The world cancer patient population (WCPP): An updated standard for international comparisons of population-based survival

Purpose: This study addresses the need for a global cancer patient-based standard population that adjusts for the expected age structure of different cancers, thus aiding the comparison of survival estimates worldwide. Methods: Counts of age-specific incidence for 36 cancer sites in 185 countries for the year 2018 were extracted from IARC's GLOBOCAN database of national estimates. We used a multinomial mixture regression to identify clusters of cancer sites with similar age-specific profiles. Results: An updated standard entitled the World Cancer Patient Population (WCPP) is presented, derived from the current estimated global numbers of cancer patients that comprises three sets of age-specific weights. Around two-thirds of cancer sites were described by a unique standard, representing the majority of epithelial cancers more often diagnosed at older age groups. The two other standards represent a number of non-epithelial cancer types, and cancers common at younger and older age groups, respectively. Conclusion: The WCPP proposed here provides a contemporary and global means to estimate age-standardised survival for international benchmarking purposes.