Correlation between stage shift and differences in mortality in the European Randomised study of Screening for Prostate Cancer (ERSPC)

LncRNA CCAT1 promotes prostate cancer cells proliferation, migration, and invasion through regulation of miR-490-3p/FRAT1 axis

Prostate cancer (PCa) is a prevalent cancer in males, with high incidence and mortality. Recent studies have shown the crucial role of long non-coding RNA (lncRNA) in PCa. Here, we aimed to explore the functional roles and inner mechanisms of lncRNA CCAT1 in PCa cells. qRT-PCR results showed that CCAT1 was upregulated in PCa tissues and cells. Functional assays demonstrated that CCAT1 knockdown suppressed cell proliferation, migration, invasion, yet promoted apoptosis, while CCAT1 promotion showed the opposite results. We also found that CCAT1 negatively regulated miR-490-3p expression and subsequently regulated FRAT1 expression. Inhibition of miR-490-3p or up-regulation of FRAT1 reversed the suppressive effects of CCAT1 knockdown on the PCa cells. In conclusion, CCAT1 regulated FRAT1 expression through miR-490-3p and then promote the PCa cells proliferation, migration, and invasion, which reveals the oncogenic function of CCAT1 in PCa progress.

Impact of cancer screening on metastasis: A prostate cancer case study

BACKGROUND

Trials of cancer screening present results in terms of deaths prevented, but metastasis is also a key endpoint that screening seeks to prevent. We developed a framework for projecting overall (de novo and progressive) metastases prevented in a screening trial using prostate cancer screening as a case study.

METHODS

Mechanistic simulation model in which screening shifts a fraction of cases that would be metastatic at diagnosis to being non-metastatic. This shift increases the incidence of non-overdiagnosed, organ-confined cases. We use estimates of the risk of metastatic progression for these cases to project how many progress to metastasis after diagnosis and tally the projected de novo and progressive metastatic cases with and without screening. We use data on stage shift from the European Randomized Study of Screening for Prostate Cancer (ERSPC) and data on the risk of metastatic progression from the Scandinavian Prostate Cancer Group-4 trial. We estimate the relative risk and absolute risk reductions in metastatic disease at diagnosis and compare these with reductions in overall metastases.

RESULTS

Assuming no effect of screening beyond initial stage shift at diagnosis, the model projects a 43% reduction in metastasis at diagnosis but a 22% reduction in the cumulative probability of metastasis over 12 years in favor of screening. These results are consistent with the empirical findings from the ERSPC.

CONCLUSION

Any reduction in metastatic disease at diagnosis under screening is likely to be an overly optimistic predictor of the impact of screening on overall metastasis and disease-specific mortality.

Treatment patterns of high-dose-rate and low-dose-rate brachytherapy as monotherapy for prostate cancer

PURPOSE

Monotherapy with high-dose-rate (HDR) or low-dose-rate (LDR) brachytherapy are both recommended modalities for prostate cancer. The choice between HDR and LDR is dependent on patient, physician, and hospital preferences. We sought to identify treatment patterns and factors associated with receipt of HDR or LDR monotherapy.

MATERIAL AND METHODS

We queried the National Cancer Database (NCDB) for patients with localized low- or intermediate-risk prostate cancer treated with HDR or LDR monotherapy. Descriptive statistics were used to analyze patterns of HDR vs. LDR. Patient characteristics were correlated with HDR vs. LDR using multivariable logistic regression.

RESULTS

We identified 50,326 patients from 2004-2014: LDR 37,863 (75.2%) vs. HDR 12,463 (24.8%). Median follow-up was 70.3 months. The overall use of monotherapy declined over time. HDR application declined relative to LDR. In 2004, 27.0% of cases were HDR compared to 19.2% in 2014. Factors associated with increased likelihood of HDR on multivariable analysis included: increasing age (OR: 1.01, 95% CI: 1.01-1.01), cT2c disease (OR: 1.25, 95% CI: 1.11-1.41), treatment at an academic center (OR: 2.45, 95% CI: 2.24-2.65), non-white race (OR: 1.34, 95% CI: 1.27-1.42), and income > $63,000 (OR: 1.73, 95% CI: 1.59-1.88). LDR was more common in 2010-2014 (OR: 0.59, 95% CI: 0.54-0.65), Charlson-Deyo comorbidity index > 0 (OR: 0.89, 95% CI: 0.84-0.95), and for patients receiving hormone therapy (OR: 0.88, 95% CI: 0.83-0.93). No difference in prostate-specific antigen (PSA) or Gleason score and receipt of HDR vs. LDR was observed. Mean overall survival was 127.0 months for HDR and 125.4 for LDR, and was not statistically different.

CONCLUSIONS

We observed an overall decrease in brachytherapy (BT) monotherapy use since 2004 for localized prostate cancer. Despite similar survival outcomes, the use of HDR monotherapy declined relative to LDR.

What's new in screening in 2015?

