Why Is Lung Cancer So Deadly?

Lung cancer remains the leading cause of cancer death in the United States, taking approximately 350 lives each day—more than breast, prostate, and pancreatic cancers combined. It also claims 2.5 times more lives than colorectal cancer, the second leading cause of cancer death in America¹.

Many assume lung cancer’s high mortality is simply because it’s common. However, this is a misconception. When compared to other prevalent cancers, the number of lung cancer deaths is disproportionately high compared to its incidence rate.

This article explores why lung cancer is so deadly, current survival rates, whether it can be cured, and how treatment options have evolved in recent years.

Every year, over 230,000 Americans are diagnosed with lung cancer². Unfortunately, more than half of these individuals will pass away within 12 months of diagnosis³.

According to medical experts, there are three primary reasons why lung cancer has such a high mortality rate:

The foremost reason lung cancer is so deadly is the absence of noticeable symptoms in early stages. People with lung cancer can—and typically do—live for years without experiencing any health changes that would prompt medical attention.

By the time symptoms appear, the cancer has often spread (metastasized) to other areas of the body, making effective treatment significantly more challenging. This late detection is a critical factor in the disease’s high mortality rate.

Though oncologists recommend chemotherapy and other treatments for advanced-stage lung cancer, some lung tumors are resistant to standard therapies. Others may initially respond but later develop resistance to anti-cancer drugs.

Due to these challenges, the five-year survival rate for distant tumors (those that have spread to other organs) is only about 8% for non-small cell lung cancer and 3% for small cell lung cancer⁹.

While cigarette smoking is the leading risk factor for lung cancer—contributing to 80-90% of lung cancer deaths according to the CDC⁴—not all cases are smoking-related.

Other significant risk factors include:

• Exposure to secondhand smoke, which contributes to more than 7,000 lung cancer deaths annually⁵
• Radon exposure, a naturally occurring radioactive gas that can accumulate in homes
• Air pollution from vehicle exhaust, industrial emissions, and other sources
• Occupational exposures to carcinogens like asbestos, arsenic, and diesel exhaust
• Genetic factors that may increase susceptibility to lung cancer

Since lung cancer isn’t top-of-mind for non-smokers, they often disregard vague symptoms such as fatigue or unexplained weight loss. Even healthcare professionals may initially overlook lung cancer in non-smokers, especially those who are younger and otherwise healthy⁶.

Studies show that treatment delays as short as one month can increase mortality risk by approximately 10%, making timely diagnosis crucial⁷.

While cancer can develop at any age, lung cancer disproportionately affects seniors. In the United States, 68% of lung cancer diagnoses occur after age 65, and 14% after age 80⁸.

Treatment is typically more complicated for older adults for several reasons:

• Comorbidities: Seniors are more likely to have chronic conditions like heart disease, diabetes, or COPD, which can limit treatment options
• Reduced physiological reserves: Older patients may have less capacity to withstand aggressive treatments
• Increased treatment toxicity: Side effects from chemotherapy and radiation therapy are often more severe in elderly patients
• Surgical limitations: Surgery to remove lung tumors may be considered too risky for some older patients

These factors collectively affect an individual’s ability to successfully fight cancer and recover from treatment.

Understanding survival rates provides important context when discussing why lung cancer is so deadly. A relative survival rate compares people with a specific type and stage of cancer to the general population without that cancer.

These statistics highlight why early detection is critical. When lung cancer is found before it has spread, survival rates are significantly higher—though still lower than many other common cancers at similar stages.

Understanding the mechanisms by which lung cancer causes death can be difficult to confront, but many patients and families appreciate knowing what to expect in advanced stages.

According to medical research, the most common causes of mortality in lung cancer patients include¹⁰:

As tumors grow within the lungs and spread to other organs, they can cause:

• Respiratory failure from obstruction of airways or destruction of lung tissue
• Organ failure when cancer spreads to critical organs like the liver or brain
• Impaired essential functions like breathing, swallowing, or mobility

People with advanced lung cancer are vulnerable to serious infections due to:

• Compromised immune function from both the cancer and its treatments
• Obstruction of airways, leading to pneumonia
• Extended hospital stays increasing exposure to hospital-acquired infections

Bleeding in the lungs can occur when tumors:

• Erode into blood vessels
• Create abnormal blood vessel growth (angiogenesis)
• Cause coagulation disorders

Blood clots that travel to the lungs are more common in cancer patients due to:

• Increased blood clotting factors produced by some cancers
• Reduced mobility during illness
• Side effects of certain cancer treatments

One of the most common questions patients ask is whether lung cancer can be cured. The answer depends largely on the stage at diagnosis and several other factors.

