Limited Stage Small Cell Lung Cancer

Small Cell Lung Cancer Limited Stage - Definition, Treatments, Prognosis

doctor talking with a patient about chest CT scan
What is limited stage small cell lung cancer, how is it treated, and what is the prognosis?. istockphoto.com

Small cell lung cancer is responsible for around 15 percent of lung cancers, whereas non-small cell lung cancer accounts for the remaining 85 percent of lung cancers.

Unlike non-small cell lung cancer, which is divided into four stages, small cell lung cancer is divided into only two stages; limited stage and extensive stage. Roughly 30 to 40 percent of people with small cell lung cancer are diagnosed early - when their tumors are still considered limited stage, whereas in 60 to 70 percent of people the disease has already progressed to extensive stage.

Small cell lung cancer tends to be more aggressive, growing rapidly and spreading quickly, but often responds well to chemotherapy and radiation therapy for a time.

Definition of Limited Stage Small Cell Lung Cancer

Limited stage small cell lung cancer involves cancer that is present in only one lung and may have spread to nearby lymph nodes or the tissue between the lungs but has not spread (metastasized) to other regions of the body.

Small cell lung cancer is separated into two stages by a staging system developed by radiation oncologists. With this staging, "limited stage" refers to tumors that are encompassed within a tolerable radiation field. "Extensive stage" small cell lung cancer, in contrast, refers to tumors which are too large or too widespread to be encompassed within one tolerable radiation field. When a small cell lung cancer has spread to distant regions of the body (metastatic disease) it is always considered extensive stage.

Your doctor may also describe your cancer in terms of TNM staging. Using this system, T stands for the size of the tumor, N stands for the presence of cancer in lymph nodes, and M is used to describe distant metastasis. With limited stage non-small cell lung cancer, a tumor may be of variable size (T) and may or may not have lymph nodes involved (N) but will always been M0 (M followed by a zero), meaning that the tumor has not spread to the other lung or to distant regions of the body.

Symptoms of Limited Stage Small Cell Lung Cancer

Unlike cancers such as lung adenocarcinoma, which usually occur in the outer regions of the lung, small cell lung cancer tends to occur more centrally, near the large airways. For this reason, early symptoms often include those related to a tumor being present in a large airway (bronchus), such as coughing, coughing up blood, and repeated episodes of pneumonia due to obstruction of the airways.

Symptoms of limited stage lung cancer can include:

  • Persistent cough - A chronic cough is often the first symptom of small cell lung cancer.
  • Coughing up blood (hemoptysis) - Coughing up blood is a common first symptom of small cell lung cancer. Even a small amount of blood is of concern, and coughing up more than a teaspoon or two of blood is considered a medical emergency.
  • Swelling in the face and neck
  • Shortness of breath
  • Wheezing
  • Repeated episodes of pneumonia or bronchitis (due to obstruction of the airways by tumor)
  • Hoarseness

Paraneoplastic symptomsSmall cell lung cancer can also result in a broad variety of symptoms due to paraneoplastic syndromes, that is symptoms that are due to hormones secreted by a tumor or by the body’s immune response to a tumor rather than the tumor itself.

Some of these include:

  • Muscle weakness in the upper limbs, vision changes, and difficulty swallowing (Lambert-Eaton myasthenic sydrome)
  • Weakness, fatigue, and a low sodium level in the blood ( syndrome of inappropriate antidiuretic hormone secretion (SIADH))
  • Loss of coordination and difficulty speaking (paraneoplastic cerebellar degeneration)
  • Clubbing - A deformity of the fingers in which the end of the fingers takes on the appearance of an upside-down teaspoon.

Symptoms of metastasis - Limited stage lung cancer is defined as a cancer which has not spread to distant regions of the body. Small cell lung cancer, however, tends to spread early, especially to the brain, and with extensive stage small cell lung cancer the first symptoms of the cancer may be those related to brain metastases, such as weakness on one side of the body, visual changes, speech changes, or seizures.

Treatment of Small Cell Lung Cancer - Limited Stage

Treatment options for lung cancer include both local treatments such as surgery and radiation therapy and surgery, and systemic treatments such as chemotherapy. Clinical trials are also looking at the possible role of targeted therapies and immunotherapy for small cell lung cancer.

Chemotherapy and radiation therapy - Many people respond well to a combination of chemotherapy and radiation therapy; with limited stage cancer, this can offer the potential for a cure. 

Surgery Surgery is rarely performed for small cell lung cancer (it is usually considered inoperable) but is occasionally considered if a tumor is present in only one lung and nearby lymph nodes. Adjuvant chemotherapy (chemotherapy after surgery) is usually recommended if surgery is done for small cell lung cancer.

Prophylactic cranial irradiation - If individuals respond well to treatment, prophylactic cranial irradiation (PCI) -- preventative radiation therapy to the brain -- has been recommended to lower the risk that any cancer cells that have spread to the brain, but aren’t seen on radiology studies, will grow and cause symptoms.

Clinical trials Clinical trials are in progress for both stages of small cell lung cancer, evaluating new treatments and treatment combinations for this aggressive cancer. The National Cancer Institute recommends that anyone with small cell lung cancer consider participating in a clinical trial.

Prognosis

Survival rates for small cell lung cancer have improved since the addition of radiation therapy to treatment and the use of PCI, but they still remain low. Survival rates for small cell lung cancer are very different according to the stage. Currently, the 5-year survival rate for stage 1 small cell lung cancer is 31 percent, and 19 percent for stage 2. Only 10 percent of people with limited-stage disease show no evidence of cancer 2 years after diagnosis. Since small cell lung cancer grows rapidly, and we have come a long way with other fast-growing cancers such as leukemia, it is hoped that better treatments will be found in the future.

What Can I Do to Help Myself?

Studies suggest that learning what you can about your lung cancer can improve your treatment. Ask questions. Find out about clinical trials that might be appropriate for you. Consider joining a support group. Ask for -- and let -- your loved ones help you in your journey with cancer.

It is important to be your own advocate when you have lung cancer. After many years of little change in the treatment of lung cancer, especially small cell lung cancer, progress is being made.

Sources:

American Cancer Society. Lung Cancer (Small Cell.) Small Cell Lung Cancer Survival Rates by Stage. Updated 02/26/16. http://www.cancer.org/cancer/lungcancer-smallcell/detailedguide/small-cell-lung-cancer-survival-rates

American Society of Clinical Oncology. Cancer.Net Lung Cancer – Small Cell: Treatment Options. 08/2015. http://www.cancer.net/cancer-types/lung-cancer-small-cell/treatment-options

National Cancer Institute. Small Cell Lung Cancer Treatment (PDQ) – Health Professional Version. Updated 07/07/16. https://www.cancer.gov/types/lung/patient/small-cell-lung-treatment-pdq

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