Studies of breast cancer survivors by Division of Research scientists showed lower risks of disease recurrence and mortality among women higher levels of vitamin D in their blood, as well as those with more social ties.
The first study, published in JAMA Oncology, found that women with higher vitamin D levels in their blood following a breast cancer diagnosis had significantly better long-term outcomes.
“We found that women with the highest levels of vitamin D levels had about a 30 percent better likelihood of survival than women with the lowest levels of vitamin D,” said Lawrence H. Kushi, ScD, senior research scientist and principal investigator of Kaiser Permanente’s Pathways study of breast cancer survivorship. The current study included 1,666 Pathways study members who provided samples between 2006 and 2013.
Although the study did not examine the effects of vitamin D intake from foods versus supplements, Kushi noted that the study supports the recommended daily levels of vitamin D (600 IU for those 1 to 70 years old and pregnant or breastfeeding women, and 800 IU for those over 71 years old).
The second study, published in the American Cancer Society journal Cancer, found that women with invasive breast cancer who were socially isolated were significantly more like to die from breast cancer or have a disease recurrence than socially integrated women.
This is believed to be the largest study to date of social networks — the web of personal relationships that surround an individual — and breast cancer survival. Funded by the National Cancer Institute, the study included 9,267 women diagnosed with stages 1 to 4 invasive breast cancer enrolled in the After Breast Cancer Pooling Project, a pooled cohort of four studies of women with breast cancer, including one conducted at Kaiser Permanente Northern California.
Within two years of a breast cancer diagnosis, women answered surveys about their personal relationships and social networks, including spouses or partners; religious, community and friendship ties; and the number of first-degree, living relatives. They were followed for up to 20 years.
Socially isolated women in this study were 43 percent more likely than socially integrated women to have a recurrence of breast cancer, 64 percent more likely to die from breast cancer, and 69 percent more likely to die from any cause.
Candyce H. Kroenke, ScD, MPH, research scientist and lead author, noted that not all types of social ties were beneficial to all women. “Ultimately, this research may be able to help doctors tailor clinical interventions regarding social support for breast cancer patients based on the particular needs of women in different sociodemographic groups,” Kroenke said.