An Ounce of Prevention, a Hope for Cure of Cervical Cancer
According to the U.S. Centers for Disease Control and Prevention (CDC), nearly 13,000 women in the U.S. are diagnosed with cervical cancer each year, but the disease can be prevented with vaccination and appropriate screening. Read how researchers in our network are discovering new ways to prevent and treat cervical cancer.
We interviewed John Chung-Kai Chan, M.D., a gynecologic oncologist at Sutter’s California Pacific Medical Center (CPMC) and Palo Alto Medical Foundation, and Denise & Prentis Cobb Hale Endowed Chair in Gynecologic Oncology Research. Dr. Chan oversees CPMC’s gynecologic research program.
- What are the most pressing challenges in preventing and treating cervical cancer today?
In most cervical cancers and pre-cancerous cervical lesions, the disease is caused by infection of human papillomavirus (HPV) usually contracted in teenage years. HPV is a group of more than 200 related viruses, of which more than 40 are spread through direct sexual contact. Among these, two HPV types cause genital warts, and about a dozen HPV types can cause certain types of cancer such as those of the cervix, anus, throat, and vagina.
The HPV vaccine not only protects against 90% of cervical cancers, but also provides protection against most of the genital cancers in men. Additionally, the vaccine protects against 90% of genital warts in both women and men.
Uptake of HPV vaccination in the U.S. is estimated to be only 40%, compared with 90% in Australia. And this low rate of HPV vaccination presents one of the biggest challenges in preventing cervical cancer. According to the CDC, up to 93% of cervical cancers could be prevented by screening and HPV vaccination.
Our goal is to prevent the development of cervical cancer caused by HPV infection through more widespread HPV vaccination and improved screening for early detection.
- What are you most excited about when we look to new advances in treatment on the horizon, or advances in our understanding of cervical cancer?
My research is focused on understanding the factors underlying low rates of vaccination in the U.S. and inequities in vaccination based on race and ethnicity, socioeconomic status, and access to care. In general, research suggests lack of awareness about the link between the HPV virus and development of cervical cancer, and a social stigma related to a sexually transmitted infections.
Through research, we can better understand why HPV vaccination rates are low, compared with a similar case study: liver cancer, and vaccination against the hepatitis B virus. Approximately 60% of liver cancers are caused by hepatitis B infection, and can be effectively prevented with vaccination.
So I’m most excited about our disparities research on HPV vaccination and prevention of cervical cancer through more effective and widespread uptake of the vaccine.
- How are cancer investigators at Sutter Health applying the latest insights in research, to develop new therapies and improve screening?
Research at Sutter gives us clues into new ways to prevent, screen for, and treat cervical cancer. For example, we are studying:
Trends and patterns in HPV vaccination, emerging and new strains of the HPV virus, and differences in uptake, and effectiveness based on race and gender. For example, trends suggest that people of color are less likely to be vaccinated against HPV than Caucasians, as are people uninsured for medical care in the U.S. Male adolescents are less likely to be vaccinated against HPV versus females (approximately 20% versus 40%, respectively). People who identify as LGBT are more likely to be vaccinated against HPV versus people who identify as heterosexual.
The effects of “herd immunity,” or protection against HPV infection through “crowd effect” where one person not vaccinated against HPV is less likely to become infected because their community has high HPV vaccination rates.
- What current cervical cancer studies at Sutter Health are you most intrigued by? Why?
My research team has begun a multidisciplinary, collaborative project including psychiatrists, sociologists, immunologists, infectious disease specialists, gynecologic researchers and physicians, and computational analysts. We are using data from the electronic health records (EHRs) of people diagnosed with depression and applying machine learning algorithms to understand the potential link between high-risk behaviors (e.g., alcohol and drug use, multiple sexual partners, unprotected sex) and contraction of the HPV virus.
Our goal is to identify people with depression who are at increased risk of contracting the HPV virus (and thus at increased risk of developing cervical cancer) and intervene with education around the benefits of HPV vaccination in helping prevent cervical cancer and other illnesses caused by HPV infection.
In a separate project, we will evaluate a serum biomarker for stress called d C-reactive protein, which increases during the body’s response to stress and/or infection. We will compare levels of C-reactive protein to better understand the link between depression, stress, and contraction of the HPV virus.
Beyond research into more effective and widespread HPV vaccination strategies, we are also engaged in clinical trials of new and investigational drugs to treat cervical cancer.
For example, in one clinical trial we’re studying the anti-cancer effects of a new class of cancer medications called PD-1 inhibitors, a type of immunotherapy that block cancer cells’ ability to evade the immune system. One such PD-1 inhibitor called pembrolizumab (Keytruda®) has shown promise in treating cervical cancer when combined with other biologic agents.