Despite the many chemotherapy drugs for ovarian cancer, none is fully effective, which means the cancer commonly recurs. That poses challenges for physicians, who must use knowledgeable guesswork to figure out a drug strategy for each patient.
But in a step toward personalized medicine, a test known as ChemoFx analyzes chemotherapy-drug effectiveness on a patient's live cancer cells to help identify the drug regimen with the best potential to fight the recurrent cancer.
Patients generally survive longer when the cancer is sensitive rather than resistant to chemotherapeutic drugs. Unfortunately, in many types of cancer, the response rate is often about 25 percent. The challenge is determining cancer sensitivity before treatment. While the test, developed by Precision Therapeutics Inc., has been available for years, it's been unclear whether it improved outcomes.
That is, until now.
A study published online in the journal Gynecologic Oncology shows that ChemoFx -- approved for laboratory prognostic use and covered by Medicare -- is effective in extending the lives of patients with ovarian cancer by 14 months. That represents a 65 percent improvement in overall survival.
The gist of the study is that ChemoFx can be used to provide better treatments for patients with ovarian cancer and extend their lives, said Thomas C. Krivak, director of gynecologic oncology research at Allegheny Health Network in Pennsylvania.
If doctors can determine what chemotherapy drugs the patient's cancer cells respond to, once the cancer returns, they can narrow treatment options and spare the patient ineffective, toxic treatments that bring unwanted side effects, the study indicates. It also would provide new treatment options for many more patients. As the study says, the test can "assist clinicians in the optimal prioritization of therapy."
Live-cell samples from a biopsy, once sent to Precision's laboratory, undergo a five-step process involving robotic automation. Cells are grown, then treated with commonly used chemotherapies to determine sensitivity or resistance. A report sent to the physician details which drugs or drug combinations were effective.
The study involved 262 patients from 2004 to 2011 whose ovarian cancer had recurred, with 55 percent whose cancers were sensitive and 45 percent whose cancers were resistant to platinum-based chemotherapy drugs during the initial round of treatment. Resistance and sensitivity are based on whether the cancer returned earlier or later than six months.
Robert W. Holloway, director of gynecologic oncology at the Florida Hospital Cancer Institute in Orlando, said the study doesn't mean outcomes for each future patient automatically will improve, but it strongly suggests that choosing sensitive drug therapy for the first treatment following cancer recurrence "significantly improves survival, rather than selecting drugs purely based on other considerations."
The recurrence of ovarian cancer usually results in reduced quality of life through bowel dysfunction, pain and an inability to maintain proper nutrition, leading to generalized weakness and death.
"Getting a quick response (after the cancer recurs) means the patient might live to fight another battle another day, hopefully in another year," said Holloway, who did not participate in the study. "Losing the first battle of recurrence often means cutting the war short."
Precision has tested more than 24,000 gynecological specimens sent to the lab by 1,500 doctors in the past 2-1/2 years, said Sean McDonald, Precision president and CEO.
For ovarian cancer, there are more than 20 approved chemotherapy drugs, "none of which works particularly well, which clearly makes therapy decisions even more complex for the physician and the patient," McDonald said, noting the test's ability to personalize the treatment for the patient's unique cancer.
The company is developing similar tests for lung and colon cancer with confidence that "this technology will work across a wide range of cancers," McDonald said.
Krivak said the hope is to turn ovarian cancer into a chronic rather than fatal disease.
"It's baby steps in cancer or a series of baby steps in finding the best targeted chemotherapy," he said. "But this is one of the first steps in customized patient care."
(Contact David Templeton at email@example.com. Distributed by Scripps Howard News Service, www.shns.com.)