Cervical cancer used to be the number one cause of death in women about a hundred years ago. But thanks to advancements in medical science, this disease is almost preventable today. However, cervical cancer (CC) still claims the lives of over 4,000 women each year in the US.
While Pap and human papillomavirus (HPV) testing have significantly contributed to the lower mortality rates, there are still certain types of CC that are not easily detected.
Now, a new technique has just been discovered that can better identify this cancer, outperforming both the Pap and HPV screening methods. According to a recent study made public in International Journal of Cancer, an epigenetic-based test accurately detected CC at an astounding 100% in an HPV FOCAL trial.
The baseline “S5” methylation assessment used in the trial correctly identified all 8 invasive CC that developed in the 15,744 women screened. Whereas, the traditional Pap and HPV tests, by comparison, detected only 25% and 50% respectively for this cancer.
Pap tests (or Pap smears) look for abnormalities and precancers through microscopic examination of the cells in the cervix. An HPV test checks for the actual virus rather than for changes in the cervical cells. Although HPV is the leading cause of most CC, it does not necessarily indicate cancer. In fact, many women who test positive for an HPV infection will eventually clear the virus and not develop the disease, warranting unnecessary worry.
The new test analyzes the DNA of the cells. But, instead of checking for variations in the genetic code that would indicate something specific like the HPV virus, the new test inspects for chemical markers or tags that appear on top the DNA, shaping what is called the ‘epigenetic profile’.
Epigenetics is the study of changes in gene expression. Essentially, it refers to chemical and/or other modifications that regulate how genes behave, telling them whether to be turned on or off. Numerous studies have shown how a person’s epigenetic profile can influence their health, even lead to complications later on in life. What’s more is that disruption in the epigenome is known to play a critical role in cancer development.
“This is an enormous development,” said Prof. Attila Lorincz, lead researcher of the study, and developer of first HPV test in 1988. “We’re not only astounded by how well this test detects cervical cancer, but it is the first time that anyone has proven the key role of epigenetics in the development of a major solid cancer using data from patients in the clinic.”
Lorincz believes that epigenetics, not DNA mutations are better indicators of early cancers like cervical, anal, prostate, and colon. “Epigenetic changes are what this cervical cancer test picks up and is exactly why it works so well.”
In addition to the widespread study, the researchers also looked at a subset of 257 women that were HPV-positive. Again, the epigenetic test was better as it detected 93% of precancers in those women, while the Pap and HPV tests combined delivered an 86% detection rate.
“This really is a huge advance in how to deal with HPV-infected women and men, numbering in the billions worldwide, and it is going to revolutionize screening,” noted Lorincz.”We were surprised by how well this new test can detect and predict early cervical cancers years in advance, with 100 percent of cancers detected, including adenocarcinomas, which is a type of cervical cancer that is very difficult to detect.”
Even though the test could take up to 5 years to be fully rolled out, the authors believe that it will also be more cost-effective than the current methods, reducing the number of doctor’s appointments and screenings needed. More importantly, it will detect the disease at its earliest, saving thousands of lives each year.
Source: Darrel A. Cook et. al. (December 2018) Evaluation of a validated methylation triage signature for human papillomavirus positive women in the HPV FOCAL cervical cancer screening trial. Int J Cancer. doi: 10.1002/ijc.
Reference: Queen Mary University of London. “New epigenetic cervical cancer test has 100 per cent detection rate.” December 2018.