The study, by researchers from Kaiser Permanente in US, is among the first to examine exactly how social relationships influence quality of life in breast cancer patients.
It also found that tangible support (such as help with household tasks and errands) was most useful to those with late-stage cancer.
"This study provides research-based evidence that social support helps with physical symptoms. Social support mechanisms matter in terms of physical outcomes," said lead author Candyce H Kroenke, staff scientist with the Kaiser Permanente Division of Research.
Part of the Pathways study of breast cancer survivorship at the Kaiser Permanente Division of Research, the study included 3,139 female members of Kaiser Permanente in Northern California who were newly diagnosed with breast cancer between 2006 and 2011.
Within about two months of their breast cancer diagnosis, study participants answered several detailed questionnaires on their social networks (including friends and relatives, spouse/intimate relationships, and religious, social and community ties).
Women with the highest levels of social integration - the largest social networks, or the personal relationships that surround an individual - were most likely to report the best overall quality of life during breast cancer treatment, and higher levels of social support were also related to better emotional quality of life.
Moreover, of the different types of social support, positive social interaction, defined as the availability of other persons to do fun things, was the most important predictor of physical quality of life.
The study was published in Breast Cancer Research and Treatment journal.
