Lung Cancer 101

Lung cancer

November is lung cancer awareness month. As with all cancers, education and awareness will help lower the number of lung cancers each year.

Lung cancer comes from many different sources both internal and external. Many cancers spread or metastasize to the lung causing lung cancer.

However, those lung cancers that are not caused by the spread of other cancers are preventable.

Lung cancers arising from external sources like smoking and second-hand smoke along with other environmental factors can be prevented by simply avoiding the factors which cause lung cancer.


What is Lung Cancer?

Similar to other cancers, lung cancer is the growth of abnormal cells that usually line your air passages. The cells go rapidly and undergo a degenerative transformation. The main cause of lung cancer is inhaling carcinogens primarily found in cigarette and cigar.

These cells alter their genetic make-up. Primary lung cancer starts in the lung while secondary lung cancer starts in other areas of the body and metastasizes to the lung via your circulatory and lymph systems.

Because all blood in your body travels to the lungs and picks up oxygen for your cells survival, many cancers can spread to your lungs and become secondary lung cancer.

However, more than 85% of primary lung cancers are caused by smoking cigarettes. Interestingly, according to the American Cancer Society (ACS) lung cancer makes up about 14% of all newly diagnosed cancers in the United States today.


Types of Lung Cancer

The ACS also notes that there are three main types of lung cancer non-small cell, small cell, and lung carcinoid tumor.

About 85% of lung cancers are non-small cell lung cancer, about 10-15% are small cell lung cancer, and only about five percent are lung carcinoid cancer.

It is important to know and understand which type of lung cancer someone has because each type is treated differently.

1. Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most common lung cancer. There are four different types of NSCLC which are grouped depending on the treatment approach and prognosis.

NSCLS further divided into four different types:

1.1 Adenocarcinoma

About 40% of lung cancers are adenocarcinomas. Adenocarcinomas are early versions of cells which secrete mucus in your lungs.

Usually found in the outer part of the lungs, adenocarcinomas are mainly found in current or former smokers, but it is the most common type of lung cancer seen in non-smokers and women. Adenocarcinomas tend to be slower growing NSCLC and are more likely to be found before it has spread.

1.2 Squamous Cell Carcinoma

The ACS notes that squamous cell, also known as epidermoid carcinoma, accounts to about 25% to 30% of all lung cancers. It forms along the lining of the bronchial tubes or airways. Squamous cell carcinoma is often caused by smoking and typically found in the central part of the lung.

1.3 Bronchioalveolar Carcinoma

A rare type of adenocarcinoma NSCLC that forms near the lungs’ air sacs which stores air. Those who have been diagnosed with this type of NSCLC tend to have a better outcome.

1.4 Large-cell Undifferentiated Carcinoma

Appearing in about 10% to 15% of lung cancers is a rapidly growing cancer that forms near the outer edges or surface of the lungs. Due to its rapid growth, it is typically more difficult to treat.

2. Small Cell Lung Cancer (SCLC)

Small cell lung cancer accounts for 10% to 15% of lung cancer cases. According to the National Cancer Institute, there are two types of small cell lung cancer, small cell carcinoma (oat cell cancer) and combined small cell carcinoma.

Smoking, inhaling second-hand smoke, or exposure to radiations are the major risk factors for small cell lung cancer. Small cell lung cancer tends to grow rapidly and spreads to other parts of the body.

It responds well to chemo and radiation therapy and is associated with symptoms resulting from substances produced by tumor cells.

3. Lung Carcinoid Carcinoma

The ACS describes lung carcinoid tumors as uncommon and slower growing tumors. They are made up of special cells called neuroendocrine cells.

Neuroendocrine (pronounced – nuro-end-o-cren) cells are a combination of hormone-producing cells and nerve cells. Neuroendocrine cells help regulate air and blood flow to the lungs.


Identifying Lung Cancer

Lung cancers can be asymptomatic (without symptoms) or be symptomatic. According to the ACS, there are many different signs or symptoms in the early stages of lung cancer.

  • A cough that gets worse and does not go away
  • Coughing up blood or a rust-colored sputum, spit, or phlegm
  • Shortness of breath
  • Chest pain that worsens with deep breathing, coughing or laughing
  • Hoarseness in your voice
  • Weight loss or loss of appetite
  • Feeling tired or weak
  • Wheezing

Additional signs and symptoms which you can experience if the lung cancer spreads include:

Lung cancer is diagnosed using a series of diagnostic tests such as a Chest X-ray, CAT Scan, Biopsy, Endoscopy, MRI, and PET Scan.

Lung cancer is one of the most preventable cancers. Simply put, if you smoke cigarettes, or breathe second-hand smoke, your risk of getting lung cancer increases greatly.

Cancer tumors consist of “tumor markers” which when known, help determine targeted therapy to treat lung cancer.

The ways to reduce your risk of lung cancer treatment processes, diagnostic tests, and tumor markers will be explained in the next article.

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Sources:
“Lung Cancer: Facts, Types and Causes,” Medical News Today web site, Jan 05, 2017; https://www.medicalnewstoday.com/info/lung-cancer.
“Small Cell Lung Cancer Treatment (PDQ®)–Patient Version,” Cancer web site; https://www.cancer.gov/types/lung/patient/small-cell-lung-treatment-pdq, last accessed November 12, 2017.
“Small-Cell Lung Cancer,” Emedicine Health web site; https://www.emedicinehealth.com/small-cell_lung_cancer/article_em.htm, last accessed November 12, 2017.
“What Is Small Cell Lung Cancer?” Cancer web site; https://www.cancer.org/cancer/small-cell-lung-cancer/about/what-is-small-cell-lung-cancer.html, last accessed November 12, 2017.