Cancer Staging API

CDC has created software in the form of a dynamic link library (DLL) to help cancer registries collect data on stage of disease for cancers according to the TNM system of the American Joint Committee on Cancer (AJCC). Content from AJCC’s Cancer Staging Manual, 7th edition, has been licensed for use in the application programming interface (API) by NPCR registries. A version without the licensed content can be downloaded from this site. For access to the licensed version, contact


The DLL has two primary functions—

  • Helps cancer data abstractors by providing cancer site-specific picklists of valid codes for the T, N, M, and stage groups, both clinical and pathologic.
  • Helps central registries perform quality control and data consolidation by providing an algorithm to calculate the correct stage group from coded T, N, and M values.

The DLL can be incorporated in cancer registry software programs to support standardized collection of TNM data.

Technical Information, Download, and Installation

The library exposes an API. The library is written in C# and .NET. A basic understanding of C# is required to use the API. A Microsoft® Windows environment with .NET Framework version 4.5 or higher is required.

Note June 2, 2017: A revised API was released on June 2, 2017. The changes from the February 2017 release are—

  • Additional clinical N values added to TNM Path N [NAACCR item 890] for the following schemas—
    • All GISTschemas
    • Corpus Uteri Carcinomas
    • Bone
    • Melanoma of Skin
    • Soft Tissue Sarcoma
  • Prostate—Derivation algorithm for NPCR Derived Path Stg Grp [NAACCR item number 3655] was revised to use the higher of the Gleason scores coded in SSF8 and SSF10.
  • Derivation algorithm for NPCR Derived Clin Stg Grp [NAACCR Item Number 3650] modified to derive stage in situ for Tis N0 M0 regardless of grade code for the following schemas—
    • Esophagus Squamous Cell Carcinoma
    • Esophagus Adenocarcinoma
    • Esophagogastric Junction Squamous Cell Carcinoma
    • Esophagogastric Junction Adenocarcinoma

Note February 20, 2017: A revised API was released on February 20, 2017. The changes from the October 2016 release affect the derived clinical and pathologic stage groups for the following schemas—

  • Breast
  • Lung
  • Lymphomas, Primary Cutaneous
  • Malignant Melanoma of Ciliary Body and Choroid
  • Malignant Melanoma of the Iris

Note October 17, 2016: A revised API was released on October 17, 2016. The changes from the initial release include—

  • Removal of codes ‘c0’ from the pathologic N tables for schemas for which AJCC does not provide an in situ category.
  • Added validation of directly entered stage groups for lymphomas before calculation of derived stage groups.
  • Enhanced API documentation with an index and additional hyperlinks.

Download the version without the licensed content—

The contents of the zip file include—

  • The TNM staging library.
  • The API documentation (.chm file).
  • A sample code file, to be used in conjunction with the API documentation.

TNM 7th Edition Staging Batch Calculation Tool

The TNM staging batch calculation tool is a standalone application that accepts a flat file of records in NAACCR v16 format, derives values for the standard items NPCR Derived Clin Stg Grp (item 3650) and NPCR Derived Path Stg Grp (item 3655), and writes the results to an output file and log file. It can be used by any registry whether or not they hold a license for AJCC copyrighted contents. The batch calculation tool incorporates the TNM staging API version released June 2, 2017. The download file contains notes and instructions for use.

Initial release: June 30, 2017

Download: Cdc-zip[ZIP-548KB]

Page last reviewed: November 19, 2018