The most efficacious primary chemotherapy regimens used to treat
breast cancer contain anthracyclines. Unfortunately, a significant
proportion of breast cancers fail to respond to such therapy.
Therefore the aims of this study were (1) to determine the efficacy
of primary docetaxel (Taxotere) in patients that initially fail to
respond to anthracycline-based primary chemotherapy, and (2) to
compare the efficacy of docetaxel with anthracycline-based primary
chemotherapy in patients that are initially responsive to such therapy.
Patients with large (³ 3 cm) or
locally advanced (T3, T4, Tx, N2) breast cancers received four pulses
of CVAP (cyclophosphamide [Cytoxan, Neosar] 1,000 mg/m²,
vincristine 1.5 mg/m², doxorubicin 50 mg/m², prednisolone
40 mg for 5 days) primary chemotherapy. After four cycles (3-weekly)
clinical tumor response was assessed (UICC criteria). Those with a
partial (PR) or complete response (CR) were randomized to receive
either four further pulses of CVAP or four pulses of docetaxel (100
mg/m²). All patients in whom stasis or progression of disease
occurred received four further pulses of docetaxel (100 mg/m²).
Following completion of the chemotherapy regimen, final tumor
response was assessed (as above) and appropriate surgery performed.
Pathologic response was determined.
A total of 158 patients have completed eight cycles of primary
chemotherapy. 104 women were suitable for randomization (PR or CR).
In randomized patients, the final clinical PR or CR rate was 68% in
the CVAP group and 94% (X² = 11.2, P = .001) in the
docetaxel group. Nonrandomized patients had a final clinical PR or CR
of 51%. Pathologic response (CR or PR) in randomized patients was 58%
with CVAP and 78% with CVAP and docetaxel (X² = 4.5, P =
.033); in nonrandomized patients it was 36%.
In randomized patients, following completion of primary chemotherapy
axillary lymph nodes were positive in 36% who received CVAP and 43%
who received CVAP and docetaxel (X² = 0.4, P = .516); 40%
of nonrandomized patients had axillary lymph node involvement.
CONCLUSION: Primary treatment with docetaxel resulted in a
significant improvement in clinical and pathologic response.