Dr. Oxana Palesh, research assistant professor of Radiation Oncology and Psychiatry at the James P. Wilmot Cancer Center, says that women who face physical or sexual abuse or life-threatening situations see metastatic tumours return after about 2.5 years, as compared to women who have more peaceful lives, who see recurrence at about five years.
While some of the reported events are less common than others, the scientists say that they all take a toll on the women. They believe that such events might have contributed to the recurrence of disease.
"There is such a dramatic difference between women who had experienced traumatic things and those who didn't. Clearly this study demonstrates that it's important to recover from trauma or stressful event for your mental and physical health." Oxana Palesh said.
Earlier studies had shown that stress could alter the immune system's function, and that the activity of natural killer cells was linked to breast cancer progression.
In the recent study, the team interviewed 94 women categorizing them into three different groups on the basis of their life experiences as traumatic, stressful and peaceful. Childhood sexual abuses, rape, suicide of a family member or life-threatening injury were reported as traumatic experiences by the participants.
Stressful events included adoption, parent's death, living with their mother-in-law, earthquake, divorce or having a family member imprisoned.
From the study groups, 39 women reported traumatic events in their past, and the median disease-free interval was 2.5 years; 27 women who had experienced stressful situations, the interval was of 37 months. Among the 28 women who reported no stress or trauma in their past, the median disease-free interval was 62 months.
All of the women were diagnosed in their late 40s. Analysis showed that 69 percent were married, and 19 of the women were divorced or widowed in the stressed and traumatic groups.
"Extended periods of stress and trauma and its resulting cortisol production may interfere with the body's ability to fight off cancer progression. When there is consistent, long-term stress in the body, the elevated cortisol level may can change the body's normal rhythms and potentially reduce resistance to tumour growth," Palesh said.
The report is published in the Journal of Psychosomatic Research.