The role of the biostatistician in cancer research.

This article considers triumphs and challenges for biostatisticians working in oncology at the beginning of the 21st century. The impact of three major articles in biostatistics in the 20th century is considered: Cornfield's 1951 paper on estimating comparative rates from clinical data; Mantel and Haenszel's 1959 paper on obtaining summary measures of relative risk, adjusting for stratification factors in epidemiological studies; and D. R. Cox's 1972 paper, which developed the proportional hazards model for evaluating the effect of covariates on survival time outcomes. Biostatistical challenges for the 21st century are considered for the areas of clinical trials, survival analysis, and statistical genetics.