A woman is six times more likely to be separated or divorced soon after a diagnosis of cancer or multiple sclerosis than if a man in the relationship is the patient, according to a study that examined the role gender played in so-called "partner abandonment." The study also found that the longer the marriage the more likely it would remain intact.

The study confirmed earlier research that put the overall divorce or separation rate among cancer patients at 11.6 percent, similar to the population as a whole. However, researchers were surprised by the difference in separation and divorce rates by gender. The rate when the woman was the patient was 20.8 percent compared to 2.9 percent when the man was the patient.

"Female gender was the strongest predictor of separation or divorce in each of the patient groups we studied," said Marc Chamberlain, M.D., a co-corresponding author and director of the neuro-oncology program at the Seattle Cancer Care Alliance (SCCA). Chamberlain is also a professor of neurology and neurosurgery at the University of Washington School of Medicine.

The study, "Gender Disparity in the Rate of Partner Abandonment in Patients with Serious Medical Illness," was published in the Nov. 15 issue of the journal Cancer. The other corresponding author is Michael Glanz, M.D., of the Huntsman Cancer Institute at the University of Utah School of Medicine.

Why men leave a sick spouse can be partly explained by their lack of ability, compared to women, to make more rapid commitments to being caregivers to a sick partner and women's better ability to assume the burdens of maintaining a home and family, the study authors said.

Researchers at three medical centers -- the SCCA, Huntsman and Stanford University School of Medicine -- enrolled a total of 515 patients in 2001 and 2002 and followed them until February 2006. The men and women were in three diagnostic groups: those with a malignant primary brain tumor (214 patients), those with a solid tumor with no central nervous system involvement (193 patients) and those with multiple sclerosis (108 patients). Almost half of the patients were women.

Chamberlain said the study was initiated because doctors noticed that in their neuro-oncology practices, divorce occurred almost exclusively when the wife was the patient. The researchers enrolled groups of patients with other cancers and with multiple sclerosis to separate the impact of oncologic versus neurological disease. The results showed a stronger gender disparity for divorce when the wife was the patient in the general oncology and multiple sclerosis groups (93 percent and 96 percent respectively, compared to 78 percent for the primary brain tumor group).

The study also found correlations between age and length of marriage and the likelihood of divorce or separation. The older the woman was the more likely her partnership would end. However, longer marriages remained more stable.

Researchers also measured some health and quality of life outcomes among the patients who separated or divorced. They found that patients used more antidepressants, participated less in clinical trials, had more frequent hospitalizations, were less likely to complete radiation therapy and more likely not to die at home, according to the study.

"We believe that our findings apply generally to patients with life-altering medical illness," the authors wrote. "We recommend that medical providers be especially sensitive to early suggestions of marital discord in couples affected by the occurrence of a serious medical illness, especially when the woman is the affected spouse and it occurs early in the marriage. Early identification and psychosocial intervention might reduce the frequency of divorce and separation, and in turn improve quality of life and quality of care."