Analysis of trastuzumab and chemotherapy in advanced breast cancer after the failure of at least one earlier combination: An observational study

Background: Combining trastuzumab and chemotherapy is standard in her2/neu overexpressing advanced breast cancer. It is not established however, whether trastuzumab treatment should continue after the failure of one earlier combination. In this trial, we report our experience with continued treatment beyond disease progression. Methods: Fifty-four patients, median age 46 years, range 25-73 years, were included. We analysed for time to tumour progression (TTP) for first, second and beyond second line treatment, response rates and overall survival. Results: Median time of observation was 24 months, range 7-51. Response rates for first line treatment were 7.4% complete remission (CR), 35.2% partial remissions (PR), 42.6% stable disease > 6 months (SD) and 14.8% of patients experienced disease progression despite treatment (PD). Corresponding numbers for second line were 3.7% CR, 22.2% PR, 42.6% SD and 31.5% PD; numbers for treatment beyond second line (60 therapies, 33 pts 3(rd) line, 18 pts 4(th) line, 6 pts 5(th) line, 2 pts 6(th) line and 1 patient 7(th) line) were 1.7% CR, 28.3% PR, 28.3% SD and 41.6% PD respectively. Median TTP was 6 months (m) in the first line setting, and also 6 m for second line and beyond second line. An asymptomatic drop of left ventricular ejection fraction below 50% was observed in one patient. No case of symptomatic congestive heart failure was observed. Conclusion: The data presented clearly strengthen evidence that patients do profit from continued trastuzumab treatment. The fact that TTP did not decrease significantly from first line to beyond second line treatment is especially noteworthy. Still, randomized trials are warranted.