Locally Advanced Prostate Cancer: Current Controversies and Optimisation Opportunities

Real‑world retrospective study of early‑stage prostate cancer at a Portuguese Comprehensive Cancer Centre: The PEarlC study

Despite the high prevalence of localised prostate cancer (LPC) and locally advanced prostate cancer (LAPC), evidence on the characteristics of patients, treatments and clinical outcomes stratified by disease risk is limited. The PEarlC study was conducted to characterise a cohort of patients with early-stage prostate cancer that included real-world clinical outcomes. Retrospective data from a cohort of patients diagnosed with LPC/LAPC between 2015 and 2017 and followed up until December 2020 at a Portuguese comprehensive cancer centre (IPO Porto) was analysed. Patients were classified as LPC (high- or non-high-risk) or LAPC according to European Association of Urology guidelines, were eligible if diagnosed at stage I-III and followed up in Urology, Medical Oncology or Radiation Oncology outpatient clinics of IPO Porto. Data was collected from the medical/administrative records database. Clinical outcomes included prostate-specific antigen (PSA) progression-free survival, metastasis-free survival, disease-free survival, progression-free survival, overall survival (OS), PSA response (palliative) and no evidence of residual tumour (prostatectomy). Time-to-event outcomes were compared between subgroups using the log-rank test. A total of 790 patients were included (54.8% non-high-risk LPC, 30.9% high-risk LPC, 14.3% LAPC) and the median follow-up was 46.7 months. Patients had a median age of 68.0 years. The majority of patients were stage II (52.9%) and Eastern Cooperative Oncology Group 0-1 (99.9%) and received treatment with curative intent (85.4%). The median was only achieved in progression-free survival (29.9 months; 95% CI, 26.5-41.0 months), as evaluated in palliative patients. At year 5, 82.9% were free of PSA progression (curative), 87.5% were metastasis-free, 83.7% were disease-free, all patients in palliative treatment progressed and the 5-year OS rate was 92.9% (CI 95%, 90.2-95.7%). Among patients with LPC, OS was worse in high-risk vs. non-high-risk patients (5-year OS rate, 88.8% vs. 96.8%; hazard ratio=3.34, CI 95%, 1.64-7.05; P=0.001). PSA response rate was 81.4% in the palliative setting. There was no evidence of residual tumour in 61.6% of patients who underwent prostatectomy. Although most patients with early-stage prostate cancer treated at IPO Porto showed positive 5-year real-world outcomes, patients with high-risk LPC showed worse OS compared with patients with non-high-risk LPC and therefore a poorer prognosis. The present large-sample real-world study is an important contribution to reducing the evidence gap on prostate cancer.

CRISPRi screens reveal a DNA methylation-mediated 3D genome dependent causal mechanism in prostate cancer

Prostate cancer (PCa) risk-associated SNPs are enriched in noncoding cis-regulatory elements (rCREs), yet their modi operandi and clinical impact remain elusive. Here, we perform CRISPRi screens of 260 rCREs in PCa cell lines. We find that rCREs harboring high risk SNPs are more essential for cell proliferation and H3K27ac occupancy is a strong indicator of essentiality. We also show that cell-line-specific essential rCREs are enriched in the 8q24.21 region, with the rs11986220-containing rCRE regulating MYC and PVT1 expression, cell proliferation and tumorigenesis in a cell-line-specific manner, depending on DNA methylation-orchestrated occupancy of a CTCF binding site in between this rCRE and the MYC promoter. We demonstrate that CTCF deposition at this site as measured by DNA methylation level is highly variable in prostate specimens, and observe the MYC eQTL in the 8q24.21 locus in individuals with low CTCF binding. Together our findings highlight a causal mechanism synergistically driven by a risk SNP and DNA methylation-mediated 3D genome architecture, advocating for the integration of genetics and epigenetics in assessing risks conferred by genetic predispositions.

