Lung cancer is a disease in which the cells in the lungs change and grow uncontrollably, forming a tumor and destroying healthy tissue around them. When cancer begins in the lungs, it may spread to the lymph nodes or other organs. Conversely, cancer may also spread from other organs to the lungs.
According to the American Lung Association, approximately 238,000 people in the U.S. are diagnosed with lung cancer each year.
Here, UCLA Health experts Amy Cummings, MD, PhD and Sha'Shonda Revels, MD, address frequently asked questions about the disease.
Dr. Cummings is assistant professor in the Division of Hematology/Oncology at the David Geffen School of Medicine at UCLA, with a focus on early-stage lung cancer, clinical trial equity and translational immuno-oncology. She is associate director of the UCLA Health Jonsson Comprehensive Cancer Center and director of UCLA's Office of Cancer Justice, Equity, Diversity and Inclusion (OC-JEDI).
Dr. Revels, who specializes in cancer surgery, is assistant professor at the UCLA Division of Thoracic Surgery. With a passion for providing equitable health care, she focuses on increasing awareness about lung cancer screening in Black and Latino communities.
Q: How common is lung cancer?
Dr. Cummings: In the United States, lung cancer is currently the third most common cancer after breast and prostate cancer, but it is the second most common worldwide. About 1 in 16 will be diagnosed with lung cancer in their lifetime (compared to 1 out of 8 women who will be diagnosed with breast cancer and 1 in 25 who will be diagnosed with colon cancer). However, lung cancer causes more cancer-related deaths than the top other five cancers combined, which is why it is so important that we raise awareness.
Q. What causes lung cancer?
Dr. Cummings: Genomic instability, or the likelihood of cell division making mistakes, is what causes most cancers. For lung cancer, this historically was associated with smoking, although the inhalation of other substances, such as radon, asbestos, silica dust, diesel exhaust and heavy metals, can cause similar damage. However, there are also individual components that we don’t completely understand, because we know that not all smokers get lung cancer and that nonsmoking lung cancers, particularly those without an exposure history, are on the rise.
Q. What causes lung cancer in nonsmokers?
Dr. Cummings: Nonsmoking lung cancers account for as many as 1 in 4 lung cancers these days. There are a lot of hypotheses or guesses as to why, with the most likely explanation that it is not just one thing. We have studies that support an increased lung cancer risk in groups that have been exposed to indoor cooking, second-hand smoke, increased air pollution or what we call particulate matter (PM) 2.5, those with a family history of lung cancer, and those with pre-existing lung diseases like chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, tuberculosis or requiring long-term immunosuppression, including those with severe autoimmune conditions or history of an organ transplant.
Q: Does vaping cause lung cancer?
Dr. Cummings: The relationship between vaping and lung cancer is still being studied, as vaping is relatively new and cancer can take many decades to develop, but there is reason for concern. Vaping can lead to the inhalation of chemicals that we know can cause issues, like formaldehyde, volatile organic compounds and heavy metals. However, we know these products differ in the amount of these chemicals. We’ll know more over time.
Q: What are signs of lung cancer?
Dr. Cummings: Earlier-stage lung cancer may have no signs or symptoms, but some symptoms/signs of lung cancer can include a new cough that doesn’t go away or gets progressively worse, hoarseness, recurrent lung infections like bronchitis or pneumonia that don’t go away or keep coming back, unexplained weight loss, shortness of breath, wheezing, and chest pain that gets worse when you breathe deeply or laugh. Many of these symptoms can happen for reasons other than lung cancer, but if they’re lasting or getting worse over six weeks, I tend to tell people to make sure to schedule an appointment and bring it up with their doctor so they can be appropriately evaluated.
Q: What are the types of lung cancer?
Dr. Cummings: Our understanding is evolving – it used to be that the main distinction was between small cell and non-small cell lung cancer, which was determined by what the cancer cells look like under a microscope. Adenocarcinoma was used to describe cells that look more gland-like, squamous cells that look more flat or skin-like, and large cell for what didn’t fit the other categories.
We still use the adenocarcinoma and squamous descriptions for what is referred to as non-small cell lung cancer, but we’ve reclassified small and large cell lung cancer as types of high-grade neuroendocrine lung cancer. For lung adenocarcinoma and squamous cell cancer, what can give more functional insight is molecular and biomarker testing, which can identify a specific mutation or treatment approach, and we’re hoping to do the same for high-grade neuroendocrine cancers (although there’s still a lot of work to do there).
Q: How is lung cancer diagnosed?
Dr. Cummings: There are usually two parts to lung cancer diagnosis. Imaging, usually in the form of CT and/or PET-CT scans, determines the extent of the cancer or where it is exactly in the body. Biopsy by tissue and/or blood testing is then typically used to determine the cancer’s microscopic and molecular features. These are used together to come up with a treatment plan.
Q: Is lung cancer treatable?
Dr. Cummings: Absolutely. And more importantly, the technology and treatments we have are getting better and better. From robotic surgery to immunotherapy, lung cancer care is very different from what it was even 10 years ago. And our patients are better for it.
Q. How is lung cancer treated?
Dr. Revels: Thanks to significant advances in lung cancer care we have more personalized, effective and safe options for lung cancer treatment. Surgery, medications, chemotherapy, targeted therapy (based on your specific cancer genetics), immunotherapy (that helps your immune system recognize and fight the cancer) and radiation. For patients who are not strong enough for surgery, we have therapies to destroy the cancer in its place without surgery. Many patients receive a combination of the available therapies.
Q: Is lung cancer curable?
Dr. Cummings: Absolutely. It is important to understand we define cure as the ability to finish treatment without the return of cancer, which is something we only know over time. Doctors typically describe the likelihood of cure as the chance of being cancer-free and alive five years later, but it is important to note each person will have their own journey. While we use statistics to set expectations, these days, anything is possible.
Dr. Revels: Yes, lung cancer is curable, especially with early identification and prompt treatment.
Q. Who should be screened for lung cancer?
Dr. Revels: Generally, you should get screened yearly if you’re between 50 to 80 years old and you:
- Currently smoke, or you quit smoking in the past 15 years
- Have a 20 pack-year smoking history (which means you smoked at least a pack of cigarettes a day for 15-20 years)
Your physician can assist you with calculating your exposure to identify if you qualify. The UC screen website can help you count your pack years as well.
Q: How can lung cancer be prevented?
Dr. Cummings: The best way to prevent lung cancer is to know your risk. If you have smoked, find out if you are eligible for lung cancer screening. (Note that we have a tool, UC Screen, that can also connect you to a navigator if you live in California.) If you are still smoking, explore options to cut back and/or quit. Kits for home radon testing are available for purchase, and the Environmental Protect Agency (EPA) publishes maps and measurements of environmental exposures and what is considered areas of high-risk exposure. Share your risks with your doctor and be sure to draw attention to any symptoms or signs that last longer or get worse over six weeks.
Q: What is your advice to people regarding lung cancer?
Dr. Cummings: We are making advances constantly, and what we know today is just the beginning. There is a lot of information available online, and some resources are more reliable than others. Please know there is no substitute for talking with your doctor; and, if you have lung cancer, speaking with a lung cancer expert and/or multidisciplinary team is important as a lot has, and will, continue to change. Most importantly, know that there is hope. We have made tremendous progress in how we diagnose and treat lung cancer over the past 10 years, and we will continue to work together and push forward until lung cancer is eradicated for good.
