Emerging evidence suggests cancer survivors suffer impairments in health and wellbeing that pre-date their diagnosis. This study prospectively examine changes from 4-6y pre-diagnosis to 0-2y post-diagnosis. Data were from 477 cancer survivors and 5,451 cancer-free comparisons participating in the English Longitudinal Study of Ageing. We examined group-by-time interactions for self-rated health, quality of life (QoL), depression, life satisfaction and impairments in mobility, activities of daily living (ADLs) and instrumental ADLs (IADLs). All health and wellbeing markers worsened over time in both groups. A greater decline in cancer survivors' self-rated health was evident as early as 2-4y pre-diagnosis (p<.001). Around diagnosis, there were greater declines in IADL impairment (p<.001), QoL (p<.001), and depression (p<.001) in cancer survivors than controls. Mobility and ADL impairments were consistently more prevalent among cancer survivors (p<.001) and life satisfaction was consistently lower (p=.004), but the rate of change over time did not differ significantly between groups. These results suggest there may be early signs of deterioration in perceived health that precede development of symptoms leading to cancer diagnosis by many years. Some of the impaired wellbeing in cancer patients may be long-standing, while other changes are more acute and may require targeted support following diagnosis.