Introduction:

It is presumed that older patients are more likely to die from other causes of death than the cancer itself and hence the age at which a patient is diagnosed with cancer is a key determinant in the treatment modalities offered to a patient. The relationship between age at diagnosis and cause of death has not been well described for genitourinary cancers. The objective of this study is to examine the variation in causes of death with respect to age at diagnosis for patients diagnosed with non-metastatic prostate cancer.

Methods:

We retrospectively analyzed the records of patients diagnosed with localized (N0M0) prostate cancer (ICD-O-3 8140) between the ages of 45 and 74 in the US Surveillance, Epidemiology and End Results Program (SEER) from 1975 to 2015. Patients with multiple primary tumors and unknown details regarding cause of death were excluded. Univariate and multivariate Cox proportional hazards regression was performed to investigate mortality and cause of death. Kaplan – Meier survival estimates were obtained for prostate cancer – specific and all cause of death at 10 and 15 years from diagnosis to calculate attributable cause of death to prostate cancer by age at diagnosis.

Results:

We identified 687,795 patients diagnosed with localized prostate adenocarcinoma between 1975 and 2015. Treating age as a continuous variable, prostate cancer-specific hazards ratio is 1.058 (95% CI: 1.056 – 1.061, p < 0.001) and all-cause hazards ratio is 1.092 (95% CI: 1.090 – 1.093, p < 0.001) at 10 years after diagnosis while prostate cancer-specific hazards ratio is 1.057 (95% CI: 1.055 – 1.060, p < 0.001) and all-cause hazards ratio is 1.097 (95% CI: 1.095 – 1.098, p < 0.001) at 15 years after diagnosis. On multivariate analysis, patients diagnosed between the ages of 70 – 74 had a prostate cancer-specific hazards ratio of 3.78 (95% CI: 3.32 – 4.31, p < 0.001) with an all-cause hazards ratio of 7.09 (95% CI: 6.57 – 7.64, p < 0.001) 10 years after diagnosis when compared to patients diagnosed between the ages of 45 – 49 after controlling for race and marital status. At 15 years after prostate cancer diagnosis, patients diagnosed between the ages of 70 – 74 had a prostate cancer-specific hazards ratio of 3.46 (95% CI: 3.04 – 3.93, p < 0.001) with an all-cause hazards ratio of 7.09 (95% CI: 5.88 – 6.80, p < 0.001) when compared to patients diagnosed between the ages of 45 – 49.

Kaplan Meier Survival Estimates showing prostate cancer-specific vs other causes of death at 10 years (top) and 15 years (bottom) from diagnosis

Attributable cause of death to prostate cancer at 10 years (top) and 15 years(bottom) from diagnosis

Conclusion:

Patients diagnosed with prostate cancer at a younger age are more likely to die from prostate cancer than other causes of death when compared to patients diagnosed at an older age.

Funding: N/A