Young women with HPV-16/-18 are significantly more likely to develop high-grade cervical intraepithelial neoplasia (CIN), compared with young women who do not have HPV-16/-18, and therefore require close monitoring, according to a 9-year study of more than 500 women.
Specific strain of HPV had less effect on risk in women aged 30 years or older, compared with younger women, reported lead author Maria Fröberg, MD, PhD, of Karolinska University Hospital and Institute in Stockholm and her colleagues.
“With today’s introduction of HPV primary screening into several organized screening programs and with many triage algorithms available, further research is needed to ensure safe follow-up management and prevent the unnecessary treatment of transient positive HPV findings associated with regressive high-grade CIN,” the investigators wrote in Cancer.
To better understand risk associated with HPV, the investigators drew from a database of 9,464 Swedish women who were cytologically negative for cervical intraepithelial lesions or malignancy (NILM) at baseline during 2005-2007. These baseline-negative women were followed for 9 years; during this time, 96 women developed histologically confirmed, high-grade CIN (CIN2, CIN3, cervical cancer, or adenocarcinoma in situ [AIS]). For each case, five age-matched women were selected who did not develop high-grade CIN to make a control cohort of 480 women.
Approximately half of the cases had CIN2 (45.8%), and half had CIN3 or worse histopathology (CIN3+, 54.2%). HPV-16/-18 was more often associated with CIN3+, compared with CIN2 (Pearson x2, 6.12; P less than .02 [2-sided]). Women with high-grade CIN were significantly more likely to have HPV of any strain, compared with controls (odds ratio, 6.78). Women aged younger than 30 years who had HPV-16/-18 at baseline were far more likely to develop high-grade CIN (OR, 9.44) but showed less impact from other strains of HPV (OR, 2.24). In contrast, women aged 30 years or older showed similar increases in high-grade CIN risk when comparing HPV-16/-18 with other strains (OR, 8.16 vs. 9.04).
“These latter findings suggest that genotyping for HPV-16/-18 might be useful for risk stratification among younger women,” the investigators suggested, noting that “further prospective study on this topic is warranted.”
The study was funded by the Swedish Cancer Foundation, the Stockholm County Council, the Swedish Research Council, and the King Gustaf V Jubilee Fund, and the Karolinska Institute. During the study, one investigator received grants from VALGENT and the 7th Framework Programme of DG Research and Innovation (European Commission).
SOURCE: Fröberg M et al. Cancer. 2018 Dec 10. doi: 10.1002/cncr.31788.