Effects of thermoablation with or without caffeine on giant cell tumour of bone.

PURPOSE To evaluate the effect of caffeine on the apoptosis rate of giant cell tumour of bone cells during thermoablation. METHODS Giant cell tumour of bone tissue (2 cm3) was collected from 10 patients. Cells were incubated at 37ºC, 40ºC, 45ºC, 50ºC, 52.5ºC, and 55ºC for 20 minutes (3 tubes for each temperature). Caffeine was added to the tubes in amounts of 0 μg/ml (control), 50 μg/ml, and 100 μg/ml. The apoptotic effect of thermoablation with or without caffeine was evaluated. RESULTS In all test conditions, the apoptotic rate of tumour cells increased when the temperature increased. Compared with controls (no caffeine), adding 50 or 100 μg/ml of caffeine did not increase the apoptotic rate significantly at 40ºC to 52.5ºC. Caffeine had no enhancing effect at any temperature. Conversely, at 55ºC, the apoptotic rate was lower when 100 μg/ml of caffeine was added than when no or 50 μg/ml of caffeine added (p=0.045). CONCLUSION Thermoablation at 40ºC to 52.5ºC for 20 minutes increased the apoptosis rate of giant cell tumour of bone cells. Caffeine had no enhancing effect at any temperature. Conversely, at 55ºC, caffeine had cytoprotective effects on the tumour cells against thermoablation.