Lung Squamous Cell Carcinoma Stage III

Stage 3 squamous cell lung cancer means the disease has spread beyond the lung but has not yet reached distant parts of the body. About one-third of all lung cancer cases are discovered at this stage, which doctors call locally advanced cancer. Treatment usually involves a combination of therapies tailored to each patient’s specific situation.

Table of contents

• What Is Stage III Squamous Cell Lung Cancer
• Stage III Substages
• Symptoms
• Diagnosis
• Treatment Options
• Outlook and Prognosis

What Is Stage III Squamous Cell Lung Cancer

Squamous cell carcinoma is a type of non-small cell lung cancer (NSCLC), which means it grows from specific cells in the lungs. This form accounts for about 25-30% of all non-small cell lung cancer cases^[1]. Squamous cell lung tumors usually develop in the central part of the lung or in the main airways called bronchi^[2].

When doctors describe stage 3 lung cancer, they mean the cancer has started to spread beyond the original lung but has not yet reached distant organs in other parts of the body^[3]. This is sometimes called locally advanced cancer. The disease remains confined to one side of the chest, though it may have spread to nearby lymph nodes (small organs that help fight infection) or surrounding tissues^[1].

Stage 3 squamous cell lung cancer represents a critical point in the disease. Around one-third of all lung cancer diagnoses occur at stage 3, partly because the cancer often does not cause noticeable symptoms in earlier stages^[3]. While this stage is more difficult to treat than earlier stages, patients can still benefit from aggressive treatment approaches designed to extend life and potentially achieve long-term survival^[4].

Stage III Substages

Doctors divide stage 3 non-small cell lung cancer into three substages: 3A, 3B, and 3C. These divisions help doctors understand exactly where the cancer has spread and plan the best treatment approach^[1].

Stage 3A describes tumors that range from very small (3 cm or less) to medium-sized (between 5 and 7 cm). The cancer may have spread to lymph nodes in the area where the windpipe divides or in the space between the lungs on the same side as the cancer. In some cases, the cancer has grown into nearby structures like the chest wall, the membrane covering the lung, or nerves near the lung, but there may be no lymph node involvement^[1].

In Stage 3B, the cancer has similar tumor sizes but has spread to lymph nodes on the opposite side of the chest from where the cancer started, or to lymph nodes in the neck area above the collarbone. The cancer may also have grown into important structures like the heart, major blood vessels, the windpipe, the food pipe, or the bones of the spine^[1].

Stage 3C represents the most advanced form of stage 3 disease. The cancer has spread to lymph nodes above the collarbone or on the opposite side of the chest. It may have grown into the chest wall, heart, breastbone, and other nearby tissues, but still has not spread to distant organs like the liver or bones in other parts of the body^[8].

Symptoms

Many people with stage 3 squamous cell lung cancer do not notice symptoms until the disease has progressed^[3]. However, because squamous cell carcinoma often starts in the central airways of the lungs, it may cause symptoms earlier than some other types of lung cancer^[7].

The most common symptom is a cough that does not go away. Other symptoms may include weight loss without trying, shortness of breath or wheezing, chest pain, and coughing up blood or rust-colored mucus. Some patients develop a hoarse voice^[8].

If the cancer has spread to nearby structures, it can cause additional symptoms. For example, if it reaches the bones near the lungs, patients may experience bone pain. The specific symptoms depend on which areas the cancer has affected^[8].

Diagnosis

Doctors typically discover lung cancer after investigating symptoms. Most people are not routinely checked for lung cancer unless they have a high risk, such as a history of smoking^[8].

If lung cancer is suspected, a chest X-ray is often the first imaging test performed. If this suggests cancer, doctors will order more detailed tests^[8]. A CT scan (computed tomography scan) uses X-rays and computers to create detailed three-dimensional pictures of the lungs and surrounding areas^[8].

To confirm the diagnosis, doctors need to examine actual cancer cells. This requires a biopsy, which means taking a small sample of tissue from the lung. The sample is then studied under a microscope to determine what type of lung cancer is present^[8].

Once doctors confirm the cancer type, they perform additional tests to determine the exact stage. These may include other imaging tests to see if the cancer has spread to lymph nodes or nearby structures. This process, called staging, uses a system that looks at the size of the tumor, whether lymph nodes are affected, and how far the cancer has spread^[8].

Treatment Options

Stage 3 squamous cell lung cancer requires a complex treatment approach that usually combines different types of therapy. The specific treatment plan depends on many factors, including the exact substage of cancer, which nearby structures are affected, and the patient’s overall health^[4].

Treatment decisions for stage 3 lung cancer require discussion by a multidisciplinary team of doctors, including surgeons, cancer specialists who give chemotherapy, radiation specialists, and imaging experts. This team approach helps ensure patients receive the most appropriate combination of treatments^[4].

Chemoradiation, which means giving chemotherapy and radiation therapy at the same time, is often used for stage 3 disease. Chemotherapy uses drugs to kill cancer cells throughout the body, while radiation therapy uses high-energy beams to destroy cancer cells in specific areas. The chemotherapy drugs most commonly used include cisplatin combined with etoposide^[11].

For some patients with stage 3A disease, surgery may be an option after chemoradiation if the treatment shrinks the tumor enough. Different types of surgery include lobectomy (removing one section of the lung), bilobectomy (removing two sections), or pneumonectomy (removing the entire lung). The type of surgery depends on where the cancer is located and how much it has spread^[11].

However, surgery is generally not recommended for stage 3B and 3C disease because the cancer has spread too widely within the chest to be completely removed^[11].

After surgery, patients typically receive additional chemotherapy. The drug combinations used may include cisplatin or carboplatin paired with other drugs like vinorelbine, gemcitabine, docetaxel, or paclitaxel. For squamous cell carcinoma specifically, doctors avoid using pemetrexed, which is reserved for other types of lung cancer^[11].

Targeted therapy may be available for some patients whose cancer cells have specific genetic changes. These treatments work differently than chemotherapy by targeting particular abnormalities in cancer cells. However, targeted therapies are less commonly available for squamous cell carcinoma compared to other types of lung cancer^[11].

Immunotherapy is a newer type of treatment that helps the body’s own immune system fight cancer. Recent research has shown that adding immunotherapy to treatment plans can improve outcomes for some patients with stage 3 lung cancer^[4].

Outlook and Prognosis

The outlook for patients with stage 3 squamous cell lung cancer depends on many factors, including the exact substage, the patient’s overall health, and how well the cancer responds to treatment^[3].

Stage 3 represents a diverse group of patients whose cancers can differ significantly in size, location, and extent of spread. Because of this diversity, predicting outcomes for individual patients is difficult^[8].

While there is currently no cure for stage 3 lung cancer, treatments can help extend life and reduce symptoms. Some patients do achieve long-term survival with aggressive treatment combinations. Recent advances in treatment, particularly the addition of immunotherapy and improvements in surgical techniques, have led to better outcomes for many patients^[3].

The management of stage 3 disease remains under active investigation. Researchers continue to study questions such as the best order of treatments, which patients are most likely to benefit from surgery, and how long patients should receive various therapies. These ongoing studies aim to further improve outcomes for people diagnosed with this stage of disease^[4].