Epidemiology of Gynecologic Cancers

Gynecologic cancers comprise a group of cancers that begin in the female reproductive organs. The 5 main types of gynecologic cancers are cervical, ovarian, uterine (endometrial cancer and uterine sarcoma), vaginal, and vulvar. Although they are often grouped together, each gynecologic cancer has distinct risk factors, signs and symptoms, prognosis, and disease burden.¹ This article focuses on cervical and ovarian cancers.

Prevalence and incidence of gynecologic cancers

The prevalence, incidence, and mortality rates for the gynecologic cancers vary across diseases. In 2014, gynecologic cancers accounted for approximately 12% (94,990 out of 810,320) of all new cancer diagnoses in women in the United States.² Of the 5 gynecologic cancers, there are approximately 249,496 and 186,138 women currently living with cervical and ovarian cancers, respectively, in the United States.³

Ovarian and cervical cancers represent 1.3% and 0.7% of new cancer cases, respectively, in US women.^3,4 Age-adjusted incidence rates per year based on cases diagnosed from 2006 through 2010 are 12.5 per 100,000 persons for ovarian cancer and 7.9 per 100,000 persons for cervical cancer.^3,4

Rates of ovarian cancer are highest in women age 55 to 64 years (median age at diagnosis: 63 years) whereas rates of cervical cancer are highest in women 35 to 44 years old. Of note, the median age at diagnosis of cervical cancer is 49 years.^3,4 White women have the highest incidence of ovarian cancer and Hispanic women have the highest incidence of cervical cancer, with approximately 13.3 and 10.9 new cases per 100,000 persons, respectively.^3,4

In recent years, there has been a significant reduction in the incidence of ovarian cancer that has coincided with the decreased use of menopausal hormone therapy, following the Women's Health Initiative report, which demonstrated that the health risks outweighed potential benefits when hormone therapy was used to help prevent chronic disease in healthy postmenopausal women.^5,6 Over the past 30 years, the incidence of cervical cancer has decreased more than 50%, largely due to widespread screening with the Pap smear.^7,8 The availability of two vaccines against human papilloma virus (HPV) has led to a reduction in the prevalence of HPV and will likely influence the burden of HPV-associated diseases, including cervical cancer.⁹ The incidence rates of uterine, vaginal, and vulvar cancers have remained relatively stable over the last 10 years.¹⁰

Mortality and survival rates for gynecologic cancers

Patient survival rates vary across the different types of gynecologic cancers and are largely dependent on the stage at which a particular cancer is diagnosed. Five-year survival rates for the years 2003 to 2009 range from 44% for ovarian cancer to 69% for cervical cancer.² It is important to note that the diagnosis for ovarian cancer tends to occur in distant-stage disease (approximately 61% of cases) when the cancer has metastasized. In these patients, 5-year survival is only 27%, whereas, patients diagnosed with localized disease have a predicted 5-year survival greater than 90%.⁴

Conversely, cervical cancer diagnoses tend to occur earlier in the disease process, with 47% of patients receiving a diagnosis when cancer is localized to the primary site and 36% having disease classified as regional. In these patients, 5-year survival rates are 91% and 57%, respectively.³

In general, mortality rates increase with age in women with ovarian cancer. Because ovarian cancer tends to develop in older women, the median age at death is 71 years. The median age at death from cervical cancer is 57 years.^3,4 Black women are more than twice as likely to die from cervical cancer as white women.³

Risk factors for ovarian and cervical cancers

Factors associated with an increased risk for ovarian cancer include: increased age, nulliparity, obesity, hormone-replacement therapy postmenopausal status, fertility drugs, a family history of ovarian, breast, or colorectal cancer, and a personal history of breast cancer. Factors associated with a decreased risk for ovarian cancer include: reproductive history (especially multigravida), oral contraceptive use, tubal ligation or hysterectomy.¹¹

Factors associated with an increased risk for cervical cancer include: HPV infection, smoking, immunosuppression (either from human immunodeficiency virus infection or from immunosuppressive drugs), chlamydia infection, long-term use of oral contraceptives, reproductive history (especially multigravida), younger age at first full-term pregnancy, poverty, and family history of cervical cancer.¹² Infection with the HPV is the leading risk factor for cervical cancer, accounting for approximately 90% of all cervical cancer.¹³ Intrauterine device use is associated with a decreased risk for cervical cancer.¹²

Disparities in quality of care for gynecologic cancers

Despite increased awareness about the importance of screening for earlier detection and treatment of gynecologic cancers, studies suggest numerous disparities in the quality of care for these diseases-in particular with respect to race and socioeconomic status.¹⁴ Overall, it appears that a lack in access to standard care for gynecologic cancers is the major contributing factor to healthcare disparities in this field.¹⁴

Conclusion

Nearly 30,000 women in the United States are estimated to have died from gynecologic cancers in 2014.² Approximately 95,000 women are diagnosed with gynecologic cancers each year.² While improvements in screening and detection have been made for some of these diseases-most notably, cervical cancer-still others, such as ovarian cancer, are diagnosed in the late stages of disease and long-term prognosis is poor. Of the five most common types of gynecologic cancer (cervical, ovarian, uterine, vaginal, and vulvar), ovarian cancer is associated with the highest mortality rate and is the fifth leading cause of cancer death in the United States. Risk factors vary across diseases. Risk of ovarian cancer increases with age. Cervical cancer is strongly linked to HPV infection. There are disparities in the quality of care for gynecologic cancers, largely attributable to differences in access to standard care.

Published: November 08, 2017