Radiotherapy and Hormone Treatment in Prostate Cancer

Epigenetic regulation of TP53 is involved in prostate cancer radioresistance and DNA damage response signaling

External beam radiotherapy (RT) is a leading first-line therapy for prostate cancer (PCa), and, in recent years, significant advances have been accomplished. However, RT resistance can arise and result in long-term recurrence or disease progression in the worst-case scenario. Thus, making crucial the discovery of new targets for PCa radiosensitization. Herein, we generated a radioresistant PCa cell line, and found p53 to be highly expressed in radioresistant PCa cells, as well as in PCa patients with recurrent/disease progression submitted to RT. Mechanism dissection revealed that RT could promote p53 expression via epigenetic modulation. Specifically, a decrease of H3K27me3 occupancy at TP53 gene promoter, due to increased KDM6B activity, was observed in radioresistant PCa cells. Furthermore, p53 is essential for efficient DNA damage signaling response and cell recovery upon stress induction by prolonged fractionated irradiation. Remarkably, KDM6B inhibition by GSK-J4 significantly decreased p53 expression, consequently attenuating the radioresistant phenotype of PCa cells and hampering in vivo 3D tumor formation. Overall, this work contributes to improve the understanding of p53 as a mediator of signaling transduction in DNA damage repair, as well as the impact of epigenetic targeting for PCa radiosensitization.

Effect of Salvage Radiotherapy and Endocrine Therapy on Patients with Biochemical Recurrence After Prostate Cancer Operation- a Meta‑Analysis

CONTEXT

Several studies reported the application of androgen deprivation therapy and radiotherapy in patients with biochemical recurrence after prostate cancer operation.

OBJECTIVE

To perform a systematic review and meta-analysis evaluating of endocrine therapy and radiotherapy in patients with biochemical recurrence after prostate cancer surgery. The primary end point was biochemical progression-free survival (bPFS). Secondary end point was overall survival (OS).

METHODS

A systematic review of PubMed/Medline, Embase, and Cochrane databases to identify relevant studies published in English up to March 2020. Twelve studies were selected for inclusion.

RESULTS

There were 11 studies included in the present study. Including two randomized controlled trials and nine cohort studies. The meta-analysis shows a significant bPFS benefit from androgen deprivation therapy and radiotherapy in patients with biochemical recurrence after prostate cancer operation. (hazard ratio [HR]: 0.57; 95% confidence interval CI, 0.52-0.63; p < .001). For patients with GS < 7 and low-risk patients, combined treatment can have a benefit for BPFs (HR: 0.53; 95% CI, 0.37-0.76; HR: 0.58; 95% CI, 0.36-0.93). Androgen deprivation therapy and radiotherapy in patients with biochemical recurrence was associated with a slightly OS improvement (HR: 0.73; 95% CI, 0.57-0.93; p = 0.01).

CONCLUSIONS

Compared with salvage radiotherapy alone, This meta-analysis shows a significant bPFS benefit from endocrine therapy combined with salvage radiotherapy in patients with biochemical recurrence after prostate cancer operation. And benefit more for high-risk groups. However, there was no significant benefit in group GS ≥ 8. It shows a slightly OS benefit from endocrine therapy combined with salvage radiotherapy in patients with biochemical recurrence.

Research Progress for the Clinical Application of Circulating Tumor Cells in Prostate Cancer Diagnosis and Treatment

Prostate cancer is a life-threatening and highly heterogeneous malignancy. In the past decade, circulating tumor cells (CTCs) have been suggested to play a critical role in the occurrence and progression of prostate cancer. In particular, as the “seed” of the cancer metastasis cascade, CTCs determine numerous biological behaviors, such as tumor invasion into adjacent tissues and migration to distant organs. Many studies have shown that CTCs are necessary in the processes of tumor progression, including tumorigenesis, invasion, metastasis, and colonization. Furthermore, CTCs express various biomarkers relevant to prostate cancer and thus can be applied clinically in noninvasive tests. Moreover, CTCs can serve as potential prognostic targets in prostate cancer due to their roles in regulating many processes associated with cancer metastasis. In this review, we discuss the isolation and detection of CTCs as predictive markers of prostate cancer, and we discuss their clinical application in the diagnosis and prognosis of prostate cancer and in monitoring the response to treatment and the prediction of metastasis.

Peritoneal Flap in Robot-Assisted Radical Prostatectomy

BACKGROUND

Lymphocele is the most common complication arising after pelvic lymph node dissection (PLND) in the setting of robot-assisted radical prostatectomy (RARP). The only data available until now on the utility of a peritoneal flap to prevent lymphocele were retrospectively acquired.

METHODS

A randomized, controlled, multi-center trial with blinded assessment of endpoints was carried out on 232 patients with prostate cancer who underwent RARP with PLND. The patients in the intervention group were given a peritoneal flap; in the control group, surgery was performed without this modification. The two joint primary endpoints were the rates of symptomatic lymphocele during the same hospitalization as the operative procedure (iT1) and within 90 days of surgery (iT2). The secondary endpoints were lymphocele volume, the need for treatment of lymphocele, complications requiring an intervention, and the degree of postoperative stress incontinence. German Clinical Trials Register number: DRKS00011115.

RESULTS

The data were evaluated in an intention-to-treat analysis, which, in this trial, was identical to an as-treated analysis. 108 patients (46.6%) were allotted to the intervention group. There were no statistically significant intergroup differences with respect to any clinical or histopathological criteria. A median of 16 lymph nodes were removed (interquartile range, 11-21). A symptomatic lymphocele arose in 1.3% (iT1) and 9.1% (iT2) of the patients, without any statistically significant difference between the two trial groups (p = 0.599 and p = 0.820, respectively). Nor did the groups differ significantly with respect to lymphocele volume (p = 0.670 on hospital discharge [T1], p = 0.650 90 days after surgery [T2]) or the type and frequency of need for subsequent surgical intervention (p = 0.535; iT2). 81.5% of all patients (n = 189) had no complications at all in the first three months after surgery. Nor were there any intergroup differences at 90 days with respect to the degree of stress urinary incontinence (p = 0.306) or complications (p = 0.486).

CONCLUSION

A peritoneal flap after RARP was not found to influence the rate of postoperative lymphocele, whether asymptomatic or requiring treatment.