Cervical cancer screening has undergone significant changes over the last few decades. In the mid-1970s, over 50 percent of women were having annual Pap tests (in the form of the conventional Pap ‘smear’) which would begin at 18 years old and continue annually until death. However, more recently, the guidelines recommend that women between the ages of 21 and 65 undergo interval screening every 3 to 5 years. The screening options for clinicians have also expanded beyond conventional Pap smear to include cytology alone, cytology with reflex HPV adjunctive testing, primary HPV screening, and co-testing with cytology and HPV (regardless of cytology result).

Pros and cons of cervical cancer screening options 

As with any screening option, there are pros and cons to each choice. For example, cytology alone does not detect HPV, which is responsible for more than 99 percent of cervical cancers. Using reflex HPV testing with cytology can be helpful in clarifying ambiguous cytologic findings (such as ASCUS). However, this method depends on abnormal cytologic findings to trigger the reflex HPV test.

Co-testing with cytology and HPV testing (regardless of cytology result) detects more disease than either test alone; approximately twice as many cases of cervical dysplasia and cancers as cytology alone(3) and up to 16 percent more cases than primary HPV testing(4).

The alternative option, primary HPV screening, has been shown to miss twice as many cervical cancers than co-testing (1). Similarly, other studies (2) have shown that 1 in 5 women with cervical cancer would be missed when only screening with HPV testing. (Primary HPV screening also misses out on the myriad of benefits of cytologic examination, including but not limited to the presence of endometrial cells, adequacy of the transformation zone, infectious organisms, and so on.) 

PathAdvantage strongly believes in co-testing for cervical cancer screening because it is the best way to get an in-depth understanding of the patient’s overall cervical health. While other methods are limited in the scope of the information they provide, co-testing ensures that the specimen is being utilized to its full potential in order to deliver the most comprehensive findings.


  1. Austin et al. Enhanced detection of cervical cancer and precancer through use of imaged liquid-based cytology in routine cytology and HPV cotesting. American Society for Clinical Pathology. 2018; 1-8.
  2. Blatt et al. Comparison of cervical cancer screening results among 256,648 women in multiple clinical practices. Cancer Cytopathology. 2015; 282-288.
  3. Dillner et al. Long term predictive values of cytology and human papillomavirus testing in cervical cancer screening: joint European cohort study. BMJ. 2008;337:a1754.
  4. Katki et al. Cervical cancer risk for women undergoing concurrent testing for human papillomavirus and cervical cytology: a population-based study in routine clinical practice. Lancet Oncol. 2011;12:663-72