How many types of lung cancer are there? What is the difference between them?

Dr. Boris Naraev is a medical oncologist at Banner MD Anderson Cancer Center.

 Question: How many types of lung cancer are there? What is the difference between them?

 Answer: Lung cancer comes in two specific types. One is called non-small cell lung cancer, and the other is small cell lung cancer. Non-small cell lung cancer is the most frequently diagnosed type of lung cancer, with more than 85 percent of all lung cancers falling into this category.

There are two major cell-based, or histologic, subtypes that are considered non-small cell lung cancer. Adenocarcinoma, the most common form affecting men and women in the U.S., develops in the glands of the lungs. The second most common is squamous cell carcinoma, which forms along the lining of the bronchial tubes. Tumors that are not diagnosed as adenocarcinoma or squamous cell carcinomas are grouped into a third category, which includes large cell carcinomas, sarcomatoid carcinomas, adenosquamous carcinomas, carcinoid carcinomas or tumors not otherwise specified.

Non-small cell lung cancers result from specific genetic alterations and accordingly can also be classified into molecular subtypes. Lung cancer patients are routinely tested for them and may be selected for certain therapies developed specifically for these molecular subtypes. Because every cancer is unique, treatment plans have to be customized to fit the patient and his or her specific stage of cancer, histology and molecular profile.

Small cell lung cancer is more often associated with a history of smoking and tends to be very aggressive. This cancer develops in the bronchi of the lungs, which is the area where air moves into the lungs from your windpipe. Small cell lung cancer tumors grow quickly and then move to other areas of the body faster than non-small cell lung cancer. The cancer has often spread by the time it is diagnosed. This type of cancer generally responds better to chemotherapy alone or in combination with radiation.