Objectives: 1) to find out the distribution of prostate cancer by risk of progression; 2) to determine the cause-specific survival by risk of progression in prostate cancer; 3) to identify the factors associated with the risk of dying from this cancer.
Methods: Incident prostate cancer cases diagnosed between 2006 and 2011 were identified through the Mallorca Cancer Registry. Inclusion criteria: invasive cases with code C61.9 and any histology. Cases identified exclusively through death certificate were excluded. We collected: age; date and method of diagnosis; date of follow-up or death; T, N, M and stage according to the TNM 7th edition; Gleason score; PSA; histology according to the ICD-O 3rd edition 6 ; comorbidities and treatments. We calculated risk in 4 categories: low, medium, high and very high. End point of follow-up was 31 December 2014. Multiple imputation (MI) was performed to estimate cases with unknown risk of progression. Survival analysis was performed using the actuarial and Kaplan-Meier methods, as well as the Cox regression model.
Results: We identified 2921 cases. After MI, 9.5% had low risk, 24.9% medium risk, 42.7% high risk and 22.9% very high risk. Five years after diagnosis, survival after MI was 89% globally, that being 100% for low risk cases, 96% for medium risk, 93% for high risk and 69% for very high risk. Cases with histology other than adenocarcinoma, with high and, especially, very high risk of progression, as well as with systemic, mixed and observation/unspecified treatments have worse prognosis. Treatment showed a strong relationship with age and life expectancy.
Conclusions: Risk of progression and treatment were the main variables associated to survival in prostate cancer.