Adults who remain single have significantly higher risk of developing cancer, finds study

Background of this study included a comprehensive review of Surveillance, Epidemiology, and End Results (SEER) database in 12 states in the United States, examining only adults 30 years and older from 2015 to 2022. Although many studies have already demonstrated the benefits of marriage to health outcomes, such as early diagnosis and higher survival rates, the authors chose to explore the role of marriage on "incidence", the risk of getting the disease. Using the never-married group as a comparison, and controlling for age and race/ethnicity, the authors found a statistically significant protective effect of marriage throughout the analysis period.

Key findings:

• Findings indicate that the "marriage gap" phenomenon exists in all racial and ethnic groups examined in the paper, although it is present at different intensities.

• Specifically, the rate was relatively higher in the case of never married individuals, and the Incidence Rate Ratio (IRR) ratio stood at 1.68 for males and 1.85 for females.

• The findings indicated that never-married women demonstrated a tendency to develop cancers almost twice as often as ever-married individuals, while the risk of developing cancer was between 1.62 IRR in white males and 1.96 IRR in black men.

• Notably, the paper reports an exceptional case in the context of the relationship between race and marriage status when considering cancer risks.

• Specifically, while never-married black men demonstrate the highest incidence rates across all groups, ever-married black men show even lower risks of developing cancers in comparison to ever-married white men.

• For instance, the probability of anal cancer development is fivefold among never-married men in comparison to their ever-married peers, while the same pattern is evident when speaking about the risk of cervical cancer in the latter group.

The state of marital status is a significant predictor of cancer risk in the United States as evidenced by the findings showing that ever-married individuals have a reduced risk as compared to their never-married counterparts. As revealed by the study, the benefit associated with being married applies to most cancer locations as well as almost all races despite having an especially clear impact on the risk of behavioral/environmental cancers. Despite a possible selection bias that causes healthier people to be more likely to get into relationships, the size of the hazard ratios indicates that there is a practical protection offered by the social and behavioral environment of marriage in terms of reducing the risk of cancer.

Reference:

Pinheiro, P. S., Balda, A. N., Cranford, H. M., Crane, T. E., Kobetz, E. N., & Penedo, F. J. (2026). Marriage and Cancer Risk: A Contemporary Population-Based Study Across Demographic Groups and Cancer Types. Cancer research communications, 6(4), 783–791. https://doi.org/10.1158/2767-9764.CRC-25-0814