Overview
When small cell lung cancer has spread to both lungs or is detectable beyond the lungs, it is referred to as extensive.
A variety of factors ultimately influence a patient’s decision to receive treatment of cancer. The purpose of receiving cancer treatment may be to improve symptoms through local control of the cancer, increase a patient’s chance of cure, or prolong a patient’s survival. The potential benefits of receiving cancer treatment must be carefully balanced with the potential risks of receiving cancer treatment.
The following is a general overview of the treatment of extensive small cell lung cancer. Circumstances unique to your situation and prognostic factors of your cancer may ultimately influence how these general treatment principles are applied. The information on this Web site is intended to help educate you about your treatment options and to facilitate a mutual or shared decision-making process with your treating cancer physician.
Most new treatments are developed in clinical trials. Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. Participation in a clinical trial may offer access to better treatments and advance the existing knowledge about treatment of this cancer. Clinical trials are available for most stages of cancer. Patients who are interested in participating in a clinical trial should discuss the risks and benefits of clinical trials with their physician. To ensure that you are receiving the optimal treatment of your cancer, it is important to stay informed and follow the cancer news in order to learn about new treatments and the results of clinical trials.
Patients with extensive disease small cell lung cancer are rarely curable with currently available standard treatment strategies. Because the cancer has spread outside the chest, it cannot be treated with radiation or removed surgically. Small cell lung cancer is very responsive to chemotherapy and the current standard treatment of extensive disease is chemotherapy. Before chemotherapy was used, the average patient only survived approximately 1.5 months. Single-agent chemotherapy improved the average survival to 4 months and the development of combination chemotherapy regimens has further increased the average survival to approximately 9 months.
Historically, the standard treatment for extensive small cell lung cancer has consisted of combination chemotherapy, mainly with Platinol® or Paraplatin® and etoposide. However, more recent research has indicated that combinations including Camptosar® may be more effective.
Camptosar® was first approved in Japan in 1994 for the treatment of extensive SCLC and is currently the standard of care in that country. Previous clinical trials conducted by the Japanese Clinical Oncology Group (JCOG) demonstrated that chemotherapy combinations involving Camptosar® improve the overall survival in patients with extensive SCLC, compared with the standard regimen of Platinol® and etoposide.
Results from a large clinical trial conducted by JCOG were presented at the 36th annual meeting of the American Society of Clinical Oncology in May, 2000 and were recently updated. Patients involved in the clinical trial had extensive SCLC and were treated with either Camptosar® plus Platinol® or etoposide plus Platinol® and then directly compared. The results indicated that 89% of patients treated with Camptosar® had a partial or complete disappearance of cancer, compared to only 67% of those treated with Platinol® and etoposide. One year following treatment, 60% of patients treated with Camptosar® were still alive, compared with 40% of those who received etoposide. Furthermore, the Platinol®/Camptosar® regimen produced fewer side effects than the Platinol®/etoposide combination.
Now, two years following treatment, long-term results from this trial have been reported in the New England Journal of Medicine. The average survival following treatment was 12.8 months for patients receiving Camptosar®/Platinol®, compared to only 9.4 months for patients treated with etoposide/Platinol®. Patients treated with Camptosar® are almost 3 times more likely to be alive two years following treatment than patients treated with etoposide/Platinol®. Overall, 19.5% of patients treated with Camptosar®/Platinol® survived for two years following treatment compared to only 5.2% of patients treated with etoposide/Platinol®. Enrollment in this trial was terminated early due to the significant differences in survival between the two treatment regimens.
This further confirms the results of previous trials indicating that Camptosar®/Platinol® is a superior treatment regimen for patients with extensive SCLC.
Strategies to Improve Treatment
While some progress has been made in the treatment of small cell lung cancer, better treatment strategies are needed, as the majority of patients still experience disease recurrence. The progress that has been made in the treatment of small cell lung cancer has resulted from the development of multi-modality treatments, new anti-cancer agents and participation in clinical trials. Future progress in the treatment of small cell lung cancer will result from continued participation in appropriate clinical trials. There are several areas of active exploration aimed at improving the treatment of small cell lung cancer.
