Cervical Cancer and HPV: An Overview

Impact of Cervical Cancer

Cervical cancer poses a significant health threat to women globally, with approximately 99.7% of cases linked to the human papillomavirus (HPV). Despite the implementation of screening programs aimed at reducing mortality rates, an estimated 4,210 women in the United States succumbed to cervical cancer in 2017.

Screening Methods

For many years, cytology samples, commonly known as Pap smears, have been the standard for detecting cancerous cells. Research has focused on the efficacy of HPV testing, both independently and in conjunction with Pap smears, to enhance the identification, prevention, and treatment of cervical cancer.

Comparative Effectiveness of HPV Testing and Pap Smears

Lack of Comprehensive Data

Currently, there is limited information on the effectiveness of HPV testing compared to cytology among women in North America.

Research Methodology

A study conducted in Canada from January 2008 to May 2012 involved women aged 25 to 65 with no prior history of cervical cancer. A total of 19,009 participants were randomly assigned to receive either HPV testing or liquid-based cytology (LBC) using the Pap smear. Women who tested negative with HPV were invited for rescreening after 48 months, while those who tested positive underwent further Pap smear testing. Conversely, women screened with LBC returned for rescreening at 24 months.

Findings from the Study

Incidence of Grade 3+ Cervical Cancer

A publication in JAMA by Dr. Gina Ogilvie and her colleagues revealed that fewer cases of grade 3+ cervical cancer were detected at 48 months among women screened with HPV testing compared to those screened with Pap smears. Despite matching participants based on sociodemographic and lifestyle factors, women across all age groups who initially tested negative with Pap smear screening had higher occurrences of cervical cancer than those who tested negative with HPV testing.

Detection Rates of Grade 2+ Cervical Cancer

It is important to note that HPV tests are less likely to identify grade 2+ cervical cancer compared to Pap smears, potentially leading to more invasive follow-up procedures such as colposcopy and biopsy.

Study Limitations

The study faced several limitations, including potential selection bias, as participants were predominantly highly educated and from two specific geographical areas. This raises concerns about the applicability of the findings to rural and remote populations, who may face a higher risk of cervical cancer.

Conclusion

The research indicates that cervical cancer screening using HPV testing is associated with a lower likelihood of grade 3+ cervical cancer at 48 months compared to liquid-based Pap smear screening. However, further research is necessary to evaluate the cost-effectiveness and long-term outcomes of HPV testing.

Reference

Ogilvie, G., van Niekerk, D., Krajden, M., Smith, L., Cook, D., & Gondara, L. et al. (2018). Effect of Screening With Primary Cervical HPV Testing vs Cytology Testing on High-grade Cervical Intraepithelial Neoplasia at 48 Months. JAMA, 320(1), 43. doi: 10.1001/jama.2018.7464