Preclinical and pilot clinical studies of docetaxel chemoradiation for Stage III non-small-cell lung cancer.

PURPOSE: Local and distant failure rates remain high despite aggressive chemoradiation (CRT) treatment for Stage III non-small-cell lung cancer. We conducted preclinical studies of docetaxel's cytotoxic and radiosensitizing effects on lung cancer cell lines and designed a pilot study to target distant micrometastasis upfront with one-cycle induction chemotherapy, followed by low-dose radiosensitizing docetaxel CRT. METHODS AND MATERIALS: A preclinical study was conducted in human lung cancer cell lines NCI 520 and A549. Cells were treated with two concentrations of docetaxel for 3 h and then irradiated immediately or after a 24-h delay. A clonogenic survival assay was conducted and analyzed for cytotoxic effects vs. radiosensitizing effects of docetaxel. A pilot clinical study was designed based on preclinical study findings. Twenty-two patients were enrolled with a median follow-up of 4 years. Induction chemotherapy consisted of 75 mg/m(2) of docetaxel and 75 mg/m(2) of cisplatin on Day 1 and 150 mg/m(2) of recombinant human granulocyte colony-stimulating factor on Days 2 through 10. Concurrent CRT was started 3 to 6 weeks later with twice-weekly docetaxel at 10 to 12 mg/m(2) and daily delayed radiation in 1.8-Gy fractions to 64.5 Gy for gross disease.
RESULTS: The preclinical study showed potent cytotoxic effects of docetaxel and subadditive radiosensitizing effects. Delaying radiation resulted in more cancer cell death. The pilot clinical study resulted in a median survival of 32.6 months for the entire cohort, with 3- and 5-year survival rates of 50% and 19%, respectively, and a distant metastasis-free survival rate of 61% for both 3 and 5 years. A pattern-of-failure analysis showed 75% chest failures and 36% all-distant failures. Therapy was well tolerated with Grade 3 esophagitis observed in 23% of patients.
CONCLUSIONS: One-cycle full-dose docetaxel/cisplatin induction chemotherapy with recombinant human granulocyte colony-stimulating factor followed by pulsed low-dose docetaxel CRT is promising with regard to its antitumor activity, low rates of distant failure, and low toxicity, suggesting that this regimen deserves further investigation.