Unmarried men are more likely to die from cancer regardless of their age or disease stage, according to a Norwegian study out Friday.

Researchers from the University of Oslo looked at cancer survival rates from patients diagnosed with the disease between 1970 and 2007 and compared this to their marital status.

They found that the death rates for men with cancer, who had never been married, almost doubled from 18 percent to 35 percent, while in unmarried women, it rose from 17 percent to 22 percent, compared to married patients.

The risk of mortality was greater for unmarried people regardless of age, education, site of tumor, time since diagnosis and cancer stage, according to the study.

"The differences in survival between unmarried and married people with cancer could possibly be explained by better general health at time of diagnosis or better adherence to treatment regimes and follow-ups," according to Astri Syse, from the Cancer Registry of Norway.

Researchers believe that the differences between couples and singletons could actually be much higher if data took into account cohabiting couples.

Hakon Kravdal, from the University of Oslo, said, "One problem with this kind of study is that cohabiting people are scattered throughout the never married, divorced/separated or widowed groups. Consequently, presuming co-habiters to have the same benefits as married couples, the actual differences between couples and singletons are probably much higher."