Culture of human head and neck cancer stem cells using soft agar.

The soft-agar stem-cell assay was applied to head and neck cancer. We have successfully grown 23 (64%) of 36 head and neck tumors from both primary lesions and metastases. More poorly differentiated tumors had positive cultures more frequently than well-differentiated tumors. The plating efficiency (colonies per cells in the inoculum) averaged 0.006% (range, 0.001% to 0.08%). The system allows testing and sensitivity of individual tumors to cancericidal drugs, and our initial trials using methotrexate, bleomycin sulfate, and cisplatin (cisplatinum) show a high degree of variability between individual tumors.