Stage 3B Non-Small Cell Lung Cancer

By Lynne Eldridge, MD 

Updated on May 05, 2023

 Medically reviewed by Doru Paul, MD

Stage 3B non-small cell lung cancer (NSCLC), along with stage 3C and stage 4 NSCLC, are considered advanced lung cancer. In general, when cancer reaches this point, it's treatable but not considered curable.

Although the road to feeling well and seeking possible remission may be tough, there is hope. Recent advancements in treatment have been improving survival rates and helping those with late-stage lung cancer manage symptoms.

This article will go over what stage 3B NSCLC is, in addition to several treatment options that can help you enjoy a higher quality of life and a better prognosis.


Jose Luis Pelaez Inc / Getty Images


Stage 3 lung cancer is divided into three sub-stages, of which stage 3B is one. It is defined as a tumor of any size that has spread to distant lymph nodes or has invaded other structures in the chest (such as the heart or esophagus).

About 17.6% of people with NSCLC are already at stage 3B when they're diagnosed.1 For others, an earlier diagnosis of stage 1, 2, or 3A tumors can develop into more advanced lung cancer (stage 3B or beyond).

Staging is a process used to describe how much cancer is in the body. As a general rule, know that the lower the stage number, the less the cancer has spread.2

To identify how advanced cancer is, oncologists use the TNM system. They rate the size of the tumor, determine whether any lymph nodes are involved and, if so, their location. They also check whether cancerous lung cells have spread to other regions of the body.

Using this system, stage 3B is divided into four possible designations.2

Stage 3B Lung Cancer

TNM Designations


T1a/T1b/T1c, N3, M0

Size: No more than 3 centimeters (cm)
Spread: To lymph nodes near the collarbone(s) and/or to hilar lymph nodes or mediastinal lymph nodes
M0 metastases: No spread to other body parts

T2a/T2b, N3, M0

Size: Between 3 cm and 5 cm and meets one or more of the following criteria: • Has grown into a main bronchus, but is not within 2 cm of the point where the windpipe splits into the main bronchi • Has grown into the membranes surrounding the lungs • Partially clogs the airways
Spread: Has spread to hilar or mediastinal lymph nodes on the opposite side of the chest from where the tumor is located or to the lymph nodes located above the collar bone (supraclavicular lymph nodes) on the either side
M0 metastases: No spread to other body parts

T3, N2, M0

Size: Tumor meets one or more of the following criteria: • Is between 5 cm and 7 cm • Has grown into the chest wall, the inner lining of the chest wall, the phrenic nerve, or membranes of the sac surrounding the heart • Two or more separate tumor nodules are in different lobes of the same lung
Spread: Cancer has spread to lymph nodes on the same side as the primary tumor
M0 metastases: No spread to other body parts

T4, N2, M0

Size: Tumor meets one or more of the following criteria: • Is larger than 7 cm  • Has grown into the space between the lungs, heart, large blood vessels near the heart, windpipe, esophagus, diaphragm, backbone, or the point where the windpipe splits into the main bronchi • Two or more separate tumor nodules are in different lobes of the same lung
Spread: To lymph nodes on the same side as the primary tumor
M0 metastases: No spread to other body parts

 Stage 3A vs. Stage 3B Lung Cancer


Common symptoms of stage 3B NSCLC include:

  • Persistent cough

  • Shortness of breath3

General symptoms of cancer such as fatigue and unintentional weight loss may also be present.3

Additional symptoms of stage 3B NSCLC can vary depending on where the tumor is. For example, hemoptysis (coughing up blood) can occur when tumors are near the airways. When a tumor involves areas such as the esophagus and other chest structures, dysphagia (difficulty swallowing) and hoarseness may be present.

In approximately 7% to 23% of lung cancers, a complication can occur in which fluid containing cancer cells builds up in the membranes that line the lungs.4 This is called a pleural effusion, and it can cause pain in the back, chest, and ribs. Other symptoms may include increased shortness of breath.


