September 21, 2020
Institute for Quality and Efficiency in Health Care (IQWiG), Germany
Human papillomavirus (HPV) is a type of virus that can cause abnormal tissue growth and other changes to the cell. There are more than 150 related viruses which are categorized into different types that may lead to wart formation or even cancer. It is transmitted through intimate skin-to-skin contact but is most commonly transmitted through sexual intercourse.
According to data from the HPV Information Centre (2017), every year, 6,670 women are diagnosed with cervical cancer and 2,832 women die from the disease. Cervical cancer is ranked as the 2nd most frequent cancer among women in the Philippines and the 2nd most frequent cancer among women between 15 and 44 years of age. About 58.6% of invasive cervical cancers are attributed to HPV 16 and 18.
The Centers for Disease Control and Prevention (CDC) recommends that girls and boys ages 11 or 12 undergo routine HPV vaccination. However, some organizations prefer administering the vaccine as early as 9 or 10. It is ideal to give the vaccine at this age, before late school-aged individuals or early adolescents actually have sexual contact and exposure to HPV.
A Papanicolau test or Pap smear is a cytology-based test that identifies cell changes or abnormal cells that are collected from the cervix. It is done to detect if these cell changes may lead to cancer or not. The HPV test, on the other hand, checks for the presence of the virus. This test screens for strains most commonly linked to cancer, namely, HPV 16 and 18.
The 2014 study done at the Institute for Quality and Efficiency in Health Care (IQWiG) in Germany assessed the benefit of HPV testing alone or in combination with cytology-based testing in primary screening versus exclusively applied cytology-based testing in primary screening with regard to patient-relevant outcomes.
Cervical cancer screening is known to be an essential part of a woman’s health care. It is a way to detect abnormal cells that may be precancerous cervical lesions or early cervical cancers. When it was done routinely, it has been shown to have greatly reduced the number of new cervical cancers diagnosed yearly and the deaths that resulted from the disease.
The main goal of this study is to do a comparative benefit assessment of screening strategies for cervical cancer. These strategies include HPV testing alone or in combination with cytology-based testing versus exclusively applied cytology-based testing. For this goal, the term “benefit” refers to patient-relevant outcome.
Randomized control trials (RCT) with a minimum duration of one year were included for this systematic review. These studies have investigated HPV testing alone or in combination with cytology-based testing in primary screening versus a strategy that exclusively applied cytology-based testing. The assessment of incidence could only be based on the results of a second screening round; thus, the benefit assessment primarily refers to results of the second screening round. The primary screening done with regard to patient-relevant outcome refers to Cervical Intraepithelial Neoplasia 3/ Carcinoma-in-situ (CIN3/CIS), invasive cervical cancer, and CIN3+.
The benefit assessment of both CIN3+ and invasive cervical cancer provided an indication that HPV testing alone or in combination with cytology-based testing led to lower incidences of both conditions than cytology-based testing alone. First round screening for CIN3+ revealed a higher identification rate when using HPV testing alone or in combination while heterogeneous results were seen in invasive cervical cancer. Lastly, for CIN3/CIS, the benefit assessment no longer provided a hint of an effect of HPV testing alone or in combination with cytology-based testing versus cytology-based testing alone.
Patient-relevant outcomes on overall survival and disease-specific mortality, in relation to the benefit of HPV screening, remained unclear due to insufficient data. No comparative assessment of harm was done. No recommendation for a specific screening strategy could be made at the time.