Finding The Best Treatment For Recurrent Ovarian Cancer

By Rachael Myers Lowe, cancerpage.com

(February 15, 2006) -  An estimated 4 out of 5 women with ovarian cancer are diagnosed after the cancer has spread beyond the ovary.  Once the cancer has spread treatment is more difficult and a cure is less likely.   Treatment generally consists of surgery to remove as much tumor as possible followed by chemotherapy to kill remaining cancer cells. 

While most ovarian cancers respond to the first line of chemotherapy, most tumors recur and begin to grow again. At that point, a patient is less likely to be treated with the chemotherapy combo received after she was first diagnosed. The tumor has developed a resistance to those agents so the treating physician will try several other chemotherapy agents that have been approved for second line treatment. Depending on a patient’s medical history and response to the first line of therapy, she may be moved through various chemotherapy treatments until one is found that affects her tumor.  Finding the treatment that works is a process of hit or miss.

By its very nature this is a less than desirable way to identify an effective treatment.  As a patient moves through these steps - which can take up to two months each – she’s being treated with toxic chemicals, her tumor may be mutating and she’s developing sensitivities to the toxicities.

Treating physicians have sought a method to more accurately identify the second-line chemotherapy with the best chance of controlling the cancer.

According to a new study published in the International Journal of Gynecological Cancer (IJGC) researchers have developed a test - the ChemoFX Assay - that can identify within about two weeks which chemo agent will be most lethal to an individual patient’s cancer.

In a study of 256 women with recurrent ovarian cancer “the time women went before a worsening of their disease was two to three times longer if they were treated with an assay-sensitive drug compared to an assay-resistant drug,” says the study’s lead author, Dr. Holly Gallion, of Precision Therapeutics, the company that has developed the new assay technology.

“The bottom line is the assay is able to predict the patient’s response to treatment,” Gallion told cancerpage.com.

It’s not a simple lab test, Dr. Gallion says. Live tumor tissue obtained during surgery or from a core biopsy is grown in the lab and subjected to the various chemotherapy agents available to a patient. What had been done in the patient is now done in a Petri dish.

Informed decision making

The assay determines which agents are most potent against a specific tumor and what concentration works best; no more hit or miss in the patient. Armed with that information, the treating physician and patient can proceed with a chemo regimen likely to work right out of the gate and subjecting the patient to less toxicity.

If the assay finds that the tumor responds to none of the currently available treatments, a patient could be referred to a clinical trial before a history of less useful treatments rules her out as a clinical trial candidate.

The test costs between $2-3,000. But the promise is that it not only causes less physical strain on the patient but also eliminates the purchase of drugs that won’t work anyway.

Dr. Gallion says there’s no reason to believe the assay won’t work in other tumor types and it’s possible it would help doctors make a chemotherapy choice for first line treatment. Validating tests are currently being conducted.

The American Cancer Society estimates 20,180 American women will be diagnosed with ovarian cancer in 2006.

SOURCE:

• Cancerpage telephone interview with Dr. Holly Gallion on 2-15-06.