A study of more than 730 000 people who were diagnosed with any one of 10 different cancers between 2004 and 2008, is one of the largest ever to look at the link between marital status and health.
Researchers found a strong tie between tying the knot and clearing cancer.
Married people in the study were 20% less likely than people who were single, widowed or divorced to die of the disease. They were also more likely to catch their cancer at an early stage and to get appropriate treatment for their disease.
"We were really surprised by the results, how profound a difference it was," said study author Dr Ayal Aizer, chief resident of Harvard University's radiation oncology programme, in Boston. In some cases, the benefit associated with marriage was bigger than the benefit seen from medical treatment.
"For half of the cancers we looked at, the benefit of marriage was greater than the benefit conferred by chemotherapy in terms of improving survival," Aizer said.
Marriage good for health
The benefits of marriage appeared to be more pronounced for men than women. Married men were 23% less likely than bachelors to die of cancer, while married women were around 16% more likely than single women to beat the disease.
The reason? Probably prodding by the partner. Men, even physicians, are reluctant to get exams when symptoms surface.
"In my own personal relationship, my wife has been a key driver of getting me to the doctor on a regular basis," Aizer admitted.
But the study, which was published online in the Journal of Clinical Oncology, doesn't prove that marriage vows are the sole reason that some people beat cancer while others do not. The study only uncovered an association between marriage and better results, not cause-and-effect.
And researchers weren't able to look at whether the quality of a person's marriage played a role in how they battled back cancer.
Other studies that have taken marital quality into account have found that unhappy marriages are also unhealthy ones, said Leslie Schover, a clinical psychologist at M.D. Anderson Cancer Center, in Houston.
"It isn't quite as cut-and-dried as they make it sound," said Schover, who wasn't involved in the research.
"I think it's reasonable to say that for many people, being married is something that helps them take care of their health," she added.
Other experts agree, saying it's more likely that marriage is a stand-in measure for the kind of crucial support people can receive from close personal relationships.
"It can make a huge difference if someone is there for you during stressful periods like chemotherapy or radiation treatments," said Janice Kiecolt-Glaser, a professor of psychology and psychiatry at Ohio State University who studies the impact of marriage on health.
"The success of those treatments is dependent in part on successful completion, and support makes people more likely to adhere to medical advice and finish the treatment as they should," Kiecolt-Glaser said.
For more information on marriage and health, head to the U.S. Centers for Disease Control and Prevention.