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Course Sample:
Introduction
The three most common gynecologic cancers, cervical, endometrial and ovarian, account for 10 % of deaths from malignancy in women in the United States1. While the signs and symptoms of these tumors have some commonality, each has a distinct presentation, management and pattern of spread. Cervical and endometrial cancers are detectable in the earliest, curable stages while ovarian cancer is difficult to detect and is usually diagnosed in more advanced stages. The goal of this course is to compare and contrast the demographics, risk factors, screening, prevention, and signs and symptoms of the three cancers and to provide an overview of the staging and treatment of each.
Comparative Demographics
Incidence
Table 1 shows the comparative incidence and mortality for cervical, endometrial, and ovarian cancer in the United States.
Table 1: 2007 Statistics for Common Gynecologic Malignancies1
|
Statistica |
Cervical Cancer |
Endometrial Cancer |
Ovarian Cancer |
Total |
|
New Cases |
11,150 |
39,080 |
22,430 |
72,660 |
|
Deaths |
3,670 |
7,400 |
15,280 |
26,350 |
|
a United States data
only |
Cervical Cancer: This is the least common female malignancy in the United States (U.S.). In 2007, 11,150 new cases are expected with 3,670 deaths due to this disease1. World wide cervical cancer is the most common cause of death from gynecologic malignancy2. In developing countries, cervical cancer is the most common malignancy in middle aged women as well as the leading cause of female cancer deaths3. In the U.S., women in lower socioeconomic groups, those with limited access to health care, minorities and the elderly are more commonly affected, primarily due to not having routine screening exams.
Endometrial Cancer: Endometrial cancer is the most common female pelvic malignancy worldwide, and is the fourth most common cancer in U.S. women. 75% of cases occur in postmenopausal women; 5% arise in women < 40 years old. It is more common in Western cultures, although immigrant populations assume the risk of their adopted country over time. Urban and white populations have an increased incidence of the disease over black and rural women. In the U.S., the incidence of this cancer has decreased since 1975, although deaths from it have increased between 1987 and 1998; this may be due in part to decreased mortality from other causes and changes in reporting11.
Ovarian Cancer: This is the most lethal of the common gynecologic malignancies and the fourth leading cause of cancer death in women in the United States. The incidence increases with age with peak incidence at age 75-79. The median age at diagnosis is 63 years. Ovarian cancer is more common in Caucasians than African Americans. It is more prevalent in industrialized countries with the exception of Japan where the incidence of ovarian cancer is low (3/100,000)20.
Risk Factors
Cervical Cancer: Sexual activity is a risk factor for cervical cancer; it is practically non-existent in the celibate. Initiation of sexual activity before the age of sixteen or within one year of the onset of menses confers a high risk of developing this cancer, postulated due to the cervix being more susceptible to oncogenic agents at this stage of development3. Other risk factors include cigarette smoking, oral contraceptive use (which may be related to increased sexual activity),
multiple sexual partners, high parity (>/= 7 full-term pregnancies), and immune system alterations such as HIV, and immunosupression (transplant patients, steroids, etc.). In utero exposure to diethylstillbesterol (DES) also increases the risk of cervical cancer; these women require more frequent screening than the general population.
Cervical Cancer and Human Papilloma Virus Infection (HPV) : HPV is a common viral infection with over 200 types of HPV known to exist. Most infections are asymptomatic and resolve spontaneously. However, over the last decade, genital HPV infection has been identified as a cause of cervical cancer. Thirty known types of HPV infect the male and female genital tracts and can be transmitted via sexual intercourse. About 15 of these increase the risk of cervical cancer1. HPV types 6, 11, 16, and 18 are responsible for about 70% of all cervical cancers (and premalignant cervical lesions) and 90% of genital warts. HPV types 31, and 45 are associated with increased risk of developing cervical neoplasia, but to a lesser degree than types 16 and 18. Oncogenic types of HPV are also associated with cancers of the anus, vagina, vulva, penis, and oral cavity and pharynx11. Most women infected with HPV do not develop this malignancy. Testing for HPV infection using DNA identification technology exists but its role in cervical cancer is unclear at present. This is discussed further with early detection and screening. Likes and Itano provide an excellent overview of HPV infection10.
Endometrial Cancer: Hormone replacement therapy with estrogen alone (i.e., unopposed with progesterone) increases the risk of endometrial adenocarcinoma 4 ? 15 fold12. Risk increases with duration of unopposed estrogen as well as increasing age. Women who use combined hormone replacement therapy (estrogen plus progesterone) have the same risk as those who do not take postmenopausal hormonal therapy. (However, combined hormone replacement therapy has been associated with an increased risk of breast cancer.) Tamoxifen, an anitestrogen, increases the risk of this cancer about two-fold, but its efficacy in breast cancer outweighs the risk. Tamoxifen related endometrial cancers have the same prognosis as those arising de novo. Oral contraceptive use protects against endometrial cancer. Other risk factors include obesity, high-fat diet, early menarche, late menopause, and nulliparity. Thirty pounds above ideal body weight (IBW) increases risk three-fold and fifty pounds over IBW increases risk ten fold. Women with polycystic ovarian syndrome and hereditary non-polyposis colorectal cancer (HNPCC) are also at high risk for endometrial cancer. In HNPCC women have a 20-60% chance of developing endometrial cancer by age 70, although the risk varies with the specific genetic mutation the patient has inherited13. Hypertension, diabetes, endometrial hyperplasia, and a family history of endometrial, breast, or colon cancer are also risk factors.
Ovarian Cancer: Many factors are associated with the risk of ovarian cancer. Table 2 shows factors that increase and decrease the risk.
Table 2: Favorable and Unfavorable Risk Factors for Ovarian Cancer
|
Increase Risk |
Decrease Risk |
|
Nulliparity or lst pregnancy at > 35 y.o. |
lst pregnancy at < 25 y.o. |
|
Infertility |
High parity |
|
Hormone replacement therapy |
Breastfeeding |
|
Fertility (ovulation inducing) drugs |
Oral contraceptive use |
|
Family history of ovarian cancer |
Tubal ligation (ovaries left intact) |
|
Obesity |
|
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