Results from a landmark study demonstrate that Aventis's cancer treatment Taxotere (docetaxel) administered as neo-adjuvant (pre-surgery) chemotherapy significantly increases the five-year survival rates of women with large or locally advanced breast cancer when compared to standard neo-adjuvant chemotherapy. The study also showed that women receiving Taxotere had significantly higher tumour response rates, and had significantly higher rates of breast conserving surgery.
The study showed that after a five-year follow-up, 97 per cent of women who received four cycles of an anthracycline-based chemotherapy followed by four cycles of Taxotere prior to surgery were still alive compared to 78 per cent who received eight cycles of anthracycline-based chemotherapy prior to surgery (p=0.04). The study also showed that patients receiving neo-adjuvant Taxotere chemotherapy had a higher complete pathological response (31per cent vs. 15per cent, p = 0.06) than those receiving standard therapy. This resulted in significantly more breast conserving surgery in women who received Taxotere. Breast conserving surgery was possible in 67per cent of women who received Taxotere compared with only 48per cent in patients who only received anthracycline-based chemotherapy (p=0.01). The study results, conducted by the University of Aberdeen, were presented at the 26th Annual San Antonio Breast Cancer Symposium.
"The survival advantage, effective tumour shrinkage response and breast conserving surgery seen in this study strongly suggests that women with large and locally advanced breast cancer may benefit by receiving sequential Taxotere as part of their neo-adjuvant regimen, " said Dr. Andrew Hutcheon, consultant medical oncologist, Grampian University Hospital Trust, Scotland, UK.
Patients with large or locally advanced breast cancer initially received four cycles of anthracycline-based chemotherapy (cyclophosphamide 1000 mg/m2, vincristine 1.5 mg/m2 [max 2 mg], doxorubicin 50 mg/m2, prednisolone 40 mg/day for five days every 21 days). Following initial treatment, tumour response was assessed and graded. Patients who demonstrated a partial or complete response to treatment were randomized to either four more cycles of anthracycline-based chemotherapy or four cycles of Taxotere (100 mg/m2 every 21 days).
After 162 patients were enrolled, and following four cycles of anthracycline-based chemotherapy, the breast cancers in 102 patients (63per cent) achieved a partial or complete clinical response. The 102 patients were then randomized to receive four additional cycles of chemotherapy. Forty-seven patients received four cycles of neo-adjuvant Taxotere and fifty patients received another four cycles of anthracycline-based chemotherapy. Patients who received Taxotere had significantly higher response rates than those who received anthracycline-based chemotherapy both in terms of the overall clinical response (shrinkage of the tumour mass on physical examination) 85per cent vs. 64per cent, p=0.03) and complete pathologic response (disappearance of all invasive cancer confirmed by microscopic examination) 31per cent vs. 15per cent, p=0.06.
At a median follow-up of 65 months, 97per cent in the Taxotere group were still alive versus 78per cent in the anthracycline-based chemotherapy group (p=0.04). The Taxotere group had a disease-free survival rate of 90per cent versus 72per cent in the anthracycline-based chemotherapy group (p=0.04). There were four deaths in the anthracycline-based chemotherapy followed by Taxotere arm and 12 deaths in anthracycline-based chemotherapy arm.
Taxotere was better tolerated than the anthracycline-based treatment. Significantly fewer hematologic events were experienced by women in the Taxotere arm of the study (p=0.029 for leukopenic events and p=0.006 for granulocytopenic events). In the study, Taxotere patients received a significantly higher percentage of the total intended drug (92per cent vs. 86per cent), requiring less dose reduction due to hematologic toxicity than patients who received the anthracycline-based regimen.