Cancer
Lung Cancer
An overview of lung cancer, its established risk factors and the role of screening, with notes on data availability in Texas.
Beginner explanation
Lung cancer is cancer that forms in tissues of the lung, usually in the cells lining the air passages. MedlinePlus describes it as the leading cause of cancer death in both men and women.[1]
There are two main types, which grow and are treated differently: small cell lung cancer and non-small cell lung cancer. Non-small cell lung cancer is the more common type.[1]
Key definitions
- Low-dose CT (LDCT)
- A scan that uses a small amount of radiation to make detailed images of the lungs; the recommended lung cancer screening test.
- Pack-year
- Smoking an average of one pack of cigarettes a day for one year. One pack a day for 20 years, or two packs a day for 10 years, both equal 20 pack-years.
- Radon
- A naturally occurring radioactive gas from rocks, soil and water that cannot be seen, smelled or tasted and can build up indoors.
- Staging
- Tests that find out whether and how far cancer has spread, used to guide treatment.
- False positive
- A screening result that suggests cancer when none is present.
Condition characteristics
Lung cancer may cause no signs or symptoms until it is advanced. Possible symptoms include:[1]
- A cough that does not go away or gets worse
- Chest pain or discomfort
- Coughing up blood
- Trouble breathing, wheezing or hoarseness
- Loss of appetite, unexplained weight loss or feeling very tired
- Trouble swallowing, or swelling in the face or neck veins
Source[1]
Diagnosis can involve a medical and family history, physical exam, imaging such as a chest X-ray or CT scan, lab tests and a biopsy. For most patients, current treatments do not cure lung cancer, and treatment depends on the type, how far it has spread and the person’s overall health.[1]
Risk factors
Cigarette smoking is the number one risk factor. CDC reports that it is linked to about 80% of U.S. lung cancer deaths, and that people who smoke are 15 to 30 times more likely to get or die from lung cancer than people who do not. Risk rises with the number of years smoked and cigarettes per day, and falls after quitting.[2]
Other risk factors include:[1, 2]
- Secondhand smoke
- Radon in homes or workplaces — the risk is higher for people who smoke, but radon also causes lung cancer in people who have never smoked
- Workplace substances such as asbestos, arsenic, diesel exhaust and some forms of silica and chromium
- Air pollution
- A personal or family history of lung cancer
- HIV infection and previous radiation therapy to the chest
- Beta carotene supplements (not beta carotene from food), especially in people who smoke heavily
- Arsenic or radon in drinking water, mainly from private wells
Prevention and public health context
Not smoking, quitting smoking, avoiding secondhand smoke and testing homes for radon all reduce exposure to the main known causes.[2]
The U.S. Preventive Services Task Force recommends yearly LDCT screening for people who have a 20 pack-year or more smoking history, who smoke now or quit within the past 15 years, and who are 50 to 80 years old. Screening people at high risk can reduce deaths by finding lung cancer early. CDC reports that only about 18% of eligible U.S. adults have been screened.[3, 4]
Screening has risks too: false positives that lead to unneeded tests, overdiagnosis of cancers that would never have caused harm, and radiation from repeated scans. People should discuss their own risk with a health professional.[3]
Texas data context
Lung and bronchus cancer incidence by Texas county (2019–2023, age-adjusted) is on the Explore map, from Texas Cancer Registry data published on State Cancer Profiles; about 50 small counties are suppressed. County lung cancer death rates are not shown yet.
Because cancer rates rise with age, any future comparison of counties would need age-adjusted rates rather than raw counts.[5]
Related measures on the Explore map
No verified county-level measure exists for this topic, so no map link is offered.
Advanced material (optional)
NCI notes that a rise in recorded cancer incidence can reflect a true increase in disease or the arrival of a new screening test that detects cancers that would not have caused problems (overdiagnosis). Because LDCT screening is expanding, lung cancer incidence trends must be read alongside mortality trends.[5]
Smoking causes cancer in many parts of the body, not just the lung — including the mouth, throat, esophagus, stomach, colon, rectum, liver, pancreas, larynx, kidney, bladder and cervix — and can also cause acute myeloid leukemia.[2]
References
- Lung Cancer. MedlinePlus, U.S. National Library of Medicine. https://medlineplus.gov/lungcancer.html (accessed 2026-10-18).
- Lung Cancer Risk Factors. Centers for Disease Control and Prevention. https://www.cdc.gov/lung-cancer/risk-factors/index.html (accessed 2026-10-18).
- Screening for Lung Cancer. Centers for Disease Control and Prevention. https://www.cdc.gov/lung-cancer/screening/index.html (accessed 2026-10-18).
- Cancer Screening Tests. Centers for Disease Control and Prevention. https://www.cdc.gov/cancer/prevention/screening.html (accessed 2026-10-18).
- Cancer Statistics. National Cancer Institute (NIH). https://www.cancer.gov/about-cancer/understanding/statistics (accessed 2026-10-18).