Married adults present lower cancer rates than those who never married, according to a large-scale U.S. Study analyzing over 4 million cancer cases.
The research, conducted by scientists at the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine, found that individuals who never married had significantly higher incidence rates across multiple cancer types, particularly those preventable through lifestyle changes or screening.
After adjusting for age, sex, and race, the study published in Cancer Research Communications revealed that never-married men faced a 68% higher risk of cancer compared to married, divorced, or widowed men, while never-married women faced an 85% higher risk.
The analysis drew from a database covering over 100 million people, focusing on malignant cancer cases in adults aged 30 and older across 12 U.S. States between 2015 and 2022. Never-married individuals made up approximately 20% of the study cohort.
Researchers emphasized that the findings do not imply marriage itself prevents cancer, nor should marriage be promoted as a health intervention. Instead, they suggest marital status may serve as a demographic indicator for underlying risk factors.
“These results indicate that social factors like marital status could be important markers for population-level cancer risk,” said Paulo Beirão, lead researcher and cancer epidemiologist at the center.
Frank Benedetto, deputy director of population sciences, added that unmarried individuals should prioritize preventive care: “If someone is not married, it becomes even more important to monitor cancer risk factors, adhere to regular screenings, and engage in preventive healthcare.”
For more on this story, see Study: Marriage Linked to Lower Risk of Cancer.
A separate study from Lund University in Sweden, involving over 1.1 million men who became first-time fathers between 1994 and 2014, found that men with severely reduced fertility faced elevated risks for specific cancers later in life.
Men lacking spermatozoa entirely were at highest risk for serious health issues, while those with normal sperm quality tended to live longer. Compared to peers, men who conceived via intracytoplasmic sperm injection (ICSI) due to severe infertility had nearly double the risk of colorectal cancer and triple the risk of thyroid cancer.
Researchers attributed these links to a combination of genetic factors and lifestyle influences, noting that genetic abnormalities affecting sperm quality may impact other bodily systems. Epigenetic factors tied to environment and behavior — including obesity, smoking, and physical inactivity — likewise played a significant role.
Does marriage directly reduce cancer risk?
No. Researchers explicitly state the study does not show that marriage prevents cancer or recommend marriage as a preventive health strategy.
Which cancers showed the strongest links to marital status in the U.S. Study?
The study highlighted increased risk for preventable cancers, such as those linked to smoking and infectious agents, though it did not specify exact cancer types beyond this general category.
What explains the cancer risk among men with infertility?
Researchers suggest a combination of genetic factors affecting sperm quality and lifestyle influences like obesity, smoking, and lack of physical activity may contribute to increased cancer risk in men with severe infertility.