New Combination Chemotherapy Regimens: Results from a recent clinical trial indicate that a combination of Camptosar® and Platinol® chemotherapy is superior to “standard regimen” of Platinol® and etoposide for patients with extensive small cell lung cancer. Clinical trials are now underway to evaluate Camptosar® combined with Gemzar®, taxanes and other anti-cancer therapies in an effort to improve the treatment of extensive disease. In addition to Camptosar®, other chemotherapy agents including paclitaxel and Ifex® have also been combined with etoposide and platinum compounds, producing 3-drug regimens. These 3-drug regimens can be administered safely, produce higher response rates and may improve survival rates compared with previous 2-drug regimens.
High-Dose Chemotherapy: High-doses of chemotherapy are more effective at killing cancer cells than lower doses. However, high-dose chemotherapy (HDC) destroys many other cells in the body, including stem cells. Stem cells are immature blood cells produced in the bone marrow which mature into either red blood cells, which carry oxygen to tissues; white blood cells, which fight infection; and platelets, which aid the blood in clotting. A stem cell transplant (SCT) is a procedure that replaces the stem cells that are destroyed by high-dose chemotherapy and/or radiation therapy with healthy stem cells. There are two main types of stem cell transplants. Autologous stem cell transplants use a patient’s own stem cells, which are collected prior to the high-dose treatment and then re-infused after the treatment. Allogeneic stem cell transplants use stem cells collected from the blood or bone marrow of a related or unrelated donor.
Early attempts at using very high doses of chemotherapy and bone marrow transplant produced very high cancer response rates, but the treatment was associated with significant side effects. In the 1990s, several technologic advances have made high-dose chemotherapy safer and easier to deliver. This treatment approach continues to be evaluated at some cancer centers. To learn more, go to Stem Cell Transplantation.
Biologic Therapy: Following cancer treatment with chemotherapy, patients often achieve a complete remission (disappearance of the cancer). Unfortunately, many patients in remission will later experience a relapse of their cancer. This is because not all of the cancer cells were destroyed. Doctors refer to this as a state of “minimal residual disease”. Many doctors believe that applying additional cancer treatments when only a few cancer cells remain represents the best opportunity to prevent the cancer from returning. Biologic agents that work in various ways to stimulate the immune system are being evaluated to prevent or delay relapses. Examples of biologic agents that can be used to treat minimal residual cancer include cytokines, vaccines and monoclonal antibodies. Large multi-institutional and several smaller clinical trials are ongoing to evaluate these new approaches.
Gene Therapy: Currently, there are no gene therapies approved for the treatment of lung cancer. Gene therapy is defined as the transfer of new genetic material into a cell for therapeutic benefit. This can be accomplished by replacing or inactivating a dysfunctional gene or replacing or adding a functional gene into a cell to make it function normally. Gene therapy has been directed towards the control of rapid growth of cancer cells, control of cancer death or efforts to make the immune system kill cancer cells. A few gene therapy studies are being carried out in patients with lung cancer. If successful, these therapies could be applied to patients with earlier stage disease.
Photodynamic Therapy: Photodynamic treatment is now in clinical trials for patients with extensive SCLC whose cancer is causing endobronchial obstruction. Photodynamic therapy works through the use of a photosensitizing agent and light. The photosensitizing agent is typically comprised of a porphyrin, which is a naturally occurring substance in the body involved in a variety of biological processes. The photosensitizing agent is injected into a patient’s vein a couple of hours prior to surgery. During this time, the agent selectively collects in rapidly growing cells such as cancer cells. During surgery, the physician applies a certain wavelength of light through a hand held wand directly to the site of the cancer and surrounding tissues. The energy from the light activates the photosensitizing agent, causing the production of a toxin that accumulates in the cancer cells and ultimately destroys them.