Types of Medications for Small Cell Lung Cancer

Medications prescribed for small cell lung cancer are primarily chemotherapy drugs which destroy cancer cells. Antiemetic medications to prevent side effects such as nausea, vomiting and diarrhea are routinely administered along with chemotherapy.

Medications prescribed for small cell lung cancer are primarily chemotherapy drugs which destroy cancer cells. Antiemetic medications to prevent side effects such as nausea, vomiting and diarrhea are routinely administered along with chemotherapy.

Immunotherapy with monoclonal antibodies that stimulate the immune system to fight cancer is also used in the treatment of small cell lung cancer. 

Other medications used for SCLC include medications such as painkillers and corticosteroids for symptom relief, and palliative care to enhance quality of life during the terminal stages of the disease.

Small cell lung cancer is an aggressive type of cancer that starts in the lung’s respiratory tubes (bronchi) in the middle of the chest. Cancers are a group of diseases in which abnormal cells evade the body’s regulatory mechanisms to grow uncontrollably.

Cancers arise from genetic mutations which enable cancer cells to grow, divide, migrate and avoid programmed death (apoptosis) that normal cells undergo when damaged or no longer needed.

Lung cancers are of two main types:

• Small cell lung cancer (SCLC): SCLC accounts for approximately 10% to 15% of lung cancers. SCLCs tend to grow and spread (metastasize) rapidly. SCLC responds well to radiation and chemotherapy, but for most people cancer eventually returns.
• Non-small cell lung cancer (NSCLC): Lung cancers other than small cell lung cancer are grouped into non-small cell lung cancers, because their treatments and prognoses are generally similar. Approximately 85% of lung cancers are non-small cell lung cancer. The three types of NSCLC are:
  • Adenocarcinoma
  • Squamous cell carcinoma
  • Large cell (undifferentiated) carcinoma

Other types of lung cancers include carcinoid tumors, sarcomas and hamartoma, a benign tumor, but these are rare. This article will emphasize SCLC.

The two types of small cell lung cancer are:

• Small cell carcinoma: Small cell carcinoma is named after the size and shape of the cancer cells. It is also called oat cell carcinoma because the cells look like oats under the microscope.
• Combined small cell carcinoma: Combined small cell carcinoma is small cell carcinoma combined with any of the non-small cell carcinomas.

Symptoms of SCLC can develop and worsen in a matter of weeks as the tumor grows rapidly. The symptoms of the primary tumor in SCLC include:

• Cough
• Coughing up blood (hemoptysis)
• Shortness of breath
• Chest pain, especially with deep breaths

Tumor growth and spread put pressure on the veins, nerves and other organs in the chest region, resulting in symptoms that include:

• Swelling of face and hands
• Hoarseness of voice
• Difficulty swallowing
• Shortness of breath
• Stridor, a sound caused due to the compression of the airways
• Lung infection, inflammation and fever

Symptoms of metastatic SCLC depend on the region of metastasis. The most common sites of metastasis include the brain, liver, adrenal glands, bones and bone marrow. Following are some of the common symptoms from metastasis:

• Brain:
  • Headaches, usually worse when waking
  • Blurred vision
  • Nausea and vomiting
  • Sensitivity to light
  • Slurred speech
  • Confusion
• Vertebral column and spine:
  • Back pain
  • Loss of bladder and bowel functions
  • Paralysis of the limbs
• Bone: Bone pain
• Liver: Jaundice and abdominal pain

Small cell lung cancers are neuroendocrine cancers, which means they develop in specialized cells that have traits of both nerve cells and hormone-producing endocrine cells. Cancer causes these cells to release substances which make the immune system attack healthy nerve cells resulting in certain rare disorders known as paraneoplastic syndromes.

