Background/Aim & Objectives
Recruitment to the Forgotten Cancers Project (FCP) is based on self-reported diagnosis of less common cancers. This preliminary analysis examines the level of agreement between self-reported cancer type and verified diagnoses.
Method
Victorian FCP participants’ self-reported diagnoses, to June 2014, were linked with cancer registrations at the Victorian Cancer Registry (VCR).
Results
469 participants, reporting 544 cancers were linked with the VCR. There was a high degree of agreement between self-reported diagnoses and those recorded at the registry with 76% of tumours showing exact agreement. Of these, 436(98%) were invasive or in-situ cancers and for 87%, the date of diagnosis reported by the participant and that recorded by the VCR was within 12 months.
An additional, small proportion (6.2%) of cancers showed some minor misclassification, most commonly involving incorrect assignment to adjacent organs (e.g. stomach/oesophagus). 6.4% of tumours were reported by the participant were not located on the registry and 28 people (5%) were not able to be matched. An additional 34 tumours found on the registry were not reported by the participant.
Conclusion
Incorrect enrolment in the study would be wasteful of both participants’ time and limited research resources. It is reassuring that the majority of people enrolling in the study are eligible. The results also provide insight into the nature of misclassification in self-reported cancer diagnoses.
Key message
These findings suggest that epidemiological studies based on unverified cancer diagnoses can have confidence in a high level of accuracy in self-reported diagnoses.