New drugs, hormone blocking agents cutting cancer reoccurrence by 50 percent
Two thirds of breast cancers in women are hormone fed. Giving women with this type of breast cancer hormone-blocking agents such as aromatase inhibitors can significantly improve their odds of living ten more years without the cancer reoccurring, said Issam Makhoul, MD, a professor of medicine and director of the Division of Medical Oncology in the Department of Internal Medicine at the University of Arkansas for Medical Sciences (UAMS).
"Female hormones feed the fire," Makhoul said. "You have to cut them off. Hormone blocking agents can cut the risk of reoccurrence by 50 percent. There are some side effects, which can vary. In many cases, side effects are more an inconvenience than complications that are functionally affecting the patients. Some patients get hot flashes, aches and pains, but that is a minority. Side effects are usually transient and patients are advised to continue their treatment."
If someone can't tolerate aromatase inhibitors, they can be prescribed a different class of drugs like tamoxifen, which also results in saving the lives of many women.
"Tamoxifen cuts the risk of reoccurrence in half," Makhoul said. "For 100,000 women with breast cancer who have a 40 percent chance of reoccurrence, that would mean 40,000 cases of breast cancer reduced to only 20,000 cases. That is something substantial when we look at large numbers of patients. We have about 240,000 breast cancers per year in our country. Considering the fact that two thirds of those are hormone driven, that is 158,000 women who will have their risk of cancer coming back cut in half. We are changing the natural history of the disease by providing our patients with these drugs and convincing them to take them."
Getting patients to take the drugs can be a challenge. Makhoul said at the time the drugs are prescribed, the patients feel normal and when they start taking the drugs they may start having new and annoying symptoms such as aches and pains andor mood swings, or vaginal dryness. So they may abandon them.
This is the wrong move.
"It is far better for women to talk to their doctor and find ways to treat the side effects, and continue the treatment because that is their life saver, basically," he said.
Another advance in chemotherapy is that oncologists are doing neoadjuvant chemotherapy before surgery.
"There are many reasons to do that," Makhoul said. "Sometimes the tumors are large, have invaded the chest wall or skin, have involved a large number of lymph nodes, or the patient has inflammatory breast cancer that presents like mastitis causing breast swelling, redness and sometimes pain. Chemotherapy before surgery makes the tumors smaller and makes it more possible for surgeons to remove all the cancer without leaving anything behind. Cutting out less also preserves the breast, so you do not have to do a mastectomy."
Approximately 25 percent of all breast cancers carry on the surface of cancer cells a special protein called Human Epidermal Receptor 2 (HER2) that can be targeted with a new class of drugs such as the monoclonal antibody trastuzumab (Herceptin®). Makhoul said that targeting HER2 resulted in significant improvement in cure rates whether patients have early stage or advanced stage or even metastatic breast cancer. The probability of survival and cure in early stage cancer of this type has jumped up to 80 to 90 percent of women who do chemotherapy and antibodies.
"We start with chemo and monoclonal antibodies, then stop the chemo and continue with monoclonal antibodies for a year," Makhoul said. "With stage IV or metastatic breast cancer of the HER2 positive type, many get complete remission with no cancer visible on any scans available. I think many are cured, but we continue treatment because we don't know in case we stop the treatment if the cancer would reemerge. The treatment is well tolerated."
The most recent development in the treatment of stage IV metastatic hormone driven breast cancer is a new class of drugs called cyclin dependent kinase 4/6 (CDK4/6) inhibitors. When added to hormone blocking agents they are likely to double the time of disease control.
There is also great hope for immunotherapy, but Makhoul said that this new class of drugs is still in clinical trials and nothing is yet ready for prime time. Immunotherapy in melanoma and lung cancer has become a part of standard of care.
"However, we do not know yet which subset of breast cancer patients would benefit more from this treatment," he said.
Gwendolyn Bryant-Smith, MD, is shown reading a mammogram.
Progress has also been made in access in Arkansas to the gold standard in breast cancer detection, digital Breast tomosynthesis or 3-D mammography. UAMS has had digital breast tomosynthesis since 2014. "Digital breast tomosynthesis (DBT) in multiple research studies has been shown to increase the detection of invasive cancer by 41 percent," said Gwendolyn Bryant-Smith, MD, director of breast imaging at UAMS. "The really good part about DBT is an overall improvement in finding more invasive breast cancers which are the cancers that are associated with more morbidity and mortality."
Multiple studies have shown 3-D mammograms reduce by 15 percent the number of patients who have to be called back because the first mammogram was inconclusive.
"Dense tissue is white and cancer is white," Bryant-Smith said. "For patients with dense breast tissue, the worry is that the dense tissue might be covering up a cancer. DBT can be very helpful in finding cancer in dense tissue."
An analogy might be a photographer trying to take a picture of a door and having a tree in front of the door. A direct photo shows little detail of the door because the tree is obscuring portions of the door. But if the photographer moves to either side of the tree, more detail of the door can be seen.
"DBT helps us see through overlapping structures so we don't have to call patients back for extra pictures as often," Bryant-Smith said. "There are cost savings from not having to take extra views."
DBT has the potential to change the entire pathway of breast cancer detection in that it requires fewer callbacks and less confusion about whether it is breast tissue versus a real lesion.
"It is really an improvement and we should encourage women to be screened," Bryant-Smith said. "When breast cancer is found early, there may be less need for aggressive treatment."
More and more sites in Arkansas are getting DBT, although it is not yet available everywhere in the state.
Bryant-Smith testified in the Arkansas Senate for legislation which requires all providers in the state to pay for DBT.
"That is a significant improvement because that was not the case before Aug. 1 of this year," she said. "Now this life-saving test is made more available to the public because it can be covered by insurance companies. Multiple studies have shown it to be a major improvement in breast cancer screening."
Many women in Arkansas fail to get screenings.
"Overall, our morbidity and mortality is higher as a result," she said. "A lot of patients are still not being screened and are coming in with late stage disease. We really push mammography, but still have a lot of work to do and improvements to make in this state. We encourage all healthcare providers to make sure their patients are getting screening mammograms. It does save lives."
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