Lung cancer causes more cancer deaths in the United States than breast, prostate, and colorectal cancer combined. That is not because it is the most common diagnosis but because it is usually found late, after symptoms appear and the disease has spread. The picture has changed considerably in recent years: low-dose CT screening can find lung cancer while it is still curable, and for advanced disease, targeted drugs and immunotherapy have replaced chemotherapy as the first treatment in a large share of patients.
Risk Factors
- Smoking: By far the dominant cause, and risk rises with both the amount and the duration. Quitting lowers risk substantially over time but never returns it to that of a person who never smoked, which is why former smokers remain eligible for screening.
- Radon: The leading cause among people who never smoked. It is an odorless, colorless gas that seeps from soil and accumulates indoors, and levels vary from one house to the next on the same street, so testing your own home is the only way to know. Test kits are inexpensive and widely available, and elevated levels can be fixed.
- Secondhand smoke, asbestos, and diesel exhaust: Each raises risk, and asbestos combined with smoking raises it far more than either alone.
- Air pollution: A smaller but real contributor, including the fine particulates that drift into Florida during wildfire smoke and Saharan dust events.
- Previous lung disease: COPD and pulmonary fibrosis raise risk independently of smoking history.
Symptoms
Early lung cancer is typically silent, which is the case for screening. When symptoms appear they include a cough that persists or changes in character, coughing up blood even once, shortness of breath, chest or shoulder pain, hoarseness, recurrent chest infections, and unexplained weight loss or fatigue. In a long-term smoker a changing cough is easy to attribute to smoking itself, and that attribution is the most common reason diagnosis is delayed. Coughing up blood warrants an appointment regardless of how well you otherwise feel.
Screening and Early Detection
The US Preventive Services Task Force recommends annual low-dose CT for adults aged 50 to 80 with a 20 pack-year history who currently smoke or quit within the past 15 years. Screening reduces lung cancer deaths in this group, it is covered by Medicare and most insurance, and uptake remains strikingly low: most eligible people have never been offered it. Our guide to low-dose CT screening explains what the scan involves and what an abnormal result actually means, and cancer screenings by age sets it alongside your other due screenings.
Screening finds pulmonary nodules in a substantial proportion of people scanned, and nearly all of them are benign. A structured follow-up schedule, rather than immediate biopsy, is the standard and correct response.
Diagnosis
A suspicious finding leads to further imaging, usually a diagnostic CT and often a PET scan, followed by a tissue biopsy obtained through bronchoscopy, a needle through the chest wall, or sampling of lymph nodes. Tissue does two jobs. It confirms the diagnosis and establishes the type, most commonly non-small cell lung cancer, and it supplies material for molecular testing. That testing looks for specific mutations such as EGFR and ALK and measures PD-L1 expression, and its results change the first treatment offered. Waiting for full molecular results before starting treatment is usually the right call rather than a delay.
Treatment
Early-stage disease is treated with surgery, sometimes with radiation as an alternative for people who cannot tolerate an operation, and often with drug treatment before or after. Locally advanced disease usually combines chemotherapy and radiation. In advanced disease, treatment is chosen by molecular profile: an EGFR mutation is treated with a targeted pill such as osimertinib or, in some settings, erlotinib, while tumors without a targetable mutation are commonly treated with immunotherapy such as pembrolizumab, alone or with chemotherapy. These treatments are taken for long periods and are managed by oncology, but their side effects frequently present first to primary care.
What Primary Care Handles
The practice's role runs from before diagnosis to long after treatment.
Getting eligible people screened
The single most valuable thing we do about lung cancer is work out who qualifies for screening and arrange it. That takes an accurate smoking history, which is why we ask about pack-years in a way that can feel pedantic. If you have ever smoked regularly and are over 50, ask whether you qualify.
Treating nicotine dependence properly
Quitting improves outcomes at every stage, including after diagnosis. Nicotine dependence responds to medication combined with support far better than to willpower alone, and our article on what actually works for quitting sets out the options. Treatment roughly triples the odds of success.
Immunotherapy side effects are different
Immunotherapy can cause the immune system to attack normal tissue, producing colitis, thyroid disease, rash, hepatitis, or pneumonitis, sometimes months after treatment starts. These are treated differently from ordinary drug side effects and need to be recognized quickly, so tell any doctor you see that you are on immunotherapy. Our pulmonary care team coordinates closely with oncology on breathlessness and cough during treatment.
When to Seek Care
Book an appointment for a cough lasting more than three weeks or one that changes, any coughing up of blood, new breathlessness, chest pain, hoarseness that persists, repeated chest infections, or unexplained weight loss. The National Cancer Institute and the CDC both publish reliable overviews.
If you have ever smoked and have never been told whether you qualify for screening, schedule a visit and let us work it out.