Prognosis Research Strategy (PROGRESS) 2: prognostic factor research

Abstract

Prognostic factor research aims to identify factors associated with subsequent clinical outcome in people with a particular disease or health condition. In this article, the second in the PROGRESS series, the authors discuss the role of prognostic factors in current clinical practice, randomised trials, and developing new interventions, and explain why and how prognostic factor research should be improved.

Figure 1. Tumour grade as a prognostic factor in breast cancer.

Kaplan-Meier curves for disease-free survival for three groups of breast cancer patients defined by tumour grade status (1, 2, or 3). Curves are derived from 246 breast cancer patients treated with tamoxifen who had 94 recurrences or deaths over a possible 7 years of follow-up (reproduced with published data relating to Schumacher et al [1]). The distinct curves, significant log rank result, and hazard ratio estimates suggests tumour grade is a prognostic factor, as it identifies three groups of patients with a different average prognosis.

Figure 2. Evaluation of whether homocysteine is a prognostic factor, and whether modifying it improves clinical outcome in patients with coronary disease (drawn from data in [35]).

Path element adapted from Chart 7.1 in the Cooksey report (2006) http://bit.ly/Ro27rL (made available for use and re-use through the Open Government License).

Figure 3. Discovery of prognostic factors: a genome-wide association study of survival among people with breast cancer, and replication in 15 studies (Mid-figure forest plot based on example plots in .

Path element adapted from Chart 7.1 in the Cooksey report (2006) http://bit.ly/Ro27rL (made available for use and re-use through the Open Government License).