PURPOSE OF REVIEW

The aim of this review was to highlight important articles in the field of prostate cancer screening published during 2015 and early 2016. Four major areas were identified for the purpose: screening strategies, post-United States Preventive Services Task Force (USPSTF) 2011-2012, screening trends/patterns, and shared decision making.

RECENT FINDINGS

Several studies furthered the evidence that screening reduces the risk of metastasis and death from prostate cancer. Multiplex screening strategies are of proven benefit; genetics and MRI need further evaluation. Prostate-specific antigen (PSA) screening rates declined in men above age of 50 years, as did the overall prostate cancer incidence following the USPSTF 2011-2012 recommendation against PSA. The consequences of declining screening rates will become apparent in the next few years. More research is needed to identify the most optimal approach to engage in, and implement, an effective shared decision-making in clinical practice.

SUMMARY

Data emerging in 2015 provided evidence on the question of how best to screen and brought more steps in the right direction of 'next-generation prostate cancer screening'. Screening is an ongoing process in all men regardless of whether or not they might benefit from early detection and treatment. After the USPSTF 2011-2012 recommendation, the rates of PSA testing are declining; however, this decline is observed in all men and not solely in those who will not benefit from the screening. The long-term effect of this recommendation might not be as anticipated. More studies are needed on how to implement the best available evidence on who, and when, to screen in clinical practice.

Novel PSCA targeting scFv-fusion proteins for diagnosis and immunotherapy of prostate cancer

PURPOSE

Despite great progress in the diagnosis and treatment of localized prostate cancer (PCa), there remains a need for new diagnostic markers that can accurately distinguish indolent and aggressive variants. One promising approach is the antibody-based targeting of prostate stem cell antigen (PSCA), which is frequently overexpressed in PCa. Here, we show the construction of a molecular imaging probe comprising a humanized scFv fragment recognizing PSCA genetically fused to an engineered version of the human DNA repair enzyme O6-alkylguanine-DNA alkyltransferase (AGT), the SNAP-tag, enabling specific covalent coupling to various fluorophores for diagnosis of PCa. Furthermore, the recombinant immunotoxin (IT) PSCA(scFv)-ETA' comprising the PSCA(scFv) and a truncated version of Pseudomonas exotoxin A (PE, ETA') was generated.

METHODS

We analyzed the specific binding and internalization behavior of the molecular imaging probe PSCA(scFv)-SNAP in vitro by flow cytometry and live cell imaging, compared to the corresponding IT PSCA(scFv)-ETA'. The cytotoxic activity of PSCA(scFv)-ETA' was tested using cell viability assays. Specific binding was confirmed on formalin-fixed paraffin-embedded tissue specimen of early and advanced PCa.

RESULTS

Alexa Fluor® 647 labeling of PSCA(scFv)-SNAP confirmed selective binding to PSCA, leading to rapid internalization into the target cells. The recombinant IT PSCA(scFv)-ETA' showed selective binding leading to internalization and efficient elimination of target cells.

CONCLUSIONS

Our data demonstrate, for the first time, the specific binding, internalization, and cytotoxicity of a scFv-based fusion protein targeting PSCA. Immunohistochemical staining confirmed the specific ex vivo binding to primary PCa material.

Changes in mortality and incidence of prostate cancer by risk class in different periods in Italy: the possible effects of PSA spread

PURPOSE

In Italy, the spread of prostate-specific antigen (PSA) testing varies in different areas. A peak of incidence was reached in 2003-2004 in some areas, while in others the incidence is still increasing. Mortality has declined since 1999 in some areas, while it remains stable in others. We compared mortality and the risk of advanced cancer over 2 periods (1996-1998; 2005-2007) and by geographic area characterized by a different spread of PSA, to understand the possible impact of PSA on the epidemiology of prostate cancer.

METHODS

In 8 Italian Cancer Registries (CRs), 4,632 cases diagnosed over 2 periods, 1996-1998 and 2005-2007, were sampled to assess risk class. The CRs were classified into late and early phase of PSA testing depending on whether an incidence peak had been reached by 2008. Incidence by risk class was estimated based on overall incidence in each CR and on risk class distribution in the sample. We calculated standardized mortality (MRR) and risk class-specific incidence rate ratios (IRR) to compare the 2 periods.

RESULTS

Incidence increased from 1996-1998 to 2005-2007 (IRR 1.5; 95% CI 1.4, 1.6). High-risk and metastatic cancer incidence decreased only in late-phase areas (IRR 0.78; 95% CI 0.69, 0.88; and 0.40; 95% CI 0.30, 0.54, respectively), while in early-phase areas, incidence remained virtually stable (IRR 1.2; 95% CI 1.0, 1.4; and 0.77; 95% CI 0.59, 1.0, respectively). Mortality decreased only in late-phase areas (MRR 0.81; 95% CI 0.85, 0.97; vs 1.1; 95% CI 0.92, 1.2) in early-phase areas.

CONCLUSIONS

Mortality reduction and a decrease in high-risk and metastatic cases occurred simultaneously only in areas in late phase of PSA spread.