Male to female ratio is 10 men to 7 women, most common between 45~70 years of old.
Most primary lung cancer involve the bronchial tubes; this causes a persistent cough that worsens with time.
The resulting sputum may gradually increase in quantity and become blood-streaked, chest pain, shortness of breath.
There are four major type of primary lung cancer, based upon the cell structure of the tumor:
2 Squamous cell cancer
3 Undifferentiated large-cell cancer
4 Undifferentiated small-cell cancer.
The usual pattern of metastasis of primary lung cancers involves the brain, liver, adrenal glands, and bone.
Such spread may occur early and produce symptoms at these remote sites before the appearance of chest symptoms.
Many form of secondary lung cancer occur; these are metastases that
have spread via the bloodstream from primary cancers in other organs
and tissues; breast, colon, prostate, kidney, thyroid, stomach, cervix,
rectum, testicle, bone and melanoma.