Lung Cancer: Five Things You Need to Know

Medically reviewed by Pasi A. Jänne, MD, PhD

Lung cancer develops in the tissue of the lung, usually in the cells that line the air passages. Here are some common questions about the disease, answered by Pasi A. Jänne, MD, PhD, Director of Dana-Farber’s Lowe Center for Thoracic Oncology.

What are the types of lung cancer?

There are several types of lung cancer:

  • Non-small cell — Non-small cell lung cancer is named for the size of the cells when viewed under a microscope. It begins when epithelial cells inside the lining of the lungs grow rapidly or uncontrollably, often forming a tumor. This is the most common form of lung cancer.
  • Small cell — Small cell lung cancer is also named for the size of the cells when viewed under a microscope. Affecting approximately 15 percent of lung cancer patients, it typically starts in the bronchial.
  • Mesothelioma — Although it is not technically a lung cancer, mesothelioma shares many of the same symptoms as lung cancer. Malignant mesothelioma is a disease in which cancer cells form in the linings of the organs, most often the pleura and sometimes the peritoneum.

What are the risk factors for lung cancer?

The Centers for Disease Control and Prevention (CDC) estimates 90 percent of lung cancers are caused by cigarette smoke. However, there are also other risk factors:

What are the symptoms of lung cancer?

Some of the more common symptoms include a cough that does not go away, trouble breathing, chest discomfort, wheezing, hoarseness and streaks of blood in mucus. Other symptoms can include loss of appetite, weight loss for no reason, and unusual tiredness.

Patients with mesothelioma may notice lumps, pain or swelling in their abdomen, or pain under the rib cage.

Pasi Janne, MD, PhD, Director of the Lowe Center for Thoracic Oncology at Dana-Farber.
Pasi Janne, MD, PhD, Director of the Lowe Center for Thoracic Oncology at Dana-Farber.

How do doctors diagnose lung cancer?

When lung cancer is suspected, patients typically have a CT scan, MRI, or PET/CT scan to produce a detailed image of their lungs. If a mass is detected, either a fine needle biopsy, core needle biopsy, bronchoscopy, or endobronchial ultrasound (EBUS) will be done to remove a piece of tissue from a node or tumor. If necessary, surgeons may remove a tissue sample. If so, a pathologist will examine the tissue to determine whether cancer is present and, if so, the type and stage of the cancer.

What are the treatment options for lung cancer?

Treatment options are determined in part by the type of lung cancer and how advanced it is. For non-small cell lung cancer, patients in early stages first undergo surgery to remove tumors and may need no further treatment. For more advanced cases, patients are likely to have combination treatment with surgery, chemotherapy, and radiation.

Stage IV non-small cell lung cancer is widespread when diagnosed and very difficult to cure. Treatment options include surgery, chemotherapy, and – for patients whose tumors have certain common gene mutations – targeted therapies such as ALK or EGFR inhibitors. All lung cancer patients at Dana-Farber have their cancer analyzed for several genetic alterations; the results of which can help identify whether a targeted therapy is most the appropriate treatment.

The newest type of treatment for metastatic non-small cell lung cancer is immunotherapy; for example, the drug pembrolizumab (Keytruda) might be an option as a first-line treatment.

Patients with small cell lung cancer typically have chemotherapy and/or radiation therapy. This is because the disease often does not have symptoms and is diagnosed at a more advanced stage where surgery would not have an impact on the progress of the cancer. Chemotherapy and/or radiation are also often the first steps for more advanced stages of non-small lung cancer.

A combined approach of surgery, radiation therapy, and chemotherapy is used to treat mesothelioma, as there is not one universally accepted standard for treatment of the disease.

Learn more about treatment from the Lowe Center for Thoracic Oncology at Dana-Farber.