Prediagnostic self-assessed health and extent of social networks predict survival in older individuals with cancer: a population based cohort study.

Objectives: To assess the association between social networks on survival after cancer diagnosis in a population-based sample of elderly Israelis (>60 yo) living in the community in 1985 and followed for up to 20 years.

Materials And Methods: We conducted a historical prospective study, using baseline measurements from a 1985 survey of a representative sample of community-dwelling population. Five distinct social networks were defined using information regarding number and intensity of social contacts: traditional-family (reference category), friends and neighbors, narrow-family, diverse, and attenuated. Cancer was ascertained through the Israel Cancer Registry, and mortality through the Population Registry after 20 years of follow-up.

Results: The final study population included 676 participants diagnosed with cancer after 1985. Persons in the diverse network showed a lower risk of death (HR=0.74, 95% CI: 0.56-0.98) after adjusting for age, sex, smoking and self-assessed health. On the other hand, poor self-rated health at baseline (HR=1.39, 95% CI: 1.10-1.74 poor vs. all other categories of self-assessed health) was associated with increased risk of death. After excluding cancers amenable to early detection (breast, prostate, and colon) a borderline significant decreased risk of death following a diagnosis of cancer (HR=0.72, 95% CI: 0.52-1.01) was found.

Conclusion: There is evidence of a significant protective association between diverse social networks present before a cancer diagnosis and survival after the onset of disease. Social support from a variety of sources may be an important element in improving cancer survival in older individuals.