Each year, cervical cancer affects an estimated 12,900 women in the US, and results in over 4,000 deaths, according to the American Cancer Society. But a recent study shows that rates may be higher than reported.

Screening for Cervical Cancer

The main screening test for cervical cancer is the Pap smear. A Pap smear collects cells from the cervix and identifies pre-cancerous cell changes that may become cancerous if not treated. Pap smears are highly effective in reducing cervical cancer incidence and death in women of reproductive age. Most screening guidelines recommend women get Pap smears every three years from age 21 to 65.

Guidelines also recommend that women get tested for HPV (human papilloma virus) every five years, beginning at age 30. HPV refers to more than 40 virus types that infect the skin and mucous membranes in the genital area. Certain strains of the virus can lead to genital warts, while others can cause cancers of the cervix, vulva, vagina, anus, or penis.

Recent Study Raises Questions

A recent review of a national database suggests that the estimated incidence of invasive cervical cancer is actually higher than previously published rates—from 11.7 cases per 100,000 women to 18.6, an increase of almost 60 percent.

What's the reason for the increase? The review excluded women who have had a hysterectomy, and thus are at a lower risk of developing cervical cancer since they no longer have a cervix. Approximately 20 percent of women over the age of 20 have had a hysterectomy.

The review also noted that the incidence rate increased from 14.8 cases per 100,000 women to 27.4 in the 65+ age group, a population of women that has historically had a low incidence of cervical cancer. For African-American women, the rate increased from 74.7 to 128.6 cases per 100,000 women.

The authors suggest there may be potential benefits of extending screening guidelines to include older women. However, not all experts agree. A spokesperson from the American Cancer Society believes the rates will still be low in women over 65 who were adequately screened. She says screening older women is less effective because of difficulties sampling cells from the cervix.

New Potential Screening Tool

The Food and Drug Administration just approved a stand-alone HPV test for primary cervical cancer screening in women 25 and older. The test detects viral DNA from 14 different HPV strains (strains linked to cancer in men and women). However, most screening guidelines don’t recommend the HPV test as a primary screening tool.

The Bottom Line

The United States Preventive Task Force, an independent panel of experts that reviews data and makes screening and treatment recommendations, says there are no substantial benefits to screening women over 65 who have been adequately screened and who have had no abnormal findings. The rate of cancerous lesions in women previously screened is low.

Although approximately 12,000 women developed cervical cancer in 2013, most cases occur in women who have not been properly screened. Experts recommend that regular Pap smears are still a woman's best bet for preventing cervical cancer.

Sharmila Makhija MD MBA FACOG reviewed this article.

Sources

“What Are the Key Statistics About Cervical Cancer?” American Cancer Society. Page last revised January 7, 2015.

Bankhead, Charles. “Have Cervical Cancer Rates Been Underestimated?” May 12, 2014, accessed July 3, 2014.

McCarthy, Michael. “Guidelines Underestimate US Cervical Cancer Rates and Older Women’s Risk, Study Finds.” BMJ 2014 348. doi: http://dx.doi.org/10.1136/bmj.g3296, May 14 2014, accessed July 3, 2014.

Rustagi, Alison S., Aruna Kamineni, Sheila Weinmann, Susan D. Reed, Polly Newcomb, and Noel S. Weiss. “Cervical Screening and Cervical Cancer Death Among Older Women: A Population-Based, Case-Control Study.” American Journal of Epidemiology 2014 179(9): 1107- 1114.

Adamson Fryhofer, Sandra. “Rethinking Cervical Cancer Screening.” Medscape. June 16, 2014, accessed July 3, 2014.

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“What Should I Know About Screening?” Centers for Disease Control and Prevention. March 7, 2014, accessed July 3, 2014.

“What You Need To Know About Cervical Cancer.” National Cancer Institute. March 29, 2012, accessed July 3, 2014.

“Cervical Cancer: Screening.” U.S. Preventive Services Task Force. March 2012, accessed July 3, 2014.