Innovative treatments have recently been introduced for HER2 metastatic breast cancer patients, directly targeting the tumor without harming adjacent cells. Will a cure for cancer be discovered in the future? Dr. Noa Efrat Ben Baruch, former Head of Oncology at the Kaplan Medical Center, explains.
Breast cancer is most common among women, and although the majority of cases are diagnosed early, there is a group of patients diagnosed at the metastatic phase or whose disease recurs in a disseminated manner. Innovative treatments have recently been introduced for HER2 metastatic breast cancer patients, directly targeting the tumor without harming adjacent cells. Will metastatic breast cancer become a chronic disease in the future? What are the significant developments in treating the disease?
What is the prevalence of breast cancer?
“Approximately 5,000 women are diagnosed each year in Israel. Breast cancer is the most common cancer in Israel, although it affects about half of the population – women.”
How many women have metastatic breast cancer?
“Metastatic breast cancer is actually cancer located in the breast or lymph nodes, which has metastasized out of the breast and nodes to the bones, lungs, liver or brain. It means that the cancer has spread to the body. Between 3%-4% of women with breast cancer are diagnosed as metastatic patients. In addition, some women diagnosed with early breast cancer suffer a recurrence of the disease and develop metastatic breast cancer, despite receiving treatment. Approximately 25% of all women with breast cancer suffer from a metastatic disease.”
How is metastatic cancer detected?
“When a woman presents with a lump in her breast, she is referred to a biopsy and imaging tests. In some cases, she will undergo surgery immediately. A PET CT is usually conducted in order to determine whether the cancer has metastasized.”
Must treatment for metastatic breast cancer begin immediately?
“Breast cancer is not leukemia, where treatment is started immediately. Each cancer is treated in a reasoned manner. It is very rare that treatment must begin immediately. Patients must first undergo a biopsy to determine the tumor characteristics, because they apply to the type of treatment used. It is important to have all of the information in order to provide the patient with the best treatment for her.”
What kinds of cancer are there?
“To date, we have divided breast cancer into three types. The first is hormonal breast cancer, and it is the most common. Approximately 70% of the patients will be diagnosed with this type of cancer, and they will receive anti-hormonal medication. The second type is caused by an overexpression of the HER2 protein located in the cell membrane, and it develops into a much more malignant and treatment-resistant form of cancer. In this case, chemotherapy is less effective. The third type is triple negative breast cancer – where the tumor has no hormones and no HER2 expression. In this case, patients are given chemotherapy only.”
“In the past, there were not enough effective treatments for HER2 patients, and the mortality rate was higher among women with this metastatic disease. A revolutionary finding over 20 years ago enables antibody treatment for the disease so that it can become a kind of “chronic disease.” Patients with early-stage breast cancer will undergo surgery to remove the tumor, along with chemotherapy and antibody treatments.
“An advanced generation of drugs was developed for HER2 metastatic breast cancer patients several years ago called antibody mediated chemotherapy, and there is even a new and more advanced generation acting as a “guided missile.” The treatment actually contains chemotherapy that directly targets the malignant cell and is activated only when reaching it. In other words, the chemotherapy works only on the cancerous cells. It is a true revolution with fewer side effects.”
Does HER2 have different levels of expression?
“Yes. HER2 is examined in a pathological test. The protein is viewed under a microscope, and its expression is rated by membrane intensity between 0-3. Levels 0, 1 and 2 are considered HER2-negative, and Level 3 is HER2-positive. Until now, we related only to the “negative” and “positive” descriptors. Today, we know that there are different levels of expression, and cancers with Levels 1 and 2 may have therapeutic implications. Some studies examine whether medium and low-level HER2 is significant, and there are already findings that demonstrate that such patients can indeed be treated.”
Can the body be resistant to medication?
“Yes. That is one of the greatest problems in cancer treatment and specifically in breast cancer. Women who usually respond well and over time do not develop a resistance to the treatments. If a treatment ceases to work, it probably happens in the beginning. Cancer is very smart, and it develops bypassing resistance trajectories and resistance to various drugs.”
Do you believe a cure for cancer will be found?
“Cancer is not just one disease – it is many diseases. We have a group of treatments called immunotherapy, where we teach the body’s immune system to fight the cancer. We prescribe drugs that teach the body how to identify the cancer as a foreign object, and that’s a true breakthrough, because the drugs work on many tumors, but less on breast cancer. But in principle, each tumor is unique, and it is very difficult to find just one cure.”
Should someone with metastatic breast cancer consider it a treatment for life?
“Yes, it is a permanent treatment. Metastatic breast cancer can become a chronic disease for years, but unfortunately, this is not always the case. There are many new developments that help us, but not always.”
This article was written in cooperation with AstraZeneca