Study shows promise for cancer diagnosis
DEAR DOCTOR: I recently read that a modified Pap smear has the potential to show early warning signs of ovarian and endometrial cancers, as well as cervical cancer. When might it be available?
DEAR READER: An almost all-purpose test is a tantalizing prospect.
Already, the Pap smear and HPV testing are crucial screenings in the diagnosis of cervical cancer and have led to a significant decline in death rate from the disease. Yet thus far, screening tests for endometrial (uterine) cancer and ovarian cancer have not been promising.
Endometrial cancer and ovarian cancer combined still claim the lives of about 25,000 women in the United States per year because such cancers are often found only after they have spread to other portions of the body. A screening test to find these cancers could dramatically reduce those numbers.
Such a test could be available in the relatively near future. A greater understanding of the gene mutations involved in these two cancers has spurred some scientists to propose a simple technique to find these mutations using DNA testing of the fluid obtained through the Pap smear. A study published in March assessed the technique’s ability to detect such mutations. Researchers looked for mutations within 18 genes and also for an abnormal number of chromosomes using a technique called “Pap SEEK.”
This was a retrospective study, meaning that the test was conducted among women who had already been diagnosed with cancer. It’s unclear how well the test would work as a screening. A large screening study is needed to help us understand the true potential benefits of the test.
However, the results are encouraging, especially as a way to detect endometrial cancer when used on samples taken from farther within the cervix and to detect ovarian cancer when used with a blood test.
The test may not be available for several years, but it’s good to know that our increased ability to conduct DNA testing is likely to help us catch these cancers early enough to save more lives.