Ductal and acinar components of mixed prostatic adenocarcinoma frequently have a common clonal origin

The Oncological and Functional Prognostic Value of Unconventional Histology of Prostate Cancer in Localized Disease Treated with Robotic Radical Prostatectomy: An International Multicenter 5-Year Cohort Study

BACKGROUND AND OBJECTIVE

The impact of prostate cancer of unconventional histology (UH) on oncological and functional outcomes after robot-assisted radical prostatectomy (RARP) and adjuvant radiotherapy (aRT) receipt is unclear. We compared the impact of cribriform pattern (CP), ductal adenocarcinoma (DAC), and intraductal carcinoma (IDC) in comparison to pure adenocarcinoma (AC) on short- to mid-term oncological and functional results and receipt of aRT after RARP.

METHODS

We retrospectively collected data for a large international cohort of men with localized prostate cancer treated with RARP between 2016 and 2020. The primary outcomes were biochemical recurrence (BCR)-free survival, erectile and continence function. aRT receipt was a secondary outcome. Kaplan-Meier survival and Cox regression analyses were performed.

KEY FINDINGS AND LIMITATIONS

A total of 3935 patients were included. At median follow-up of 2.8 yr, the rates for BCR incidence (AC 10.7% vs IDC 17%; p < 0.001) and aRT receipt (AC 4.5% vs DAC 6.3% [p = 0.003] vs IDC 11.2% [p < 0.001]) were higher with UH. The 5-yr BCR-free survival rate was significantly poorer for UH groups, with hazard ratios of 1.67 (95% confidence interval [CI] 1.16-2.40; p = 0.005) for DAC, 5.22 (95% CI 3.41-8.01; p < 0.001) for IDC, and 3.45 (95% CI 2.29-5.20; p < 0.001) for CP in comparison to AC. Logistic regression analysis revealed that the presence of UH doubled the risk of new-onset erectile dysfunction at 1 yr, in comparison to AC (grade group 1-3), with hazard ratios of 2.13 (p < 0.001) for DAC, 2.14 (p < 0.001) for IDC, and 2.01 (p = 0.011) for CP. Moreover, CP, but not IDC or DAC, was associated with a significantly higher risk of incontinence (odds ratio 1.97; p < 0.001). The study is limited by the lack of central histopathological review and relatively short follow-up.

CONCLUSIONS AND CLINICAL IMPLICATIONS

In a large cohort, UH presence was associated with worse short- to mid-term oncological outcomes after RARP. IDC independently predicted a higher rate of aRT receipt. At 1-yr follow-up after RP, patients with UH had three times higher risk of erectile dysfunction post RARP; CP was associated with a twofold higher incontinence rate.

PATIENT SUMMARY

Among patients with prostate cancer who undergo robot-assisted surgery to remove the prostate, those with less common types of prostate cancer have worse results for cancer control, erection, and urinary continence and a higher probability of receiving additional radiotherapy after surgery.

Genomic analysis of aggressive ductal adenocarcinoma of the prostate

BACKGROUND

Genomic profile analysis using next-generation sequencing can potentially elucidate the pathogenesis of rare cancers. Ductal adenocarcinoma, a rare subtype of prostate cancer, has an aggressive nature. This is the first study to analyze the genomic profile of ductal adenocarcinoma in an Asian population.

METHODS

We identified 12 patients newly diagnosed with ductal adenocarcinoma of the prostate at two hospitals, and nine patients (75.0%) had the pure type. Genomic assessment was performed using either the PleSSision testing platform or FoundationOne CDx.

RESULTS

At least one genomic alteration occurred in 11 patients (91.7%), and the most frequently mutated gene was tumor suppressor protein p53 (TP53), which was found in six cases (50.0%). Alterations characteristic of this cohort were found in four cases (33.3%) of retinoblastoma transcriptional corepressor 1 (RB1), which was only observed in the pure type. Compared to previous study results, the frequency of genetic alterations in the phosphoinositide 3-kinase (PI3K) pathway (n = 3; 25.0%) and Wnt-β-catenin pathway (n = 5; 41.7%) was comparable, but no alterations in the DNA damage repair (DDR) pathway were observed. None of the patients presented high tumor mutation burden or microsatellite instability.

CONCLUSIONS

We found that the Asian cohort with ductal adenocarcinoma had actionable alterations, and a high frequency of alterations in TP53 and RB1 reflected the aggressive nature of the tumor. Genetic analysis using next-generation sequencing is expected to help elucidate the pathogenesis of ductal adenocarcinoma.