Cancer treatment continues to improve, but those improvements are typically incremental. New drugs and surgical procedures typically offer modest improvements over what’s currently available. Research into the genetic basis of cancers have yielded exciting new targeted therapies and we may, one day, find the key or keys that enable us to treat most cancers in very specific ways.
That having been said, cancer researchers have known for a long time that screening and prevention are the real keys to beating “The big C”. It is much better to either prevent a cancer from occurring or find it in its earliest stages, than to search for more effective therapies for advanced disease.
Screening for cancer is complicated and imperfect. If your screening test isn’t specific enough, you end up with a lot of false positives. If your screening test isn’t sensitive enough, you end up with too many false negatives.
Creating the best screen involves not just designing a good test, but identifying the right population of patients to screen, so that you strike the right balance between sensitivity and specificity. In the U.S. we currently screen for breast, colorectal and prostate cancer.
Reviewing the Recommendations
The U.S. Preventive Services Task Force is an independent group of national experts in prevention and evidence-based medicine that works to improve the health of all Americans by making evidence-based recommendations about clinical preventive services such as screenings, counseling services, or preventive medications. They’ve recently stirred up significant controversy by questioning the scientific basis of current recommendations for breast and prostate cancer screening.
Specifically, they recommended that most women delay their first mammogram until age 50, unless they are at particularly high risk for breast cancer. They also recommended that screening mammograms be performed every 2 years, rather than every year and that mammography need not be done after age 74. Lastly they concluded that breast self-exams have little value, based on findings from several large studies. Needless to say, there was a hue and cry when the recommendations were released, which provoked an intense discussion over the validity of those guidelines. The American Cancer Society, despite these recommendations, still advises women to begin screening mammography at age 40.
More recently, the Task Force recommended that men need not have an annual PSA test to screen for prostate cancer. The data suggested that only one man in 1,000 will be helped by PSA testing and that many more will undergo invasive testing and treatment that will not prolong their lives and, in fact, may do them harm. Again, this has stirred up a firestorm of controversy that will play out in the coming months. No doubt, many men will continue to request yearly PSA testing and many doctors will offer it to their patients. One benefit of the controversy will be to stimulate thoughtful conversations between doctors and patients about whether PSA testing is advisable for a particular individual.
Screening for Lung Cancer
Lung cancer is the number one cause of cancer deaths in theU.S. An effective screening test has eluded us, until now. A large, multicenter National Cancer Institute-sponsored trial has concluded that chest CT scans screening for lung cancer decreases the death rate from lung cancer in screened individuals by 20 percent. In addition, a recent study in the journal Health Affairs found lung CT screening to be cost effective at the population level. The National Comprehensive Cancer Network has embraced lung CT screening and now recommends its use for patients deemed at risk for developing lung cancer. Thus, we now have a method for screening individuals at risk for lung cancer that allows for earlier diagnosis, saves lives and is cost effective.
Notice that I said “individuals at risk”. That means specific patients with specific risk factors benefit from screening, not everyone. That is a key point when considering screening. It does no good to screen everyone. You’ll end up spending too much money, screening too many people and find too many false positives.
So, what’s a person to do? First and foremost, talk to your doctor. In screening, one size does not fit all. Your family history, associated conditions, lifestyle and other factors influence your risk of developing cancer in your lifetime. Let your doctor help you make these important decisions.
At FMH, we are developing a Lung CT Screening Program that will begin this summer. We are doing this in a prudent, responsible way. A team made up of pulmonologists, radiologists and thoracic surgeons are collaborating to ensure only those who will benefit from the screening will undergo the test and that results will be interpreted and acted upon appropriately. Evidence-based, scientific guidelines are being used to define which patients are eligible for screening, how to interpret the studies and how to deal with positive screens. Anything less would be unacceptable and not in keeping with our mission of serving our community. I’ll keep you posted.