According to the 2012 Annual Report to the Nation on the Status of Cancer, overall death rates in the U.S. continued to decline from 2003 to 2008, thanks to prevention, earlier detection and better treatments. New cases of all types are declining at a rate of 0.6% per year for men and 0.5% for women, with decreases are seen in breast, lung, colorectal, brain and cervical cancer. Cases are still increasing in kidney, pancreas, liver, leukemia and melanoma.
Research has explained a great deal about the causes of cancer. Cell transformation and uncontrolled growth can be triggered by environmental factors, including exposure to tobacco, chemicals, radiation and diet. Internal factors also play a role: these include inherited genetic mutations, hormones, and medical conditions like certain viral infections and immunodeficiency. Historically, cancer treatment has focused on combinations of surgery, radiation and anticancer drugs to remove tumors and kill fast-growing tumor cells. In the future, targeted therapies will be based on genetic features of an individual’s cancer.
Breast cancer research and treatment are in an era of great change and advance, thanks to landmark genetic studies that are pointing the way to new, targeted treatments and suggesting better uses for existing treatments.
In September 2012, in the journal Nature reported the first comprehensive genetics study of breast cancer, which some experts hailed as “a road map to a cure.” The study identified four genetically distinct subtypes of breast cancer, and found that individual tumors seem to be driven by distinct subsets of genetic changes. One rare type, called “triple negative,” appears to be more like ovarian cancer. This raises the possibility that ovarian cancer drugs might be effective in treating this breast cancer subtype.
Better understanding of cancer subtypes lets physicians select the most effective treatment for a specific type of disease. Targeted breast cancer therapies like Herceptin and Tykerb, which are effective for HER2 positive women, are changing cancer treatment. Experts expect that most cancer patients will use targeted treatments within the next five to 10 years.
The two newest treatments for breast cancer are Afinitor and Perjeta, both approved in 2012. Afinitor is used in combination with Aromasin to treat menopausal women with a certain type of advanced breast cancer (hormone-receptor positive, HER2-negative). Perjeta is used in combination with Herceptin to treat HER2-positive breast cancer.
Lung cancer treatment depends on the type of cancer and on the stage of disease progression. When lung cancer is diagnosed in early stages, surgery and radiation may be used to remove or destroy tumors. But most lung cancer is diagnosed in later stages when treatment focuses on chemotherapy. A number of drugs can be used alone and in combination.
The goal is to select the drug most effective for specific cancer cell types and tumor characteristics, matching the right drug to the right patient. In the last decade, clinical research has developed new agents that increase treatment options, including targeted therapies like the monoclonal antibody Avastin, which is effective in from 50% to 60% of patients with non-small cell lung cancer.
In 2012, the Food and Drug Administration approved Abraxane for the treatment of non-small cell lung cancer. Newer drugs for non-small cell lung cancer include Tarceva, Erbitux and Alimta.
Treatment for prostate cancer varies depending on a man’s age, the stage of the disease, and other medical conditions. Physicians use a numeric scale, called the Gleason score, to measure the stage: “2” indicates the most slow growing (non-aggressive) and “10” the most aggressive disease. In many cases, physicians may simply monitor the cancer using PSA levels and biopsies to be sure it does not spread. Other treatment options include surgery to remove the prostate and various types of radiation therapy to destroy cancer cells inside the prostate.
Clinical research is developing new treatments, including hormonal therapies and chemotherapy. Hormonal therapy helps reduce levels of testosterone, which drives tumor growth. Hormonal therapies include LH-RH agonists (luteinizing hormone releasing hormones) and androgen blocking drugs. Patients who do not respond to hormonal therapy may be treated using chemotherapy and immunotherapy. The newest therapies are Xtandi, approved in 2012; and Zytiga, approved in 2011; and Provenge, approved in 2010. Provenge is a vaccine that uses the immune system to treat cancer. Xtandi and Zytiga treat metastatic disease when home and chemotherapy are not effective.
Thanks to advances through clinical research, Hodgkin lymphoma is a highly treatable cancer. Hodgkin lymphoma is usually treated with chemotherapy, radiation therapy, or both. Ten-year survival rates are nearly 80 percent. The newest drug for Hodgkin lymphoma is Adcetris, approved in 2011.
Non-Hodgkin patients are usually treated with chemotherapy. The outcome for NHL patients is improving, mainly due to monoclonal antibody therapies that target lymphoma cells, such as Rituxan and Campath. Two newer monoclonals, Zevalin and Bexxar, were approved in 2002 and 2003. A number of therapies have been introduced since 2005 to treat subtypes of lymphoma. These include Treanda for indolent B-cell NHL, and two drugs, Folotyn and Istodax for peripheral T-cell lymphoma.
More than 274, 000 Americans are leukemia survivors. Thanks to advances in chemotherapy, survival rates have quadrupled over the past 50 years. Different treatment approaches are used to treat each type of leukemia, so accurate diagnosis is very important. Drug therapies are used to clear the blood and bone marrow of cancerous cells. Targeted immunotherapies and stem cells are also important treatment approaches. Stem cell transplants are replacing bone marrow transplants to restore bone marrow after high doses of chemotherapy.
Treatment advances in the 2000s include monoclonal antibodies, including Campath and Arzerra approved for CLL in 2009. These agents attach to cancer cells to target them for destruction by the body’s immune system. Tyrosine kinase inhibitors, such as Gleevec and the newer Tasigna, are important advances in the treatment of CML. The newest treatment for ALL is Erwinaze, approved in 2011. Two drugs were approved in 2012 to treat types of CML: Bosulif and Synribo.