Purpose: To investigate the association between cohabitation status, clinical stage at diagnosis, and disease-specific survival in cutaneous malignant melanoma (CMM).
Methods: This nationwide population-based study included 27,235 patients from the Swedish Melanoma Register diagnosed with a primary invasive CMM between 1990 and 2007 and linked data to nationwide, population-based registers followed up through 2012.
Results: After adjustment for age at diagnosis, level of education, living area, period of diagnosis, and tumor site, the odds ratios (ORs) of higher stage at diagnosis were significantly increased among men living alone versus men living with a partner (stage II v stage I: OR, 1.42; 95% CI, 1.29 to 1.57; stage III or IV v stage I: OR, 1.43; 95% CI, 1.14 to 1.79). The OR for stage II versus stage I disease was also increased among women living alone (OR, 1.15; 95% CI, 1.04 to 1.28). After adjustments for the factors listed earlier, the CMM-specific survival was significantly decreased among men living alone (hazard ratio [HR] for death, 1.48; 95% CI, 1.33 to 1.65; P < .001). After additional adjustments for all potential and established prognostic factors, CMM-specific survival among men living alone versus men living with a partner remained significantly decreased (HR, 1.31; 95% CI, 1.18 to 1.46; P < .001), suggesting a residual adverse effect on survival not accounted for by these parameters.
Conclusion: In all age groups among men, living alone is significantly associated with reduced CMM-specific survival, partially attributed to a more advanced stage at diagnosis. This emphasizes the need for improved prevention and early detection strategies for this group.