New Considerations in Defending Against Lung Cancer Cases Part 1: HPV Status

For some time now, we have been writing, discussing, and suggesting that there is great value in thinking about genetic and other “omic” data when defending toxic tort or product liability cases involving disease allegations of any kind. But these “omic” data are especially critical in cases involving allegations of cancer causation.

On this note, we were intrigued when we saw a recent post reporting that defense experts and lawyers in asbestos litigation spent some time thinking about the Human Papilloma Virus (HPV) as a possible factor in a lung cancer case. Needless to say, it is refreshing to see this thinking being applied in an actual case, even though it settled before trial. (Nicholson v. Akzo Nobel, Cal. Super. Ct., No. RG13700989).

HPV and Recent Lung Cancer Case

So, you may be wondering: What is HPV and how does it relate to a lung cancer case? Have I missed something obvious?

HPV belongs to a large family of viruses that have a well-established causative role in various types of cancer such as those of the cervix and pharynx. As a testament to HPV’s well-described association with cancer, Merck’s GARDASIL vaccine was developed to protect against various types of HPV which have been shown to cause “70 percent of cervical cancer cases, 70 percent of vaginal cancer cases, and up to 50 percent of vulvar cancer cases.”

But there is much less scientific evidence on a role for HPV infection in the development of lung cancer (see later for some high-level summaries of recent science). Indeed, while the overall scientific evidence is clear that HPV can cause cancer, the data describing the relationship between HPV and lung cancer is still developing. Given the potential implications for plaintiff and defense attorneys, it is crucial to continue monitoring the emerging science to make sure you are adequately prepared to present or defend your case without being ambushed.

Evaluating the strength of the evidence, of course, takes us to Daubert and tactics. As more and more genomic facts are noticed (intentionally or not), plaintiff and defense lawyers are going to face more and more Daubert issues. It is of course one thing to raise a possibility, and yet a different tactic to actually try to present an expert opinion based on well-developed scientific data.

We raise that gap for a couple of reasons. First, if doctors and lawyers press too far when it comes to possibilities that are not backed up with solid evidence, they can lose a motion in limine (or more) and set a bad precedent that could hurt many parties on their side. On that point, for example, we are well aware that some asbestos defendants are still ruing the days when other defendants took massive adverse verdicts in some cases that perhaps never should have been tried.

With this concern in our minds, we were interested to see the comments of two law professors on the HPV and lung cancer case. Both expressed some doubts about the HPV defense being ready for prime time, but also appreciated the attention to the facts and the strategic thinking.

Here are some pertinent quotes from a recent news article:

“Even assuming there is a connection between HPV and lung cancer, further studies will be necessary to determine the nature of that connection. For example, does the presence of HPV infection increase the risk of developing lung cancer, or is there some sort of synergistic mechanism between HPV and the development of cancer in the lung?” said Jean Eggen, a Professor at Widener University School of Law in Wilmington, Delaware.

“The answer to these questions could vary depending on the type of tumor involved and on individual differences in patients, including but not limited to types and amounts of exposure to substances such as asbestos or tobacco products. Clearly these are questions researchers need to probe further,” Eggen said.

In the same article, another professor, Richard Henke of Western Michigan University’s Cooley School of Law, agreed that causation may be problematic. Nevertheless, he stated: “the specter of this new finding may serve to motivate the settlement of actual cases. That alone is significant.”

Link between HPV and Lung Cancer is Emerging, and Less Established

Below we describe some recent scientific developments on the association between HPV and lung cancer, some of which indicate that HPV may be independently causative of lung cancer in non-smokers (inclusive of never smokers), in addition to playing a role in the causation of lung cancer in smokers.

The mechanism underlying HPV’s role in the carcinogenic process and tumor progression has been known for many years (e.g. Munger, 2004). In short, the virus encodes a number of proteins which disrupt the cell cycle machinery causing a deregulation of the cell cycle, which ultimately leads to uncontrolled cell proliferation (a.k.a. cancer).

With regard to epidemiological data, a number of recent studies have reported their findings, including two meta-analyses.

In one recent study, investigators evaluated the association between HPV infection and lung cancer among Taiwanese women. Data were collected from a number of Taiwanese population databases, and included 24,162 individuals who were identified with HPV infection and 1,026,986 uninfected individuals. Lung cancer incidence among infected and uninfected individuals was compared. After adjusting for age, gender, low income, residential area, and comorbidity, the risk of lung cancer was higher in women, while all cancer risks were high in both men and women. According the authors, these data demonstrate a significant increase in lung cancer risk among Taiwanese women who are positive for HPV (Lin, 2016).

In a meta-analysis conducted by investigators in China, nine published studies were evaluated and included 1,094 cases of lung cancer. The analysis was conducted using HPV in general, and for various subtypes such as HPV 16 and HPV 18.  Overall, for HPV in general it was reported:  “A statistically significant association was observed between HPV and LC patients” (Zhai, 2016).

Another meta-analysis sought to assess the association between HPV infection and lung cancer risk in never-smokers and women. Overall, the ORs in women and in never-smokers were 5.32 and 4.78, respectively. According to the authors, these data suggest a “significant effect of HPV infection in LCNSW [lung cancer in never-smokers and women] (Bae, 2015).

Overall, the scientific evidence is clear that HPV can cause cancer, as is the case for cervical cancer and other types of cancer. However, the data describing the relationship between HPV and lung cancer is still developing. Given the potential implications for plaintiff and defense attorneys, it is valuable to understand the big picture science and continue monitoring the emerging science to make sure you are adequately prepared to defend your case and to reduce the likelihood of being ambushed by your opponents.


As a further takeaway, our view is that spotting occasional genomic issues is great, but in our experience, issue-spotting is much more efficient, useful and effective when there is an organized, disciplined plan in place to identify the relevant genomic issues and obtain the relevant information for the case. In our work with defense teams, our overall goal is to translate the latest scientific findings into actionable steps lawyers can take to effectively obtain the information your experts would like to have. That takes a disciplined approach, and doing so can benefit both clients and lawyers, on any side of the issues.

Over the past year, we’ve had fascinating conversations related to how genomics and related technologies may seriously impact toxic tort litigation in the future. We encourage our readers to talk to us about the many potential ways we can help develop a focused and efficient relationship that can help you take difficult scientific concepts and determine how they may apply to your case.

How Are You Monitoring the Science?

Are you struggling to maintain an up-to-date awareness of the science related to your cases? We’ve designed a tool to help busy litigators and litigation teams stay current on the science – we call it DataTrove®. Click here to learn more about our unique tool.

Giovanni Ciavarra, Ph.D.

Kirk Hartley, Esq.