What is Bronchogenic Carcinoma?

Symptoms, Causes, Diagnosis, and Treatments

brochogenic carcinoma under the microscope
Yale Rosen/Flickr/CC BY 2.0

Historically, bronchogenic carcinoma was the term used to describe the origin of some types of lung cancer—namely those that arise in the bronchi (the largest airways of the lungs) and bronchioles. Now, this term is used interchangeably with lung cancer of all types. While the name bronchogenic carcinoma may sometimes be used in the old way—referring to lung cancers arising in the central airways instead of the periphery of the lungs—it is most often used to describe any type or subtype of lung cancer. Symptoms may include a persistent cough, coughing up blood, or repeated lung infections, with a chest CT scan and biopsy being the most common way in which it is diagnosed. Treatment options have expanded considerably in recent years, and now include surgery, radiation therapy, chemotherapy, targeted therapy, and immunotherapy.

While bronchogenic carcinoma is clearly associated with smoking, its important to note that there are a number of potential causes, including radon, air pollution, and more, and at the current time, the majority of people who develop these cancers are non-smokers (either never smokers or former smokers).

Types

There are 2 main types of bronchogenic carcinoma:

History

Bronchogenic carcinoma (lung cancer) was once considered rare. In a book published in 1912 titled Primary Malignant Growths of hte Lungs and Bronchi, the author was only able to verify 374 published cases of the disease. In 2018, lung cancer is the leading cancer-related cause of death of both men and women in the United States.

Over the last 5 decades, the most common types and location of lung cancer have changed. In the past, the most common forms were squamous cell lung cancer (a type of non-small cell lung cancer) and small cell lung cancer (oat cell carcinoma.)

At present, the most common form of lung cancer is lung adenocarcinoma. It's thought that part of this change may be related to the addition of filters to cigarettes. Instead of cancers such as squamous cell lung cancer and small cell lung cancer which usually arise in the large airways of the lungs, lung adenocarcinoma often arises in the distant airways in the periphery of the lungs. It's felt that the addition of filters allows toxic chemicals in cigarette smoke to be drawn further down into the lungs. Of course, lung cancer occurs in never smokers as well as people who smoke, and adenocarcinoma is the most common form of lung cancer in never smokers.

Symptoms

Using the older definition of bronchogenic carcinoma, symptoms are often related to the growth of cancer in the large airways. As such, common symptoms of lung cancer may include:

  • Coughing up blood
  • Recurrent pneumonia due to obstruction of the airways by a tumor
  • Persistent cough

At the current time, lung adenocarcinoma is the most common form of lung cancer, accounting for 40 to 50 percent of cases. These tumors tend to grow in the periphery of the lungs, rather than in the central airways like the bronchi, and for that reason, the typical symptoms noted above may be absent. The early symptoms of lung adenocarcinoma may instead be signs such as:

  • Unexplained weight loss
  • Fatigue
  • Shortness of breath, especially with exercise

Causes

Most people are familiar with smoking as a cause of lung cancer, but there are other important causes of bronchogenic carcinoma as well. Some of these include:

Diagnosis

The diagnosis of bronchogenic carcinoma may be made in several ways. Sometimes a physician finds an abnormality on a chest x-ray prompting further evaluation with a chest CT scan or other imaging method. A PET scan may be done, as this is the most sensitive way of finding the spread of lung cancer and accurately staging the disease. This is important, as while surgery is the treatment of choice for early-stage lung cancer, it would not be recommended for people with metastatic lung cancer.

When an abnormality is found on an imaging study, physicians often recommend a lung biopsy of some form to confirm the diagnosis, as well as to learn about the molecular profile of the lung cancer (genetic testing). This is extremely important as newer treatments for some subtypes of lung cancer have become available. If you have non-small cell lung cancer, especially lung adenocarcinoma or squamous cell carcinoma, talk to your talk about possible gene mutations in your tumor. Though a lung biopsy is still the gold standard for doing this testing, in 2016 a blood test called a liquid biopsy was approved for testing for some of these mutations. PD-L1 testing, and now tumor mutation burden testing, are tests that can sometimes estimate who will best respond to the immunotherapy drugs now available for lung cancer.

Screening

Low-dose CT screening is now available for bronchogenic carcinoma, in people who meet certain criteria. It's been found that for people between the ages of 55 and 80, who have a 30 pack-year history of smoking, and either smoke or quit in the past 15 years, screening may decrease the mortality rate from lung cancer by 20 percent. If you meet these criteria, or if you have other risk factors for lung cancer, talk to your doctor about screening.

Treatments

The treatments your doctor recommends will depend on several factors, including the type and stage of lung cancer you are diagnosed with. It is important to learn about your diagnosis, as studies suggest that people who are actively involved in their lung cancer care have better outcomes. Treatments may include lung cancer surgery, chemotherapytargeted therapiesradiation therapy, and immunotherapy.

Prognosis

Sadly, the prognosis of bronchogenic carcinoma remains poor, with the 5-year survival rate just a little over 18 percent. Prognosis varies based on the type and stage of lung cancer, with survival rates being much better when diagnosed in the earlier stages of the disease. Though these statistics are sobering, advances in the treatment of lung cancer are improving the survival, even for people with metastatic (stage 4) disease.

Coping and Support

Many people are working together in an attempt to reduce the stigma of lung cancer being a "smoker's disease." Not only do never smokers and people who quit long ago develop lung cancer, but regardless of smoking history, every patient with lung cancer deserves love, compassion, and the best medical care available.

Check on lung cancer support groups either in your community or online. Educate yourself about your disease and new advances that may pertain to you. If your loved one has been diagnosed with lung cancer, check out these tips on supporting a loved one with cancer, and coping when your loved one has lung cancer.

A Word From Verywell

Bronchogenic carcinoma has gone from a relatively rare disease to the leading cause of cancer-related deaths worldwide in the last century. Certainly, smoking has been responsible for a significant portion of these cancers, but research is needed to look for other causes. Why? Though the overall incidence of lung cancer has been decreasing in recent years, it has increased significantly for young women who have never smoked.

On a positive note, after many years of limited improvement in the survival rate for this disease, life expectancy is now improving. Targeted therapies are now allowing many people to control their disease for many months or years with oral medications. Immunotherapy drugs have sometimes resulted in a "durable response" such that some physicians believe it may be possible to cure some advanced lung cancers. Hopefully, reducing the stigma of bronchogenic carcinoma as a smoker's disease will lead to greater funding and better treatments in the future.

Was this page helpful?
Article Sources