The primary endpoints for the Golden Retriever Lifetime Study are four cancers common among golden retrievers: lymphoma, osteosarcoma, hemangiosarcoma and high grade mast cell tumors. The size of the study was based on the anticipated number of each of these cancers.
During the first few years of the study, the incident rate for each of the four primary cancers was below original projections. However, as the study has progressed, the rate of diagnosis has increased and the gap between the projections and actual diagnoses has narrowed.
Most deaths of participating dogs as of January, 2018, have been for causes other than the primary cancers, as shown in the graph below.
Causes of Death as of January 2018