Expected benefit from chemotherapy in the treatment of extensive disease

This review examined the effectiveness of chemotherapy in the treatment of extensive-disease small-cell lung cancer.

Small cell lung cancer is an aggressive form of lung cancer, which often progresses very quickly. In the majority of cases the cancer has already metastasized (spread) beyond the lungs by the time of diagnosis. Chemotherapy is the first-line treatment of small-cell lung cancer, however, cancer often progresses despite treatment and survival rates remain low. Since chemotherapy treatments are not without risks and side effects, and the benefit of treatment is often short-lived, some patients with extensive disease opt for supportive care to control their symptoms over chemotherapy. In order to better quantify the benefit of chemotherapy in treating extensive-disease small-cell lung cancer, this review compared cancer outcomes among patients treated with chemotherapy to those receiving supportive care alone.

Five studies were analyzed in this review. Two studies, including 88 patients, focused on the effectiveness of first-line chemotherapy versus supportive care. Three studies, including a total of 932 patients, examined the effectiveness of second-line chemotherapy (further treatments for patients experiencing recurrence or progression following first-line chemotherapy) versus supportive care.

First-line treatment with the chemotherapy agent ifosfamide was found to increase survival by an average of 78.5 days compared to patients receiving supportive care alone or a placebo. 47% of patients receiving first line chemotherapy experienced at least a partial response to treatment (as measured by tumor shrinkage).

Second-line treatment with a variety of chemotherapy agents was also shown to lead to significantly increased survival times. Chemotherapy treatment with the combination of methotrexate and doxorubicin increased survival time by an average of 63 days compared to best supportive care. Survival rate at six-month following methotrexate-doxorubicin chemotherapy was 37%, compared to 20% among patients receiving supportive care alone. Second-line treatment with the chemotherapy agent topotecan led to an average increase of 84 days in survival time compared to supportive care. Following topotecan treatment, the six-month survival rate was 49% of patients, compared to 26% of patients receiving supportive care. In addition, patients treated with topotecan reported increased quality of life compared to patients receiving supportive care.

This review concluded that, although not curative, both first- and second-line chemotherapy treatments offer a substantial increase in survival time for patients with extensive-disease small-cell lung cancer.

This review included a very small number of studies, each of which compared different treatments and followed different protocols. The review also called into question the quality of the results reported in these studies.