A phase III randomized study comparing the effects of oxandrolone (Ox) and megestrol acetate (Meg) on lean body mass (LBM), weight (wt) and quality of life (QOL) in patients with solid tumors and weight loss receiving chemotherapy
A study by DeWys, et. al. in 1980 showed that unintentional weight loss in cancer patients is a significant problem and is a poor prognostic factor. It is associated with decreased survival and QOL, and increased toxicity to cancer treatment. The weight loss in cancer patients is disproportionately seen as a loss of muscle mass rather than fat, which may be a reason for the negative effects mentioned above. Common drugs such as megestrol acetate (or Megace) and corticosteroids (such as dexamethasone and prednisone) have been standardly used to reduce unintentional weight loss, and can actually help patients gain weight. Oxandrolone (Oxandrin, Ox) is an oral anabolic steroid, which has a high anabolic-to-androgenic ratio. For this reason, it is proposed that this drug promotes weight gain by promoting muscle regrowth and increasing LBM. Ox has been used for a variety of medical disorders causing involuntary weight loss, and has often been used by body builders to build muscle. The purpose of this phase III study was to compare the effects of Ox to Meg (a current standard) on LBM and weight of patients.
155 cancer patients who had experienced a 3% or greater loss of body weight were randomly assigned to receive Ox twice a day or Megace daily while undergoing chemotherapy. 60% of those enrolled had advanced disease. There was a significant improvement in weight and change in fat mass in the Megace group. The Ox group actually lost weight and fat mass. There was a 50% study dropout rate, which was much higher in the Ox arm (69%) versus 39% in the Megace arm.
It is unclear whether the advanced stage of disease played a role in the patients on Ox losing weight. The authors neglected to discuss why the drop out rate was so high, which could be related to toxicity. The researchers are now looking to perform a trial comparing megace to Ox given with megace and it will be useful to see if the combination improves weight outcomes.