Strategies to Improve Treatment of Extensive Small Cell Lung Cancer
Researchers are currently investigating new treatments for extensive small cell lung cancer. Participation in trials of these treatments will lead to improved therapies. If you wish to participate in a clinical trial, please talk to your doctor about the potential benefits and side effects of the treatment.
New Combination Chemotherapy Regimens - Results from a recent clinical trial indicate that a combination of Camptosar® (irinotecan) and Platinol® (cisplatin) 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® (gemcitabine), taxanes and other anti-cancer therapies in an effort to improve the treatment of extensive disease. In addition to Camptosar, other chemotherapy agents including Taxol® (paclitaxel) and Ifex® (ifosfamide) have also been combined with etoposide and platinum compounds, producing three-drug regimens. These three-drug regimens can be administered safely, produce higher response rates and may improve survival rates compared with previous two-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.
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 and molecularly targeted agents that work in various ways to stimulate the immune system or specific receptors and pathways are being evaluated to prevent or delay relapses and to extend the survival for patients with SCLC. 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.
Bevacizumab was studied in combination with both cisplatin-etoposide and cisplatin-irinotecan in two phase II studies conducted by the Eastern Cooperative Oncology Group and Cancer and Leukemia Group B, respectively. Both studies demonstrated modest effectiveness. Other targeted agents, such as the histone deacetylase inhibitors and small molecule vascular endothelial growth factor (VEGF) TKIs, are being studied for the treatment of SCLC.
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 biologic processes.
The photosensitizing agent is injected into a patient’s vein a couple of hours before 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.
This content was last modified on
November 16, 2007
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