Early Screening for Lung Cancer

Early screening for a disease, unlike testing, takes place before the patient has any symptoms. When screening for cancer, early detection can encourage patients to seek treatment sooner, when more curative options are available. The earlier cancerous cells are detected, the easier they are to treat with radiation, chemotherapy, or surgery. Too, catching lung cancer in an early stage, before it has spread throughout the body, can increase a patient’s odds of survival and improve their prognosis.

Today, lung cancer is the leading cause of cancer-related death in the U.S, making up nearly a quarter of all cancer deaths in the country. In 2018, nearly a quarter of a million new cases of the disease were diagnosed and over half a million people today live with a lung cancer diagnosis – meaning the majority of diagnoses occurred in the last few years. Recently, the large number of new cases can be contributed to the late onset of symptoms and limited treatment options available at later stages of the disease.

This is an image of a statistic explaining the positive impact early cancer screens have on improving survival rate.
While the current 5-year survival rate for lung cancer is about 18 percent, other cancers with widely-available screenings have markedly higher survival rates – breast cancer, colon, and prostate have 5-year survival rates of 91, 66, and 99 percent respectively. Thus, the importance of effective early screening methods is paramount in preventing cancer-caused death. Other common cancer screening methods include mammograms for breast cancer, colonoscopies to detect colon cancer, and HPV tests for cervical cancer.

To date, only three screening tests have received serious attention from the medical research community: low-dose spiral CT (LDCT) scans, chest x-rays, and sputum cytology (i.e., phlegm cell analysis). Of the three, only LDCT scans are broadly recommended for the early detection of lung cancer and prevention of early death and have been shown to reduce mortality rates by 20 percent.

What Is an LDCT Scan?

A low-dose spiral computer tomography scan, or LDCT scan, is similar to an x-ray, takes only minutes to administer, and is a painless procedure. Depending on the machine used, the patient either lays on a table and is inserted into a large body scanner (like an MRI machine), or the scanner moves around the patient. The machine does not touch the patient but often makes soft whirring or clicking sounds.

As such, LDCT scans give doctors detailed information about tumors from multiple angles. A single scan, through the use of a low dose of radiation, can reveal the size, shape, and location of any tissue or organ abnormalities in both two- and three-dimensions. Nonetheless, a single screening cannot differentiate between malignant and benign tumors. To properly diagnose lung cancer, mesothelioma, or other disease, doctors typically need to conduct a series of tests and biopsies.

Risks of Low-Dose Spiral Computed Tomography (LDCT)

While the early detection of cancer can lead to recovery from the disease, using LDCT scans for lung cancer screening can come with its own risks. For instance, repeated exposure to the radiation used in LDCT scans may cause lung cancer tumors to grow. Additionally, early screening does not help patients whose tumors have already spread to other places in the body (such as the lymph nodes or brain).

In other cases, false-positive as well as false-negative results can be among the risks for early lung cancer screening. In false-negative results, the screening fails to reveal the presence of cancer. Typically, this prolongs the amount of time it takes for patients to seek treatment, even when common symptoms of lung cancer are present. In false-positive results, the screening shows the presence of cancer when there is none. Often, this leads to additional testing and invasive biopsies that generally require their own recovery time. In both situations, the patient is subjected to undue anxiety and stress – which can come with their own serious health complications.

Lastly, the risk of early screening is the overdiagnosis of illnesses that would have never become uncomfortable or life-threatening. For instance, an LDCT scan that shows a tumor in one lung may lead to a litany of aggressive and lengthy treatments like surgery, chemo, and radiation therapy. In most cases, it is impossible to know if withholding treatment helps patients live longer or not; researchers tend to believe that treatment may be more detrimental to patients with serious pre-existing medical problems related to smoking.

Who Should Get a Lung Cancer Screening?

For some patients, lung cancer screenings can lead to earlier diagnoses and a greater number of treatment options. However, according to the American Cancer Society, not everyone needs to undergo an LDCT scan for cancer screening. The ACS screening guidelines are based on aspects that put individuals at high risk or are a direct cause of lung cancer. For people between the ages of 55 and 74 years old and are in “fairly good health”, yearly lung cancer screenings are advised if the patient:

  • Is a current smoker or quit smoking in the past 15 years
  • Have a 30-pack smoking history (i.e., the number of years the patient smoked multiplied by the number of packs per day)
  • Enter smoking cessation counseling for current smokers
  • Know of the potential risks and benefits of LDCT scans
  • Can visit an experienced lung cancer screening center

Because the average LDCT scan can cost 300 dollars or more (before insurance), patients are advised to make an appointment with their primary care physician for a referral to a specialist or prescription for screening based on a high-risk history.

Ultimately, the goal of early screening is to prevent cancer death. Patients with a history of cigarette smoking or exposure to toxins (such as asbestos) should speak with their doctor as soon as possible if they suspect they may have cancer symptoms.