The research will be published in the November 1, 2009 issue of Cancer, a peer-reviewed journal of the American Cancer Society.
According to the study's authors, the results suggest that the stress associated with marital separation may compromise an individual's immune system and lead to a greater susceptibility to cancer.
Research has shown that personal relationships have a significant role in physical health-specifically that good relationships are beneficial and poor relationships are deleterious.
Also, many studies of cancer prognosis have found that patients who are married live longer than those who are single. However, little information is available regarding differences in survival among the various types of people who are unmarried.
To look for trends in cancer survival among patients who are separated, divorced, widowed, and never married, researchers led by Gwen Sprehn, Ph.D., of the Indiana University School of Medicine in Indianapolis analyzed data from the Surveillance Epidemiology and End Results (SEER) database, a population-based cancer registry in the United States.
The researchers assessed the 5 and 10 year survival rates of 3.79 million patients diagnosed with cancer between 1973 and 2004.
They found that married patients had the highest 5 and 10 year survival rates, at 63.3 percent and 57.5 percent respectively. At the other end of the spectrum, separation carried the poorest survival outcome. Specifically, the 5 and 10 year survival rates for separated patients were 45.4 percent and 36.8 percent respectively.
The 5 and 10 year survival rates of widowed patients were the next lowest, at 47.2 percent and 40.9 percent respectively; for divorced patients, the respective survival rates were 52.4 percent and 45.6 percent; and for never married patients, they were 57.3 percent and 51.7 percent.
"Patients who are going through separation at the time of diagnosis may be a particularly vulnerable population for whom intervention could be prioritized," says Sprehn.
"Identification of relationship-related stress at time of diagnosis could lead to early interventions which might favorably impact survival. Ideally, future research will study marital status in more detail over time and also address individual differences in genetic profile and biomarkers related to stress, immune, and cancer pathways in order to determine mechanisms which might underlie this possible critical period for cancer pathogenesis," the expert added.