The following guest post is by Michael Joyner, MD, a medical researcher at the Mayo Clinic. These views are his own. You can follow him on Twitter @DrMJoyner.
It has been almost six months since the “Cancer Moonshot” initiative was proposed by President Obama. Here are some reflections on all of the hype surrounding the initiative and some data that, in my opinion, have not gotten the attention they deserve.
How much money is $700 Million? The Cancer Moonshot includes a little less than 700 million dollars of additional funding to the National Institutes of Health (NIH) for cancer research. Currently the National Cancer Institute (NCI) budget is about five billion per year. If you total up all of the federal, philanthropic and industry funding since the War on Cancer began in 1971, it is on the order of several hundred billion dollars. So while additional research funding is welcome, the amount proposed is simply not that much in the grand scheme of things.
Cancer is preventable. Much of the focus of the moonshot is on cancer treatment. However, cancer is highly preventable as noted in a recent editorial in JAMA Oncology:
Cancer is preventable. In fact, most cancer is preventable—with estimates as high as 80% to 90% for smoking-related cancers, such as lung and oropharyngeal cancer, and as high as 60% for other common, lifestyle-related cancers, such as colorectal and bladder cancer. This large excess of cancer is not inevitable but rather can be tackled by a broad range of interventions at multiple levels, including strategies at the clinician level, the individual level, the community level, and the society level through regulatory change.
Are these estimates a best-case scenario based on observational studies, which as HealthNewsReview.org likes to point out, have limitations? Perhaps. But preventable cancer would still represent a massive target even if the numbers were only half as big. Of note, behaviors like not smoking, getting some exercise and weight control that are associated with much lower cancer risk are also linked to reduced risk of heart disease and diabetes. The graph below is just one example of how cancer deaths vary by state based on smoking rates. The data suggest that even a 10% or 15% drop in smoking rates would have a profound impact on cancer mortality. How low would it go if no one smoked?
Why are cancer rates declining? A number of the proponents of the Moonshot argue that cancer deaths have declined by about 20-25% since the early 1990s — the implication being that technological advances during that time are having a big impact on overall cancer burden. More sophisticated treatments are certainly having some effect, but we should recognize that the decline in cancer rates started only after a big smoking-related rise that began in the early 1970s before peaking in the early 1990s.
Additionally, the vast majority of the improvement has been due to tobacco control and prevention efforts. Many times the same people pushing for more focus on therapy do a bit of bait and switch with these facts. In a recent commentary, for example, the head of the Fred Hutchinson Cancer Center pushed for a doubling of cancer research funding. He pointed to studies on the link between hormone replacement therapy and breast cancer as an example of what could be accomplished. While this is a clear success and good news, it’s also another example of the power of prevention-based approaches as opposed to treatment. Reaping the benefits here doesn’t require any Moonshot; the key is to reduce exposure to the hormones that are causing the excess cancers in the first place.
How are the blockbuster drugs doing? The short answer is not too well, and they cost a lot. The next graph plots the costs of new cancer drugs against the improvement in survival they confer to patients. When the percentage increase in survival is converted to actual months of extra survival time for patients, typically it translates to a whole lot of money for just a few months.
The next graph shows that exciting new drugs that “work” in clinical trials sometimes don’t do as well in the real world. The drug sorafenib was shown to prolong survival by a few months in liver cancer, but the analysis of real world data from Medicare told a different story:
Survival after sorafenib initiation in newly diagnosed Medicare beneficiaries with HCC (hepatocellular carcinoma) is exceptionally short, suggesting trial results are not generalizable to all HCC patients. The downsides of sorafenib use—high drug-related symptom burden and high drug cost—must be considered in light of this minimal benefit.
Targeted therapy, the matching of tumor genetics to drugs that attack specific molecular targets, is also running into trouble. As depicted in the graph below, SHIVA, the only randomized clinical trial comparing targeted therapy to the use of standard approaches showed no difference in outcomes. In other words, choosing “targeted” treatments that are effective against a patient’s specific tumor mutation yielded no improvement in progression free survival over standard care.
According to the researchers, a key lesson from SHIVA is that:
One of the most important take-aways from this study is that the practice of matching drugs to mutational profiling of tumors should not be done outside of a research study.
This evidence-based approach is clearly at odds with the practice of some very high profile oncologists who seem to be advocating a more “improvisational” approach to cancer therapy in high profile places like the New York Times. This approach has been questioned in social media but not much has been said in the mainstream media.
Immunotherapy is perhaps the brightest spot in cancer treatment. However, it is not a slam dunk and one recent clinical trial failed in pancreatic cancer. So even for something as potentially revolutionary as immunotherapy, we all need to keep our expectations about what these drugs can do realistic.
The Moonshot has misplaced priorities. The data highlighted above raise serious questions about exactly what can be accomplished by the Cancer Moonshot. Cancer incidence and death rates will likely continue to decline as long as smoking rates continue to fall and before the obesity epidemic starts to drive cancer upward again. Other measures like the HPV vaccine will also help prevent cancer. However, when you look at the data as a whole and the hype around the Moonshot, you can’t help but be reminded about the relative value of prevention vs. cure. (Hint: one is worth about 16 times as much as the other.) Perhaps the most interesting question here is why only about 6% of the NCI’s budget is devoted to cancer prevention.
Dr. Joyner has done preclinical technical consulting for GSK, Amgen, Boston Scientific, Edwards, and Nonin on issues related to physiological monitoring, cardiovascular disease and diabetes. He is on the board of Xcede, a startup focused on tissue sealants. As a clinical anesthesiologist he prescribes no drugs or products related to his consulting.