Types of Lung Cancer: Understanding the Key Variants

In India, the battle against lung cancer is a poignant reality. It is the most common type of cancer diagnosed globally, and one of the top reasons for cancer-related deaths worldwide. In India, lung cancer makes up 5.9% of all cancer cases and is responsible for 8.1% of all cancer-related deaths^[1].

These statistics are worrying and emphasise the urgent need for awareness, prevention, and improved healthcare measures to combat this serious disease. In this article, we will discuss the different types of lung cancer to help fight against the disease.

What is Lung Cancer?

Lung cancer arises when harmful cells in the lungs multiply uncontrollably. To combat this disease, treatments like surgery, chemotherapy, immunotherapy, radiation, targeted drugs, etc. are recommended. If you find yourself at a higher risk, it is advisable to undergo screening to detect potential issues early on.

Types of Lung Cancer -

Lung cancer is known to be of different types –

Non Small Cell Lung Cancer (NSCLC)

Non-Small Cell Lung Cancer is the most prevalent type and tends to grow slowly. In many cases, Non-Small Cell Lung Cancer progresses gradually and symptoms may not appear until it has reached an advanced stage. Non-small cell lung cancer (NSCLC) is of three primary types –

1. Adenocarcinomas: Adenocarcinomas are commonly found in various cancers like breast, prostate, and colorectal cancers. In the case of lung adenocarcinoma, it originates in the outer region of the lung, specifically in glands that produce mucus and aid in breathing. Typical symptoms include coughing, hoarseness, weight loss, weakness, etc. This type of cancer is often diagnosed in both current and former smokers, and its identification is based on the cells that typically generate mucus.
   
2. Squamous Cell: Squamous cell cancer usually originates in the lining of the bronchial tubes. It is closely associated with a smoking history and can lead to symptoms such as coughing, breathing difficulty, etc.
   
3. Large-Cell Undifferentiated Carcinoma: Large-cell undifferentiated carcinoma is a type of lung cancer that grows and spreads rapidly. It can appear in any part of the lung. This aggressive form of lung cancer tends to progress swiftly and can be found in various areas within the lung, making it challenging to treat. Another closely related subtype is large-cell neuroendocrine carcinoma, which grows rapidly and bears similarities to Small-Cell Lung Cancer.

Small Cell Lung Cancer

Small Cell Lung Cancer, also known as ‘oat-cell cancer’ due to its oat-like appearance under a microscope, usually originates in the bronchi. It grows rapidly and swiftly spreads to other parts of the body, including the lymph nodes. This aggressive lung cancer accounts for less than 20% of all lung cancers and is primarily linked to tobacco smoking.

In comparison to Non-Small Cell Lung Cancer, this type tends to grow and spread more quickly. However, it often shows a good response to chemotherapy and radiation treatment. Despite this, many individuals who develop Small Cell Lung Cancer experience relapses.

Small Cell Lung Cancer is further categorised based on the types of cells present and their microscopic appearance -

• Small cell carcinoma (oat-cell cancer)
• Combined small cell carcinoma

Other Types of Lung Cancer

Apart from the main types of lung cancer discussed earlier, here are some less common ones – Add below content in

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• Lung Carcinoid Tumours: These tumours make up less than 5% of all lung tumours and typically grow slowly.

• Mesothelioma: This type of cancer is often discovered in the lining of the lungs, but it can also develop in the lining of the abdomen, heart, or chest. It is closely linked to exposure to asbestos, a mineral known to be harmful to health.

• Rare tumours: These include sarcoma, thymoma, adenoid cystic carcinoma, lymphoma, and hamartoma (benign lung tumours).

To conclude

From the most common non-small cell lung cancer to aggressive small cell lung cancer, each type presents unique challenges and treatment approaches. By having a comprehensive understanding of the different types of lung cancer, you are better equipped to tackle this formidable disease. Through education, awareness, and early detection, you can take a proactive approach to lung cancer and increase your chances for a successful outcome.