Timing is everything in avoiding unnecessary risks that can come with cancer screenings
By Nancy Maes
Screenings for cancer are filled with a haunting question: what if they find something?
People might be so fearful of the disease that they cling to the notion that no news is good news. But statistics from screenings should overcome the anxiety. For example, the results of The National Lung Screening Trial published in 2011 found that a low-dose CT scan for at-risk patients who are heavy smokers is more effective than a chest X-ray in lowering the risk of dying of lung cancer.
Screening by CT scan of the chest showed a 20 percent reduction in mortality because the cancer is being detected at an earlier time and [has a greater chance of being] cured,” says Robert Winn, MD, professor of medicine and director of the lung cancer program at the University of Illinois Hospital & Health Sciences System (UI Health).“The standard approach now is to do an annual screening in populations that are 55 or older and have smoked more than a pack a day for 30 years.”
Michael Warso, MD, associate professor of surgery and chief of the division of surgical oncology in the department of surgery at the UI Health, suggests people do a monthly self-exam for skin cancer to look for abnormal growths following the A.B.C.D.E. rules: Asymmetry of a spot or mole; Borders that are blurred; Color that is not uniform; Diameter that is larger than one-quarter inch; Elevation of the surface is raised.
Abnormalities should be checked by a doctor. Warso says, “The overall cure rate is [greater than] 95 percent for basal and squamous cancers, and if you find a melanoma early, it also has a very good survival rate.”
What if the screening results indicate that cancer might be present, and a biopsy is necessary to learn whether the findings are accurate or not?
“It’s relatively uncommon to see something that looks like breast cancer on a mammogram that is not breast cancer, although the false-positive rate is around 20 percent,” says Gale England, MD, surgeon in the cancer center at Advocate Good Samaritan Hospital.
“It’s stressful for women during the time they’re waiting to get the results, which is three to four days, but even when they are diagnosed with breast cancer, they often start thinking right away about treatment.
“The general consensus recommends a screening mammogram starting at the age of 40 for a baseline and then yearly after that. It’s easier to treat breast cancer at an earlier stage, and the treatment is often better tolerated, and the chance of long-term survival is better,” says England.
But what if the screening itself presents risks? Stephen Steiner, MD, a gastroenterologist at Weiss Memorial Hospital points out that during a colonoscopy, polyps may be removed and tissue may be sampled, but with a very small risk of perforation and bleeding.
However, “Colorectal cancer found through screening is much more likely to be found at a curable stage than if we wait for symptoms to develop,” Steiner says. “Most medical societies would agree that if you have no risk factors for colon cancer, age 50 is the appropriate age to start screening every 10 years. For people around the age of 75–80, it becomes questionable whether we should screen for colon cancer, and certainly by age 85 it probably does not make sense.”
The screening guidelines for two cancers have changed recently to avoid the risks they present. The United States Preventive Services Task Force and other professional medical societies no longer recommend annual Prostate-Specific Antigen (PSA) tests for men to detect prostate cancer because it can lead to overdiagnosis and overtreatment.
“There is a lot of evidence accumulating that the harms of these tests outweigh the benefits,” says Kevin Polsley, MD, assistant professor of internal medicine and pediatrics at Loyola University Health System.
“An elevated PSA can be caused by a prostate infection or an enlarged prostate. But an elevated PSA can lead to a biopsy that can cause complications, and a lot of the cancers detected are slow growing and will never cause a problem.” Polsley recommends a PSA test only for men who show symptoms of cancer.
The American Cancer Society and other medical associations no longer recommend an annual Pap test for cervical cancer. The screening should be given every three years for women between the ages of 21 and 29 and every five years, along with an HPV test for women 30 and older.
“These recommendations take into account the risks of overtreating infections that could be temporary including unneeded biopsies and the potential for complications from such procedures and the anxiety that they entail,” says obstetrician/gynecologist Marie Cabiya, MD, attending faculty physician at Advocate Illinois Masonic Hospital. “I try to reassure my patients that cervical cancer is a very slow-growing disease. If someone follows the recommended screening interval, it’s unlikely they will [overlook any] cancer in that time.”
She recommends that women, nevertheless, continue to have a yearly gynecological exam to see whether the recommended intervals are still appropriate for the patient and to discuss other issues.
“Like many things in medicine, our ability to perform tests and do procedures is far in advance of our ability to know exactly how to use [the results],” Steiner says. “The more informed the patient is, the better the health care they are going to receive.”
