Clear cell adenocarcinoma (CCA) is a rare form of vaginal and cervical cancer in which the inside of the tumorous cells appear clear when viewed through a microscope. It is one of first conditions associated with the use of the drug diethylstilbestrol (DES), and since in premenopausal women not exposed to DES there is virtually no risk of CCA, a discussion of CCA goes hand-in-hand with a discussion of DES.
DES is a synthetic, nonsteroidal female sex hormone with similar physiological effects as those of estrogen. It was prescribed to pregnant women in the 1940s and 50s to reduce the risk of miscarriages. After turning out to have had the opposite effect, it was tested as a “morning after” contraceptive pill. In the late 1960s it was discovered that women whose mother had taken DES during pregnancy had unusually high rates of vaginal cancer.
DES has since been implicated in a number of disorders and conditions, including:
- Structural differences in the anatomy of the reproductive tract
- Vaginal epithelial changes
- Fertility problems
- Pregnancy complications
- Structural changes in the mullerian tract, possibly resulting in a decrease in menstrual flow
Women who were prescribed DES and their daughters who were exposed in utero have a higher risk for developing breast cancer, and although few studies have been conducted in men who were exposed in utero, non-neoplastic genital abnormalities have been reported and higher rates of other abnormalities are suspected.
For premenopausal women exposed to DES in utero, the rate of CCA is approximately 1.5 in 1000, or about 40 times the rate for those not exposed. Approximately 740 cases from various parts of the world had been reported by 2003 to the Registry for Research on Hormonal Transplacental Carcinogenesis. Most cases were diagnosed when the women were in their late teens and early 20s. But cases of CCA have been diagnosed in women who were in their 30s, 40s, and even 50s.
It is estimated that from five to ten million people have been exposed to DES during pregnancy. Many are not aware that they were exposed to DES in utero, or even if they took DES during pregnancy. DES or a similar drug was given, more specifically, from 1938 to 1971 to women with problems or a history of problems during pregnancy. If you suspect that you may have taken DES or a similar drug, or that your mother took DES or a similar drug during pregnancy, you should consider contacting the attending physician or hospital in which the delivery took place and request a review of the medical records.
If the physician has retired or died, another doctor may have taken over the records. The county health department or medical society may know where the records are stored. Some pharmacies keep records for a long time and military medical records are kept for 25 years. In some cases, it may simply not be possible to determine if you were exposed to DES or similar drug.
If you are a woman who believes that she was exposed to DES in utero, you should consider taking the following precautions:
- Pelvic exam – the doctor should not only physically examine the reproductive organs but the rectum as well, and should include palpation, or feeling, the vagina, cervix, uterus, and ovaries for any lumps.
- Pap test – the routine cervical Pap test should be supplemented with a “four-quadrant” pap test, in which samples are taken from all sides of the upper vagina.
- Iodine staining – an iodine solution is used to stain the linings of the vagina and cervix to detect abnormal tissue including adenosis, a non-cancerous glandular tissue.
- Colposcopy – a magnifying instrument is used to view the cervix and the vagina. Not considered a routine test, but should be performed especially if the Pap test result was not normal.
- Biopsy – small samples of tissue are removed and examined under a microscope to detect the presence of cancerous cells.
- Breast exam – the risk of breast cancer may be higher among DES-exposed daughters, who should rigorously follow routine breast cancer screening recommendations.
If you suspect you may have taken DES, if you are a male who was exposed in-utero, or if you simply would like additional information regarding DES and similar drugs, following are some excellent resources:
- Centers for Disease Control and Prevention (CDC)
- DES Action USA
- The Registry for Research on Hormonal Transplacental Carcinogenesis (Clear Cell Cancer Registry)
- National Cancer Institute (NCI): DES Daughters – Women Exposed in Utero