Breast cancer survivors with good social support networks seem to live longer and to have a lower risk of their cancer returning, according to a new study.

In earlier research, the study’s lead author had found that women with few social ties before a breast cancer diagnosis were at an increased risk of death from the malignancy.

“I wanted to do this study in a large cohort of women to try and replicate the findings I generated a decade ago,” said Candyce Kroenke, of Kaiser Permanent Northern California Division of Research in Oakland.

For the new study, published December 12th in Cancer, the researchers analyzed data collected from 9,267 women in the United States and China within two years of their breast cancer diagnosis.

In addition to other information about the women, the researchers had data on their relationships with spouses and friends and their ties to religion, society and community.

Altogether, over about 11 years, there were 1,448 recurrences of breast cancer and 1,521 deaths, including 990 deaths due to breast cancer.

Women with few social connections had a 43 percent higher risk of breast cancer returning, compared to well-connected women, the researchers found.

Similarly, isolated women were 64 percent more likely to die from breast cancer and 69 percent more likely to die of any cause during the course of the study, compared to their counterparts with many social ties.

The links between social isolation and poor outcomes were strongest among women without advanced cancers.

Kroenke said the types of relationships that appeared to be important to women’s health varied.

For example, not having a spouse or partner and having few community ties was associated with an increased risk of death from breast cancer among older white women, but not other women.

The study can’t say why large social networks may help protect women’s health. Kroenke said it could be related to a number of factors, including lifestyle, social support and physiology.

“It’s something we’re hoping to explore in the future,” she said.

Doctors are increasingly recognizing social determinants of health are important, said Kroenke. They should be aware of women’s social ties and support, and whether there is something clinically that can be done to support patients.

“Women who are going through breast cancer should get the support they need and ask for help,” she said.