Women with breast cancer who are happily married have a better chance of survival than those in unhappy relationships, according to scientists.
Previous research has shown women with larger social networks are more likely to survive the disease. Now a new study has found the quality of a woman's personal relationships are just as important as how many people she interacts with.
A team from the Kaiser Permanente Division of Research in California studied 2,264 women who were diagnosed with early-stage, invasive breast cancer between 1997 and 2000.
After providing information on their personal relationships, they were characterised as socially isolated - few ties, moderately integrated, or socially integrated, with many ties.
Study leader Candyce Kroenke, said: 'We found that women with small social networks had a significantly higher risk of mortality than those with large networks.'
The study found that socially isolated women were 34 per cent more likely to die from breast cancer or other causes than socially integrated women.
However, the quality of relationships also mattered. Women with a small group of unsupportive family and friends were 61 per cent more likely to die from cancer than those with a few highly-supportive supporters, according to the scientists.
Researchers measured levels of social support from friends and family using a survey that asked women to rate the quality of their relationships on a five-point scale within the past week.
For example, the questions included, 'My family has accepted my illness,' 'family communication about my illness is poor,' and 'I feel distant from my friends.'
Based on their survey results, the women were additionally characterised as having high or low levels of social support.
The study found levels of support within relationships were important risk factors for breast cancer mortality.
Dr Kroenke added: 'Women with small networks and high levels of support were not at greater risk than those with large networks, but those with small networks and low levels of support were.
'We also found that when family relationships were less supportive, community and religious ties were critical to survival.
'This suggests that both the quality of relationships, rather than just the size of the network, matters to survival, and that community relationships matter when relationships with friends and family are less supportive.'
Dr Kroenke said the study suggests that interventions designed to help women with breast cancer improve the quality of their relationships could have an impact on breast cancer outcomes, adding: 'Women in the study also gained health advantages from developing community and religious ties.'
The findings were published in the journal of Breast Cancer Research and Treatment.