This item stores the results of NPCR's derived algorithmic calculation of post neoadjuvant stage group based on AJCC T, N, and M and relevant biomarkers and prognostic factors. The algorithm derives AJCC 8th ed. stage group for 2018, however, updates to future AJCC editions are anticipated. NPCR did not derive post neoadjuvant stage group for 7th ed.

The purpose of the derived stage fields is to segregate data values for AJCC stage groups derived from the NPCR algorithm from values directly entered from the medical record or by the registrar. NPCR's primary interest is in the directly-entered values, but derived values will have a purpose primarily at the central registry. It is important to not mix data values from the two sources in the same data items.

NPCR does not collect post neoadjuvant stage information, but the NPCR derivation algorithm supports collection by CoC accredited facilities and other registries.