Why Is Lung Cancer So Deadly?

Posted on December 2, 2022 in Lung Cancer

Written by Smith, Jennifer Leigh

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Lung cancer is the leading cause of cancer death in the United States.

Each day, the disease takes 350 lives — more than breast, prostate, and pancreatic cancers combined. Lung cancer also kills 2.5 times more people than colorectal cancer, the second leading cause of cancer death in America¹.

Many people assume that lung cancer takes so many lives because it’s common. However, this is a misconception. When compared to very prevalent cancers, the number of lung cancer deaths is still disproportionately high. Download our Lung Cancer eBook for detailed insights and information.

So, why is lung cancer so deadly? We answer this question below.

3 Reasons Why Lung Cancer Is So Deadly

Every year, 236,740 Americans are diagnosed with lung cancer². Tragically, more than half of these men and women will pass away within 12 months³.

According to the medical community, there are three primary reasons why lung cancer is so deadly:

  1. Lung cancer is difficult to diagnose because patients are often asymptomatic in the early stages of the disease.
  2. Contrary to popular belief, lung cancer has many different causes besides smoking.
  3. The disease tends to affect older individuals who have coexisting health conditions that complicate cancer treatment.

1. Lung Cancer Is Hard to Detect

The number one reason why lung cancer is so deadly is that symptoms don’t appear in the early stages. Patients with lung cancer can — and usually do — live for years without noticing any changes in their health.

By the time symptoms do occur, the cancer has often spread (metastasized) to other parts of the body. This metastasis makes effective treatment more difficult.

Though oncologists recommend chemotherapy for advanced-stage lung cancer, some lung tumors are resistant to chemotherapy. Other tumors may respond at first, only to develop a resistance to the anti-cancer drugs later on.

Because of this, the five-year survival rate for tumors that have spread to other organs (called distant tumors) is only 5 percent³.

2. Lung Cancer Isn’t Always Caused by Smoking

Cigarette smoking is the leading risk factor for lung cancer. According to the CDC, 80 to 90 percent of all lung cancer deaths can be attributed to tobacco usage⁴. But not all cases are caused by smoking.

Exposure to secondhand smoke, for example, contributes to more than 7,000 lung cancer deaths each year⁵. Exposure to radon, air pollution, and asbestos can also increase your risk of developing lung cancer. Genetics can contribute too.

Since lung cancer is not top-of-the-mind for nonsmokers, they often disregard vague symptoms such as fatigue or unexplained weight loss.

Even medical professionals struggle to recognize lung cancer in nonsmokers, especially those who are young and otherwise healthy. In one retrospective study, for example, patients with aggressive cases of lung cancer were initially treated for everything from common colds to headaches⁶.

Unfortunately, a single month of delayed cancer treatment can increase the risk of death by 10 percent⁷.

3. Lung Cancer Patients Tend to Be Older

Cancer can develop at any age. However, lung cancer tends to be more prevalent in seniors. In the United States, 68 percent of lung cancer patients are diagnosed after 65 years of age and 14 percent are diagnosed after 80 years of age⁸.

Typically, cancer treatment is more complicated for these older adults — yet another reason why lung cancer is so deadly.

For example, since seniors are more likely to have chronic health conditions such as diabetes and heart disease, surgery to remove a lung tumor may be considered too risky. Comorbidities may also contribute to more serious chemotherapy and radiotherapy side effects.

All of these factors can affect an individual’s ability to successfully fight cancer and recover from treatment.

Lung Cancer Survival Rates

A relative survival rate compares people with a specific type and stage of cancer to the general population.

For example, the five-year relative survival rate for localized, non-small cell lung cancer (NSCLC) is 64 percent⁹. This means that people with localized NSCLC are, on average, about 64 percent as likely as people without that cancer to live for at least five years after diagnosis.

Though these figures can’t tell you how long you will live, they can provide insight into the potential efficacy of your treatment.

5-Year Relative Survival Rates for Non-Small Cell Lung Cancer

  • Stage: Localized (within the lungs), 5-Year Relative Survival Rate: 64%
  • Stage: Regional (spread to nearby lymph nodes, tissues, or organs), 5-Year Relative Survival Rate: 37%
  • Stage: Distant (spread to distant parts of the body), 5-Year Relative Survival Rate: 8%
  • Stage: All stages combined, 5-Year Relative Survival Rate: 26%

5-Year Relative Survival Rates for Small Cell Lung Cancer

  • Stage: Localized (within the lungs), 5-Year Relative Survival Rate: 29%
  • Stage: Regional (spread to nearby lymph nodes, tissues, or organs), 5-Year Relative Survival Rate: 18%
  • Stage: Distant (spread to distant parts of the body), 5-Year Relative Survival Rate: 3%
  • Stage: All stages combined, 5-Year Relative Survival Rate: 7%

Common Causes of Mortality

Thinking about dying from lung cancer can be unnerving, both for patients and their loved ones. However, understanding more about how the disease behaves in its advanced stages can offer a sense of control and even peace.

According to one study, common causes of lung cancer mortality include¹⁰:

  • Tumor burden: About one-third of patients pass away when their tumors grow considerably in size, causing organ failure. Metastasis can also compromise a patient’s ability to function normally (e.g. swallow, breathe, walk), which contributes to mortality.
  • Infections: Approximately 20 percent of individuals with advanced-stage lung cancer die from infections like pneumonia and sepsis.
  • Pulmonary hemorrhage: Bleeding in the lungs is responsible for 12 percent of lung cancer deaths.
  • Pulmonary embolism: A blood clot in the lung, or pulmonary embolism, kills 10 percent of lung cancer patients.

Next Steps

  • Recognize the symptoms of lung cancer to assess whether you begin experiencing any of them and ensure you are doing your best to avoid future complications.
  • Learn about the various stages of lung cancer.

At SERO, our cancer doctors in Charlotte are dedicated to improving patient lives with up-to-date information and state-of-the-art treatment options for lung cancer care. For a consultation, contact us today.


1. Risk of Dying from Cancer Continues to Drop at an Accelerated Pace. (2022).

2. Key Statistics for Lung Cancer. (2022).

3. Lung Cancer Fact Sheet. (2022).

4. Lung Cancer: What Are the Risk Factors? (2022).

5. Tobacco-Related Mortality. (2020).

6. Lung Cancer in Young Nonsmokers Is on the Rise: Uncovering the Cause. (2021).

7. Every Month Delayed in Cancer Treatment Can Raise Risk of Death by Around 10%. (2020).

8. Lung Cancer in Elderly Patients. (2016).

9. Lung Cancer Survival Rates. (2022).

10. Causes of Death of Patients With Lung Cancer. (2012).