer agent has been studied in an extensive phase II clinical trial program involving 162 patients with second-line metastatic
breast cancer, 134 of whom were
anthracycline resistant. Doses of 100 mg/m2 of
docetaxel, administered over 1 hour every 3 weeks, produced an overall response rate of 50% (range, 41% to 58%) in 129 evaluable patients, with a median duration of 6 months (range, 2 to 17 months). The response rates achieved to date with
docetaxel in
anthracycline-resistant patients compare favorably with those produced by the best monotherapies currently available, and are equivalent to those achieved with current
combination chemotherapy options.
Docetaxel also was found to be highly effective in patients with a poor prognosis, having
metastases in three or more organs (53%), and/or visceral sites of disease (47%). Furthermore, the overall response rate for
docetaxel in the intent-to-treat population (42.5%) is superior to the response rate of either
doxorubicin as second-line
therapy (29.3%) or
paclitaxel (
Taxol; Bristol-Myers Squibb Oncology, Princeton, NJ) when used as first- or second-line
therapy (29%) in metastatic disease. In conclusion,
docetaxel appears to be a very effective therapeutic option for women with second-line metastatic
breast cancer.