What Is Limited-Stage Small Cell Lung Cancer?

Limited-stage is the first of two stages of small cell lung cancer (SCLC). The cancer is in one lung and possibly the lymph nodes on the same side of the chest.

Symptoms of limited-stage small cell lung cancer include coughing, coughing blood, shortness of breath, and more. Because it's usually aggressive, limited-stage SCLC is treated with chemotherapy and radiation without delay once it is diagnosed.

Staging

Staging for SCLC is used to determine how it should be treated and also provides insight into the prognosis of the disease.

For small cell lung cancer to be classified as limited-stage it must meet these criteria:

• The cancer is present in only one lung.
• It may have grown within the tissue directly next to the lungs.
• It may have invaded nearby lymph nodes.
• It must be confined to a small enough area that radiation therapy can be applied with a single radiation field.

If SCLC is found to have spread (metastasized) to the other lung or to distant regions of the body, it will be defined as extensive—the second and final stage of this cancer.

Roughly 30% to 40% of people with small cell lung cancer are diagnosed when their tumors are considered limited-stage, whereas 60% to 70% are designated as having extensive-stage SCLC at the time of diagnosis.

Sometimes SCLC is also classified according to the TNM staging criteria, which is the system used to stage non-small cell lung cancer (NSCLC), the more common type of lung cancer.

Using this system, T represents the size of the tumor, N indicates the extent of lymph node involvement, and M describes the degree of metastasis, with each of these factors given a numerical value between 0 and 4.

Limited-Stage SCLC Symptoms

At this early stage, SCLC might not cause any symptoms. However, because it starts in the bronchi (airways), it can cause breathing problems even if it hasn't spread beyond one area of the lung.

If limited-stage SCLC enlarges within one lung, respiratory effects can be more prominent. Lymph node involvement can cause additional symptoms.

Symptoms of limited-stage SCLC can include:

• Persistent cough
• Coughing up blood (hemoptysis)
• Shortness of breath
• Chest pain or soreness
• Pain with breathing
• Recurrent respiratory infections such as pneumonia or bronchitis
• Hoarse voice
• Clubbing: An oxygen deprivation-induced deformity of the fingers in which the ends take on the appearance of a flipped-over teaspoon
• Enlargement or tenderness of the arm due to lymph node involvement
• Wheezing
• Swelling in the face and/or neck due to vein obstruction

Paraneoplastic Symptoms

Sometimes SCLC can also produce paraneoplastic syndromes, which may be the earliest noticeable effects of the tumor.

These syndromes occur when the cancer cells produce antibodies (a type of immune protein) or hormones that overstimulate distant cells in the body such as in the brain.

Paraneoplastic effects associated with SCLC include:

• Muscle weakness in the upper limbs, vision changes, and difficulty swallowing due to Lambert-Eaton myasthenic syndrome
• Weakness, fatigue, and a low sodium level in the blood with the syndrome of inappropriate antidiuretic hormone secretion (SIADH)
• A round, full face and weight gain, increased thirst, excessive hair growth, and weakness associated with Cushing's syndrome
• Loss of coordination and difficulty speaking resulting from paraneoplastic cerebellar degeneration

Causes

Small cell lung cancer is most often caused by smoking, exposure to radon or asbestos, or secondhand exposure to cigarette smoke.

These substances contain toxins that can harm the lungs and lead to changes in the DNA (genes) of cells in the lungs. These mutations can cause the uncontrolled growth of the cells.

Diagnosis

Limited-stage SCLC often shows up incidentally on a chest X-ray, computerized tomography (CT) scan, or a lymph node CT scan being performed for a reason, such as a pre-surgical evaluation.

Less often, SCLC causes noticeable symptoms that prompt a person to see a healthcare provider. Their evaluation will likely involve some form of scanning along with a thorough physical exam and review of their medical history.

A lung biopsy or a lymph node biopsy, in which a tissue sample is taken for close examination under a microscope, is typically needed to get a definitive diagnosis of the type of cancer. It may be performed using fine needle aspiration, a bronchoscopy procedure, or an open surgery.

