Never-married adults face a significantly higher risk of developing cancer compared to those who have been married, according to a massive U.S. population-based study published on Wednesday.
The research, appearing in the journal Cancer Research Communications, found that never-married men have a 68% higher cancer incidence rate than their “ever-married” counterparts, a group that includes those who are currently married, divorced, or widowed. The disparity was even more pronounced for women, with never-married females showing an 83% higher risk.
The study analyzed data from 2015 to 2022, covering more than 62 million people across 12 U.S. states. Researchers noted that the protective association of marriage was observed across almost all major cancer sites and racial groups.
The findings suggest that marriage serves as a structural determinant of health, influencing risk through cumulative social and behavioral pathways. The strongest associations were found in cancers linked to lifestyle factors and infections:
Anal cancer in men was five times more likely among the never-married.
Cervical cancer in women was nearly three times more likely among those who never married.
Significant disparities were also recorded for lung, esophageal, and liver cancers, which are frequently tied to tobacco and alcohol use.
Dr. Paulo S. Pinheiro, lead author and epidemiologist at the University of Miami Health System, noted that married individuals often benefit from increased social support, healthier habits, and better access to preventive care.
Conversely, those who are unmarried and more isolated may be less likely to engage in regular cancer screenings.
The study challenged long-standing assumptions that marriage benefits men more than women, finding instead that it is a major social stratifier of risk for both sexes.
The data also revealed a striking trend among Black Americans. While never-married Black men had the highest cancer rates of any group studied, married Black men had lower incidence rates than married White men. Experts suggested this may be due to the strong role of spousal support in encouraging early medical evaluation.
While the correlation is strong, researchers and outside experts cautioned that the “marriage benefit” may be partially driven by other factors. Some individuals may be “selected” into marriage because they already possess better baseline health, higher income, or more stable social integration.
Dr. Joan DelFattore, a scholar who has written extensively on marital status and healthcare, argued that the results might also reflect systemic rewards for marriage. She pointed out that many insurance plans prioritize spouses and some doctors may hold unconscious biases, assuming single patients lack the support systems necessary for aggressive treatment.
As U.S. marriage rates continue to decline, the study authors warned that never-married adults represent an increasingly large and potentially vulnerable population that may require targeted public health interventions and enhanced screening efforts.