Paraneoplastic syndromes include disorders such as syndrome of inappropriate antidiuretic hormone (SIADH) and Eaton-Lambert syndrome. Common symptoms of paraneoplastic syndromes include:

• Fatigue
• Loss of appetite
• Muscle weakness
• Trouble with balance and walking
• Electrolyte imbalance in the blood such as low sodium (hyponatremia) and high calcium (hypercalcemia)

Tobacco smoke, including secondhand, is the predominant cause of SCLC. Approximately 98% of SCLC patients have smoking in their history. Other risk factors include:

• Exposure to radon, an inert gas produced by uranium decay
• Exposure to carcinogenic substances such as asbestos, silica, arsenic and others
• Taking beta carotene supplements and being a heavy smoker
• Air pollution
• Previous radiation therapy to the chest for other cancers
• Family or personal history of lung cancer

Small cell lung cancers are particularly aggressive and incurable in the extensive stage. The general survival rate at five years for localized SCLC (confined to the lung) is 27%. For SCLC that has spread within the chest region, survival rate at five years is 16%. The five-year survival rate is 3% for metastatic SCLC that has spread to distant parts of the body.

A combination of two chemotherapy drugs constitutes the primary treatment for small cell lung cancer. Choice of chemotherapy drugs and additional treatments depend on the cancer stage at the time of diagnosis, and the patient’s age, gender and general health. SCLC in classified into two stages:

• Limited stage: Limited stage SCLC is cancer that is confined to one side of the chest, in one lung and the lymph nodes on the same side. Only about 30% of patients are at this stage at the time of diagnosis. Standard treatment for limited stage SCLC is combination chemotherapy along with radiation therapy.
• Extensive stage: Extensive stage is incurable in SCLC because cancer has metastasized to the other lung, brain, bone, bone marrow or liver tissue. Nearly 70% of patients are at an extensive stage at the time of diagnosis. Combination chemotherapy, with or without immunotherapy, is the primary treatment for extensive stage SCLC, to prolong survival and enhance quality of life.

Treatments for small cell lung cancer include the following:

Medications

Systemic treatments with chemotherapy medications are effective for SCLC because they can work on cancer cells all over the body. Other medications prescribed for SCLC boost the immune system, provide relief from symptoms of SCLC, treat side effects of chemotherapy and complications from paraneoplastic syndromes.

Radiation therapy

Radiation therapy is the use of high energy X-rays to destroy cancer cells. Radiation therapy can only kill cancer cells directly in the path of the radiation beam and can also damage healthy cells, which makes it useful only for limited stage SCLC with localized tumors. Radiation therapy is performed in addition to chemotherapy.

Prophylactic (preventative) cranial irradiation

Prophylactic cranial irradiation describes mild radiation doses to the brain to reduce the risk of SCLC spreading there. This procedure is used only for patients with limited stage SCLC who have achieved remission after chemotherapy along with radiation or surgery.

Laser therapy

Laser therapy is the use of laser beams to kill cancer cells.

Surgery

Surgery plays a minimal role in SCLC treatment. Surgery for SCLC involves surgical removal (resection) of the cancerous portion of the lung and nearby lymph nodes. Surgery, after or before chemotherapy, may be an option for a small number of patients to control relapse in early stage localized tumors. Diagnosis of SCLC at such an early stage occurs in fewer than 5% of SCLC patients.

Clinical trials and palliative care

People who have a relapse of SCLC, or refractory SCLC that does not respond to standard treatment have the option of enrolling in clinical trials for new treatments. People in advanced and terminal stages of SCLC are treated with palliative care to manage pain and other complications from the cancer.

The goals of medications for SCLC are to induce remission, prevent relapse and complications, and provide palliative care. Medications may be administered through various routes such as oral, injections or intravenous infusions.

The two main types of medications used in treatment of SCLC are:

• Chemotherapy: Chemotherapy medications are toxic compounds which are highly effective in killing cancer cells in SCLC. Combination chemotherapy, typically with two chemotherapy drugs, is the primary treatment for both stages of SCLC. Antiemetics and corticosteroids are administered to treat the side effects of chemotherapy.
• Immunotherapy: Immunotherapy medications are lab-produced protein molecules known as monoclonal antibodies that enhance the immune system’s ability to fight the cancer cells.

Other medications prescribed for SCLC include pain relievers, antibiotics to prevent infections and medications to treat specific cancer symptoms and correct electrolyte imbalance that can occur from paraneoplastic syndromes (a rare and harmful type of immune response to cancer cells).

Chemotherapy

Chemotherapy medications work in various ways to prevent cell growth and replication of DNA during cell division. Chemotherapy drugs are toxic to all cells in the phase of growth and division, including healthy ones. Small cell lung cancer is an aggressive cancer in which cancer cells are constantly growing and dividing, and thus are highly responsive to chemotherapy treatment.

A combination of two chemotherapy drugs is the typical treatment regimen for SCLC. Choice of chemotherapy agents depends on the disease stage. Because of SCLC’s metastatic nature, doctors commonly prescribe many chemotherapy drugs with established clinical efficacy off-label, in addition to the chemotherapy medications approved by FDA specifically for SCLC.

• FDA-approved
  • FDA-approved chemotherapy medications include the following:
    • Lurbinectedin (Zepzelca)
    • Topotecan hydrochloride (Hycamtin)
    • Doxorubicin hydrochloride (Adriamycin, Caelyx, Rubex)
    • Etoposide
    • Etoposide phosphate (Etopophos)
• Off-label
  • Chemotherapy drugs used off-label for SCLC include:
    • Everolimus (Afinitor)
    • Cisplatin
    • Carboplatin
    • Cyclophosphamide (Cytoxan)
    • Ifosfamide (Ifex)
    • Irinotecan hydrochloride (Camptosar)
    • Vincristine sulfate
    • Vinorelbine tartrate
    • Paclitaxel (Abraxane)
    • Docetaxel (Taxotere)
    • Gemcitabine hydrochloride (Gemzar)
• Combination chemotherapy
  • Most widely used combination regimens for both stages of SCLC are:
    • Cisplatin or carboplatin with etoposide
    • Cisplatin or carboplatin with irinotecan

Immunotherapy: PD-1/PD-L1 inhibitors

Immunotherapy medications for SCLC are monoclonal antibodies known as PD-1/PD-L1 inhibitors, which work by enhancing the activity of T-cells, a type of immune cell. T-cells induce programmed death in damaged or mutated cells, including cancer cells, but cancer cells develop the ability to evade immune activity.

T-cell activity is inhibited when protein molecules known as PD-1 and PD-L1 on the T-cell surface interact. Cancer cells escape programmed death by secreting PD-L1 or inducing the T-cells in the tumor microenvironment to produce PD-L1. PD-1/PD-L1 inhibitors block the interaction between PD-1 and PD-L1.

PD-1/PD-L1 inhibitors approved by FDA for SCLC are:

• Nivolumab (Opdivo)
• Pembrolizumab (Keytruda)
• Atezolizumab (Tecentriq)
• Durvalumab (Imfinzi)

Antiemetics and corticosteroids are always prescribed with chemotherapy medications to prevent nausea, vomiting and other side effects. FDA-approved medications for chemotherapy side effects include:

Antiemetics

• Metoclopramide hydrochloride (Reglan)
• Ondansetron hydrochloride (Zofran)
• Granisetron (Sancuso, Sustol)
• Palonosetron hydrochloride (Aloxi)

Corticosteroids

• Prednisone
• Methylprednisolone
• Dexamethasone

• Please visit our medication section of each drug within its class for more detailed information.
• If your prescription medication isn’t on this list, remember to look on MedicineNet.com drug information or discuss with your healthcare provider and pharmacist.
• It is important to discuss all the drugs you take with your doctor and understand their effects, possible side effects and interaction with each other.
• Never stop taking your medication and never change your dose or frequency without consulting with your doctor.