For localized lung cancer (confined to the lungs with no spread to lymph nodes or distant organs), there is a real possibility of cure with appropriate treatment. Treatment approaches that may lead to cure include:

• Surgical resection: Removing the tumor and a margin of healthy tissue
• Stereotactic body radiation therapy (SBRT): Precisely targeted radiation for patients who cannot undergo surgery
• Combined approaches: Surgery followed by chemotherapy or radiation to eliminate any remaining cancer cells

Patients with early-stage lung cancer who receive appropriate treatment have five-year survival rates of 60-70%, with many considered cured of their disease⁹.

For lung cancer that has spread beyond the lungs, a complete cure is less likely, though not impossible. Treatment goals for advanced disease often focus on:

• Extending survival time
• Reducing symptoms
• Improving quality of life
• Achieving long-term disease control

It’s important to note that treatment advances are continuously improving outcomes for patients with all stages of lung cancer. Some patients with advanced disease can achieve long-term survival with current therapies, particularly those whose tumors have specific genetic mutations that can be targeted with newer drugs.

Given that early detection dramatically improves survival rates, lung cancer screening is crucial for high-risk individuals. The U.S. Preventive Services Task Force recommends annual screening with low-dose CT scans for people who:

• Are aged 50-80 years
• Have a 20 pack-year smoking history (equivalent to smoking one pack daily for 20 years)
• Currently smoke or have quit within the past 15 years

Early detection through screening can identify lung cancer when it’s still localized and potentially curable, addressing one of the primary reasons the disease is so deadly.

While lung cancer statistics can be alarming, there are proactive steps you can take:

1. Quit smoking or never start—this is the single most effective way to reduce lung cancer risk
2. Test your home for radon, the second leading cause of lung cancer
3. Discuss screening with your doctor if you’re in a high-risk group
4. Know the symptoms and seek medical attention promptly if they appear
5. Consult with cancer doctors in Charlotte if you’re diagnosed with lung cancer to explore all treatment options

For a consultation about lung cancer treatment options, contact SERO today.

1. American Cancer Society. “Risk of Dying from Cancer Continues to Drop at an Accelerated Pace.” (2022). https://www.cancer.org/latest-news/facts-and-figures-2022.html
2. American Cancer Society. “Key Statistics for Lung Cancer.” (2022). https://www.cancer.org/cancer/lung-cancer/about/key-statistics.html
3. American Lung Association. “Lung Cancer Fact Sheet.” (2022). https://www.lung.org/lung-health-diseases/lung-disease-lookup/lung-cancer/resource-library/lung-cancer-fact-sheet
4. Centers for Disease Control and Prevention. “Lung Cancer: What Are the Risk Factors?” (2022). https://www.cdc.gov/cancer/lung/basic_info/risk_factors.htm
5. Centers for Disease Control and Prevention. “Tobacco-Related Mortality.” (2020). https://www.cdc.gov/tobacco/data_statistics/fact_sheets/health_effects/tobacco_related_mortality/index.htm
6. UT Southwestern Medical Center. “Lung Cancer in Young Nonsmokers Is on the Rise: Uncovering the Cause.” (2021). https://utswmed.org/medblog/lung-cancer-young-nonsmokers/
7. BMJ. “Every Month Delayed in Cancer Treatment Can Raise Risk of Death by Around 10%.” (2020). www.bmj.com/company/newsroom/every-month-delayed-in-cancer-treatment-can-raise-risk-of-death-by-around-10
8. Journal of Thoracic Disease. “Lung Cancer in Elderly Patients.” (2016). https://jtd.amegroups.com/article/view/7750/html
9. American Cancer Society. “Lung Cancer Survival Rates.” (2022). https://www.cancer.org/cancer/lung-cancer/detection-diagnosis-staging/survival-rates.html
10. Archives of Pathology & Laboratory Medicine. “Causes of Death of Patients With Lung Cancer.” (2012). https://meridian.allenpress.com/aplm/article/136/12/1552/128624/Causes-of-Death-of-Patients-With-Lung-Cancer