Cancer has been much in the medical news over recent months, and with both good and diverse reasons. The good reasons all relate to genuine and important advances in medical knowledge, and options for patients. These range from immunotherapy for lung cancer, to the recently revealed insights, informed by genetic markers, about when breast cancer does not require chemotherapy.
The diversity of news is also noteworthy, as the above suggests. A whole new kind of chemotherapy for one cancer is juxtaposed with new research about when not to use chemotherapy for another. Advice about prostate cancer screening, informed by the latest research, has shifted from “don’t do it,” to “talk it over with your doctor, and decide together.” The American Cancer Society has responded to observations of rising rates of colon cancer at younger ages with advice to begin screening at 45, rather than 50.
And all the while, the best of news and the worst of news about cancer overall: cancer mortality rates continue to decline steadily in the U.S., while overall rates of cancer diagnoses fall slowly or not at all. We are ever better at treating cancer, while seeing much less progress in preventing it outright.
Cancer is scary. It is prevalent. And, it is in the news nearly all of the time for one reason or another. This combination of factors produces a cacophony that might be confusing at best, overwhelming at worst. When should you be screened for a given cancer? What should you do if one is found? Whose advice can you trust? And what, if anything, can be done to lower the risk of getting cancer in the first place? Let’s take these one at a time.
You might think that we should screen for cancer whenever we “can.” In other words, if we know how to look for and find cancer early, we should do so. But that thinking is wrong.
Cancer screening is “looking for trouble” in the most literal sense. Finding trouble you can fix makes very good sense. Looking for trouble you don’t know how to fix adds probable expense, inconvenience, and anxiety to your life, without redemption. Quite simply, looking for trouble only makes sense under certain conditions.
We should screen for cancer not just when we have the means to find it, but when we can use our tests to rule it both in (so we know who needs treatment), and out (so we know who does not) reliably. We should screen when the cancer in question can be treated effectively. We should screen when treating the cancer found early produces meaningfully better outcomes than simply waiting to treat it once it becomes apparent. Finally, the treatment (or “cure”) must, of course, be better than the untreated disease. Some combinations of cancer and testing meet all of these criteria; many do not.
And some, like prostate cancer, are right on the line. We have tests to find prostate cancer, and we have effective treatment. But the tests to find prostate cancer can at times mistake benign conditions for cancer, and to a lesser extent, miss cancer that’s actually there. More problematic, the tests do not yet readily distinguish between prostate cancers destined to progress, and those apt to remain idle and indolent. For that latter group, treatment can be more harmful than the untreated disease, thus failing to meet the criteria above.
Fortunately, you don’t have to sort through all of this yourself. The United States Preventive Services Task Force (USPSTF) exists to do that job for us all. They meticulously review the relevant scientific evidence at regular intervals, factor in the above considerations, and generate official recommendations accordingly. You can trust the counsel of the USPSTF.
However, you should also understand its limitations. The evidence criteria used by the USPSTF are a very high bar. Often, we have early hints about a change in cancer detection or treatment before that evidence matures and becomes “definitive.” There is an important difference between absence of evidence (i.e., something that may well be true, but we simply have not proven it yet), and evidence of absence (i.e., something we have proven to be untrue). But either can be a reason why the USPSTF does not recommend cancer screening.
So, if you tend to like more assertive action, you can look to the more disease-specific organizations. The American Cancer Society, for example, is focused just as the name suggests: entirely, and exclusively on cancer. While they align well with the USPSTF, they tend to be a bit more assertive about screening and treatment when the evidence is still uncertain and evolving. So it is that the official recommendation from the USPSTF is to begin colon cancer screening at age 50, while the ACS has just dropped their recommendation to age 45.
You will find similar trends with other disease and specialty specific groups. The American Urological Association, for instance, has always offered more aggressive prostate cancer screening recommendations than the USPSTF.
Your doctor should know all of these guidelines, of course, but that’s no reason not to empower yourself. My advice is as follows: (a) check the USPSTF position for the most robustly, evidence-based guidance; (b) check any competing position from the organization or specialty devoted to that condition for reasonable, if less definitive, and probably more aggressive guidance; (c) choose, with input from your doctor, within that range the approach that best suits you.
As the new findings about breast cancer indicate, throwing every treatment at every cancer is not the right approach. In some cases, no treatment at all- just watchful waiting- makes sense.
While you may be on your own, at your computer, trying to figure out cancer screening options, you will not be on your own making treatment decisions. The medical professionals who find cancer should be with you.
My advice here -other than listening to professionals you trust- is to know that sometimes treatment is urgently required, and sometimes it can be worse than the disease. Here, too, the USPSTF and specialty organizations will often have pertinent guidance. At a minimum, as you confront treatment options for yourself or a loved one, ask your doctors: what does the USPSTF have to say about treating this cancer? What does the __________ organization (fill in the blank appropriately) have to say? Asking those questions and getting good answers will help you make a fully informed decision.
The motivations of your doctor(s), a specialty organization addressing your condition or concern, and the USPSTF overlap, but vary. They should all be trustworthy sources, but perhaps that much more so when combined. My advice is to triangulate, and use all three. Factor in your own personal preferences and priorities. Sometimes the right answer is fairly obvious and pretty much of a one-size-fits-all variety. More often, however, it’s not.
At its best, screening can only ever find cancer once it exists. Preventing it outright is obviously better.
Here, too, there has been potential for confusion in the medical news of the past several years. I think the case is clear: lifestyle as medicine can dramatically reduce our cancer risk. Eat well, be active, don’t smoke or drink excessively, get enough sleep, manage stress, and prioritize relationships. That is powerful, preventive medicine. We see it reach its fullest potential in the world’s Blue Zones, where people routinely live to 100; don’t get chronic diseases, including cancer, very often; and enjoy the combination of more years in life, and more life in years than the rest of us.
A proviso, and analogy, are warranted however. The proviso is that doing everything “right” cannot guarantee any of us we will avoid cancer. We have considerable control over our medical destinies, but that control is not perfect, and never will be.
The analogy is a vessel at sea. Using lifestyle as medicine is like being a good captain, with a good crew, on a good ship. You control ship and sails, and that matters enormously. But you will never control wind and waves, and alas at times, those can cause even the most seaworthy vessel to founder. We can only ever change the likelihood of a safe crossing.
Cancer screening is among the most important of opportunities in preventive medicine. But it is also an exercise in looking for trouble. Done haphazardly, trouble is just what it can find. But done thoughtfully with input from a few reliable sources, it makes you the beneficiary of the many rapid advances in this critical domain of modern medicine.
David L. Katz, MD, MPH, FACPM, FACP, FACLM, is the Founding Director (1998) of Yale University’s Yale-Griffin Prevention Research Center, and former President of the American College of Lifestyle Medicine. He has published roughly 200 scientific articles and textbook chapters, and 15 books to date, including multiple editions of leading textbooks in both preventive medicine, and nutrition. He has made important contributions in the areas of lifestyle interventions for health promotion; nutrient profiling; behavior modification; holistic care; and evidence-based medicine. David earned his BA degree from Dartmouth College (1984); his MD from the Albert Einstein College of Medicine (1988); and his MPH from the Yale University School of Public Health (1993). He completed sequential residency training in Internal Medicine, and Preventive Medicine/Public Health. He is a two-time diplomate of the American Board of Internal Medicine, and a board-certified specialist in Preventive Medicine/Public Health. He has received two Honorary Doctorates.