Incremental dose-response effect of age on mortality in non-seminoma testis cancer patients

Age ≥ 40 predisposes to higher testis cancer-specific mortality (CSM) in non-seminoma. However, it is unknown, whether an incremental dose-response effect applies to subgroups of testis cancer patients (tertiles aged ≥ 40). We tested this hypothesis in contemporary non-seminoma patients.

The Surveillance, Epidemiology, and End Results (SEER) database (2004-2018) was used. Kaplan-Meier plots and multivariable Cox regression models tested the effect of age on CSM after stratification for stage (I vs. II vs. III).

Of 13,679 non-seminoma patients, 11,034 (81%) were aged < 40 vs. 2,645 (19%) were aged ≥ 40. Of patients aged ≥ 40, 943 were aged 40 to 44 (young age tertile) vs. 855 were aged 45 to 52 (intermediate age tertile) vs. 847 were aged ≥ 53 (old age tertile). In overall multivariable analyses relative to patients aged < 40, young age tertile (Hazard ratio [HR] 1.4, P < 0.01), intermediate age tertile (HR 1.9, P < 0.001) and old age tertile (HR 3.6, P < 0.001) were associated with higher CSM. In stage-specific multivariable analyses relative to patients aged < 40, old age tertile predicted higher CSM in stage I (HR 4.7, P < 0.001), stage II (HR 9.9, P < 0.001) and stage III (HR 3.0, P < 0.001). In stage III, intermediate age tertile (HR 1.9, P < 0.001) and young age tertile (HR 1.5, P = 0.007) also predicted higher CSM.

We identified a dose-response effect of increasing age in non-seminoma patients aged ≥ 40, in the overall analysis as well as in stage-specific analyses.