Treatment of Metastatic or High-Risk Solid Cancer Patients by Targeting the Immune System and/or Tumor Burden: Six Cases Reports

This article summarizes the histories of six patients with different solid tumors treated with a new strategy based on tumor burden reduction and immune evasion as potential targets. All six patients were at a high risk of relapse and were likely to have a minimal residual disease following conventional therapy: biochemical recurrence (BCR) following radical prostatectomy (RP) (two prostate cancers patients), removal of distant metastases (one colorectal and one breast cancer), and complete response (CR) of distant metastases to conventional therapy (one breast cancer and one esophageal–gastric junction cancer). Four of the patients, two after RP and BCR, one after removal of a single pulmonary metastasis from breast cancer, and one after CR to chemotherapy of peritoneal metastases and ascites from an esophageal–gastric junction primary cancer, regularly received cycles of a new drug schedule with the aim of inhibiting immune suppression (IT). In these four patients, preliminary laboratory tests of peripheral blood suggested an interleukin (IL)-2/IL-12 mediated stimulation of cellular immune response with a concomitant decrease in vascular endothelial growth factor (VEGF) immune suppression. The fifth case was a breast cancer patient with distant metastases in CR, while receiving beta-interferon and interleukin-2 in addition to conventional hormone therapy. To date, all five patients are alive and doing well and they have been unexpectedly disease-free for 201 and 78 months following BCR, 28 months following the removal of a single pulmonary metastases, 32 months following CR to chemotherapy of peritoneal metastases and ascites, and 140 months following diagnosis of multiple bone metastases, respectively. The sixth patient, who had colorectal cancer and multiple synchronous liver metastases and underwent nine surgical interventions for metastatic disease, although not disease-free, is doing well 98 months after primary surgery. Our six cases reports can be interpreted with the hypothesis that immune manipulation and/or a concomitant low tumor burden favored their clinical outcome.

Current Perspectives on Nasopharyngeal Carcinoma

Of the ~129,079 new cases of nasopharyngeal carcinoma (NPC) and 72,987 associated deaths estimated for 2018, the majority will be geographically localized to South East Asia, and likely to show an upward trend annually. It is thought that disparities in dietary habits, lifestyle, and exposures to harmful environmental factors are likely the root cause of NPC incidence rates to differ geographically. Genetic differences due to ethnicity and the Epstein Barr virus (EBV) are likely contributing factors. Pertinently, NPC is associated with poor prognosis which is largely attributed to lack of awareness of the salient symptoms of NPC. These include nose hemorrhage and headaches and coupled with detection and the limited therapeutic options. Treatment options include radiotherapy or chemotherapy or combination of both. Surgical excision is generally the last option considered for advanced and metastatic disease, given the close proximity of nasopharynx to brain stem cell area, major blood vessels, and nerves. To improve outcome of NPC patients, novel cellular and in vivo systems are needed to allow an understanding of the underling molecular events causal for NPC pathogenesis and for identifying novel therapeutic targets and effective therapies. While challenges and gaps in current NPC research are noted, some advances in targeted therapies and immunotherapies targeting EBV NPCs are discussed in this chapter, which may offer improvements in outcome of NPC patients.

Outcomes of T3a Prostate Cancer with Unfavorable Prognostic Factors Treated with Brachytherapy Combined with External Radiotherapy and Hormone Therapy

OBJECTIVE

To evaluate the outcomes of T3a prostate cancer with unfavorable prognostic factors treated with permanent interstitial brachytherapy combined with external radiotherapy and hormone therapy.

METHODS

From January 2003 to December 2008, 38 patients classified as T3a prostate cancer with unfavorable prognostic factors were treated with trimodality therapy (brachytherapy + external radiotherapy + hormone therapy). The prescription dose of brachytherapy and external radiotherapy were 110 Gy and 45 Gy, respectively. The duration of hormone therapy was 2-3 years. The endpoints of this study included biochemical failure-free survival (BFFS), distant metastasis-free survival (DMFS), cancer-specific survival (CSS), and overall survival (OS). Survival curves were calculated using the Kaplan-Meier method. The Log-rank test was used to identify the prognostic predictors for univariate analysis.

RESULTS

The median follow-up was 71 months. The serum pre-treatment prostate-specific antigen (PSA) level ranged from 10.0 to 99.8 ng/ml (mean 56.3 ng/ml), the Gleason score ranged from 5 to 9 (median 8), and the percentage of positive biopsy cores ranged from 10% to 100% (mean 65%). The 5-year BFFS, DMFS, CSS, and OS rates were 44%, 69%, 82%, and 76%, respectively. All biochemical failures occurred within 40 months. The percentage of positive biopsy cores was significantly correlated with BFFS, DMFS, and OS (all P=0.000), and the Gleason score with DMFS (P=0.000) and OS (P=0.001).

