Background to the Cancer Outcomes and Services Dataset (COSD)

The National Cancer Dataset (NCDS) was revised in order to meet the current information requirements for the NHS. The Cancer Reform Strategy (2007) identified better information and stronger commissioning as two of the key drivers to achieve the goal that cancer services in this country should be amongst the best in the world. The subsequent Improving Outcomes: A Strategy for Cancer (January 2011) further supports this concept to demonstrate cancer outcomes using high quality data and intelligence for all stakeholders.

What is the COSD?

In January 2013 the COSD replaced the previous National Cancer Dataset as the new national standard for reporting cancer in the NHS in England. It incorporated a revised generic Cancer Registration Dataset (CRDS) and additional clinical and pathology site specific data items relevant to different tumour types.

The COSD specifies the items to be submitted electronically by service providers to the National Cancer Registration and Analysis Service (NCRAS) on a monthly basis. It replaces the existing monthly NCRS upload and may include separate files from different hospital systems.

The COSD also identifies the items that the NCRAS will obtain from other sources such as Cancer Waiting Times, Cancer Screening Programmes and ONS. (Some items from these other datasets will be included in COSD provider submissions for patient identification and record matching.)

Data is submitted by NHS Providers of Cancer Services and will linked with data from other sources by the NCRAS at patient level using NHS number, and tumour level (where there are multiple primary tumours diagnosed) in order to compile the full dataset.

The COSD was originally developed by the NCIN in collaboration with its Site-Specific Clinical Reference Groups and is now managed by Public Health England (PHE).

What is different from current data collection?

The COSD enables providers to send data from a variety of different systems, such as MDT (Multidisciplinary Team) software, PAS (Patient Administration Systems) and Pathology systems, to the NCRAS for compilation.

It is expected that the majority of the generic core and the new site-specific clinical data items will be submitted from MDT software systems. Pathology reports for suspected and confirmed cancer should continue to be submitted directly to the NCRAS and may be used by the NCRAS to extract the relevant pathology items for COSD where no structured reports are currently available. Other items may be recorded in PAS or Radiology Information Systems (RIS) and separate extracts may be submitted from these systems too.

COSD is aligned with, and shares data items with, other related datasets such as Cancer Waiting Times (NCWTMDS), Radiotherapy (RTDS), Systemic Anti-Cancer Therapy Dataset (SACT), the Diagnostic Imaging Dataset (DID) and the national clinical audits. The separate submissions of these datasets are not affected by the COSD standard.


The standard has been mandated since the 1st January 2013 and applies to all new diagnoses of cancer and all diagnoses of secondary or metastatic breast cancer from that date. All relevant data items within COSD should be submitted within 25 working days of the month of diagnosis or of treatment.

There has been a phased approach to its implementation. Further information on this approach is included in the specification and guidance documents.

The Information Standards Notice (DCB1521) which covers these changes is available on the NHS Digital website along with a number of additional documentation, including a revised specification and change request paper. The new version of the COSD Dataset and accompanying User Guides, as well as details of how to request the new XML Schema are available via the Downloads webpage.