Non-small-cell lung carcinoma

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 19, 2016
StartDiseasesNon-small-cell lung carcinoma

Non-small-cell lung carcinoma or non-small cell lung cancer (NSCLC) is the most common kind of lung cancer. All types of cancer involve the body’s cells continuing to grow past the point at which normal cells stop growing. This abnormal, uncontrolled cell growth eventually creates a tumor.


Definition & Facts

Lung cancer is the most common cause of deaths from cancer; every 1 out of 4 deaths from cancer are due to lung cancer. All types of lung cancer are strongly linked to smoking. Lung cancer usually begins in the lining of the bronchus or the bronchioles which deliver air to the alveoli – the air sacs of the lungs that absorb oxygen.

Lung cancer can be categorized as non-small cell carcinoma, small-cell carcinoma or lung carcinoid tumor. In addition, there are other lung cancers that can develop such as lymphomas and sarcomas, but these are rare. Cancers that originate in other parts of the body may also metastasize to the lungs.

Non-small-cell lung carcinoma is the most common type of lung cancer, accounting for up to 85% of all lung cancer cases. They tend to grow less quickly than small-cell carcinomas though are less responsive to chemotherapy.

Subcategories of non-small lung carcinoma are squamous-cell carcinoma, adenocarcinoma, and large-cell carcinoma. Squamous-cell carcinoma makes up a quarter to a third of lung cancer cases. Adenocarcinomas are the most common subtype, and they affect women more frequently than men. While most people with adenocarcinomas have a history of smoking, adenocarcinomas are also the most common cancers among non-smokers. Large-cell carcinomas grow and metastasize quickly, accounting for up to 15% of all lung cancers.

Symptoms & Complaints

While lung cancers are often asymptomatic prior to metastasizing, the primary symptoms of lung cancer including non-small-cell lung carcinoma typically involve chronic irritation and coughing. Specifically, the patient develops a cough that won’t subside after a few weeks and remains constant and present.

Additionally, there is a noticeable decrease in the ability to breathe, unexplained weight loss, or in severe cases, the patient begins to cough up blood.


The most common cause of lung cancer is smoking: up to 80% of lung cancer cases are caused by smoking. In addition to cigarette smoking, cigar smoking and pipe smoking cause non-small cell lung carcinoma. Secondhand smoke also causes non-small cell lung carcinoma.

Additionally, exposure to environmental toxicants like radon and asbestos can cause NSCLC. Radon is the leading cause of lung cancer among non-smokers. Exposure to asbestos, which can happen while working in mines and certain industrial settings, can also cause NSCLC in addition to mesothelioma and asbestosis.

Adenocarcinomas are caused by uncontrolled cell growth that begins in the cells of the lungs that produce mucus. Squamous-cell carcinomas begin in the squamous cells which are flat cells lining the airways. The tumor involved will frequently grow at central air passages where the smoke contact occurs the most. Finally, unlike the above two conditions, the third group of non-small-cell lung carcinomas, large cell (undifferentiated) carcinoma can develop as a tumor in any part of the lung. Worse, it has an ability to grow fast and spread quickly.

Diagnosis & Tests

Given how quickly some of the subtypes of small-cell lung carcinomas can develop and grow, early diagnosis of the condition is extremely important for the patient. Typically, diagnosis is initially made with the use of a chest X-ray. The patient is scanned and the cancer shows up as a noticeable matter in the X-ray print.

In addition, better imaging and detail can be obtained through MRIs as well as through PET scans and CT scans. These last two scans give doctors far more information with regards to the growth rate and depth of the tumor into neighboring tissue.

However, a true confirmation of the cancer’s presence is performed by biopsy. A doctor inserts the appropriate equipment via a handful of different approaches and gathers a physical sample of the tumor, then tests them for cancer. The diagnosis is then made, along with a staging conclusion about how far the tumor has spread within the lung tissue and throughout the body.

Treatment & Therapy 

A number of treatment options may be available for a lung cancer patient, depending on which stage of tumor development the patient is diagnosed with. At the early stage level, surgery may eliminate the cancer entirely. As the condition moves out of stage 0 and into stage 1, surgery is still possible, but the patient may need prolonged treatment, either through radiation therapy or chemotherapy or a combination of the two.

By stage 2 chemotherapy is frequently used to reduce the cancer before a surgery occurs, if the patient is physically strong enough to handle the procedure. By stage 3 and beyond, all treatment methods will be used in combination to halt the cancer growth and then remove it as much as possible. Unfortunately, the patient’s endurance is often worn down which can delay surgery applied. If the cancer that is present has spread to the rest of the body, then chemotherapy tends to be the treatment approach applied.

Prevention & Prophylaxis

Avoiding smoking tobacco or quitting smoking as soon as possible decrease a person’s chances significantly of developing non-small-cell carcinoma. Even after a diagnosis, statistics are available that show those who quit smoking immediately see improved changes of recovery after a cancer diagnosis.

Additionally, work or living conditions that can produce significant, chronic carcinogenic material that can be inhaled should be avoided. In addition, prolonged exposure to chemicals in paints and aerosols should be avoided. If one has to work in these environments or around these chemicals, a proper industrial-grade gas mask should be worn at all times.