Are there different types of lung cancer? 

Lung cancer is not a single disease but a group of cancers that start in the lungs and are classified based on the specific type of cells affected. In the United Kingdom, healthcare professionals categorise these cancers to determine the most appropriate management and support for each individual. Understanding the differences between these types is fundamental to recognising how the condition progresses and the various ways it may manifest in the body. 

What We’ll Discuss in This Article 

• The primary classification of lung cancer into two main groups. 

• Detailed characteristics of non-small cell lung cancer and its subtypes. 

• An overview of small cell lung cancer and its typical progression. 

• Less common types of lung cancer and chest-related tumours. 

• How doctors identify the specific type of cancer present. 

The Primary Classification of Lung Cancer 

Lung cancer is primarily divided into two main groups based on how the cells look under a microscope. Lung cancer is usually divided into two main groups: non-small-cell lung cancer (NSCLC), which is the most common type, and small-cell lung cancer (SCLC). These categories are essential because the cells behave differently and require distinct clinical approaches. While both types involve the uncontrolled growth of abnormal cells within the lung tissue, their rate of growth and patterns of spreading often vary significantly between patients. 

Understanding Non-Small Cell Lung Cancer 

Non-small cell lung cancer is the most prevalent form of the disease, accounting for the vast majority of all diagnosed cases in the UK. Non-small-cell lung cancer (NSCLC) is the most common type, accounting for around 80 to 85 out of 100 cases. This category is further broken down into three main subtypes, each originating from different cell types within the respiratory system. 

• Adenocarcinoma: This is the most common subtype and usually starts in the mucus-secreting cells of the lung. It is often found in the outer areas of the lungs. 

• Squamous cell carcinoma: This type develops in the flat cells that line the inside of the airways. It is frequently linked to a history of smoking and is often found near the centre of the lungs. 

• Large cell carcinoma: This subtype is named for the large, abnormal-looking cells that can be seen under a microscope. It can grow in any part of the lung and tends to grow more quickly than other NSCLC types. 

Characteristics of Small Cell Lung Cancer 

Small cell lung cancer is a less common but typically more aggressive form of the disease that almost exclusively affects people with a history of heavy smoking. Small-cell lung cancer (SCLC) is less common but usually spreads faster than non-small-cell lung cancer. Because it grows rapidly, it is often already at an advanced stage by the time symptoms become noticeable enough for a person to seek medical advice. This type of cancer usually starts in the breathing tubes in the centre of the chest and can spread quickly to other organs. 

Comparison of Major Lung Cancer Types 

The differences between the two primary types of lung cancer are significant in terms of prevalence, growth patterns, and clinical presentation. The following table highlights these distinctions. 

Feature	Non-Small Cell Lung Cancer (NSCLC)	Small Cell Lung Cancer (SCLC)
Commonality	Approximately 80% to 85% of cases	Approximately 15% to 20% of cases
Growth Speed	Generally slower progression	Rapid growth and early spread
Subtypes	Adenocarcinoma, Squamous, Large Cell	Rarely divided into further subtypes
Location	Can be central or in outer lung areas	Usually starts in central airways

Rare Types and Related Chest Tumours 

Beyond the two main categories, there are rarer forms of cancer that can affect the lungs or the surrounding tissues in the chest. These rare types require specialised diagnostic tools and often present differently than the more common forms of lung cancer. 

• Mesothelioma: This is a cancer that affects the pleura, which is the thin lining surrounding the lungs. It is almost always caused by exposure to asbestos. 

• Lung Neuroendocrine Tumours: These are rare tumours that grow from neuroendocrine cells, which are cells that receive messages from the nervous system and release hormones. 

• Metastatic Lung Cancer: This refers to cancer that started in another part of the body, such as the breast or bowel, and has spread to the lungs. This is not technically lung cancer but is often managed by lung specialists. 

Conclusion 

Lung cancer is categorised into two main types, non-small cell and small cell, which account for the vast majority of cases in the UK. Identifying the specific cell type is a critical step in the clinical pathway to ensure that patients receive the most appropriate care. While non-small cell cancer is more common, small cell cancer is known for its more rapid progression. If you experience severe, sudden, or worsening symptoms, such as severe difficulty breathing or coughing up blood, call 999 immediately. 

Authority Snapshot (E-E-A-T Block) 

This guide explains the medical classification of lung cancer types based on UK clinical standards and is intended for general public information. It was written and reviewed by Dr. Stefan Petrov, a UK-trained physician with experience in general medicine and emergency care. The content is strictly aligned with current NHS and NICE clinical guidance to ensure accuracy and patient safety.