American College Of Surgeons - Inspiring Quality: Highest Standards, Better Outcomes

Cancer Registry Reference Date

Request to Change Registry Reference Year

Reference date changes should not be requested in the months of December and January during the preparations for and submission of the annual NCDB call for data. Thank you.

To ensure a valid statistical database, the CoC requires that a start date be established for CoC accredited registries. This date is known as the reference date (RD). A RD is established by the cancer committee prior to initial survey, and should be set as January 1, of a given year. The RD is a reference point for many standards and activities of the Accreditation Program. Once this date is established, abstracts must be completed for all reportable primaries diagnosed and/or initially treated at the facility since the RD. Registries in cancer programs seeking approval from the CoC must first accrue one (1) year of data.

Accredited programs are encouraged to maintain their original RD and database whenever possible. Occasionally, circumstances may cause a registry to petition for a change in reference date. Each request is given individual consideration. The original reference date must be maintained unless one of the following occurs:

  • Natural disaster in the service area
  • Changes in service area population or census
  • Inconsistencies or lapse in the database
  • High lost-to-follow-up rate caused by registry longevity
  • Changes in data acquisition methods
  • Lack of registry staffing for an extended period, over a year
  • Formation of Program mergers or networks

Examples of circumstances that do not warrant a RD change (requests will be denied) are:

  • Reduction in cancer registry staffing due to budget constraints
  • Follow-up burden on cancer registry
  • Data inaccessible
  • Monthly follow-up volume is becoming unmanageable

The RD is documented in the cancer registry policy and procedure manual. Effective immediately, reference dates may be changed only once every five (5) calendar years, and may only be requested if the registry has at least 10 years of complete data in the registry database. This new policy applies for any pending or newly requested changes in RD.

NCDB generates two main outcome measures, process and survival. In order to adequately assess survival outcomes, the NCDB needs complete follow up information. This new policy will provide for submission of a rolling 5 years of data with 60 months of follow up to the NCDB, and will result in more robust survival statistics.

Deficiencies within any cancer program standard must be resolved prior to submitting a reference date change request. RD changes may not be requested within six months before a scheduled survey or in the months of December and January during the preparations for and submission of the annual NCDB call for data.

Questions or concerns regarding processing of reference year changes should be e-mailed to Questions about reference dates or NCDB data submissions should be e-mailed to

New Programs

Because newly accredited programs must have one (1) year of complete data for accreditation purposes, new programs will be required to accumulate eleven (11) years of data in the registry database prior to requesting a change in RD. For example, a new program is that accredited with the RD of 01/01/2000 may not request a change in RD until they have the diagnosis years of 2000–2011 in their registry database.

Established Programs

Established individual programs will be assessed for their qualification to request a RD change based on 2 factors: the date of their last change in RD, and how many years of data are in their registry database. If a program has not requested a RD change in over five (5) years but requests a new RD that would result in less than 10 years in the registry database this request will be denied, and a new RD that takes into account the 10-year rule will be suggested. Example, current RD of the program is 01/01/1995, established in the calendar year of 2010. This program cannot request a RD change until the calendar year of 2015, and the latest RD that may be requested at that time would be 01/01/2003 (registry database includes complete data for diagnosis years of 2003–2013). If the Program requests a RD change to a diagnosis year later than 2003, the requested RD will need to be revised to 01/01/2003 prior to approval.

New Program Mergers

When two or more programs merge into a single entity, the RD for each of the individual programs is preserved or a new one assigned. For the merged entity the RD that will be assigned is the earliest RD of the individual programs to be merged if all are accredited, the earliest accredited program’s RD, or the merged program may choose to select a new RD.

The RD change policy for merged programs differs slightly from that for established individual programs in that the 10-year rule is applied from the earliest RD (diagnosis year) that all of the programs have in common. For example, two programs are merging in the calendar year of 2015, one with an RD of 01/01/2000 the other with a RD of 01/01/1993. If the programs choose to keep these RDs then the newly merged entity would have data beginning with the diagnosis year of 2000 in common, and this would be the date to which the 10-year rule would be applied. The merged program would not be able to request a RD change until the calendar year of 2020 (five [5] years from 2015), at which time the latest RD that may be requested would be 01/01/2008 (registry database includes complete data for diagnosis years of 2008–2018).

New Program Networks

This policy is applied at the individual facility level for programs forming networks. See Established Programs above.

Download the Reference Date Application

General reference data questions may be sent to with “Reference Date” in the subject line.