Cancer Education · Lung Tumor Biology · Research Overview

Lung Cancer: What Is It?

Lung cancer is a disease in which abnormal cells in lung tissue grow uncontrollably and may form tumors, invade nearby structures, or spread to other parts of the body. It is broadly classified into non-small cell lung cancer and small cell lung cancer.

NSCLC
SCLC
EGFR
PD-L1

What is lung cancer?

Lung cancer begins when cells in the lung acquire biological changes that allow uncontrolled growth, resistance to normal cell-death signals, tissue invasion and, in some cases, metastatic spread.

Simple scientific definition

Lung cancer is a malignant disease of lung tissue. It may originate in the airways, alveolar regions, bronchial epithelium or other lung-associated cellular compartments. Over time, malignant cells may form a primary lung tumor and interact with blood vessels, immune cells and the tumor microenvironment.

Main classification NSCLC and SCLC are the two major clinical and biological groups.

Main types of lung cancer

Lung cancer is commonly grouped into non-small cell lung cancer and small cell lung cancer because these groups differ in biology, progression patterns and research focus.

Non-Small Cell Lung Cancer

NSCLC is the most common lung cancer category. It includes adenocarcinoma, squamous cell carcinoma and large cell carcinoma. Research often focuses on biomarkers such as EGFR, ALK, ROS1, KRAS, BRAF, MET, RET, NTRK and PD-L1.

Small Cell Lung Cancer

SCLC is generally more aggressive and is strongly associated with tobacco exposure. Research frequently investigates neuroendocrine biology, rapid proliferation, DNA damage response, immune evasion and treatment resistance.

Common risk factors

Lung cancer risk is influenced by environmental exposure, lifestyle factors, occupational hazards, air quality, inherited susceptibility and chronic lung conditions.

Tobacco smoke Cigarette smoking is the leading risk factor for lung cancer.
Secondhand smoke and air pollution Inhaled environmental pollutants can contribute to lung cancer risk.
Occupational exposure Asbestos, silica, diesel exhaust and other workplace exposures are recognized risk factors.
Radon exposure Radon is an environmental radioactive gas associated with lung cancer risk.
Genetic susceptibility Some individuals may have inherited or acquired molecular factors that influence risk.
Risk
Smoke Radon Asbestos Air Genes

Lung cancer biomarkers studied in research

Biomarker research is important in understanding lung tumor biology, molecular subtypes, immune interactions, resistance mechanisms and experimental therapeutic response.

EGFR

Growth factor receptor signaling, mutation-driven tumor biology and targeted research models.

ALK

Gene rearrangement research, kinase pathway studies and molecular subtype characterization.

KRAS

Oncogenic signaling, resistance biology, MAPK pathway activation and tumor progression studies.

PD-L1

Immune checkpoint biology, tumor immune evasion and immuno-oncology research.

TP53

DNA damage response, cell-cycle control, apoptosis regulation and genomic instability research.

Ki-67

Cell proliferation studies and tumor growth activity assessment in research workflows.

Common signs and symptoms studied clinically

This section is educational only and not a diagnostic guide. People with symptoms should consult a qualified healthcare professional.

Persistent cough Shortness of breath Chest discomfort Coughing blood Unexplained weight loss Fatigue Recurrent respiratory infections

Quick answer: Lung cancer in simple terms

This section is written for AI Overview, Google, Bing Copilot, Perplexity and scientific search engines.

What is lung cancer?

Lung cancer is a malignant disease that starts in the lungs when abnormal cells grow in an uncontrolled way. These cells may form tumors, interfere with lung function and spread to lymph nodes or distant organs.

What are the two main types of lung cancer?

The two main types are non-small cell lung cancer, often abbreviated NSCLC, and small cell lung cancer, abbreviated SCLC. NSCLC is more common, while SCLC is usually associated with faster growth and strong links to smoking exposure.

Can non-smokers get lung cancer?

Yes. Although tobacco smoke is the leading risk factor, lung cancer can also occur in people who have never smoked. Other risk factors include radon, air pollution, secondhand smoke, occupational exposure and genetic susceptibility.

Which research products are useful for lung cancer studies?

Lung cancer research commonly uses antibodies, ELISA kits, recombinant proteins, cell culture reagents, molecular biology tools, qPCR reagents, apoptosis assays, viability assays, immune checkpoint markers and pathway analysis reagents.

Research product categories for lung cancer biology

Use this section to connect the educational page to your lung cancer research product catalogue.

Lung Cancer Antibodies

EGFR, ALK, PD-L1, KRAS pathway, TP53, Ki-67, cytokeratins and immune markers.

ELISA Kits

Cytokines, growth factors, inflammatory markers, angiogenesis markers and tumor-associated proteins.

Cell Culture Reagents

Media, supplements, matrices and reagents for lung cancer cell models and drug-response studies.

Molecular Biology Tools

DNA/RNA extraction, qPCR reagents, mutation research tools and pathway expression analysis.

FAQ: Lung Cancer

Search-friendly answers for educational, scientific and AI-search visibility.

What is lung cancer?

Lung cancer is a malignant disease that begins in lung tissue when abnormal cells grow uncontrollably and may form tumors or spread to other parts of the body.

What are the main types of lung cancer?

The main types are non-small cell lung cancer, or NSCLC, and small cell lung cancer, or SCLC. NSCLC includes adenocarcinoma, squamous cell carcinoma and large cell carcinoma.

What causes lung cancer?

Tobacco smoke is the major risk factor. Other risk factors include secondhand smoke, radon, air pollution, asbestos, silica, diesel exhaust, chronic lung disease and genetic susceptibility.

Can lung cancer happen in people who never smoked?

Yes. Non-smokers can develop lung cancer due to other environmental, occupational, molecular or genetic risk factors.

Is this page medical advice?

No. This page is for educational and research information only. It is not intended to diagnose, prevent, treat or cure disease.

Scientific References

Authoritative references help improve scientific credibility, SEO trust and AI-search interpretation.

  1. National Cancer Institute. Lung Cancer Overview.
  2. National Cancer Institute. Non-Small Cell Lung Cancer Treatment PDQ.
  3. World Health Organization. Lung Cancer Fact Sheet.
  4. American Cancer Society. Lung Cancer Statistics 2026.
  5. American Cancer Society. What Is Lung Cancer?