Social vulnerability is associated with increased mortality in older patients with cancer

•Social vulnerability, although reported to complicate treatment decision making in real world practice, has received scant attention in old age patients with cancer so far.•Growing evidence indicates that social vulnerability may affect the completion of adjuvant therapies, compliance and both social isolation and perceived deprivation status may modulate the immunoendocrinological response to cancer, affecting clinical outcomes.•Social vulnerability was associated with one -year mortality in a real world old age patients with heterogeneous solid cancers, even adjusted for age, gender and frailty (on the basis of the clinical accumulation model of Rockwood, 40 items).•The study, although preliminary in nature, moved a step forward in the understanding of the multidimensional nature of social support and of its magnitude in the prediction of long-term clinical outcomes in this highly vulnerable population.