Could social isolation impact survival in breast cancer patients?

A new study has demonstrated that socially isolated breast cancer patient have increased risk of cancer recurrence and higher mortality rates compared with patients who have larger social networks. The researchers suggested social isolation could be used as a prognostic factor and should be taken into consideration by clinicians.

The findings, published recently in Cancer, reported that breast cancer patients with larger social networks had better outcomes; however, different demographics of women benefited from different types of relationships.

The research group from the Kaiser Permanente Division of Research (CA, USA) examined data regarding 9267 women from the After Breast Cancer Pooling Project collected within approximately 2 years after their diagnosis. The team analyzed information on these individuals with the aim of assessing the impact of social networks on their survival outcomes.

Over a median follow- up of 10.6 years, the team observed 1448 cancer recurrences and 1521 deaths, 990 of which were attributed to breast cancer. They demonstrated that compared with socially integrated patients, socially isolated patients had a 40% higher risk of recurrence and a 60% higher risk of death from breast cancer. In addition, the researchers discovered that associations between social networks and survival appeared to be stronger in those with stage I and stage II cancer.

The scientists demonstrated that certain types of social ties were more beneficial in certain demographic groups. For example, the presence of a spouse correlated with lower breast cancer-specific mortality in older Caucasian women. By contrast, ties to relatives and friends predicted better outcomes in women who were not of Caucasian descent.

Lead author Candyce Kroenke (Kaiser Permanente Division of Research) commented: “It is well established that larger social networks predict lower overall mortality in healthy populations and in breast cancer patients, but associations with breast cancer-specific outcomes like recurrence and breast cancer mortality have been mixed.”

“These findings, from a large pooled cohort of nearly 10,000 women with breast cancer, confirm the generally beneficial influence of women’s social ties on breast cancer recurrence and mortality; however, they also point to complexity, that not all social ties are beneficial, and not in all women,” she continued.

Although different demographics of women benefited from different types of relationships, this study demonstrates that breast cancer outcomes appear to be improved in socially integrated women. Additional research is required in order to understand the mechanisms through which social networks influence outcomes and to investigate potential interventions; however, the researchers suggested that clinicians should assess information on social networks as a marker of prognosis in breast cancer patients.

Sources: Krownke CH, Michael YL, Poole EM et al. Postdiagnosis social networks and breast cancer mortality in the After Breast Cancer Pooling Project. Cancer. doi: 10.1002/cncr.30440 (2016) (Epub ahead of print); http://eu.wiley.com/WileyCDA/PressRelease/pressReleaseId-130042.html