Research informs new national cervical cancer screening recommendation

August 21, 2018, UC Davis
Dr. Joy Melnikow, M.D., MPH. Credit: UC Davis Health

A comprehensive analysis of eight clinical trials and four cohort studies on cervical cancer screening by researchers from UC Davis and Kaiser Permanente Northwest has found that while Pap smears are still highly effective for detecting pre-cancerous cells and cancer, testing for the virus that causes these cancers also is an excellent screening tool.

The findings, published August 21 in the Journal of the American Medical Association (JAMA), were used to inform the U.S. Preventive Services Task Force, which published its updated recommendation on cervical in the same issue of the journal. The Task Force is an independent panel of experts that makes evidence-based recommendations on disease prevention. The Task Force also provides an annual report to Congress on the evidence base for clinical preventive services and recommends priority areas that deserve further examination.

The research was led by Joy Melnikow, director of the UC Davis Center for Healthcare Policy and Research, a family and community medicine physician and expert on evidence-based cancer screening.

The systematic review found that in the first round of screening, testing for high-risk viral types of human papillomavirus (HPV) consistently found a higher rate of precancerous cell changes compared to the Pap smear, also called cytology, which detects pre-cancerous cells and cancer cells. It also found that high-risk HPV tests were associated with higher false-positives and with follow-up testing than screening with Pap smear.

High-risk HPV, a virus that spreads through sexual contact, causes 90 percent of cervical cancer. In most women HPV infections resolve spontaneously, but in some the virus persists and may eventually lead to cervical cancer. Effective screening is associated with low rates of cervical cancer of cervical cancer death.

Melnikow and her colleagues examined studies of high-risk HPV tests alone or in combination with a Pap smear. All of the studies were conducted in organized screening programs in which women were invited to have screening at regular intervals.

The systematic review looked at both the benefits and harms of cervical cancer screening for high-risk HPV. Benefits would include detection of invasive cervical cancer or pre-cancer (cervical intraepithelial neoplasia, CIN). They also looked for the rates of false positive test results, frequency of colposcopy (a test done if a Pap test is abnormal), biopsies and any associated psychological harms.

Melnikow said that the current analysis did not specifically review the evidence on Pap smear, also referred to as cytology, because prior evidence reviews have established that the method is safe and effective.

The analysis showed that high-risk HPV testing used alone led to a statistically significant increased detection of severely abnormal cells, or CIN3+ compared with cytology in a first round of screening. Co-testing studies found no statistical increase in CIN3+ detection.

"Our work demonstrated that there is now strong evidence for the effectiveness of high-risk HPV testing used alone as a cervical cancer screening test," said Melnikow. "We also found that both HPV screening strategies had higher false-positive and colposcopy rates than Pap smears. These false positives could lead to more treatments with potential harms."

"We found that regular screening with any method will lead to lower rates," said Melnikow. "In the U.S., where most women are not part of an organized screening program, our biggest challenge is reaching women who have not been screened."

Explore further: ACOG: New recommendations for cervical cancer screening

More information: Journal of the American Medical Association (2018). DOI: 10.1001/jama.2018.10400

Related Stories

ACOG: New recommendations for cervical cancer screening

December 23, 2015
(HealthDay)—In a practice bulletin published in the January issue of Obstetrics & Gynecology, new recommendations are presented for cervical cancer screening and prevention.

Screening for cervical abnormalities in women offered HPV vaccination

September 19, 2017
Human papillomavirus (HPV) testing detects a higher number of precancerous cervical lesions than cytology-based Pap smears in a female population including a proportion offered HPV vaccination, according to a new study published ...

Risk of CIN3 drops with negative HPV, cytology co-tests

November 28, 2017
(HealthDay)—The five-year risks of cervical intraepithelial neoplasia grade 3 (CIN3), adenocarcinoma in situ, and cervical cancer (≥CIN3) decrease after each successive negative human papillomavirus (HPV) and cytology ...

Self-sampling identifies twice as many women at risk of cervical cancer

February 15, 2018
Using self-sampling followed by HPV testing, more than twice as many women at risk of developing cervical cancer could be identified and offered preventive treatment. This is shown by researchers at Uppsala University in ...

Previous screening results important for decision about smear tests after age 60

October 25, 2017
Being screened again after the age of 60 reduces the risk of cervical cancer in women who have previously had abnormal smear tests and in women who did not have smear tests in their 50s, researchers at Karolinska Institutet ...

Screening, HPV vaccine can prevent cervical cancer: FDA

February 8, 2017
(HealthDay)—Women can reduce their risk of cervical cancer through vaccination and screening, the U.S. Food and Drug Administration says.

Recommended for you

Could the zika virus fight the brain cancer that killed john McCain?

September 18, 2018
(HealthDay)—Preliminary research in mice suggests that the Zika virus might be turned from foe into friend—enlisted to curb deadly glioblastoma brain tumors.

Eating foods with low nutritional quality ratings linked to cancer risk in large European cohort

September 18, 2018
The consumption of foods with higher scores on the British Food Standards Agency nutrient profiling system (FSAm-NPS), reflecting a lower nutritional quality, is associated with an increased risk of developing cancer, according ...

CRISPR screen reveals new targets in more than half of all squamous cell carcinomas

September 18, 2018
A little p63 goes a long way in embryonic development—and flaws in p63 can result in birth defects like cleft palette, fused fingers or even missing limbs. But once this early work is done, p63 goes silent, sitting quietly ...

Enlarged genotype-phenotype correlation for a three-base pair deletion in neurofibromatosis type 1

September 18, 2018
International collaborative research led by Ludwine Messiaen, Ph.D., shows that while a three-base pair, in-frame deletion called p.Met992del in the NF1 gene has a mild phenotype for people with the genetic disorder neurofibromatosis ...

Artificial intelligence can determine lung cancer type

September 17, 2018
A new computer program can analyze images of patients' lung tumors, specify cancer types, and even identify altered genes driving abnormal cell growth, a new study shows.

Researchers develop mechanism for characterizing function of rare tumor cells

September 17, 2018
Scientists have long known that circulating tumor cells, rare cancer cells that are released into the bloodstream, have the potential to provide vital information about a person's specific cancer. But until now, they have ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.