Normal Cell Tests Do Not Guarantee Women Won’t Develop Pre-Cancerous Changes Leading to Cervical Cancer

HPV16 & 18 were associated with an increased risk of pre-cancerous cervical changes and cervical cancer

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An international team of researchers has uncovered an increased risk of cervical cancer in women whose cervical cells test positive for certain high-risk human papillomavirus (hrHPV) types, but do not show any signs of cellular abnormalities. 

These researchers conducted a study to determine what risk women may face if they test positive for HPV, but their cervical cells do not show any indication of being cancerous. 

About a dozen high-risk HPV types have been identified, with types 16 and 18 responsible for most HPV-caused cancers.   

A test called liquid-based cytology, which is similar to the Papanicolaou [Pap] smear, was utilized for this study. 

Conventional Pap smears can have false-negative and false-positive results because of inadequate sampling and slide preparation, and errors in laboratory detection and interpretation. 

However, liquid-based cytology rinses cervical cells in preservatives so that blood and other potentially obscuring material can be separated. It also allows for additional testing of the sample, such as for HPV. 

The study included 576 women with normal findings on liquid-based cytology of the cervix who were followed for 9 years. 

During that follow-up period, 92 of the women developed high-grade pre-cancerous cervical changes and 4 women developed cervical cancer. 

These 96 women were compared with 480 women with normal findings on follow-up cervical cytology and matched by age. All 576 baseline cervical samples were tested retroactively for HPV. 

For women younger than 30 years, only HPV16 and HPV18 were present significantly more often among cases than controls and were therefore associated with an increased risk of pre-cancerous cervical changes and cervical cancer. 

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For women aged 30 years and older, other HPV types in addition to HPV16 and HPV18 conferred a significant risk. 

"These findings can help in the ongoing development of guidelines for cervical cancer screening. They strongly indicate that testing for HPV needs to be incorporated into screening programs," said principal investigator Sonia Andersson, MD, Ph.D., of the Karolinska University Hospital and Institute in Sweden. 

"Women younger than 30 with a positive HPV16 or HPV18 finding need to be closely followed, whereas other HPV types are much less likely to be associated with increased risk in these younger women,” said Dr. Anderson in a press release.

“Normal cell tests are therefore no guarantee that a woman won’t develop precancerous changes that can lead to cervical cancer,” says Dr. Andersson.   

“Among women above age 30, any HPV positive finding should be closely followed." 

Dr. Andersson also noted that women who are found to have pre-cancerous cervical changes should receive appropriate gynecologic treatment to help prevent the development of invasive cervical cancer. 

Separately, on November 2nd, 2018, a new study found women with hrHPV positive cervical tumors had a substantially better prognosis than women with hrHPV-negative tumors. 

These researchers found that women with hrHPV-positive tumors had 39 percent lower excess mortality than women with hrHPV-negative tumors, irrespective of other standard factors for invasive cervical cancer (ICC) prognosis. 

This means the presence of hrHPV in women with ICC was associated with improved survival rates.