Pattern of solid and hematopoietic second malignancy after local therapy for prostate cancer

Area of Science:

• Oncology
• Radiation Oncology
• Cancer Epidemiology

Background:

• Second malignancies (SM) are rare but serious risks following prostate cancer (PCa) treatment.
• External beam radiotherapy (EBRT) and brachytherapy (BT) are common PCa treatments with potential long-term sequelae.

Purpose of the Study:

• To evaluate the risk of SM after EBRT, BT, or radical prostatectomy (RP) for localized PCa.
• To compare SM incidence across different treatment modalities and over time.

Main Methods:

• Utilized the Surveillance, Epidemiology, and End Results (SEER) database for PCa patients diagnosed 1999-2005.
• Applied multivariate Fine and Gray proportional hazards models to assess risks for solid and hematopoietic SM.
• Excluded patients with short follow-up periods to ensure robust analysis.

Main Results:

• EBRT and BT demonstrated similar increased risks for both solid and hematopoietic SM compared to RP.
• A significant decrease in solid and hematopoietic SM was observed for EBRT in more recent years (2002-2005) versus earlier years (1999-2001).
• Adjusted hazard ratios indicated a protective effect of recent EBRT utilization against SM.

Conclusions:

• EBRT and BT carry statistically equivalent risks for SM compared to RP.
• The observed reduction in SM with recent EBRT use may be linked to advancements like Intensity-Modulated Radiation Therapy (IMRT).
• Further research into treatment evolution and its impact on long-term cancer survivorship is warranted.