Lung cancer can develop silently for years, often producing no symptoms until the disease has advanced, and experts say routine screening remains one of the most effective tools for catching it early. Current guidelines from the American Cancer Society recommend an annual low-dose CT scan for people between the ages of 50 and 80 who currently smoke or have a history of smoking, or who have at least a 20 pack-year smoking history.
Daniel J. Boffa, a thoracic surgeon at Yale University and chair of the American College of Surgeons Commission on Cancer, said screening reduces the chance of dying from lung cancer by 20%. But the share of eligible Americans who do not comply with screening recommendations translates to tens of thousands of preventable deaths every year, he said.
«It's one of the most powerful things you can do to reduce your chances of having your life shortened by lung cancer,» Boffa said, urging people over 50 with a smoking history to get screened.
Early-stage lung cancer usually produces no symptoms, according to Lary Robinson, an oncologist at Moffitt Cancer Center in Tampa, Florida. When symptoms do appear, they are most often related to the lungs and include a persistent cough, shortness of breath or coughing up blood. Unexplained weight loss can result from any form of cancer, and neurological symptoms such as persistent headaches may also warrant a doctor's visit.
The American Cancer Society advises people to discuss the purpose of screening, how it is performed, and its benefits, limitations and possible harms with their health care providers before deciding to undergo a scan. Those who still smoke should be counseled about quitting and offered resources to help. People with serious health problems likely to limit their lifespan should not be screened, nor should those who would be unable to receive treatment if lung cancer were detected.
About one in seven lung cancers affects someone who has never smoked, yet there is currently no set screening guideline for never-smokers. Boffa described the search for individuals who would benefit from screening as an intense area of research. For now, people with a direct family history of lung cancer who never smoked should consider annual screenings, as should higher-risk groups such as Asian women. Boffa said he anticipates better guidance for at-risk never-smokers within the next year or two.
Most screenings detect a lung nodule or other abnormality, which is more often an infection, scar or inflammation than a tumor. In about one-third of patients, screenings also detect unrelated health issues, including hardening of the heart arteries or a nodule elsewhere in the body. Boffa said more than 99% of nodules are benign, making a conversation about expectations important before screening.
«It's not uncommon to find something. Most of the time, it's not something that's going to affect how long you live,» he said.
The CT scan takes only a couple of minutes and does not involve the enclosed space of an MRI, so people who get claustrophobic usually do not have difficulty with lung cancer screening, Boffa said. Results typically come back within a few days.
Boffa also noted that advances in treatment have improved survival even at advanced stages, and that screening should not be viewed as a pathway to a terminal diagnosis. «People are really reluctant to be diagnosed with lung cancer because it does carry a stigma,» he said. «For years, there was a reputation that it was a terminal diagnosis. It's just been amazing what research has done for lung cancer.»
Looking ahead, Boffa said he hopes that within four or five years a screening CT scan will serve mainly to confirm a positive blood test performed at a doctor's office, an approach that could make screening easier and help detect more lung cancers.