Abnormal Vaginal Bleeding and breast cancer
In premenopausal females, vaginal bleeding is considered abnormal when menstrual cycles last longer than 7 days or when there is excessive uterine bleeding (more than 80 cc/cycle). Vaginal bleeding is also considered abnormal when it occurs between menstrual cycles or after a physical examination or coitus. As menopause approaches, menstrual cycles may become dysregulated such that there are variable periods of amenorrhea followed by episodes of prolonged and usually painless vaginal bleeding.
Bleeding that occurs closer than 21 days between day 1 of one cycle and day 1 of the next cycle or bleeding that lasts longer than 7 days should be evaluated. It is important to note that vaginal bleeding is always considered abnormal in postmenopausal women.
Abnormal vaginal bleeding can be a sign of endometrial pathology, including endometrial cancer, and therefore must be evaluated carefully.
Abnormal vaginal bleeding is cause for heightened concern in patients who have been diagnosed with breast cancer because these patients are at increased risk for the development of endometrial cancer. Vaginal bleeding can also be a presenting symptom of benign endocervical polyps or endometrial hyperplasia caused by tamoxifen treatment.
It is important to consider endometrial malignancy in premenopausal women who present with abnormal vaginal bleeding and any postmenopausal woman who presents with any vaginal bleeding. Approximately 5% of all cancers of the endometrium occur in premenopausal women.
In patients who present with vaginal bleeding, obtaining a careful history of the bleeding is essential. The history may reveal other common sites of bleeding, such as the urinary tract and the lower intestinal tract. Patients sometimes have difficulty identifying the site of origin of the bleeding.
Similar bleeding episodes may have occurred previously. Patients may have a history of endometrial or endocervical polyps or fibroids or recent use of hormonal agents; any of these factors could contribute to vaginal bleeding. Patients who develop oligomenorrhea (infrequent menstruation) within the year before menopause may develop episodes of uterine bleeding due to changes in their estrogen levels.
The initial clinical evaluation of abnormal vaginal bleeding should include a pregnancy test, if appropriate; a coagulation profile; and determination of the following laboratory values: fasting serum prolactin level, thyroid-stimulating hormone level, and follicle-stimulating hormone level. Measuring the luteinizing hormone level is rarely useful because it varies considerably during the day.
An examination of the abdomen and pelvis is always necessary to determine the site and cause of the bleeding. Clinical findings might include a friable cervix with nabothian follicles, suggesting chronic cervicitis; polyps extruding from the cervix, particularly in a patient undergoing treatment with tamoxifen; or an enlarged and irregularly shaped uterus, suggesting a diagnosis of leiomyomata.