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Doctors may examine a sample of your lung cancer under the microscope. This helps them grade the cells according to how they look.

Healthy lung cells are described by doctors as well differentiated. This means they look like other healthy lung cells and have all the parts they need to work normally. Lung cancer cells do not look and work like healthy lung cells. They are called less well differentiated.

Lung cancers are graded as shown in the table below. The grade of your cancer indicates how fast it is likely to grow. G1 is the slowest. G4 is the fastest.

This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment. ©BMJ Publishing Group Limited 2008. All rights reserved.