A small study suggests that older women diagnosed with HER2-positive, metastatic breast cancer can benefit from Herceptin (chemical name: trastuzumab) treatment. These results were presented at the 2010 annual meeting of the European Society for Medical Oncology (ESMO).
Herceptin is a targeted therapy medicine approved by the U.S. Food and Drug Administration (FDA) to treat advanced-stage, HER2-positive breast cancers and to lower the risk of recurrence of early-stage, HER2-positive breast cancer with a high risk of recurrence. HER2-positive cancers make too much of the HER2 protein. The HER2 protein sits on the surface of cancer cells and receives signals that tell the cancer to grow and spread. About one out of every four breast cancers is HER2-positive. Herceptin works by attaching to the HER2 protein and blocking it from receiving growth signals. Herceptin is given intravenously. A newer form of Herceptin, Herceptin Hylecta (chemical name: trastuzumab and hyaluronidase-oysk), can be given as an injection.
Researchers looked at the medical records of 21 women age 65 and older diagnosed with HER2-positive, metastatic breast cancer and treated with Herceptin. Half were older than 72. Fifteen of the women got chemotherapy in addition to Herceptin. The other women got Herceptin alone (called monotherapy).
One of the women had a severe allergic reaction to her first dose of Herceptin. Since she got only that one dose, her results weren't included in this analysis.
The 20 women who were still in the study all got some benefit from Herceptin:
- the cancer went away completely for some period of time in one woman (complete response)
- the cancer shrank for some period of time in eight women (partial response)
- the cancer stayed the same -- didn't grow, but didn't improve -- for some period of time in 11 women
For more than 7.8 months the cancer didn't grow in half the women (called median time to progression); the cancer didn't grow for shorter time periods in the other women. In one woman, the cancer didn't grow for more than 5 years. In another woman, the cancer didn't grow for more than 2 years.
Half the women lived for more than 32.6 months (called median survival); the other women lived for shorter periods of time. When these research findings were reported, 10 of the 20 women were still alive and the researchers continue to follow them.
Overall, the severity and type of side effects caused by Herceptin in this study were similar to side effects seen in younger women treated with Herceptin. Serious side effects of Herceptin can include a severe allergic reaction, weakening of the heart muscle, and lung problems.
Four of the 21 women in this study had severe side effects related to Herceptin. Besides the one woman who had a severe allergic reaction, two other women stopped getting Herceptin because they had signs of a weakened heart (measured as a reduction of left ventricular ejection fraction). One other woman stopped getting Herceptin because she developed a lung problem (pulmonary hypertension).
While this study didn't directly compare older women to younger women, the results suggest that older women diagnosed with HER2-positive breast cancer can benefit as much from Herceptin as younger women. The study also suggests that Herceptin has a similar safety profile when used to treat older women.
You can learn more about Herceptin in the Breastcancer.org Targeted Therapies section.
Editor’s Note: This article was updated with information about Herceptin Hylecta, which the FDA approved on Feb. 28, 2019.