Trastuzumab showed clinical benefit in HER-2–positive breast cancer

Gianni L. Lancet. 2011;doi:10.1016/S1470-2045(11)70033-X.

Issue: March 25, 2011

Patients with HER-2–positive breast cancer who crossed over from observation to trastuzumab experienced fewer DFS events than patients who remained on observation, according to study results.

The phase 3 Herceptin Adjuvant (HERA) trial was conducted at several international sites. The aim was to determine DFS and OS after a median follow-up of 4 years in 3,401 patients with HER-2–positive early breast cancer.

Patients in the 1-year trastuzumab (Herceptin, F. Hoffmann-La Roche) group experienced 4-year DFS at a rate of 78.6% vs. 72.2% in the observation group (HR=0.76; 95% CI, 0.66-0.87). Four-year OS was 89.3% in the treatment group and 87.7% in the observation group (HR=0.85; 95% CI, 0.70-1.04), a difference that the researchers said was not significant.

The crossover rate from observation to treatment was 52%. Treatment with trastuzumab began at a median of 22.8 months (range, 4.5-52.7) from randomization.

Further analysis was conducted among the 885 patients who crossed over. There were fewer DFS events among patients receiving trastuzumab than in those who remained under observation (adjusted HR=0.68; 95% CI, 0.51-0.90).

Although higher incidences of grade 3 to grade 4 adverse events were reported in the trastuzumab group, those events occurred in less than 1% of patients. The most frequently reported adverse events included congestive cardiac failure, hypertension, arthralgia, back pain, central-line infection, hot flush, headache and diarrhea

The current data are from outcomes reported at 1 year, with a median follow-up of 48.4 months (interquartile range, 42-56.5).

Eligible participants had received standard neoadjuvant or adjuvant chemotherapy, or both. There were 1,703 patients randomly assigned trastuzumab and 1,698 patients randomly assigned to the observation group for the intention-to-treat analysis.

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