Histological characteristics of the largest and secondary tumors in radical prostatectomy specimens and implications for focal therapy

Immunohistochemical markers as predictors of prognosis in multifocal prostate cancer

The impact of tumor focality on prostate cancer (PCa) prognosis has been addressed in several studies with conflicting results. Tumor foci from multifocal (MF) PCa can show highly heterogeneous molecular features. Our aim was to analyze the protein expression of PTEN, SPOP, SLC45A3, ETV1, ERG and the "triple hit" (ERG overexpression, PTEN plus SLC45A3 loss) in unifocal (UF) and MF PCa, to evaluate their value as prognostic markers according to focality, and the role of tumor heterogeneity in MF disease. PTEN, SPOP, SLC45A3, ETV1 and ERG immunohistochemical expression was evaluated in 185 PCa from 9 TMAs, 51 UF and 134 MF. In a subset of 69 MF cases, the dominant and secondary foci (DF and SF) were compared. Heterogeneity was considered when both tumor foci presented different expression patterns. Relationship with clinicopathological features was also analyzed. MF PCa was diagnosed in significantly younger patients when compared to UF ones (p = 0.007). ETV1 overexpression was associated with UF disease (p = 0.028). A shorter time to PSA recurrence was related to SLC45A3 wt expression in UF PCa (p = 0.052), and to SPOP expression loss (p = 0.043) or "triple hit" phenotype in MF PCa (p = 0.041). In MF cases, PTEN loss, SLC45A3 loss and "triple hit" phenotype were associated with the DF and had significant heterogeneity. In conclusion, our results indicate that UF and MF PCa have relevant and consistent molecular differences. The analysis of an immunohistochemical panel, composed by PTEN, SPOP, SLC45A3, ETV1 and ERG, could be useful to predict outcome in MF cases.

Evolving imaging methods of prostate cancer and the emergence of magnetic resonance imaging guided ablation techniques

Established therapies for prostate cancer (PCa), surgery and radiotherapy, treat the entire gland regardless of the location of the cancerous lesion within the prostate. Although effective, these methods include a significant risk of worsening genitourinary outcomes. Targeted image-guided cancer therapy has gained acceptance through improved PCa detection, localization, and characterization by magnetic resonance imaging (MRI). Minimally-invasive ablative techniques aim to achieve comparable oncological outcomes to radical treatment while preserving genitourinary function. Transurethral ultrasound ablation (TULSA) and next-generation transrectal high-intensity focused ultrasound (HIFU) utilize MRI guidance to thermally ablate prostate tissue under real-time MRI monitoring and active temperature feedback control. Previous trials performed by our group and others, including a large multicenter study in men with localized favorable-risk disease, have demonstrated that TULSA provides effective prostate ablation with a favorable safety profile and low impact on quality of life. Recently, MRI-guided HIFU focal therapy was also shown as a safe and effective treatment of intermediate-risk PCa. Here we review the current literature on ablative techniques in the treatment of localized PCa with a focus on TULSA and HIFU methods.

Targeted and Systematic Biopsy for the Diagnosis and Management of Prostate Cancer - A Case for Lesion Targeted-Only Biopsies

For much of the 1990s, transrectal ultrasound systematic biopsy was the standard approach for prostate cancer diagnosis. However, in the past decade multiparametric magnetic resonance imaging, multiparametric ultrasound and image fusion targeting have come to the fore. Here we present the state-of-the-art diagnostic strategies in prostate cancer detection and examine the case for target-only biopsy, as well as the benefits and limitations.

Focal therapy, time to join the multi-disciplinary team discussion?

Organ preserving management is common place in renal cancer, breast cancer and many other solid organ tumours. Current strategies in managing intermediate risk prostate cancer include either whole gland treatment, in the form of radical radiotherapy or radical prostatectomy, or active surveillance. The former is associated with significant post-treatment functional morbidity, whilst the latter associated with the burden of surveillance activity and patient anxiety. Focal therapy would logically fit as a middle ground for suitable patients in whom treatment would be recommended, but where much better functional outcomes may be possible. Ideally this comes without restricting the successful prevention of harm from the cancer. Historically limitations in developing tissue preserving focal therapy strategies in prostate cancer, were due to inaccuracies in tumour characterisation prior to treatment and during follow up. Consequently for example many patients undergoing an active surveillance strategy were being upgraded and upstaged within a short period. Recently high level evidence supporting the use of MRI and targeted biopsies, in particular the PROMIS and PRECISION trials have strengthened clinician confidence in accurate disease characterisation, thus making focal therapy to become a more feasible management option. With improved diagnostic strategies and the publication of reassuring medium term oncological and functional outcomes after focal therapy for intermediate risk prostate cancer, has the time come to require consideration of focal therapy within our multi-disciplinary team (MDT) meetings and with patients? In this review we will consider patient selection and the evidence for the various focal ablation options as well as the surveillance of these patients after treatment. The forthcoming trials to determine comparative effectiveness will be discussed.