Lung Cancer

Cancer of the lung is common.  Two hundred and twenty six thousand patients will be told that they have lung cancer this year in America. Over the course of a lifetime, one out of every thirteen men and one out of every sixteen women will develop lung cancer.  The odds increase when people are exposed to carcinogens such as tobacco smoke, high radon levels and asbestos.  The two main forms of Lung Cancer are Small Cell Lung Cancer (SCLC) and Non-Small Cell Lung Cancer (NSCLC).  On this page, we will review the different forms of this cancer and how one determines whether they are facing lung cancer.

Non Small Cell Lung Cancer (NSCLC) 

Non Small Cell Lung Cancer (NSCLC) accounts for 75 to 85% of all lung cancers.  Based on how the cancer appears under the microscope, it can be further divided into:

Lung Cancer Pie Chart Rizwan Nurani
  • Squamous Cell Carcinoma: The second most common type of NSCLC
  • Adenocarcinoma:  Common.  The most common typeof Lung Cancer in America.  Multiple subtypes can be identified such as lepidic, acinar, papillary, and solid patterns. It can occur in non-smokers.
  • Bronchoalveolar Carcinoma:  A subset of Adenocarcinoma that easily spreads along and through the Lungs air sacs. This term is currently in routine use but will likely be phased out as a better molecular classifiction of adenocarcinomas in implemented.
  • Large Cell Carcinoma:  Can be more aggressive

Recent evidence has shown that NSCLC is really a collection of very different cancer sub-types.  When the cancers are analyzed with special staining or at a genetic and molecular level, they can be divided into even more groups.  In the near future, targeted treatment will be based on these molecular profiles.  At this point in clinical medicine, molecular profiling is sometimes helpful in advanced cancers but less helpful when the cancers are in an earlier stage.

Small Cell Lung Cancer (SCLC)

PET Lung Cancer Rizwan Nurani

Small Cell Lung Cancer (NSCLC) accounts for 15% of all lung cancers.  Compared to NSCLC it is tends to be more aggressive with a faster growth pattern and an ability to more quickly spread to distant organs.  On the more positive side it also tends to show a faster response to treatments such as radiation therapy and chemotherapy.  Unlike NSCLC adenocarcinomas, it is very rare for SCLC to occur in non-smokers.  Based on how small cell lung cancer appears under the microscope, it can be further divided into: 

  • Small Cell Carcinoma, Classical Variant
  • Combined Small Cell Carcinoma:  Has components of both SCLC and NSCLC
  • Large Cell Neuroendocrine Cancer
  • Carcinoid Tumors:  Typical or Atypical

Risk Factors for the development of Lung Cancer

Cigarette smoking

Cigarette smoking is the primary contributor to the development of lung cancer.  Ninety percent of Lung Cancers are caused by cigarettes.  If someone smokes one pack of cigarettes every day from the time they were 20 to the time they are 60, they face a twenty fold higher risk of developing lung cancer compared to a non-smoker.


Quitting Cigarette smokin immediately starts decreasing ones risk of death.  Over time the risk of lung cancer also falls.  By 15 years the risk of lung cancer has fallen from a 20 fold increase to just a 2 fold increase.

The geographic prevelance of lung cancer is strikingly similar to the smoking rates in an particular state.

State Smokin rates Rizwan Nurani

Percentage of State Population that Smokes Tobacco; Darker colors are Higher

State Lung Cancer Rates Rizwan Nurani

Lung Cancer Rates by State; Higher rates are Brown and Lower Rates are Green

Asbestos Exposure

Asbestous exposure can lead to the development of lung cancer.  Amongst people exposed to both asbestos and cigarettes there is a particularly higher risk of developing lung cancer.

© Rizwan Nurani 2012