Adenocarcinoma Of The Lung: Causes, Symptoms, Diagnosis, Prognosis, Treatment

Adenocarcinoma of the lung Causes, symptoms, diagnosis, prognosis

There are different ways to break down Non-Small-Cell lung cancer (NSCLC) into categories or types. First of all, they divide into large cell carcinoma, adenocarcinoma, and Squamous cell carcinoma.

In this article, we’re briefly going through the essentials of the adenocarcinoma of the lung and what you need to know about its causes, symptoms, diagnosis, treatment, and prognosis.

What Is Adenocarcinoma Of The lung?

What is adenocarcinoma of the lung

Lung adenocarcinoma is a frequently occurring type of NSCLC. It develops in bronchioles and grows more slowly than other types of lung cancer. It takes place when the abnormal cells of the lungs multiply out of control and form a tumor. The tumor can spread to other parts of the body like the brain, liver, and lymph nodes.

It is the most common lung cancer in the United States. It is strongly associated with smoking history. Adenocarcinoma of the lung mostly occurs in the mucosal glands responsible for the secretions and alveoli that help the air in and out of the lungs. 40% of cancer cases occurring in the lung will be adenocarcinoma. Most patients with adenocarcinoma of the lung are under 45 years.

What Causes Adenocarcinoma Of The Lung?

What causes adenocarcinoma of the lung

The most common cause of adenocarcinoma is chronic tobacco smoking. Smokers are 13 times more likely to develop adenocarcinoma than non-smokers. Smoking includes cigar, pipe, and cigarette smoking.

The second major cause is exposure to radon gas. Regular breathing in an environment contaminated with radon gas increases the chances of developing adenocarcinoma of the lung.

The third major cause is asbestos exposure. Asbestos is found in our ceiling tiles, fireproofing, and insulation material. People living in this type of building have an increased risk of adenocarcinoma of the lung.

Warning Signs and Early Symptoms Of Adenocarcinoma

Signs and symptoms

Many patients with adenocarcinoma of the lungs have no symptoms. However, it can be diagnosed by X-Rays or a CT scan. We can list a few symptoms typically observed at the last stage of adenocarcinoma:

  • Fever
  • Chest pain
  • Wheezing
  • Coughing up blood
  • Persistent coughing
  • Shortness of breathing
  • Hoarseness
  • Poor appetite
  • Weight variation
  • Raspy voice

Treatment and Prognosis Of Adenocarcinoma

Treatment and prognosis Of Adenocarcinoma

Various tests can be used to diagnose adenocarcinoma of the lung. These are the most important:

Imaging tests

Imaging tests include X-rays, magnetic fields, and other technologies that provide a picture from the inside of the body. They are done to determine how far cancer has spread.

  • Computed tomography scan (CT scan): A computer tomography scan uses a computer associated with an advanced X-ray machine to get a detailed image from the inside of the body. As compared to simple X-rays, a computer tomography scan provides multiple pictures in different directions. As a result, the location, shape, and size of the mass of the tumor or nodule can be identified.
  • Magnetic resonance imaging scan (MRI scan): This imaging test uses radio waves and a magnet, offering a detailed picture of the inside. It is used to determine whether the lung cancer has spread to other body parts such as the spinal cord, lymphatic system, and the brain.
  • Positron emission tomography scan (PET scan): This tomography scan is used after a CT scan to confirm the malignant nature of the nodule or mass. It can also be used to determine how far cancer has spread to other parts like bones, the brain, etc. Some hospitals use a combination of CT scan and PET scan known as positron emission tomography-computed tomography scan. The purpose is to diagnose the tumor’s mass in the chest and determine how much it has spread.

Laboratory Tests

Laboratory tests

One or more laboratory tests can be performed to diagnose or confirm lung cancer, assessing how far it has spread. Standard blood tests such as Complete Blood Count cannot diagnose lung cancer, but they are used to evaluate the organs’ function. The growth of abnormal cells can be diagnosed with other studies:

Biopsies

  • Sputum cytology: If someone has deep coughing with sputum production, this test can be performed. The sputum is observed under a microscope to look for lung cancer cells or infection.
  • Biopsies: It is also known as tissue sampling. In this case, the doctor performs a biopsy by using an instrument that passes through our throat to the lungs and pinpoints the infected area. The biopsy can be achieved with a closed or open method. Different techniques can be used, including Thoracentesis, Thoracoscopy, a Transthoracic needle biopsy, or a Mediastinoscopy.

Treatment Of Adenocarcinoma Of The Lung

Surgery

There are many approved treatment methods for adenocarcinoma. These include:

  • Surgery
  • Radiation therapy
  • Chemotherapy
  • Immunotherapy
  • Angiogenesis inhibitors

The treatment chosen method will depend on the patient’s overall health condition and how far it has spread to other organs.

Surgery

Surgery features the complete removal of the tumor. Three kinds of surgery methods are practiced for the treatment of adenocarcinoma of the lung.

  • Lobectomy: In lobectomy, the affected lobe or part of the lung is removed.
  • Pneumonectomy: In pneumonectomy, the entire lung is removed. It is practiced when the cancer is in the center of the lung.
  • Wedge resection: In wedge resection, only a limited section of the lung is removed. Before surgery, an electrocardiogram and spirometry are carried out to check the health state of the patient.

Radiotherapy

Radiotherapy

In radiotherapy, different radiations are applied to destroy cancerous cells. It is practiced if the patient is not a suitable candidate for surgery.  The radiations can be directed to the affected part or can be passed with a catheter.

Chemotherapy:

In chemotherapy, different medicines are taken by patients to cure cancer or to shrink it before surgery. This treatment takes place in a cycle, in which drugs are taken for some days, followed by a break period. The number and duration of the cycles depend on the type and extent of cancer spread.

Immunotherapy:

In immunotherapy, medicines are taken to boost up immunity. So, immunotherapy fights against cancer and kills cancerous cells with your immune cells and substances. It is mostly used along with chemotherapy. These medicines are usually given intravenously but can cause fatigue, joint pain, and swelling.

Angiogenesis inhibitors:

As the abnormal cells develop and grow, they need new blood vessels to supply oxygen to all new growing cells. This process is known as angiogenesis. When the newly developed cells get more oxygen and nutrients, they grow and spread more speedily. Angiogenesis inhibitors can stop the growth of abnormal cells by stopping the development of new blood vessels. Due to insufficient nutrients and oxygen, the cells die, and the growth of abnormal cells slows down. Currently, “Bevacizumab and Ramucirumab” are the two approved angiogenesis inhibitors.

References:

Myers, D. J., & Wallen, J. M. (2020). Cancer, lung adenocarcinoma. StatPearls [Internet].

Travis, W. D. (2011). Pathology of lung cancer. Clinics in chest medicine32(4), 669-692.