[Incidence, therapy, and prognosis of prostate cancer in Baden-Württemberg: analysis based on cancer registry data]

BACKGROUND

Prostate cancer (PCa) is the most common solid tumor in men in Germany. Collection of epidemiological and clinical data has been centralized for several years due to legal requirements via the state cancer registries. Thus, the reporting of diagnosis, therapy, and progression of cancer is obligatory in Germany. These data needs to be processed based on the questions of the treating physicians.

OBJECTIVES

Intention of this work was to present the development of new cases, disease stages, treatment procedures and prognosis of PCa in Baden-Württemberg (BW).

METHODS

For this purpose, data of the cancer registry BW regarding patients with PCa first diagnosed between 2013 and 2021 were evaluated. The evaluation was performed using descriptive statistics, Χ2 test and Kaplan-Meier analysis.

RESULTS

A total of 84,347 new diagnoses of PCa were reported. Clinical stage was present in 55.3% of patients. Assignment by International Society of Urological Pathology (ISUP) groups was present in 75.7%. A steady increase in primary diagnosis was evident through 2019. The proportion of primary metastatic disease decreased (2013: 19.6% vs. 2021: 12.0%), and the proportion of localized tumors increased (2013: 65.5% vs. 2021: 77.1%). Radical prostatectomy (RP) dominated the treatment of localized tumors with a mean of 60.1%. The proportion of robot-assisted surgery increased from 23.7% (2013) to 60.8% (2021) with a decrease in the R1 rate from 34.8 to 26.2%. Progression-free survival correlated closely with tumor stage and ISUP group.

CONCLUSION

An increase in PCa cases and a decrease of advanced tumors were observed. Treatment was mostly surgical in localized stages, with increasing proportion of robotic-assisted RP. Early diagnosis and treatment are critical for long-term prognosis.

Tumor removal limits prostate cancer cell dissemination in bone and osteoblasts induce cancer cell dormancy through focal adhesion kinase

BACKGROUND

Disseminated tumor cells (DTCs) can enter a dormant state and cause no symptoms in cancer patients. On the other hand, the dormant DTCs can reactivate and cause metastases progression and lethal relapses. In prostate cancer (PCa), relapse can happen after curative treatments such as primary tumor removal. The impact of surgical removal on PCa dissemination and dormancy remains elusive. Furthermore, as dormant DTCs are asymptomatic, dormancy-induction can be an operational cure for preventing metastases and relapse of PCa patients.

METHODS

We used a PCa subcutaneous xenograft model and species-specific PCR to survey the DTCs in various organs at different time points of tumor growth and in response to tumor removal. We developed in vitro 2D and 3D co-culture models to recapitulate the dormant DTCs in the bone microenvironment. Proliferation assays, fluorescent cell cycle reporter, qRT-PCR, and Western Blot were used to characterize the dormancy phenotype. We performed RNA sequencing to determine the dormancy signature of PCa. A drug repurposing algorithm was applied to predict dormancy-inducing drugs and a top candidate was validated for the efficacy and the mechanism of dormancy induction.

RESULTS

We found DTCs in almost all mouse organs examined, including bones, at week 2 post-tumor cell injections. Surgical removal of the primary tumor reduced the overall DTC abundance, but the DTCs were enriched only in the bones. We found that osteoblasts, but not other cells of the bones, induced PCa cell dormancy. RNA-Seq revealed the suppression of mitochondrial-related biological processes in osteoblast-induced dormant PCa cells. Importantly, the mitochondrial-related biological processes were found up-regulated in both circulating tumor cells and bone metastases from PCa patients' data. We predicted and validated the dormancy-mimicking effect of PF-562,271 (PF-271), an inhibitor of focal adhesion kinase (FAK) in vitro. Decreased FAK phosphorylation and increased nuclear translocation were found in both co-cultured and PF-271-treated C4-2B cells, suggesting that FAK plays a key role in osteoblast-induced PCa dormancy.

