The New England Journal of Medicine recently published long-term follow-up data demonstrating that higher initial doses of chemotherapy appear to increase long-term survival in patients with limited small cell lung cancer (SCLC). These results are important, as long-term treatment outcomes in SCLC patients treated with high dose chemotherapy are scarce.
Small cell lung cancers account for 20-25% of all lung cancers and are primarily diagnosed in smokers or former smokers. SCLC differs from other types of lung cancer in that it tends to spread very quickly throughout the body via the blood and lymphatic system. Limited SCLC refers to cancer that is present in only one location in the chest. The most common form of treatment for patients with limited SCLC is combination chemotherapy plus radiation to the chest and sometimes, preventive radiation to the head.
A previous clinical trial directly compared different doses of initial chemotherapy in 105 patients with limited SCLC. Patients in this trial were given either higher or lower initial doses of the chemotherapy agents cisplatin and cyclophosphamide. An average of approximately 3 years following treatment, results indicated that patients who received the higher doses of chemotherapy had improved survival compared to those who received lower doses.
Recently, the researchers who conducted this clinical trial have re-evaluated these patients after an average follow-up period of 11 years to determine if the survival benefits of higher doses of chemotherapy persisted. Two years following treatment, 42% of the patients who had received higher doses of chemotherapy were still alive, compared to only 20% of the patients who had received the lower doses. Similarly, five years following treatment, 26% of the patients who had received higher doses were alive, compared to only 8% of patients who had received lower doses. Although the survival benefits of the higher dose chemotherapy declined over time, survival was still highest 10 years following therapy in the patients who had received the higher doses of chemotherapy.
These results are consistent with findings of other studies that demonstrate increases in initial doses of chemotherapy agents appear to improve long-term survival rates in patients with limited SCLC. These results emphasize the importance of maintaining dose intensity, indicating that dose reduction due to side effects may hinder achievement of optimal outcomes. Clinical trials are ongoing evaluating escalating doses of chemotherapy in hopes of improving survival for patients with this disease. Patients with limited SCLC may wish to speak with their physician about the risks and benefits of higher dose chemotherapy regimes or about participating in a clinical trial further evaluating this issue or novel therapeutic options. Two sources of information regarding ongoing clinical trials include comprehensive, easy-to-use listing services provided by the National Cancer Institute (cancer.gov) and www.eCancerTrials.com. eCancerTrials.com also provides personalized clinical trial searches on behalf of patients. (New England Journal of Medicine, Vol 345, No 17, pp. 1281-1282, 2001)