With rare exceptions, stage 3B lung cancer is considered inoperable, which means that surgery will not cure your cancer. However, there are treatments that can help you increase your odds of living longer and enjoying those years to the fullest.

The standard therapy for stage 3B lung cancer is a combination of chemotherapy and radiation therapy, otherwise known as chemoradiation. If you respond well to two or more treatments of chemoradiation, immunotherapy is usually followed.5

Immunotherapy drugs have resulted in durable responses—i.e., long-term survival for some people with advanced lung cancer.6

One immunotherapy drug, Imfinzi (durvalumab), was approved specifically for the treatment of inoperable stage 3 NSCLC. It's used after chemoradiation therapy and was found to improve progression-free survival.

In some instances, typically if you're not healthy enough for chemoradiation, radiation therapy or chemotherapy may be used on their own.5

In addition, newer treatments and strategies such as targeted therapies are making a difference for people with advanced lung cancer.7 

Targeted therapy medications act on specific genes and proteins that contribute to the growth of cancer cells. These medications have been approved to treat EGFR mutations, ALK rearrangements, ROS1 rearrangements, and the KRAS G12C mutation. Treatment for other less common genetic alterations are being studied in clinical trials.8

Using molecular profiling (gene testing), healthcare providers can identify genetic alterations (mutations, translocations, amplifications) in cancer cells. They use targeted therapy medications to stop these mutated cells from growing or causing more damage.

Examples include the drugs Krazati (adagrasib) and Lumakras (sotorasib). They target the KRAS G12C mutation, found in about 13% of people with NSCLC. Both were recently approved for use in patients with advanced or metastatic disease after other therapies have been tried.7

In some cases, these treatments have allowed people to live with lung cancer almost as a form of chronic disease. That is, as long as they don't build up a resistance to the medication, they can live a relatively healthy life.

Some of these treatments may be combined with other therapies to manage stage 3B lung cancer.

For example, the use of bronchial artery infusion (chemotherapy) and oral icotinib hydrochloride (a targeted therapy drug that acts on EGFR mutations) has resulted in a complete remission of advanced lung cancer in at least one study and shows promise for helping other patients.9

Yet another treatment option is to enroll in a clinical trial—a study that tests new cancer treatments. Clinical trials are available for stage 3B non-small lung cancer as well as other stages and types of cancer.10


Even with the success of chemoradiation treatment and other advanced options, stage 3B lung cancer typically has a low survival rate. The improved prognosis with chemoradiation is still under 18 months.11

The median survival time (time at which 50% of patients are alive and 50% have died) is roughly 13 months with treatment. The five-year survival rate with stage 3B non-small lung cancer is sadly only 3% to 7%.1

Keep in mind that these statistics include data collected over the course of several years and, in some cases, decades. They may not reflect improvements in life expectancy that have been made using newer drugs.

 Understanding the Survival Rate for Each Stage of Lung Cancer


Stage 3B lung cancer is an advanced type of lung cancer that is currently incurable but manageable with treatment. Symptoms typically include a persistent cough and shortness of breath with the possibility of other general cancer symptoms like fatigue and unintentional weight loss.

The standard treatment for Stage 3B lung cancer is a combination of chemotherapy and radiation therapy (chemoradiation) followed by immunotherapy.

The average survival time for those receiving stage 3B cancer treatment is around one year. However, emerging treatments are showing promise in improving survival outcomes.

A Word From Verywell

It's easy to feel discouraged and overwhelmed when you receive a diagnosis of advanced lung cancer, but you're not powerless.

Learning everything you can about your cancer can help improve your prognosis, and working with your healthcare provider to find the best course of treatment will ensure that nothing is overlooked.

There's a wealth of information online that can help you increase your understanding of the disease. Be sure you're looking at peer-reviewed research and well-defined studies to ensure you're getting facts about how to treat stage 3B lung cancer specifically.

Also, learn to be your own advocate in your cancer care. Let your healthcare provider know if you want to try a particular treatment, and ask specific questions to get the answers you need to make well-informed decisions.