Among patients with limited-disease small-cell lung cancer, those who had a shorter duration between the start of treatment and the end of radiation therapy experienced improved survival. These results were published in the Journal of Clinical Oncology .
Small cell lung cancers (SCLC) account for 20-25% of all lung cancers and are primarily diagnosed in smokers or former smokers. They differ from other types of lung cancer in that they spread very quickly throughout the body via the blood and lymphatic system.
Accurate staging of SCLC is essential before definitive therapy can begin. A simple staging system is used to separate SCLC into two stages-limited and extensive:
- Limited SCLC is confined to a single location in the chest and is not detectable outside the lung.
- Extensive SCLC has spread to both lungs or is detectable beyond the lungs.
The combination of chemotherapy and radiation therapy has improved survival for patients with limited-stage SCLC, but long-term survival remains poor. Researchers continue to explore the optimal approach to treatment.
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A factor that may influence the success of treatment is the overall duration of treatment. Both normal cells and surviving tumor cells can proliferate in between doses of chemotherapy or radiation therapy, and the rate of this regrowth may increase over the course of treatment. For patients with quickly growing cancers, it may be possible to improve survival by maximizing the number of treatment doses given before rapid regrowth of cells begins. This approach, however, is likely to cause more adverse effects of treatment.
To explore whether duration of treatment influences survival with limited-disease SCLC, researchers conducted a combined analysis of four clinical trials. These trials enrolled a total of 1,056 patients. Treatment in all four trials involved platinum-based chemotherapy and radiation therapy. Duration of treatment was defined as the start of any treatment to the end of radiation therapy.
- Shorter duration of treatment was linked with significantly improved survival. Compared to the shortest duration evaluated, each one-week extension in duration of treatment reduced five-year survival by roughly 2%.
- Patients with shorter duration of treatment were also more likely to experience severe esophagitis (inflammation of the esophagus).
The researchers conclude that shorter duration from the start of chemotherapy to the end of radiation therapy appears to be linked with better survival in patients with limited-disease SCLC.
Reference: De Ruysscher D, Pijls-Johannesma M, Bentzen SM et al. Time Between the First Day of Chemotherapy and the Last Day of Chest Radiation is the Most Important Predictor of Survival in Limited-Disease Small Cell Lung Cancer. Journal of Clinical Oncology. 2006;24:1057-1063.
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