On Thursday, the morning session of the Symposium focused on the best treatment options for hormone sensitive tumors (tumors that are ER and/or PR-positive).Today, the focus turned to tumors that are HER2-positive.Trastuzumab (brand name Herceptin) was a breakthrough when it was first introduced as a treatment for HER2-positive tumors. But its widespread use has demonstrated that some HER2-positive tumors become resistant to this drug while others do not respond at all. The Friday morning sessions were focused on figuring out better ways to treat these tumors. Researchers described better ways to measure Her2 in the lab and new drugs that appear to work when the tumors stop responding to Herceptin. One researcher also described a biomarker that might be able distinguish which tumors should be treated with Herceptin and which would respond better to lapatinib. While it was all very interesting, it is also still in the â€œstay tunedâ€ category.
I was privileged to moderate a press conference that included two very interesting papers. The first paper was an analysis of the death rate of breast cancer in women who had taken hormone replacement therapy (HRT). This data came from the California Teacherâ€™s Study. The study found that the tumors that develop in women on HRT are generally â€œgood tumorsâ€ with a good prognosis. This was not too surprising, as weâ€™ve known for some time that HRT causes more breast cancers but that these cancers tend to be less aggressive. But since the women still need to undergo surgery, radiation, hormone therapy, and maybe chemotherapy, I doubt they feel that â€œgoodâ€ to the women who get them.
The second paper we discussed looked at whether having primary care doctors fill out a form describing their clinical breast exam improves their exam and helps them find more cancers. Much to everyoneâ€™s surprise, it worked! The researchers did not spend time training the doctors on how to do a better clinical breast exam. They just gave them a form to fill out, which made them pay attention. In these days of MRI, breast PET scans and digital mammography, it was refreshing to find that clinical breast exams can be improved with such a low-tech approach.Â
The morning ended with a great brain stretching talk by Dr. Larry Norton of Memorial Sloan Kettering Cancer Center. He proposed a new theory of breast cancer where some cancer cells are able to metastasize back into the breast. I am not sure I believe it, but it is making me think, which is always fun!
The afternoon session focused on using biomarkers to make treatment decisions. One researcher described a new marker for triple-negative tumors that might one day be a target for a new drug treatment. We also got an early peak at data from a clinical study that compared women on an aromatase inhibitor (AI) who took zoledronic acid (brand name zometa) immediately with those on an AI who began taking zometa only if their bone density went down. The findings suggested that zoledronic acid not only improved bone density, but seemed to decrease recurrence as well. Asked whether this was practice changing, the presenter responded, â€œNo, it is too early, and the numbers of events are too small for us to be sure.â€ One woman in the study developed jaw necrosis from the drug. There is no free lunch. Still it is very interesting that osteoporosis drugs have effects on breast cancer. Another interesting observation to ponder.
We also heard about a clinical study that combined the AI letrozole (brand name Femara) and the tyrosine kinase inhibitor lapatinib in postmenopausal women with tumors that were estrogen positive and HER2-positive. The researchers found that the combination improved progression-free survival from 3 to 8 months.An interesting test of combining targeted therapies with two targets.Obviously further studies are needed, but I expect this is the type of combination weâ€™ll be seeing more of in the future.
Stay tuned for Day 3â€¦