Overview of key data sources: cancer

The Scottish Cancer Registry has been collecting population-based information on cancer since 1958.  Details available for each case include personal, demographic and diagnosis information (site, histology, behaviour, histological confirmation, date and hospital of diagnosis).  For patients diagnosed from 1997 onwards further information has been collected including tumour stage (for breast, cervical and colorectal cancer), tumour grade, more hospital details, and treatment information (dates and locations of surgery, chemotherapy, radiotherapy and hormone therapy).  In 1997 the tumour-based database was converted into a patient-based database, and was named SOCRATES (Scottish Open Cancer Registration And Tumour Enumeration System).

Potentially new cases are identified from a number of sources, including hospital discharge records, pathology and oncology databases, and death records.  The information is linked using probability matching and a provisional registration created.  Cancer Registration Officers (CROs) visit the hospitals and pull the medical records for these provisional registrations and the registration is then either confirmed, in which case extra information is collected from the medical notes, or deleted.  The hospital visit does not occur until at least six months after the cancer diagnosis to allow treatment details to accumulate.

There are approximately 26,000 new diagnoses of malignant disease entered onto SOCRATES each year.  Studies of the data quality suggest this is very good, both in terms of accuracy and completeness of ascertainment.