They also have fewer adverse reactions to cancer treatments such as chemotherapy, say researchers who analysed all published studies about spirituality and cancer, which involved more than 40,000 patients.
It was a belief in a divine, and benevolent, force that made the difference, rather than social aspects of religion, such as going to church.
Those with a deep religious or spiritual belief suffered fewer symptoms than non-believers, researchers at the Moffitt Cancer Centre in Florida discovered. They also reported enjoying better physical health, and were better able to carry out daily tasks.
In a second analysis that looked at the patients' mental well-being, researchers discovered that patients with a spiritual belief were less anxious, depressed or distressed.
The third analysis explored social well-being, and, again, those with a spiritual belief maintained a more active social life and continued to see friends and family.
(Source: Cancer, 2015; doi: 10.1002/cncr.29353, 29352 and 29350)