Intensive combined modality therapy for limited-stage small-cell lung cancer.

BACKGROUND

Conventional-dose chemotherapy for small-cell lung cancer has resulted in high response rates but rarely in a cure. The addition of thoracic radiotherapy (chemoradiotherapy) has improved survival for patients having limited disease, resulting in a median survival of 14-18 months. Previous trials evaluating high-dose chemotherapy and autologous bone marrow transplantation have demonstrated enhanced complete response rates without documenting overall survival benefit.

PURPOSE

The purpose of this phase II trial was to determine the disease-free and overall survival, toxic effects, and relapse patterns in patients with limited small-cell lung cancer who were in partial or complete response to first-line conventional-dose chemotherapy and then received intensive systemic combined modality therapy.

METHODS

Adults with stage III small-cell lung cancer who had achieved at least a partial response to conventional-dose induction chemotherapy were treated with high-dose cyclophosphamide, cisplatin, and carmustine combined with autologous bone marrow transplantation. Cumulative doses of the three drugs were 5625, 165, and 480 mg/m2, respectively. After recovery, patients received thoracic radiotherapy (50-60 Gy in 25-30 fractions over 5-6 weeks) and cranial radiotherapy (30 Gy in 15 fractions during 3 weeks).

RESULTS

Of 19 patients in the study, six had achieved complete response, eight had a greater than 90% reduction in tumor size, and five had a 50%-90% reduction in tumor size. After high-dose therapy, 15 of the 19 were in complete response. Overall, median time to treatment failure after high-dose therapy was 12 months. Overall survival was 73% (95% confidence interval [CI] = 42%-89%) at 1 year and 53% (95% CI = 22%-77%) at 2 years. Of the 14 patients in or near complete response before high-dose therapy, 10 remain disease free with no further chemotherapy a median of 15 (4-69+) months after therapy. Actuarial 2-year disease-free survival is 57% (95% CI = 20%-82%). One patient died of Candida sepsis. Morbidity was low, and most patients returned to full-time work. With the exception of herpes zoster, there were no complications more than 3 months after high-dose therapy.

CONCLUSIONS

The majority of the patients in this study are experiencing prolonged and unmaintained disease-free survival. Our findings suggest that patients in or near complete response before high-dose therapy have the most favorable prognosis.

IMPLICATIONS

A randomized comparison between this approach and conventional-dose therapy is planned to define the utility of dose intensification with autologous bone marrow transplantation in the treatment of patients with limited-stage small-cell lung cancer who are in or near complete response.