Evaluation of treatment outcomes in ductal and intraductal prostate cancer: Insights from the National Cancer Database.

Abstract

5122 Background: Ductal and intraductal Prostate carcinoma (DPC) are rare and aggressive histological subtypes of prostate cancer. Based on risk stratification, treatment strategies for localized DPC include radical prostatectomy (RP), radiation with androgen deprivation therapy (RT±ADT), and observation. However, literature on outcomes across various treatment modalities in DPC is limited. Understanding the impact of these approaches on survival is important for strategizing DPC management. We used the national cancer database to evaluate the survival outcomes with various treatment strategies in DPC. Methods: Our study focused on patients diagnosed with localized DPC between 2004 and 2020. Patients were stratified into three arms: RP arm included those who underwent RP with or without adjuvant therapy, RT +/- ADT arm included patients who underwent RT with or without ADT, and observation arm included those who had no treatment. We performed Multivariate Cox regression analysis adjusting for age, race, NCCN risk classification, comorbidities, socioeconomic factors, and facility type. We also conducted Kaplan-Meier analysis to evaluate Overall Survival (OS) across the treatment arms. Results: We analyzed 2,650 patients with localized DPC. 1586(59.9%) underwent RP, 785(29.6%) underwent RT±ADT, and 279(10.5%) were under observation. 2-year OS for RP, RT±ADT, and observation were 98%, 94% and 78% respectively (p<0.001). Similarly, 5-year OS was 92%, 81%, and 54%, respectively (p<0.001). Multivariate Cox regression showed that RT+ADT was associated with increased mortality compared to RP (HR: 2.27; p<0.001). 2-year OS for patients with PSA ≤4 ng/dL and >4 ng/dL was 89.9% and 97.2%, respectively. Similarly, 5-year OS were 75.8% and 88.8%, respectively. Multivariate Cox regression showed that PSA <=4 was associated with an increased risk of mortality compared with PSA >4 (HR: 1.27; p<0.05). Conclusions: Surgery offers better survival than radiation in localized DPC. The association of low PSA with worse prognosis could be due to dedifferentiation-driven aggressiveness. Therefore, further evaluation of treatment strategies for DPC is warranted.