Article: Report on vaccines to prevent hereditary cancer

Contents

What the segment was about

Good Morning America aired a segment entitled “Can a vaccine help prevent breast cancer at its earliest stages?”  The segment featured women who underwent risk-reducing mastectomy and discussed early research on preventing cancer. They interviewed Douglas Hager, PhD, who described research on cancer prevention. The story goes on to discuss a preliminary plan to develop a vaccine that prevents breast cancer from occurring in people with BRCA mutations.  Hager and colleagues hope the vaccine will eliminate cells that are on the way to becoming cancer cells before cancer develops. While the potential vaccine was the focus of the story, Dr. Hager also mentions medications and other trials that could prevent cancer.  The reporter states that Hager and his colleagues identified a vaccine that has the “characteristics that will work best against BRCA-related cancers,” and noted that they may be able to begin clinical trials in 2 years. 

Preventing cancer is a passion for many in the hereditary cancer community, so this story has led to many questions. It is impossible for a short Good Morning America piece to address all the questions people facing hereditary cancer might have.  This XRAYS article addresses some of the questions and issues raised by members of our community about the state of this science.

More research is needed

While the story outlined some very exciting early research, it is important to remember that there are many steps from developing a potential vaccine in the laboratory to having one approved for use in healthy people. FDA approval of a vaccine is the end result of years of discovery and development. This includes: early laboratory research to find vaccine “targets” within abnormal cells that won’t affect healthy cells; creating the vaccine that will bind with these targets; testing the vaccine’s safety and efficacy in animal models, and producing large quantities of the vaccine. Following laboratory research, the vaccine is then tested in humans in clinical trials. Clinical trials in humans are usually conducted in phases, which begin with testing safety and determining the dose that will maximize benefit while minimizing side effects. This phase is followed by larger trials which determine whether or not the vaccine is effective while further evaluating safety.

This process can take many years. One example of this process is the development of human papillomavirus (HPV) vaccines for prevention of cervical cancer. HPV types 16 and 18, the two types responsible for 70% of cervical cancers, were discovered in the early 1980’s.  During the 1990’s researchers definitively linked HPV infection to cervical cancer and identified unique HPV targets for HPV vaccines.  In 1999 the first HPV vaccine clinical trials began with the first report of efficacy (the vaccine was doing what it was supposed to do-prevent HPV infection) following in 2001.  The FDA approved the first HPV vaccine for females in 2006 and for males in 2009—over 20 years after the first early research.

It is unclear from the Good Morning America story how far along this research is. The vaccine research cited in the story has not been published in a peer-reviewed journal, making it difficult for outsiders to evaluate or comment on the status of the research. We will continue to follow this research.

Cancer prevention studies need many participants and many years to complete.  People making decisions about cancer risk management now should consult their health care providers about their options in order to decide what is right for them.  

State of cancer vaccine research

The idea of a vaccine to prevent cancer has been around for many years and the HPV vaccines are a real-world result.  Cancer vaccines can be divided into four broad categories:

• vaccines to treat cancer (there is one vaccine approved to treat metastatic prostate cancer)
• vaccines to prevent cancer that has been treated from coming back
• vaccines to prevent cancer-causing viral infections such as the vaccines to prevent cervical cancer (human papilloma virus) and liver cancer (hepatitis B virus).
• vaccines to prevent cancer before it starts

The vaccine discussed in the Good Morning America story falls into the fourth category.  If it works, it would kill cells that are on the way to becoming cancer cells before cancer develops. The person who gets the vaccine would then be protected from developing cancer but they would still have the BRCA mutation and could still pass it onto their children. 

While there are currently no vaccines approved to prevent hereditary cancers before they start, recent research into how cancer develops has given researchers clues on how to develop one. One of the challenges in developing vaccines against hereditary cancer is that the cancer develops from the person’s own cells, so the vaccine must be able to tell the difference between a healthy cell and one that is on the way to becoming a cancer cell. This is very different than the HPV vaccine describe above, which is more like a traditional vaccine which targets a virus.

Other BRCA vaccine research

The Good Morning America segment did not cover other groups trying to develop vaccines to prevent BRCA-related cancers. A research group at the Basser Center for BRCA at the University of Pennsylvania led by Robert Vonderheide, MD, PhD and David Weiner, PhD have been studying a new vaccine that could someday prevent BRCA-related cancer in healthy BRCA mutation carriers ^2,3. They are vaccinating patients with early stage cancers that are at high risk for recurrence in order to understand the safety and immunogenicity (whether the vaccine is reacting to the target molecules) of the vaccine in these patients. While not all patients in this clinical trial are BRCA mutation carriers some are. Once this early study is completed, the goal of the next study would be to vaccinate unaffected BRCA mutation carriers to look at safety and immunogenicity in this population. If that looks good the final step would be a large randomized study to look at the risk of developing cancer following vaccination. 

FORCE will keep the community updated on results of vaccine trials and other prevention studies for people with BRCA mutations and other genes that increase risk for cancer.

BRCA affects men too  

The Good Morning America story featured two sisters affected by BRCA mutations talking about their choices for managing cancer risk and their hopes for their young daughters. The story did not mention that men also carry BRCA mutations and can pass the mutation on to their sons or daughters. Men with mutations in BRCA have an increased risk of male breast cancer, prostate cancer (which usually occurs at younger ages than the general population and can be more aggressive), and pancreatic cancer. Men with family members who have mutations in BRCA or who have a strong family history of breast or ovarian cancer should consult with a genetics expert to discuss genetic testing. Current strategies to manage cancer risk can be found here.

Research on prevention depends on clinical trials

People facing hereditary cancer often want better options for themselves and their families.  New forms of screening and prevention require rigorous clinical trials. These trials cannot be completed without mutation carriers who are willing to participate.  If you are interested in participating in ongoing trials for cancer screening or prevention, please see our Research section for studies near you. 

Posted 8/01/17

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Reference

Good Morning America. Can a vaccine help prevent breast cancer at its earliest stages?

Disclosure

FORCE receives funding from industry sponsors, including companies that manufacture cancer drugs, tests and devices. All XRAYS articles are written independently of any sponsor and are reviewed by members of our Scientific Advisory Board prior to publication to assure scientific integrity.