Why is Lung Cancer Early Detection Important?

When it comes to your health you can never be too cautious. Finding lung cancer early, when it is easiest to treat, can save your life.

Early detection of lung cancer is defined as strategies that can detect lung cancer at a stage where surgery or stereotactic body radiation therapy (SBRT) can be offered with the goal of a cure.

There are a number of factors that determine the outlook for any lung cancer patient in addition to when the lung cancer is detected, including the type of lung cancer, the patient's health in general, and the responsiveness of the patient's lung cancer to treatment.

However, lung cancer is most easily and effectively treated when it is found at an early stage. Statistically, those with lung cancer caught early on have a much higher likelihood of surviving at least five years after diagnosis than those diagnosed when the lung cancer is more advanced.

Currently, only 17% of lung cancers are diagnosed while the tumor is still localized—that is, only found at the site where it started. This is commonly referred to as stage I. The major challenge is that most people with lung cancer only have symptoms when they are in the later stages of the disease, so lung cancer is not usually suspected and discovered until it has had the chance to grow and spread.

How can lung cancer be detected early?

Lung cancer can be detected early via screening. Screening for lung cancer means checking for cancer before there are any symptoms.

For lung cancer, early-detection screening by a low-dose computed tomography (LDCT) scan (also called low-dose spiral CT scan or helical CT scan) has proven to be effective among individuals considered to be at high risk. It is also only recommended for these individuals.

LDCT is much more sensitive than chest X-rays and can detect smaller abnormalities that may be lung cancer. Chest X-rays are not recommended for lung cancer screening because they often miss early-stage lung cancers and have not resulted in decreased mortality. This is also the case for sputum cytology, a test that checks for abnormal cells in the sputum.

Who should be screened for lung cancer?

There are several sets of guidelines, including the ones outlined below, to help determine who should be screened by LDCT for lung cancer. These guidelines are primarily based on active (current or prior) tobacco exposure. The guidelines have been established in large part from the results of the National Lung Screening Trial (NLST). They are very similar, with the differences primarily related to the role of screening for the oldest patients and risk factors other than smoking. All of the patients who are recommended for screening are considered to be at high risk for developing lung cancer but do not currently have any symptoms to suggest that they do have lung cancer.

The most common guidelines for annual screening with LDCT is for adults who are:

aged 50 years and over
have a 20 to 30 or more pack a year smoking history
have risk factors other than second-hand smoke
are current smokers or quit smoking within the past 14 to 15 years

Patients should discuss these guidelines with their doctor and understand the risks and benefits before undergoing LDCT screening.

Choosing a screening center

The NCCN® recommends going to screening centers that:

Follow an organized plan that is updated to include new technology and knowledge
Have a high-quality screening program with enough staff and resources
Are accredited to do CT scans by a certifying organization, such as the American College of Radiology
Get scans read by an American Board of Radiology board-certified radiologist who is an expert in lung cancer screening
Offer modern multislice CT equipment (which is able to take multiple images in one rotation of the equipment) that does high-quality, low-dose, and non-contrast spiral CT scans
Partner with a health center that has experience and excellence in biopsy methods, board-certified pulmonologists (lung doctors), and board-certified thoracic (chest) surgeons who are experts in lung cancer

LDCT Drawbacks and Risks

Despite the benefits of LDCT lung cancer screening, including decreased mortality from lung cancer, decreased mortality from lung cancer treatment, and improved quality of life, there are some drawbacks and risks, including that LDCT may:

Find abnormalities that have to be checked with either another scan or a biopsy if considered suspicious; the vast majority of the time these end up not being cancerous
Miss very small cancers or cancers that are hidden behind other structures in the chest
Expose a patient to a small amount of radiation. While it is a smaller dose than that from a standard CT scan, multiple LDCTs can lead to greater radiation exposure. High doses of radiation exposure can lead to other types of cancer in the future
Detect tumors that would not become problematic. Such tumors may be indolent (tumors that grow slowly and may not always require treatment)
Have costs for the patient that are not covered by the patient's insurance
Cause stress while waiting for test results

In addition:

Not all tumors that are found will be at an early stage
Screening can only be done at facilities that can perform an LDCT, so a patient may have to travel to obtain a screening

When weighing whether or not to get an LDCT, it is important to keep in mind that an LDCT can find other abnormal growths in tissues outside the lungs (incidental nonpulmonary findings). These findings need to be followed up on by your doctor or specialist. You can also follow up with your doctor if you have any additional questions.

This content is brought to you by The Lungevity Foundation and the BDO Editorial Staff.