Pre-treatment erythropoietin levels cannot be used to predict individual response to epoetin alfa in anaemic cancer patients

Recombinant human erythropoietin (epoetin alfa) is an effective treatment for anaemia in cancer patients, and over two-thirds of recipients experience a substantial increase in haemoglobin concentration (> 2 g/dl). However, it would be helpful to identify responders before starting treatment. Some studies have suggested that high pre-treatment levels of endogenous erythropoietin or other pre-treatment or early response variables are associated with a poor response to epoetin alfa, and several predictive algorithms have been published. We analysed data pooled from 9 clinical trials of 1010 patients to determine the clinical usefulness of pre-treatment erythropoietin levels and other variables for predicting response. This showed that pre-treatment factors alone do not provide a clinically useful prediction of response. The sensitivity of these models increases slightly if early response variables, such as the change in haemoglobin after 4 weeks, are included, but specificity remains poor. We conclude that, while there may be a statistical relationship between certain factors and response, none approach clinically useful levels of sensitivity or specificity.