Development and validation of a new predictive model for breast cancer survival in New Zealand and comparison to the Nottingham prognostic index

The Nottingham prognostic index (NPI) was the first breast cancer prognostic model published and is widely used. It does not predict survival for each patient, but divides patients into prognostic groups. This study aimed to develop and validate a predictive model using New Zealand data, and compare it to NPI. A 10-year breast cancer-specific survival model was developed using data from the population-based cancer registry in Auckland, New Zealand. The results of the model show good internal and external validity (0.84 and 0.83 respectively), and the NZ model showed good discrimination even with the prognostic groups defined by the NPI. The model showed superiority over the NPI and demonstrated that within each NPI group, the model efficiently subdivides patients into smaller groups. Further research will assess other potential predictors, assess performance in specific subgroups and compare with models other than NPI. Read the full article