This page was reviewed under our medical and editorial policy by
Peter Baik, DO, Thoracic Surgeon
This page was reviewed on January 8, 2023.
The stage of lung cancer refers to the size of cancer, how aggressive it is and where it’s spread, if at all.
Stage 3 is “locally advanced,” meaning it’s spread regionally, in the area near the original tumor. Stage 3 non-small cell lung cancer has three subcategories: 3A, 3B and 3C.
Each subcategory of stage 3 non-small cell lung cancer—3A, 3B and 3C—may show up in various ways.
Stage 3A may have these characteristics:
Areas that may be affected just outside the lung include the chest wall (ribs, muscle or skin), the phrenic nerve (the nerve close to the lung) and the mediastinal pleura and parietal pericardium (the layers that cover the heart).
Other areas near the lung that may be affected include the diaphragm (the muscle under the lungs), esophagus (food pipe), trachea (windpipe), carina (where the trachea divides), recurrent laryngeal nerve (the nerve that goes to the voice box), chest, heart, a main blood vessel and/or the spine.
Stage 3B may have these characteristics:
Main areas of the chest that may be affected include the heart, the trachea, the esophagus or a main blood vessel.
Stage 3C may have these characteristics:
Small cell lung cancer isn’t staged using the number system, so there’s no stage 3 SCLC. Instead, SCLC is classified as limited-stage (which means it’s confined to one area of the chest) or extensive stage (which means it’s spread through the lung and may have spread to other areas of the body).
The most common symptoms of lung cancer are:
When lung cancer spreads, symptoms may include:
Some lung cancers may cause Horner syndrome (which affects the eye and part of the face), superior vena cava syndrome (which affects areas where the superior vena cava passes through) or paraneoplastic syndromes (which affect various parts of the body that don’t have cancer).
Even though stage 3 cancer is considered advanced, many treatment options are available. Treatment of stage 3A non-small cell lung cancer may include:
Treatment for stage 3B and 3C non-small cell lung cancer may also involve various combinations of chemotherapy and radiation therapy followed by immunotherapy. Patients who aren’t able to receive chemotherapy may undergo external radiation therapy alone. Other treatment options may include clinical trials and palliative care (similar to treatments for stage 3A).
According to the American Cancer Society, if non-small cell lung cancer remains confined to the lung, the five-year relative survival rate is 64 percent. That rate drops to 37 percent if the cancer spreads to areas near the lung (and 8 percent if it spreads to more distant areas of the body).
Small cell lung cancers are more challenging to treat. The five-year relative survival rate for localized cancer is 29 percent, and that rate drops to 18 percent when it spreads regionally (and 3 percent when it spreads to more distant areas of the body).
Stage 3 lung cancer survival rates vary based on which subcategories 3A, 3B or 3C the cancer has been designated, as well as the patient's overall health and other factors, such as the response to treatments.