OVERVIEW

Lung cancer is the number one cause of global cancer deaths.

Abnormal cells grow rampantly, forming tumors as they invade lung tissue. They can then spread to lymph nodes and other organs, most noticeably the heart and brain.

NSCLC, or non-small cell lung cancer, is the most common type of lung cancer.

Adenocarcinoma, Squamous cell, and large cell carcinomas are subtypes of NSCLC.

Adenocarcinomas: represent 40% of lung cancer cases and occur in the outer areas of the lung. Since they grow slower than other types, they may be more easily detected before they spread. They are found in both smokers and non-smokers, with the latter being especially prevalent among women.

Squamous cell carcinomas: represent 25-30% of all lung cancer cases and are also known as epidermoid carcinomas. They start in the flat cells lining the inside of airways (i.e. bronchus) and are typically associated with smoking.

Large cell carcinomas: represent 10-15% of lung cancers and are also known as undifferentiated carcinomas. They can spring up anywhere in the lung, grow and spread quickly, and are hard to treat.

Additional Subtypes of NSCLC (less common):

  • Adenosquamous carcinoma

  • Sarcomatoid carcinoma

Symptoms

In the early stages of lung cancer, there may be no symptoms.

The following symptoms are associated with lung cancer:

  • Shortness of breath or feeling winded

  • Wheezing sounds

  • Persistent cough, with or without mucus (coughs linked to colds disappear in one week)

  • Coughs with blood or hoarseness

  • Chest pain with or without lymph node enlargement

  • Raspy, hoarse voice

  • Unexplained weight loss of more than ten pounds

  • Headache

  • Bone pain, typically of the back, neck, shoulders, and arms

Causes and Risks

Most lung cancer deaths are attributable to smoking (80% in women and 90% in men) due to chronic cell damage by carcinogens within the tobacco.

There are also increased risks associated with exposure to these environmental pollutants:

  • Asbestos

  • Arsenic

  • Radioactive dust

  • Radon

  • Secondhand smoke

  • Gene mutations (with aging)

The risk of lung cancer increases with an HIV/AIDS diagnosis and does run in families.