27-year trends in incidence rates for testis cancer across a large statewide registry.

Purpose: To review 27-years of testicular cancer (TC) incidence data (1990-2017) within the state of Pennsylvania to better define incidence, geographic distribution, and trends over time.

Methods: The Pennsylvania Cancer Registry was reviewed for statewide and component county age-adjusted TC incidence rates and stage distribution. We reported annual percent changes (APCs) in age-adjusted rates. Maps plotting county-level incidence rates across the state in five-year time intervals were created.

Results: In Pennsylvania, 9,933 TC cases were recorded between 1990-2017. Over two-thirds of patients were < 40 years of age and 95% were White. Approximately 89% presented as local and regional disease. Age-adjusted annual rates of total TC increased from 4.80 to 7.20 patients per 100,000 with an APC of 0.94 (95% Confidence Interval (CI) = (0.59, 1.29), P < 0.01) over the study interval. Annual rates of local disease increased from 3.20 to 5.00 patients per 100,000 with an APC of 1.07 (95% CI = (0.67, 1.46), P < 0.01). Annual rates of distant disease were stable and ranged from 0.50 to 0.80 patients per 100,000 with an APC of 0.69 (95% CI = (-0.02, 1.40), P = 0.06). Geospatial investigation noted increased incidence in urban centers.

Conclusions: Although TC is rare, incidence is rising. Rates of TC in Pennsylvania almost doubled over the past two decades. Fortunately, this rising trend is primarily attributed to increases in local and regional disease. Counties with higher incidence rates cluster in urban centers which may reflect exposure risk, access to care, or reporting bias.