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Tuesday, June 1, 2010

Urban Legends, Span Email and the CA-125 Hoax

If you've had an email address for at least a year, you will quickly begin to recognize them. The message indicates you (the reader) should forward this message to as many people as possible. It may be: a new virus, a contest for free money or vacations from leading tech firms, local crime alerts, terminally ill children pursuing a world record, expensive cookie recipes, online petitions, pending government intrusion and taxation, and an immediate blessing from above if you forward the prayer chain to 10 people, etc. Perhaps you have personally forwarded a few of these messages to friends or family out of honest concern, only to find out later it was an email hoax. The number of spams, urban legends and email hoaxes is virtually staggering, yet they all carry the same primary characteristics; a bit of truth mixed with fiction and an encouragement to forward to as many people as possible.

Most urban legends have some basis in fact and this particular email, which has been passed via the internet since 1998, is no exception. There are several versions of a popular email circulating that encourages all women to have a CA-125 blood test yearly as a screening test for ovarian cancer. http://www.snopes2.com/toxins/ca125.htm . The message is rather alarming and suggests that if women don't have this test performed yearly, you are putting yourself (and your health) in grave danger. This is especially scary for women of color because like most other cancers, we suffer disproportionately from the effects of ovarian cancer. This is due to the fact that this disease is usually diagnosed at later stages when treatment is very difficult and often ineffective. This particular email implies that the CA-125 test is a widely kept secret from the female public and that physicians or insurance carriers typically discourage female patients from taking this potentially, life-saving test. I've received so many messages from readers and friends about this topic, I've decided to take a moment to debunk some myths amidst the concern.
The Facts
Yes, there does exist a test or "tumor marker" called CA-125. The level of CA-125 is usually elevated in women with ovarian cancer and in primary peritoneal cancer. It is NOT however, a "screening test" for ovarian, or any other type of cancer; nor is it the female equivalent to the PSA test that is performed on men to screen for prostate cancer. In reality, there is no good screening test for ovarian cancer nor are there any "classic symptoms" for ovarian cancer, as stated in the email. In fact, ovarian cancer is most often without symptoms until it is in later stages. Even then these symptoms are often very vague, such as bloating or general gastrointestinal discomfort, which can be attributed to anything from your menstrual cycle to the burrito you ate for lunch. It is this lack of specific symptoms and adequate screening tests that makes early diagnosis and treatment of ovarian cancer extremely difficult.
What is a screening test?
There are several characteristics of a good screening test:
1.) It must be sensitive (able to detect a particular problem or if the condition exists).

2.) It must also be specific (levels are elevated exclusively in the disease or condition you are looking for).

3.) It must have a low number of false positive results (a positive result means you actually have the disease).

4.) It must be safe, cost effective and widely available.

5.) Most importantly, it must be shown to improve survival rates for the disease you are screening for because it allows for earlier detection and treatment

Why is a CA-125 a poor screening test?
At one time the CA-125 tumor marker created quite a buzz in medical circles, because it was thought to have great potential for becoming a screening test for ovarian cancer. However, several large studies have since revealed that a CA-125 test fails miserably as a screening tool. The CA-125 test fails on most of these counts because:
1.) It is not very sensitive. The CA-125 level is only elevated in 50% of ovarian cancers, and many times it doesn't become elevated until the cancer has already spread. Therefore, a negative test does not necessarily mean that you are free from ovarian cancer.
2.) It is also very non-specific, especially in pre-menopausal women. The CA-125 level is often elevated during normal menses, endometriosis, pregnancy and fibroids. In addition, it can also be elevated in pancreatitis, appendicitis and other cancers such as breast, lung and colon cancer. Thus, an elevated level can mean many things or literally nothing at all.
3.) The CA-125 test has a high rate of false positive results. Numerous false positive results would result in expensive additional testing and risky exploratory surgeries searching for a potential cancer that most likely isn't there.

4.) CA-125 testing as a screening tool has never been shown to improve survival in ovarian cancer.

Why use a CA-125 test at all?
Used properly, the CA-125 is a good test. If one has been diagnosed with ovarian cancer and has an elevated CA-125, it is extremely useful in monitoring the response to treatment. A decrease in the level means chemotherapy is working versus an increase in the level can signify the recurrence of the cancer. Many medical professionals do use a CA-125, in combination with a pelvic exam and trans-vaginal ultrasound with patients who have a strong family history of the disease and a very high risk for developing ovarian cancer. Also, if your physician has good reason to suspect ovarian cancer, such as a mass found during a routine pelvic exam or if one is experiencing a myriad of vague unexplained symptoms (like the woman in the email who had an enlarged belly), it may be a good idea to get a CA-125 test in combination with an ultrasound.
So what do I do?
Unfortunately the best screening test for ovarian cancer that we currently have at our disposal, consists of a yearly pelvic exam followed by more extensive testing if any abnormalities are suspected. Sisters, do be encouraged. As women we have not been forgotten. Medical researchers are hard at work searching for an effective screening test for this devastating cancer. For now, the best that we can do is continue our yearly gynecologic exams and take advantage of the effective screening tests that we do have at our disposal (PAP smears and mammograms). As always, it is extremely important you follow your physician's recommendations for treatment and follow-up.
You only have one life- cherish it… and do I need to remind you to love thyself?
Blessings!

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