September 20, 2011 > New Cancer Treatments Take a Targeted Approach
New Cancer Treatments Take a Targeted Approach
Upcoming Seminar Features Experts in Cancer Care
In late August, the U.S. Food and Drug Administration (FDA) approved a new drug called Crizotinib for the treatment of late-stage, non-small-cell lung cancer in patients with a mutation in a specific gene known as anaplastic lymphoma kinase (ALK). The drug, which is taken in pill form, inhibits an enzyme produced by the mutated gene, helping to shrink or stabilize tumors.
"The survival rates for patients using this drug in clinical trials improved dramatically," says Dr. Vandana B. Sharma, a medical oncologist on the medical staff at Washington Hospital, as well as the medical director of Washington Hospital's Cancer Genetics Program.
Get the latest about cancer treatment from the experts
On Tuesday, September 27, to help people learn more about the latest advances in chemotherapy and radiation therapy, Dr. Sharma and her colleague Dr. Michael Bastasch, a radiation oncologist at the Washington Radiation Oncology Center, will present a free Health & Wellness seminar on these topics. The class, being held from 1 to 3 p.m., will take place in the Conrad E. Anderson, M.D. Auditorium located at 2500 Mowry Avenue in Fremont.
To register to attend the seminar, visit www.whhs.com.
Advancements in treatment, better outcomes
Dr. Sharma points out that in one clinical trial of Crizotinib, 74 percent of the patients in the study were still alive after one year, and 54 percent were still alive after two years. Those figures compare to other studies using conventional chemotherapy for similar patients that found a 44 percent survival rate after one year and 12 percent survival after two years.
"ALK-positive lung cancer represents only about 4 to 5 percent of all lung cancer cases," Dr. Sharma notes. While that may sound like a small group of people who might benefit from this drug, the National Cancer Institute estimates almost 220,000 new cases of lung cancer every year in the U.S., so 5 percent translates into 11,000 people.
Crizotinib is only one of the new drugs targeted at specific cancer-causing gene mutations or at the molecular characteristics of cancer cells. Another new oral medication therapy recently approved by the FDA targets a gene mutation associated with an estimated 50 percent of melanoma skin cancers.
"This drug, vemurafenib, is designed for people with melanoma whose tumors have a specific mutation in the BRAF gene that does not occur in normal cells," Dr. Sharma says.
While vemurafenib is only for patients with the BRAF gene mutation, there also is a new intravenous drug called ipilimumab for treating late-stage melanoma in all patients.
"Ipilimumab is another targeted therapy for cancer, but it targets an antibody on the T cells of the body's immune system, boosting the patient's own immune system to attack melanoma cancer cells," Dr Sharma explains. "The advances in cancer research are helping us better understand the differences between cancer cells and normal cells," she adds. "That is leading to the development of smarter drugs that target the abnormalities of cancer cells and the metabolic features that are critical to the growth and survival of cancer cells but not of normal cells. The result is better outcomes in terms of cancer cell destruction and survival rates, with less toxicity to normal cells."
Targeted radiation therapy
Targeted chemotherapy and gene therapy are not the only weapons in the arsenal in the battle against cancer. In some cases, surgery may still be the main treatment if it appears all of the tumor can be removed. In other cases, radiation therapy may be more effective. Quite often, though, the patient's treatment plan calls for a combination of therapies.
"Radiation therapy targets only cells in the tumor and the immediate surrounding area, so it is used to control cancer at the primary site," explains Dr. Michael Bastasch, a radiation oncologist at the Washington Radiation Oncology Center. "While chemotherapy is used primarily to treat cancers that have spread to other parts of the body, it also can be used to reduce the size of a tumor before surgery or radiation therapy. Low-dose chemotherapy also can be used to concentrate the effects of radiation, making radiation therapy more effective."
New technologies in radiation therapy have dramatically improved the effectiveness and safety of treatment over the past decade.
"We offer the full gamut of advanced radiation therapy treatments, including intensity-modulated radiotherapy (IMRT), image-guided radiation therapy (IGRT) and Gamma Knife radiosurgery," Dr. Bastasch says. "Using radiation therapy in combination with high-resolution CT scans, MRIs and PET scans, we can provide more accurate treatments and decrease the amount of normal tissue being exposed to radiation."
Comprehensive care looks at whole patient
With IMRT, physicians can adjust the intensity and shape of radiation beams to deliver high doses of radiation directly to tumors while avoiding healthy tissue. IGRT combines imaging and treatment capabilities to pinpoint the exact location of tumors before each dose of radiation is delivered. That compensates for the movement of tumors during the course of treatment and minimizes radiation exposure to healthy tissue. Gamma Knife radiosurgery can be used to treat brain tumors without surgical incisions or the side effects that often result from whole brain radiation therapy.
"Having the latest technology in radiation therapy and advanced drugs helps improve the outcomes in cancer treatments," Dr. Bastasch says. "But it's important to integrate the various specialties into a comprehensive treatment plan that looks at the whole patient. At Washington Hospital, we have a local team of experts across various fields, which means patients don't have to drive an hour or more each way to receive treatment at a large university facility or medical center."
The integration of care at Washington Hospital will be further enhanced with the addition of the new Sandy Amos Outpatient Infusion Center, which is scheduled to open later this fall. The center, named in recognition of staff nurse Sandy Amos, who recently retired after 36 years of service, will offer a comfortable environment for patients who require frequent infusions of chemotherapy or biological therapies.
"With the combination of infusion and radiation therapy centers right on campus, we will have even better communication among physicians and closer coordination of patient care," says Dr. Bastasch.