Lung Cancer Can Grow Silently for Years: Who Qualifies for Screening, According to Specialists

Lung cancer can grow silently for years without any symptoms. Caught before symptoms appear, the chances of survival rise sharply — yet in the United States only 15 percent of those eligible for screening actually get tested. Doctors warn that this neglect translates into tens of thousands of preventable deaths every year.

Dr Daniel J. Boffa, a thoracic surgeon at Yale University and chair of the American College of Surgeons Commission on Cancer, has described lung cancer screening as 'one of the most powerful ways' to boost survival. 'It reduces the chance of people dying of lung cancer by 20 percent,' he said.

The screening in question is a low-dose CT scan — a low-radiation scan that can detect even small abnormalities in the lungs. Boffa noted that the scan takes only a couple of minutes and does not take place in an enclosed space like an MRI, so there is little reason for fear to keep people away.

According to American Cancer Society (ACS) guidelines, people aged 50 to 80 who currently smoke or have smoked in the past, with at least a 20 pack-year history, should have an annual low-dose CT scan. A pack-year is a measure of smoking exposure — for example, one pack a day for 20 years, or two packs a day for 10 years.

Before deciding, everyone should discuss the purpose of screening, how it is done, and its benefits, limits and possible harms with their own healthcare provider, the ACS advised. Those who still smoke should also be counselled about quitting and offered help and resources to do so.

On the other hand, people with serious health problems that will likely limit their lifespan are advised not to be screened. The same applies to those who would not be able to receive treatment if lung cancer were detected.

Discussing symptoms, Dr Lary Robinson, an oncologist at Moffitt Cancer Center in Tampa, Florida, noted that in most cases early-stage lung cancer comes with no symptoms at all. In those who do have symptoms, the most common are related to the lungs: a persistent cough, shortness of breath or coughing up blood.

Robinson added that unexplained weight loss can be a symptom of any form of cancer. Neurological symptoms such as persistent headaches may also warrant seeing a doctor, rather than being ignored.

Many assume lung cancer is only a smokers' disease, but the figures say otherwise — one in seven lung cancers affects someone who never smoked. Despite that, there is currently no set screening guideline for never-smokers.

Boffa said finding which never-smokers would benefit from screening is an 'intense area of research.' For now, people with a direct family history of lung cancer should consider annual screenings, as should higher-risk groups such as Asian women. 'I would anticipate that in the next year or two, we will have better guidance for people who are at risk for lung cancer but never smoked,' he predicted.

Boffa is also looking further ahead. 'I'm hoping that within four or five years, a screening CT scan will only be confirmatory after they have a positive blood test done at your doctor's office,' he said. Such an approach could make screening easier and help detect more lung cancers.

Many avoid testing out of fear, but Boffa says that fear is increasingly outdated. Advances in treatment have improved survival even at advanced stages, so screening should not be seen as a pathway to a terminal diagnosis. Most abnormalities screening detects turn out to be infection, scar or inflammation rather than a tumour, and in about one-third of patients screening also detects unrelated problems such as hardening of the heart arteries. Against this symptomless disease, the specialists' advice is simple: if you qualify, get screened.