Monday, March 17, 2008

Testicular cancer gauge often not used

A standard part of testicular cancer care isn’t used in more than half of all patients who have the condition, researchers at the University of Michigan Comprehensive Cancer Center have found.

Serum-based tumor markers, which are one indicator of the presence of cancer cells, are helpful in several aspects of the care of patients with testis cancer, including diagnosis, prognostication and surveillance for disease recurrence following treatment. Doctors typically rely on a series of three tumor markers with this type of cancer.

In a review of more than 4,700 testicular cancer cases, a combination of two of these tumor markers were used less than half of the time, while all three tumor markers were measured in just 16 percent of the cases.

The authors of the study found that only about 45 percent of cases used the tumor markers AFP (alpha fetoprotein) and HCG (human chorionic gonadotrophin). Those two were used in conjunction with a third tumor marker, LDH or lactate dehydrogenase, 16 percent of the time. The results are reported in Urologic Oncology, Seminars and Original Investigations.

“Tumor markers play a central role in showing physicians how a patient is responding to treatment and whether the disease has recurred,” says lead author Scott M. Gilbert, M.D., clinical lecturer in the U-M Department of Urology. “We were extremely surprised by the low rates of usage.”

He notes that information obtained from the use of tumor markers impacts the treatment and potentially the outcome in patients with testicular cancer. If markers remain elevated after therapy, it indicates the cancer remains, or if they begin to rise during the surveillance period following successful treatment, the cancer has returned. Gilbert says he and his colleagues regularly check all three tumor markers in their patients.

A majority of the sites in the study failed to show improvement during the study interval, and one – Detroit – experienced a decrease in the use of tumor markers by the end of the study.

The authors point out that the low rates of usage don’t necessarily indicate that the tumor markers were being used as infrequently as the numbers would suggest. One explanation could be that the documentation in medical records was poor, and incidents of tumor marker use were not always recorded, says senior author Brent K. Hollenbeck, M.D., M.S., assistant professor in the U-M Department of Urology.

“Even if it isn’t a problem related to the care of the patients, it is a quality problem at the medical centers that are not recording the data properly. Either way, major improvements need to occur,” he says.

But other data in the study suggest that the reporting of tumor marker use may not be the problem. Using the data from the Surveillance, Epidemiology, and End Results (SEER) program, the researchers found substantially more documentation of PSA use in prostate cancer patients compared to the testicular cancer tumor markers. That information supports the notion that recording may not be the problem, but that the use of testicular cancer markers is in fact very low.