The American Cancer Society estimates that 234,000 Americans will be diagnosed with breast cancer and that 40,700 will die of the disease in 2015. It is the most frequently diagnosed cancer globally and is the leading cause of cancer-related death in women.
The cause of breast cancer is unknown in the majority of cases. However, some of the risk factors have been established, including female gender, increasing age, family history , early menarche, late menopause, older age of first live childbirth, prolonged exposure to hormone replacement therapy, previous chest wall irradiation, increased breast density on mammograms and genetic factors such as BRCA mutation.
Over the years, the treatment of breast cancer has been surgery followed by chemotherapy with or without radiation therapy in some patients.
Most of the time, surgery may include just a lumpectomy (only removing the cancerous mass) rather than mastectomy (whole breast removal) with almost the same long-term prognosis, provided that the patient who undergoes lumpectomy receives radiation therapy after surgery.
With better understanding of breast cancer biology, we now have new strategies in treating this cancer by medications that are more effective yet less toxic to the patient. Even with cancers that are known to be unfavorable or aggressive, we are now able to convert these into more favorable tumors with excellent prognosis by the use of specific therapy for these type of cancers.
With the discovery of certain receptors that are only present on cancer cells but not on normal cells, and by targeting those receptors - such as anti-estrogen receptors, anti-HER-2 and m-TOR - we are now able to treat breast cancer more precisely and more efficiently with minimal toxicity.
One of the most fascinating therapeutic strategies in oncology is the one that targets HER-2 receptors. Approximately 20 percent of breast cancers overexpress HER-2, which historically is associated with increased recurrence and overall worse prognosis compared to HER-2 negative breast cancer. However, the discovery of HER-2 directed therapy is a paradigm shift that has revolutionized the natural history of this subtype of breast cancer, resulting in increased survival of these patients. It obviously abrogated the poor prognosis of this type of breast cancer into a more chronic and favorable disease.
Until recently there were two anti HER-2 medications, Herceptin and the oral medication Lapatinib. Now, we have an additional novel anti HER-2 therapy. T-DM1 (Kadcyla) is approved for patients who progress during or within six months of Herceptin therapy in early (adjuvant) status and those who progressed in the advanced (metastatic) setting. The approval was based on a study of 978 patients who showed significant improvement in disease progression, mortality rate, and overall response rate, with fewer side effects compared to another HER-2 medication (Lapatinib) plus chemotherapy
Moreover, a fourth anti HER-2 therapy, Pertuzumab (Perjeta) in combination with Herceptin and chemo, was also approved for treatment of newly diagnosed metastatic breast cancer as well as in newly diagnosed locally advanced HER2 positive breast cancer and those with tumors more than 2 centimeters prior to surgery.
Other target pathways that are being studied successfully include mTOR, VEGF, EGFR. As a matter of fact, a new class therapy that targets n-TOR pathway (EVROLIMUS) was already approved in combination with endocrine therapy in advanced breast cancer.
The advantage of treating breast cancer as well as other cancers with these targeted therapies is that it only attacks cells that carry those receptors, thus preserving or sparing normal tissue from any bad effects. Chemotherapy does not differentiate between the cancer cells and normal cells. There is now a trend of getting away from chemotherapy in treating many types of cancer.
We are already seeing that direction in lung, kidney and prostate cancers, leukemia, lymphoma, melanoma, and maybe in the near future breast cancer.
If you have any question on this topic, please contact our offices Kingman (928) 681-1234 or in Fort Mohave (928) 770-4560. We will be glad to address your questions promptly.