Cancer is the leading cause of death globally, accounting for one in six deaths worldwide in 2020, according to the World Health Organization. Marital status has been frequently associated with cancer diagnosis, with studies finding that married individuals were more likely to be diagnosed earlier and have an increased chance of survival. However, less is known about the relationship between marriage and risk of cancer development, with the few studies that have assessed this relationship being outdated or focusing on small, regional populations. In research published in April 2026 in Cancer Research Communications, Paulo Pinheiro and colleagues utilised data from a large-scale, population-based data source for the US, known as the Surveillance, Epidemiology, and End Results (SEER) programme, to assess the risk of cancer development depending on marital status. Never-married adults had statistically significantly higher risks of cancer development compared to adults who have ever been previously married, with never-married men having a 68% higher risk of cancer, and women having a 85% increased risk.
To observe the effects of marital status and the risk of cancer, this study analysed data for 2015–2022 from 12 SEER participating states (California, Connecticut, Georgia, Hawaii, Idaho, Iowa, Kentucky, Louisiana, New Jersey, New Mexico, New York, and Utah) that provided individual-level data on marital status. Marital status was classified as either never-married or ever-married, with the ever-married group including those who were married, separated, divorced, or widowed. The SEER Research Plus 17-Registries database was used to derive incidence estimates of those aged 30 years and older who were diagnosed with cancer, as well as information on age, sex, race/ethnicity, tumour stage, and cancer site. Between 2015 and 2022, more than 62 million individuals aged 30 years and over were included in the study on average annually, with more than four million cancer cases being diagnosed. Across all cancer sites and both sexes, never-married individuals had higher risks of cancer development compared to ever-married individuals, with never-married men and women having 68% and 85% increased risks of cancer compared to ever-married men and women, respectively. Risk of cancer development by marital status also varied with cancer type, with the strongest associations being observed in anal (5-times and 2.5-times increased risk in never-married men and women, respectively), oesophageal (2.4-times and 2.7-times increased risk in never-married men and women), and cervical cancers (2.6-times increased risk in never-married women).
This study by Pinheiro and colleagues provides evidence that marriage acts as a protective factor against cancer, likely due to its influence on multiple factors already known to impact cancer incidence, including sexual behaviour, parity, and alcohol/tobacco use. For example, anal and cervical cancers are both human papillomavirus (HPV)-related cancers. However, further research is required to assess the validity of these findings. GlobalData epidemiologists forecast that in the US, diagnosed incident cases of HPV-associated anal cancer in men and women of all ages will increase from 6,700 cases in 2026 to 6,900 cases in 2029. Additionally, GlobalData epidemiologists forecast that in the US, diagnosed incident cases of locally advanced cervical cancer in women aged 18 years and older will increase from 7,300 cases in 2026 to 7,600 cases in 2030.
