New directions in supportive care.

Supportive care has traditionally emphasized symptom management and subjective evaluation of quality of life. However, recent advances in molecular biology and molecular genetics are as exciting for supportive care as they are for cytotoxic therapy. Relevant receptor mutations may alter sensitivity to antiemetics or to analgesics while variations in metabolic pathways may affect either efficacy of supportive care agents or toxicity of the chemotherapeutic agents themselves. Altered ligands for various receptors can produce differential effects conducive to better symptom management. Even symptoms such as fatigue and overall outlook may be defined in terms of appropriate enzymatic pathways. Evaluation and application of these advances in basic science are leading directly to new directions in supportive care.