Synchronous or Metachronous Prostate Adenocarcinoma and Bladder Cancer Coexistence: A Retrospective Cohort Study

Objective: Advances in modern medicine have improved the detection of synchronous and metachronous cancers. Among male genitourinary malignancies, prostate adenocarcinoma (PCa) and bladder cancers can rarely coexist. Material and Methods: This retrospective study included male patients diagnosed with PCa and bladder cancers between 2012 and 2019 at Zonguldak Bülent Ecevit University. Patients with synchronous or metachronous cancers and complete clinical data were included, while those with direct tumor infiltration or missing records were excluded. Results: Among 1,173 PCa and 591 bladder cancer cases, 15 synchronous or metachronous cases were identified. The median ages at the time of diagnosis for PCa and bladder cancer patients were 69 and 70 years, respectively. Bladder cancer was diagnosed in 7 patients during PCa follow-up, while PCa was detected in 2 patients during bladder cancer follow-up. Synchronous cancers occurred in 6 patients. All bladder cancers were highgrade or advanced stage, while PCa cases included all pathological groups except for International Society of Urological Pathology (ISUP) Grade 4. A significant association was found between the age at bladder cancer diagnosis and the PCa risk group (p=0.046). Patients had a median smoking history of 40 pack-years, with only one non-smoker. Metachronous PCa developed within 2 years of bladder cancer, while metachronous bladder tumors appeared 1-7 years after PCa, with a median of 6 years. Conclusion: The coexistence of prostate adenocarcinoma and bladder cancers in our cohort highlights the need for vigilant screening for secondary malignancies in affected patients. These findings suggest a potential link between high-grade bladder tumors and prostate cancer risk, warranting further research into shared carcinogenic pathways.