If lung cancer is detected, further tests are needed to verify its stage. For example, brain magnetic resonance imaging (MRI), ultrasound of the liver, or positron emission tomography (PET) of the adrenal glands can help healthcare providers determine if the cancer has spread.

Interestingly, when the SCLC begins further out in the lungs, it may not grow or metastasize as quickly as SCLC that is located centrally in the lungs (which is more common). It isn't clear why this occurs, but it can lead to a better outcome.

Treatment

Since SCLC tends to grow rapidly, it's usually recommended that treatment begin as soon as possible after diagnosis. And with the better outcomes of limited-stage SCLC, there is a greater anticipated benefit of prompt treatment if it is started at this stage.

In most cases, SCLC is treated with a combination of chemotherapy and radiation therapy.

Surgery is not expected to cure SCLC, but it can relieve symptoms and improve quality of life.

Chemotherapy

Chemotherapy uses strong medications to destroy cancer cells and prevent the growth and spread of cancer.

Chemotherapy for SCLC usually includes a combination of a platinum drug, such as cisplatin or carboplatin, and an alkaloid drug, such as etoposide or irinotecan, delivered in a series of four to six cycles.

Depending on the specific medication used, a cycle may include one or more infusions, each lasting between a few minutes to several hours. A chemotherapy cycle may take three or four weeks to complete.

Immunotherapy

Immunotherapy is a type of treatment that uses the body's immune system to fight diseases, including cancer. Specifically, a group of drugs described as immune checkpoint inhibitors, which prompt your immune system to fight cancer cells, are used for treating SCLC.

Immunotherapy treatments used in SCLC include:

• The CTLA-4 inhibitor Yervoy (ipilimumab)
• The PD-1 inhibitors Opdivo (nivolumab) and Keytruda (pembrolizumab)

These medications may be used along with chemotherapy or to treat recurrent SCLC that has already been treated with chemotherapy and radiation. They are also being investigated as possible first-line agents for treating SCLC.

Radiation Therapy

Radiation is used to shrink the tumor and small cancer cells that can't be seen with imaging tests. Limited-stage SCLC is encompassed within a standard radiation field.

Generally, radiation to the lungs and nearby lymph nodes is scheduled in the same weeks as chemotherapy and immunotherapy.

Prophylactic Cranial Irradiation

If you experience a complete or partial response to chemotherapy and radiation, you might be a candidate for prophylactic cranial irradiation (PCI).

This radiation therapy to the brain is sometimes recommended to reduce the risk that undetectable cancer cells in the brain would grow and cause symptoms.

Surgery

Generally speaking, SCLC is inoperable. It's considered highly aggressive and can recur after treatment—even in the limited stage.

Surgery is occasionally considered if a tumor is present in only one lung and nearby lymph nodes. Adjuvant chemotherapy (chemotherapy after surgery) is usually recommended to decrease the risk of cancer recurrence. However, surgery is not likely to be curative if there are undetectable metastases elsewhere in the body.

Overall, surgery is mainly considered a way to provide relief from SCLC symptoms. For example, if the tumor is obstructing an airway, it might be resected (removed) to make it easier to breathe. Surgery could also reduce neck or face swelling due to superior vena cava syndrome.

Prognosis

Survival of limited-stage SCLC is better than the overall survival of SCLC. With optimal treatment, one study showed a one-year survival rate of approximately 78.9%, a two-year survival rate of 58.6%, and a five-year survival rate of 27.6%.

This is similar to another study in which those with limited-stage SCLC who received standard-of-care treatment with chemotherapy and radiation had a five-year survival rate of 30% to 35%.

In contrast, the overall five-year survival of SCLC (all stages combined) is about 6.5%.

A Word From Verywell

This type of cancer can't improve without treatment, but you can have a good outcome.

The National Cancer Institute (NCI) recommends anyone with small cell lung cancer consider participating in a clinical trial. Doing so may give you access to cutting-edge treatments you would not otherwise be able to get. You can find NCI-supported clinical trials by searching their online database.

Regardless, be sure to ask your healthcare team any questions you have so you can feel confident about the steps you take. And consider connecting with a support group.