To examine the extent to which epididymo-orchitis or urinary tract infections (UTI) may precede testicular cancer (TC) in Sweden.
We conducted a nationwide, open-cohort study including 8 382 433 men between 1964 and 2018. Standardised incidence ratios (SIR) with 95% CIs were calculated to compare TC incidence rates in men diagnosed with epididymo-orchitis or UTI-either in the same calendar year as TC or in preceding calendar years (mean follow-up: 6.85 years, ±8.31 SD)-with those in men without these infections. Analyses were controlled for potential confounders and a sensitivity analysis on cystitis was also conducted.
A total of 11 903 men were diagnosed with TC during the study period; of these, 400 (3.36%) had been diagnosed with epididymo-orchitis and 122 (1.02%) with UTI. The TC incidence rate per 100 000 person-years was 5.09 (95% CI 4.99 to 5.18) for the entire study period and increased from 2.84 (2.68 to 3.02) in 1964-1973 to 8.37 (7.99 to 8.77) in 2014-2018. Among men with epididymo-orchitis (n=89 596), TC was diagnosed in 0.45%, with an overall SIR of 6.34 (95% CI 5.73 to 7.00) in the full model. For TC diagnosed in the same calendar year as epididymo-orchitis (289 cases), the SIR was 85.97 (76.33 to 96.50). For TC diagnosed in subsequent calendar years (111 cases) the SIR was 1.86 (1.53 to 2.24), with most cases diagnosed within 1-4 calendar years of follow-up (65 cases). Among men with UTI (n=294 201), TC was diagnosed in only 0.04%, with an overall SIR of 1.74 (1.44 to 2.08). The associations were not significant for TC diagnosed 1-4 years after UTI, nor between cystitis and subsequent TC.
The association between epididymo-orchitis and TC was strong and persisted for several years after the infection. The findings support clinicians maintaining a heightened awareness of TC in patients with epididymo-orchitis, particularly when in diagnostic doubt or if symptoms persist, and could be a foundation for more detailed clinical studies on epididymo-orchitis as a potential TC risk factor. Although a potential link between UTI and TC was identified, the absolute risk was almost negligible.
BMJ oncology. 2026 Apr 29*** epublish ***
Filip Jansåker, Xinjun Li, Kristina Sundquist
Center for Primary Health Care Research, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden.