If it is December, then it is time for the San Antonio Breast Cancer Symposium, where more than 9,000 scientists, doctors, advocates, pharmaceutical representatives, and medical device companies from around the world gather to talk about breast cancer.
The meeting today started with a fascinating talk by Valerie Beral, an epidemiologist from the United Kingdom. She is responsible for the Million Women Study, which was one of the first studies to suggest that there were risks associated with using hormone replacement therapy (HRT).
She opened her talk with something that I have been thinking a lot about lately: the variations in cancer risk in different parts of the world. She noted that a womanâ€™s lifetime risk of getting breast cancer by age 70 if she lives in rural Africa is 1 percent, whereas if she lives in a Western country, like the U.S., it is 6.3 percent.
Dr. Beral went on to show that most of the difference was a result of reproductive factorsâ€“such as age of first pregnancy, number of pregnancies, duration of breast feedingâ€“and nutritional factors, such as high BMI, height, and physical activity. Both oral contraceptives and HRT increase the incidence of breast cancer once, but the risk goes back to a normal rate within five years of stopping either medication. She went on to say that in Westernized countries we are all at high risk, and that it is random who actually gets breast cancer. Her recommendation was that we develop a treatment to mimic the hormones of pregnancy to prevent breast cancer.
While I really respect Dr. Beral, I think she left out part of the story.Â I doubt that the reproductive factors cause breast cancer. My guess is that they affect the local environment around the breast cells that either suppresses or makes cancer thrive. What initially causes the cells to mutate and become cancer cells are still unknown. They could be viral (my bias), environmental, hereditary, or all of the above. I must say I would rather find the cause and eliminate it than try to manipulate womenâ€™s bodies to mimic pregnanciesâ€”which is what the new Health of Women Study that the Love/Avon Army of Women is launching aims to do!
The other interesting reports were on the use of bisphosphonates (like Fosamax) for osteoporosis prevention and treatment. Researchers affiliated with the Womenâ€™s Health Initiative reported that they found a 30 percent decrease in the risk of breast cancer in the women who took bisphosphonates. A second case control study from Israel showed a similar result after a year on a bisphosphonate. Neither of these studies were randomized, controlled trials. In fact, they were not even designed to answer this question, so the data have to be considered preliminary. It also needs to be taken into account that women who have osteoporosis tend to have had less estrogen exposure, and women with less estrogen exposure tend to have a lower risk of breast cancer.
To determine whether bisphosphonates really do decrease breast cancer risk, investigators will need to do a randomized controlled study that enrolls an equal numbers of women who are at low and high risk of developing breast cancer. Still, I think this result is very interesting. If true, it is likely that the bisphosphonates are not killing cancer cells but rather affecting the local neighborhood around the cells so that it suppresses the cancer cells rather than stimulating them. Certainly, this is interesting.
Researchers also discussed an interesting new drug that appears to prevent bone metastases. The drug denosumab appears to be somewhat better than Zometa (zoledronicÂ acid) with the same side effects.
Another study showed that, as we have learned before, more is not always better. This time, we learned that adding the hormonal treatment fulvestrant (brand name faslodex) to an aromatase inhibitor was not better than using an aromatase inhibitor alone.
The final presentation discussed research looking at the use of MRI in women with BRCA1 and BRCA2. The study showed that MRI added to mammography surveillance results in a â€œstage shiftâ€ compared to mammography alone. This means that it leads to cancers being diagnosed at an earlier stage. This was an interesting study, but because the control group was not followed in a single center or in a screening program, itâ€™s hard to know what the findings really mean.
Stay tuned for Day 2!