Doctors have suspected that the hormone estrogen, which makes hormone-receptor-positive breast cancer grow, also may be associated with lung cancer. A large study found that women treated with hormonal therapy for breast cancer were less likely to be diagnosed with lung cancer compared to women treated for breast cancer without hormonal therapy. These results were presented at the 2009 San Antonio Breast Cancer symposium.
The researchers looked at the medical records of 6,655 women from Switzerland who were diagnosed with breast cancer between 1980 and 2003. About 46% of the women were treated with hormonal therapy (called anti-estrogen therapy in the article). Tamoxifen was the hormonal therapy used most because the aromatase inhibitors weren't available when many of the women were diagnosed and treated. The women were followed through 2007.
Women who got hormonal therapy to treat breast cancer:
- were 37% less likely to be diagnosed with lung cancer compared to the general population; women who didn't get hormonal therapy had the same risk of being diagnosed with lung cancer as the general population
- were 87% less likely to be diagnosed with and die from lung cancer compared to women who didn't get hormonal therapy
These results suggest that estrogen plays a role in the development, growth, and spread of lung cancer. A better understanding of the link between estrogen and lung cancer could help doctors better pinpoint how estrogen fuels breast cancer and might lead to better cancer prevention strategies and new treatment strategies for breast, lung, and other cancers.
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