On the Breslow estimator.

In his discussion of Cox's (1972) paper on proportional hazards regression, Breslow (1972) provided the maximum likelihood estimator for the cumulative baseline hazard function. This estimator is commonly used in practice. The estimator has also been highly valuable in the further development of Cox regression and semiparametric inference with censored data. The present paper describes the Breslow estimator and its tremendous impact on the theory and practice of survival analysis.