October is National Breast Cancer Awareness Month, and the time of year when organizations raise awareness and funds for the disease that is emblematic of the pink ribbon. With one out of eight women developing breast cancer within her lifetime, the disease is still a common occurrence. However, tremendous progress in the area of research and treatment has been made over the last few decades. One of the main discoveries is that breast cancer is not just one disease.
Today’s doctors and researchers commonly think of breast cancer as a series of different diseases that all happen in the breast, said Kathy D. Miller, MD and Ballvé-Lantero Professor of Medicine at Indiana University. Miller is also a Komen Scholar, a group of 50 national breast cancer researchers who work with Susan G. Komen Foundation on an ongoing basis to advise on policies, grant review and serve on task forces.
The triggers and effects of each type of cancer vary dramatically and shape the research. “We have made tremendous progress in treatment, with 90 percent of patients newly diagnosed expected to survive,” Miller said. “So the focus is now on reducing the long-term toxicity of therapies.” Of that 90 percent, approximately seven percent in the United States and developing countries have Stage 4 or metastatic cancer when they are first diagnosed.
For patients who have a higher risk of occurrence or those with metastatic cancer, the research focus is on why that particular type of cancer is resistant to current therapies, and developing treatments for those cancers. According to Miller, those treatments include hormone sensitive mainstay treatment, which blocks or interferes with the effects of hormones. This type of cancer is commonly known as HER2. Researchers have developed five new drugs in the last few years that, combined with hormone therapy, have been proven to be more effective for a longer time.
Individuals battling breast cancer that is not hormone sensitive often have what is called the Triple Negative Breast Cancer. With this cancer, estrogen, progesterone and HER2 – the three most common types of receptors that fuel breast cancer growth – are not present in the tumor. Triple Negative cancer is most commonly treated with chemotherapy. However, immunotherapy treatments are now being used to treat women with Triple Negative Breast Cancer.
Stage 0: A Challenge
One of the emerging areas of breast cancer that is a challenge to treat is Ductal Carcinoma In Situ. This breast cancer, which is often referred to as Stage 0, is a non-invasive cancer where abnormal cells are found in the lining of the breast milk duct and have not spread beyond the ducts into the surrounding breast tissue or lymph nodes. A quarter to a third of these cancers are discovered through mammography, according to Miller. As such, before screenings became more prevalent, DCIS was considered a rare disease.
The challenge with DCIS is that the cancer lesions may never become invasive and, therefore, are harmless. However at this point, researchers cannot tell the difference between DCIS cancer that will stay contained or will spread. So doctors opt to treat Stage 0 cancer as invasive breast cancer with typical treatments. As such, patients are required to go through surgeries, and possibly chemotherapy, radiation and other difficult treatments. The big focus in DCIS research is how to detect which legions are dangerous and need treatment, and those that can be spared. Shelley Hwang, MD, at Duke University is currently running a clinical trial with women newly diagnosed with DCIS.
Breast cancer prevention
While it’s still relatively unknown what causes the majority of breast cancers, there is quite a bit of developing research on how diet and exercise may impact risk for the disease. That understanding has the potential to lead to wider screening techniques and prevention.
“There is a lot of early data looking at bacteria in the stomach and how that leads to cancer,” Miller said. “For example, we know that bacteria found from people who consume a Mediterranean diet is very different than from a fast food diet, and those bacteria may impact developing breast cancer. This has incredible potential to help us understand how the disease starts. And if we can understand how it starts, we have more options for prevention and screening.”
Miller also notes that there are a lot of lifestyle choices women can make to help decrease their risk of developing breast cancer. For example, research shows women who exercise regularly and lead an active life are less likely to develop breast cancer than those who are more sedentary. Additionally, women who are at or closer to a healthy body weight and those that eat a well-balanced diet comprised of lean protein, lower fat and produce are less likely to develop cancer, she said.