CONCLUSIONS

Our study provides the first insights into how primary tumor removal enriches PCa cell dissemination in the bones, defines a unique osteoblast-induced PCa dormancy signature, and identifies FAK as a PCa cell dormancy gatekeeper.

Cutaneous Metastases in Progressive Prostate Adenocarcinoma: A Case Report and Literature Review

Prostate cancer has an indolent progression course and commonly metastasizes to the vertebrae bone and regional lymph nodes. We report a patient with prostate cancer who has developed cutaneous metastases in multiple regions, including the right infraclavicular and abdominal area, as well as the left supraclavicular region. It presented as isolated, prominent nodules that were microscopically proven to be of prostate adenocarcinoma when biopsied. This rare presentation is a marker of an advanced disease course with a poor prognosis in castrate-resistant prostate cancer. Thorough clinical examination to rule out metastasis from the prostate and other dermatological conditions is paramount as well as ensuring early detection and optimizing patient outcomes.

Determinants of outcome following PSMA-based radioligand therapy and mechanisms of resistance in patients with metastatic castration-resistant prostate cancer

[177Lu]Lu-PSMA has recently been approved for use in the post-taxane, post-novel hormonal-agent setting in patients with metastatic castration-resistant prostate cancer. As a beta-emitting radioligand targeting prostate-specific membrane antigen (PSMA), it delivers radiation to cells expressing PSMA on their surface. In pivotal clinical trials, patients were selected for this treatment based on positron emission tomography (PET)/CT imaging, requiring PSMA-avid disease with no evidence of discordant disease on 2-[18F]fluoro-2-deoxy-D-glucose PET/CT or contrast CT scan. Despite exhibiting an optimal imaging phenotype, the response for many patients is not durable, and a minority do not respond to [177Lu]Lu-PSMA at all. Disease progression is inevitable even for those who achieve an exceptional initial response. Reasons for both primary and acquired resistance are largely unknown; however, they are likely due to the presence of underlying PSMA-negative disease not identified on imaging, molecular factors conferring radioresistance, and inadequate delivery of lethal radiation, particularly to sites of micrometastatic disease. Biomarkers are urgently needed to optimize patient selection for treatment with [177Lu]Lu-PSMA by identifying those who are most and least likely to respond. Retrospective data support using several prognostic and predictive baseline patient- and disease-related parameters; however, robust prospective data is required before these can be translated into widespread use. Further, early on-treatment clinical parameters (in addition to serial prostate-specific antigen [PSA] levels and conventional restaging imaging) may serve as surrogates for predicting treatment response. With little known about the efficacy of treatments given after [177Lu]Lu-PSMA, optimal treatment sequencing is paramount, and biomarker-driven patient selection will hopefully improve treatment and survival outcomes.

Three Months' PSA and Toxicity from a Prospective Trial Investigating STereotactic sAlvage Radiotherapy for Macroscopic Prostate Bed Recurrence after Prostatectomy-STARR (NCT05455736)

Biochemical recurrences after radical prostatectomy (RP) can be managed with curative purpose through salvage radiation therapy (SRT). RT dose escalation, such as stereotactic RT (SSRT), may improve relapse-free survival in this setting. STARR trial (NCT05455736) is a prospective multicenter study including patients affected by macroscopic recurrence within the prostate bed after RP treated with SSRT. Recurrence was detected with a Choline or PSMA CT-PET. In the current analysis, the early biochemical response (BR) rate and toxicity profile after three months of follow-up were assessed. Twenty-five patients were enrolled, and data about BR and toxicity at three months after treatment were available for 19 cases. Overall, BR was detected after three months in 58% of cases. Four G1-G2 adverse events were recorded; no G ≥ 3 adverse events were detected. SSRT appears feasible and safe, with more than half of patients experiencing BR and an encouraging toxicity profile. The STARR trial is one of the few prospective studies aimed at implementing this promising treatment strategy in this scenario.