Stage 3 lung cancer

The stage of lung cancer refers to the size of cancer, how aggressive it is and where it’s spread, if at all.

What is stage 3 lung cancer?

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.

What do stage 3 lung cancer subtypes look like?

Each subcategory of stage 3 non-small cell lung cancer—3A, 3B and 3C—may show up in various ways.

Stage 3A

Stage 3A may have these characteristics:

• The cancer is 5 centimeters (cm) and has spread to lymph nodes in the mediastinum (the center of the chest) on the same side.
• The cancer is between 5 cm and 7 cm, and multiple tumors have been found in the same lobe (a section of the lung), or it’s spread to areas just outside the lung and lymph nodes near the lung.
• The cancer is larger than 7 cm and has spread to areas outside the lung, but not to nearby lymph nodes.
• The cancer has spread to more than one lobe of the same lung and may be in nearby lymph nodes.

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

Stage 3B may have these characteristics:

• The cancer is 5 cm or smaller and has spread to the lymph nodes in the chest on the opposite side of the affected lung, the neck or above the collarbone.
• The cancer is between 5 and 7 cm and has spread to the lymph nodes in the center of the chest.
• The cancer is more than 7 cm and has spread into the lymph nodes in the center of the chest or a major structure in the chest.
• The cancer has spread to the lymph nodes in the chest wall, the diaphragm or the layers that cover the heart.

Main areas of the chest that may be affected include the heart, the trachea, the esophagus or a main blood vessel.

Stage 3C

Stage 3C may have these characteristics:

• The cancer is either between 5 cm and 7 cm or it’s spread to the nerve near the lung or the layers that cover the heart. It’s also spread to the lymph nodes in the center of the chest on the opposite side of the affected lung, at the top of either lung or above the collarbone.
• The cancer is bigger than 5 cm, and tumors have been found in more than one lobe.
• The cancer is either bigger than 7 cm or it’s spread to areas near the lung (as listed under stage 3A above). It’s also spread to the lymph nodes in the center of the chest on the opposite side of the affected lung, at the top of either lung or above the collarbone.

Stage 3 small cell lung cancer

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).

Stage 3 lung cancer symptoms

The most common symptoms of lung cancer are:

• A persistent or worsening cough
• Bloody cough
• Chest pain
• Hoarseness
• Loss of appetite
• Unintentional weight loss
• Shortness of breath
• Tiredness
• Weakness
• Repeat bronchitis and pneumonia
• New wheezing

When lung cancer spreads, symptoms may include:

• Bone pain
• Headache
• Arm or leg weakness or numbness
• Dizziness or balance problems
• Seizures
• Yellowing of the skin and eyes (jaundice)
• Swollen lymph nodes

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).

Stage 3 lung cancer treatment

Even though stage 3 cancer is considered advanced, many treatment options are available. Treatment of stage 3A non-small cell lung cancer may include:

• Various combinations of chemotherapy, radiation therapy and surgery to remove all or part of the lung (for example, patients may receive chemotherapy and radiation therapy, then surgery, followed by more chemotherapy)
• Surgery followed by targeted drugs designed to work by changing how tumor cells behave
• Chemotherapy and radiation therapy followed by immunotherapy for patients who aren’t able to undergo surgery
• Clinical trials studying new types of therapy palliative care, such as radiation therapy or laser surgery, to help relieve symptoms

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).

Stage 3 lung cancer survival rate

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.