Self-collected HPV specimens may help detect cervical cancer sooner than cytology, according to study results.
The self-collected method also may help reduce patient costs and boost coverage, researchers wrote.
Although cytology-based screening has helped reduce the percentage of cervical cancers, it often must be repeated to help identify underlying abnormalities that eventually could prove to be cancerous.
HPV testing has demonstrated greater specificity and sensitivity than cytology-based screening for identification of precancerous lesions, according to study background. HPV testing also has the advantage of self-administration, as women can collect necessary samples themselves in a noninvasive manner and likely at reduced cost.
Carolina Porras, MS, of the Proyecto Epidemiologico Guanacaste, Fundacion INCIENSA in Costa Rica, and colleagues performed a secondary analysis of a large Costa Rican HPV vaccine trial to determine whether self-collected HPV samples could detect cervical intraepithelial neoplasia grade 2 or higher adenocarcinomas and do so with the same accuracy as HPV tests administered by a clinician.
Researchers identified a full analytical cohort of 5,109 women from the original enrollment in the Costa Rica Vaccine Trial. The women were aged 18 to 25 years, and all had a self-collected HPV sample with an available HPV-polymerase chain reaction result at their 6-month follow-up. A subset of 615 women also had clinician-collected specimens at the 6-month follow-up.
Patients underwent annual follow-up for 4 years. The median age at the 6-month follow-up was 22 years. The median follow-up for the full cohort was 54 months (range, 9-76 months), and median follow-up for the subset was 55 months (range, 10-74 months).
In the full cohort, one-time HPV testing on self-collected specimens detected prevalent CIN2+ with a sensitivity of 88.7% (95% CI, 77-95.7) and a specificity of 68.9% (95% CI, 67.6-70.1). During the subsequent 4 years, sensitivity was 73.9% (95% CI, 65.8-81) and specificity was 69.4% (95% CI, 68.1-70.7).
In the subset of women who also had clinician-collected specimens, self-collected HPV was considerably more sensitive than cytology (80% vs. 10%), and the relative sensitivity was 0.1% (95% CI, 0.03-0.5).
Women with normal baseline cytology were nearly three times more likely than those with a negative self-collected HPV sample to subsequently develop CIN2+ (relative complement of the negative predictive value = 2.9; 95% CI, 1-8.3).
Overall, self-collected samples were comparable to those collected by clinicians with regard to their ability to identify carcinogenic HPV types (89%; kappa = 0.78, McNemar test = 0.62).
“The similar performance of the self-collected and the clinician-collected HPV test for detection of prevalent and incident disease indicate that this could represent an invaluable tool for improving screening coverage,” the researchers wrote. “Our data indicate that PCR HPV testing on a self-collected sample is feasible and well-accepted and provides sensitivity and specificity comparable with clinician-collected specimens. In addition, it detects disease earlier than cytology and should be considered in cervical cancer screening programs to reduce cost and improve coverage.” – by Anthony SanFilippo
Disclosure: The researchers report no relevant financial disclosures.