Statistical considerations This is a study of a continuous response variable from matched pairs of study subjects and will need 38 patients to detect a true difference 1.5ml/min/kg, with a probability 0.8 and Type I error 0.05). Anticipated recruitment period is 10 months assuming a dropout rate of 20%. Randomisation is by computerised block randomisation, and patients will be stratified by receipt of neo-adjuvant chemotherapy.