The Abbott RealTime High Risk HPV test (RealTime) and Roche cobas 4800 HPV test (cobas) are widely used HPV tests which enable concurrent partial genotyping for HPV16 and HPV18 and aggregate detection of 12 other hr-HPV types. Whereas both tests are considered as clinically validated for primary cervical cancer screening, studies directly comparing their clinical performance are scarce. Objectives: To compare the clinical performance of the RealTime and cobas in a cohort of Slovenian women, who attended the routine organized national cervical cancer screening programme with +70% coverage.
During the 2009/2010 period, the clinical performance of the RealTime was evaluated on a total of 4,432 women aged 20-64 years. ThinPrep specimens were aliquoted, stored at -80°C and additional testing with cobas was performed in 2015. The main outcome measures were clinical sensitivity for the detection of CIN2+, clinical specificity for the detection of lesions less than CIN2 and predictive values, assessed separately for women >30 years old and for the total study population. Comparisons between both assays were conducted by McNemar’s test for matched pairs.
There was a high concordance between the RealTime and cobas, with a kappa value of 0.91 (95% CI, 0.88-0.94) in women >30 years old and 0.92 (95% CI, 0.90-0.94) in total study population. In women >30 years old (n=3,117), the clinical sensitivity and specificity of RealTime were 100.0% (95% CI, 86.5-100.0%) and 93.2% (95% CI, 92.3-94.1%), respectively, and those of cobas were 97.4% (95% CI, 86.2-100.0%) and 92.6% (95% CI, 91.6-93.5%), respectively. In the total study population (n=4,416), the clinical sensitivity and specificity of RealTime were 98.2% (95% CI, 90.6-100.0%) and 89.5% (95% CI, 88.5-90.4%), and those of cobas were 94.7% (95% CI, 85.4-98.9%) and 88.6% (95% CI, 87.6-89.5%), respectively. Although the clinical sensitivity of both tests was comparable in both study groups (p=1.00 and p=0.48), the RealTime was significantly more specific than cobas in women >30 years old (p=0.005) and in total study population (p<0.001). Positive and negative predictive values of RealTime in women >30 years old were 15.4% (95% CI, 11.1-20.5%) and 100.0% (95% CI, 99.8-100.0%), respectively, and of cobas 14.0% (95% CI, 10.1-18.8%) and 100.0% (95% CI, 99.8-100.0%), respectively.
A well balanced clinical performance of high-risk HPV tests has become crucial since the implementation of HPV testing in organized cervical cancer screening programmes. Both RealTime and cobas have high and comparable clinical sensitivity, however, significantly higher clinical specificity of RealTime was obtained in our cohort.