Over the past weekend I had the pleasure of participating in EMMC’s Champion the Cure Challenge and like most families, mine has been profoundly impacted by cancer. I lost my father to leukemia and a sister to breast cancer and I have two more sisters who have had breast cancer (one cured and one currently undergoing treatment). It reminds me of how much this disease, or actually group of diseases, weighs on people’s minds. It is not unusual for me to have a patient tell me that they would like to be tested for cancer and when I ask which kind, they respond, “all kinds”. I wish we had a test that could detect and significantly impact all cancers, but because essentially all of the body’s cells have the potential to undergo cancerous changes, there is no single test. Many cancers are thankfully extremely rare, and often the risk of cancer can be reduced by a healthy lifestyle (avoiding smoking, moderation in the use of alcohol, limiting sun exposure, a healthy diet, etc.).
But there is a partial answer to this common question. Some of the more common forms of cancer can be more treatable if detected early by screening tests. And one form is completely preventable (see cervical cancer below)! So let’s run through what cancer screening tests you should consider, when you should start and how often you should be screened. These recommendations come from the United States Preventive Services Task Force and are the guidelines most based in science and least influenced by those who may have a profit motive conflict of interest in making such recommendations.
Breast Cancer – mammograms are the cancer screening test that have the most public awareness. It is also the most widely embraced cancer screening test, both by patients and providers of health care. The current recommendation is for women to have a screening mammogram every other year between the ages of 50 and 74. The UDSPSTF recommends that the decision to start mammograms before age 50 (the American Cancer Society recommends starting at age 40, for instance) should be individualized and based on a woman’s personal values regarding benefits (there are not good studies showing improved outcomes in women under age 50 or over age 75) and risks (cost, radiation, unnecessary worry, interventions, etc.). The USPSTF also recommends against regular breast self examination because it has not been shown to change outcomes and may again lead to unnecessary tests and biopsies. The USPSTF recognizes that science and knowledge advance over time and these guidelines are currently being reevaluated.
Cervical Cancer – this is the area of greatest success in cancer screening. Prior to the invention of the pap smear cervical cancer was the #1 cancer killer of women and now it is quite uncommon. We have also learned that certain strains of the Human Papilloma Virus (HPV) are the cause of most cervical cancers. The USPSTF recommends screening women between the ages of 21 and 65 every 3 years with a pap smear. Women aged 30 to 65 who wish to extend the screening interval to 5 years may do so by having both a pap smear and HPV testing (which is done on the same sample). If both are normal a 5 year interval is safe and effective. This is a dramatic departure from the time when I trained and we engrained in women that they needed to have a pap smear every year! Another departure is the recommendation that pap smears should not be done under the age of 21 (mild abnormalities are common during this time, clear on their own and led to many unnecessary treatments in the past). Women over age 65 who have not had past cervical abnormalities also no longer need to have pap smears because the disease is rare after that age.
Colon Cancer – Screening is recommended for adults aged 50 to 75 by one of three methods: stool cards (which test for microscopic levels of blood in the stool) every year, colonoscopy every 10 years, or a combination of a sigmoidoscopy ( a much shorter version of a colonoscope) every 5 years and stool card testing every three years. The guidelines recommend against screening routinely after the age of 75 because there is no evidence of benefit, and they recommend against any colon cancer screening after the age of 85 because of the potential harm paired with no benefit. There is not yet enough evidence to make recommendations about CT colonography as a screening test. Many patients have questions about what to do if there is a strong family history of colon cancer, especially at an early age. This is best discussed with your primary care provider. There are also some diseases, like ulcerative colitis and familial polyposis, which increase the risk of colon cancer and may require more aggressive screening.
Lung Cancer – this is a new recommendation as of 2013. A low dose CT of the chest is recommended for adults aged 55 to 80 who meet the following two conditions:
- At least a 30 pack year history of smoking (this is calculated by the number of packs smoked per day multiplied by the number of years of smoking)
- Currently smoking or having quit less than 15 years prior
It is important to know that this recommendation has not been widely accepted. Medicare has decided against paying for it and my own specialty grouop, the American Academy of Family Physicians, states that there is insufficient evidence t make this recommendation to patients.
Skin Cancer – there is not evidence that regular full skin exams are useful in preventing or impacting serious skin cancers, but it makes sense for people to be aware of worrisome signs and to seek consultation if they appear. These signs are probably the topic for another discussion, but are readily available on line in a variety of places, including http://www.skincancer.org/skin-cancer-information/melanoma/melanoma-warning-signs-and-images .
Other Cancers – based on current evidence the USPSTF recommends against screening for testicular cancer, prostate cancer, ovarian cancer and pancreatic cancer and concludes that there is insufficient evidence to make a recommendation about screening for bladder cancer and oral cancers. They are working on new recommendations for screening for thyroid cancer. These recommendations against screening are often poorly understood by patients and providers and merit the time for in depth discussion when people have concerns about them.