Aims
A cancer diagnosis may prompt health behaviour change, but such change may extend beyond the individual to family, friends, and social networks. Social proximity to cancer, defined here as personal diagnosis, or diagnosis of a family member, friend, or someone in one's broader social circle, may be associated with health behaviours and psychological outcomes, yet this remains understudied.
Methods
Data were drawn from the 2023 South Australian Population Health Survey, a cross-sectional telephone survey of 3,004 residents aged ≥15 years. The primary exposure was social proximity to a recent (12 months) cancer diagnosis (self, someone close, social circle, or none). Outcomes included diet, alcohol, smoking, sun protection, screening, skin checks, distress, and food insecurity. Logistic regression assessed adjusted associations, controlling for demographic and socioeconomic covariates.
Results
Cancer proximity was associated with vegetable intake, alcohol, distress, screening, skin checks, and sun protection, but not fruit intake, sugar-sweetened beverages, or food insecurity. A close contact diagnosis was associated with higher odds of exceeding alcohol guidelines (OR=1.70, p<.001), moderate-to-severe (OR=2.05, p<.001) and severe distress (OR=2.38, p=.001), and meeting vegetable guidelines (OR=1.87, p<.001), while a personal diagnosis was associated with lower odds of meeting vegetable guidelines (OR=0.35, p=.046), despite the strongest screening (OR=2.87, p<.001) and skin check engagement (OR=2.74, p<.001). Broader social circle proximity was linked to increased sun protection (OR=1.57, p<.001).
Conclusions
Social proximity to a cancer diagnosis was associated with both beneficial and adverse outcomes, varying by proximity to the person diagnosed. A proximal cancer diagnosis may represent a window of opportunity, prompting behaviour change in those close to the person diagnosed, not only the patient. Targeted support and messaging strategies that leverage this period of heightened engagement could extend prevention, education, and psychosocial support beyond patients to family, friends, and broader social networks.