CONCLUSIONS

T3a prostate cancer with unfavorable prognostic factors presents not so optimistic outcome. Hormone therapy should be applied to prolong the biochemical progression-free or metastasis-free survival. The percentage of positive biopsy cores and the Gleason score are significant prognostic factors.

Efficacy of Bicalutamide 150-mg Monotherapy Compared With Combined Androgen Blockade in Patients With Locally Advanced Prostate Cancer

Purpose

We compared the efficacy, survival rate, and adverse events between bicalutamide 150-mg monotherapy and combined androgen blockade (CAB) in men with locally advanced prostate cancer.

Materials and Methods

From March 2003 to July 2012, we retrospectively included 74 patients who were treated for more than 3 months and were followed up for more than 6 months. 25 men were treated with bicalutamide 150-mg only (group 1) and 49 men received CAB (group 2). Serum prostate-specific antigen (PSA) change, survival rate, and adverse events were compared between the 2 groups.

Results

The PSA levels before and after treatment were 37.0±32.8 ng/mL and 9.5±27.0 ng/mL in group 1 (p<0.001) and 50.2±40.0 ng/mL and 20.0±35.8 ng/mL in group 2 (p<0.001). Mean survival rates were 78.9% in group 1 and 52.3% in group 2 (p=0.055). There were no statistically significant differences in adverse events between the 2 groups (p=0.304). The International Index of Erectile Function 5 (IIEF-5) score before treatment was 19.3±5.9 in group 1 and 18.3±5.8 in group 2 (p=0.487). The IIEF-5 score after treatment was 17.1±6.3 in group 1 and 14.0±6.1 in group 2, which was a statistically significant difference (p=0.036).

Conclusions

The PSA change, mean survival rate, and adverse events in patients with locally advanced prostate cancer treated with bicalutamide 150-mg and CAB did not differ significantly. However, sexual function was better in the bicalutamide 150-mg group. Therefore, bicalutamide 150-mg monotherapy could be considered as a treatment for locally advanced prostate cancer in patients concerned about sexual function.

An arranged marriage for precision medicine: hypoxia and genomic assays in localized prostate cancer radiotherapy

Prostate cancer (CaP) is the most commonly diagnosed malignancy in males in the Western world with one in six males diagnosed in their lifetime. Current clinical prognostication groupings use pathologic Gleason score, pre-treatment prostatic-specific antigen and Union for International Cancer Control-TNM staging to place patients with localized CaP into low-, intermediate- and high-risk categories. These categories represent an increasing risk of biochemical failure and CaP-specific mortality rates, they also reflect the need for increasing treatment intensity and justification for increased side effects. In this article, we point out that 30-50% of patients will still fail image-guided radiotherapy or surgery despite the judicious use of clinical risk categories owing to interpatient heterogeneity in treatment response. To improve treatment individualization, better predictors of prognosis and radiotherapy treatment response are needed to triage patients to bespoke and intensified CaP treatment protocols. These should include the use of pre-treatment genomic tests based on DNA or RNA indices and/or assays that reflect cancer metabolism, such as hypoxia assays, to define patient-specific CaP progression and aggression. More importantly, it is argued that these novel prognostic assays could be even more useful if combined together to drive forward precision cancer medicine for localized CaP.

Breast cancer causes and treatment: where are we going wrong?

This discussion paper seeks to provoke thoughts about cancer research in general, and why breast cancer in particular is not yet "curable". It asks the question - are we looking at the disease in the right way? Should we regard cancer as a progressive state, which is part of aging? Should we tailor treatment to "reset" the system or slow progression rather than try using toxic and aggressive therapy to kill every cancer cell (and sometimes also the patient)? The thesis is presented that we need to revisit our fundamental beliefs about the disease and then ask why we cling to beliefs that clearly are no longer valid. The paper also questions the role of ethics boards in hampering research and discusses the concept that breast cancer is an industry with vested interests involving profiteering by preventive, diagnostic, and therapeutic players. Finally, the paper suggests some ways forward based on emerging concepts in system biology and epigenetics.