Researchers at Penn State's College of Medicine and Brigham Young University analysed records of 127,753 patients and found that those married had a 14 per cent lower risk of death.
Similar to studies of other types of cancers, the researchers did find that married people were diagnosed at earlier stages of colon cancer and sought more aggressive treatment.
The researchers took those and other factors into account before calculating the benefit of marriage on survival odds.
"Controlling for the stage that the cancer was detected is key. Without that, it's hard to know whether the analysis is just picking up a diagnosis effect," Sven Wilson, a study co-author and professor at Brigham Young University, said.
Colon cancer is the fourth most common type of cancer in the United States for both men and women. Curiously, the marriage benefit seen in the new study was nearly identical for both men and women.
Marriage is a self-selected group, and Wilson is careful to note that the selection process makes it difficult to sort out the root cause.
One intuitive idea is that spouses serve as an important informal caregiver during a critical time, and that extra support may translate into better disease management and, hence, better outcomes.
The study has been published online in the journal Cancer Epidemiology .
