If you have lung cancer, having other health conditions at the same time may make treatment more difficult. It may even affect your cancer prognosis. Lung cancer is the second most common cancer in both men and women in the United States. The two most common types are non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).

Understanding how other health conditions are related to lung cancer can help you talk to your doctor about making treatment and lifestyle changes. Addressing related conditions may improve your quality of life, lower your risk for developing life-threatening complications, and prolong survival.

What Is a Comorbidity?

When someone has two or more diseases at the same time, these diseases are comorbidities. Comorbidities can often complicate lung cancer treatment and recovery, and contribute to disease burden. Comorbid conditions may be related to lung cancer in many different ways. Most often, risk factors that cause lung cancer can also cause comorbidities.

Age plays a large role in the risk for developing comorbidities. The longer a person lives, the more likely they are to be diagnosed with multiple chronic conditions. Lung cancer is also much more likely to be diagnosed in people who are 65 years or older, with few people diagnosed under the age of 45.

Racial disparities and socioeconomic factors also play a role in the risk of getting lung cancer. According to the American Cancer Society, Black men are about 15 percent more likely to develop lung cancer than white men. However, Black women are 14 percent less likely to get lung cancer than white women. Education and access to quality health care can have a large impact on cancer diagnosis and outcomes.

Why Do Comorbidities Matter?

When you are first diagnosed with lung cancer, it may seem like your biggest worry compared to any other conditions you may have. However, these other conditions may influence your lung cancer prognosis.

People with lung cancer tend to have the highest prevalence of comorbidities compared to other cancers. The most common comorbid conditions with lung cancer include:

• Chronic obstructive pulmonary disease (COPD)
• Congestive heart failure
• Diabetes
• Peripheral vascular disease (blood circulation disorders)
• Cerebrovascular disease (disease affecting blood supply to the brain)

Comorbid conditions may have an impact on the cancer treatment you receive, and they are also predictors for how well you will respond to treatments. The NCI Comorbidity Index, formerly called the Charlson Comorbidity Index, was developed in 1987 as a way to predict how comorbidities impact the health and overall survival of people with various medical conditions, including lung cancer.

Common Comorbidities in NSCLC

Around 84 percent of all lung cancer cases are NSCLC. Comorbidities in NSCLC have been shown to affect the outcomes of surgery, chemotherapy, and radiation therapy.

• Surgery — Some comorbidities can increase the risk of complications after surgery and affect survival outcomes, especially in men with early stage NSCLC and in those with squamous cell carcinomas.
• Chemotherapy — Some comorbidities can impact the choice of chemotherapy medications used in treatment.
• Radiation — Some comorbidities can lead to lung infections and other complications after radiation therapy.

According to one study of 400 people with NSCLC, the most common comorbid conditions include:

• Coronary artery disease and heart attack (myocardial infarction)
• High blood pressure (hypertension)
• COPD or other lung diseases
• Diabetes
• Stroke
• Tuberculosis
• Chronic kidney disease (renal disease)
• Arrhythmias
• Peripheral artery disease (narrowing of the arteries)
• Hepatitis B or C infections
• Liver disease
• HIV infection

Common Comorbidities in SCLC

About 13 percent of all lung cancer cases are SCLC. This type of lung cancer is highly aggressive and is usually diagnosed in the presence of other conditions.

The most common comorbid conditions for SCLC include:

• Diabetes
• Pulmonary disease
• Vascular disease (disease affecting the blood vessels)
• Heart disease
• High blood pressure
• Cerebrovascular accident (stroke)
• Digestive disease
• Other types of cancer

Conditions That Develop After Lung Cancer Treatment

Treatments for lung cancer can cause long-term and delayed effects that may begin months or years after treatment is complete. These long-term or late effects are known as sequelae. This term refers to conditions that begin after another disease or injury. The risk for various sequelae depends on the type of treatment and one’s overall health.

Some common sequelae after treatment for lung cancer include:

• Damage to the heart muscle (cardiotoxicity)
• Heart-related complications, such as arrhythmias, high blood pressure, and coronary artery disease
• Lung damage, including loss of lung function, difficulty breathing, inflammation, and thickening of the lining of the lungs
• Chronic swelling due to fluid buildup in the lymph nodes (lymphedema)
• Long-term numbness and tingling pain in the arms and legs (neuropathy)
• Development of other types of cancer
• Cognitive problems, such as difficulties with concentration or memory (commonly referred to as “chemo brain”)

Talking To Your Doctor About Related Conditions

Speaking with your doctor can help you better understand your individual risk factors for developing comorbid conditions and how you can lower your risk. Be sure to tell your doctor about any health conditions you’ve had. To avoid any potentially dangerous drug interactions, let your doctor know which medications you are taking for other health conditions. This includes prescription and over-the-counter drugs, vitamins, and herbal supplements.

Lung Cancer Condition Guide

• Lung Cancer: An Overview
• Symptoms of Lung Cancer
• Treatments for Lung Cancer
• Types of Lung Cancer
• Stages of Lung Cancer
• What Causes Lung Cancer?
• How Is Lung Cancer Diagnosed?