Andrew L. Pecora, MD
Oncology & Biotech News
Chief Innovations Officer, Professor, and Vice President
of Cancer Services
John Theurer Cancer Center
at Hackensack University
Over the past 20 years, our extent of knowledge has increased exponentially regarding what causes and then maintains a cancer cell phenotype. As a consequence, significant advances in the treatment of some cancers have led to clinically meaningful increases in progression-free and overall survival. We recently learned through the ENCODE project that there are approximately 20,000 genes and over four million “switches” that control cell function and behavior. Aberrations in genes and switches cause and drive cancer, and targeting a specific aberration (eg, BRAF
mutations) occasionally results in meaningful and durable responses. Despite all of this progress, one fact has not changed in 20 years: The most effective approach to treat cancer is to prevent it from occurring.
New data from a study sponsored by the National Institutes of Health appear to have proven that there is an inexpensive and relatively simple approach to reducing the incidence of most cancers that afflict men: Take a multivitamin daily. In the randomized, double-blind, placebo-controlled Physicians’ Health Study II, nearly 15,000 male US physicians aged ≥50 years received either a multivitamin or a placebo daily. Incidence of all cancers was tabulated for a median follow-up of over 10 years. The results of the study have been reported online in JAMA
. 2012. doi:10.1001/ jama.2012.14641.) and were presented in October at the American Association for Cancer Research International Conference on Frontiers in Cancer Prevention Research. As reported by the principal investigator, J. Michael Gaziano, MD, men receiving multivitamins had a statistically significant 8% overall decrease in the general incidence of cancer diagnoses.
Surprisingly, the study did not show a reduction in the incidence of prostate cancer among the group receiving multivitamins. When prostate cancer was censored, then the effect size grew to a reduction in all other cancer incidence of 12%. The authors also noted a reduction in overall cancer mortality but unlike incidence rates, the mortality reduction was not statistically significant.
There were several important considerations noted by the investigators, including that the study involved men only and that these men were generally healthy, had a low rate of tobacco use, and were highly likely to be compliant. Therefore, it is not clear if the effect would be observed in women or unhealthy individuals.
Nonetheless, the results warrant further study because an effect size this large might translate to an even greater reduction in cancer incidence among patients with a greater likelihood of acquiring cancer. The investigators stated the obvious: Cessation of smoking tobacco, avoidance of excessive sun exposure, a diet rich in fruits and vegetables, proper body mass index, and exercise remain critically important in any effort to reduce cancer incidence.
In several recent large studies, vitamin supplements, fish oil, and high-dose single vitamins have not demonstrated a clinical benefit and in some cases, actually increased toxicities and cancer incidence. In the Physicians’ Health Study II, the multivitamin contained no more than 100% of the daily recommended amount of essential vitamins. Too much of anything may not be a good thing, but the right amount now appears, at least in men, to be meaningful.
Over the centuries, well before clinical trials even existed, common knowledge accumulated through observation. The benefits of eating a balanced and varied diet have been passed down from one generation to the next at family dinner tables around the globe. In the future, do not be surprised to hear a new request at the dinner table that replaces “Please pass the salt” with “Please pass the multivitamins!”