Prostate cancer screening in low- and middle-income countries: the Mexican case

Germline DNA Repair Genes Pathogenic Variants Among Mexican Patients With Prostate Cancer

BACKGROUND

Early identification of germline mutation carriers may be relevant for the optimal management of prostate cancer and to inform cancer risk in relatives. However, population minorities have limited access to genetic testing. The aim of this study was to describe the frequency of DNA repair gene pathogenic variants (PVs) among Mexican men with prostate cancer referred for Genomic Cancer Risk Assessment and testing.

METHODS

Patients diagnosed with prostate cancer who meet criteria for genetic testing and enrolled in the Clinical Cancer Genomics Community Research Network at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico City were included. Descriptive statistics were performed using frequency and proportions for categorical variables and median and range for quantitative variables. X2 and t test were used for group comparisons.

RESULTS

A total of 199 men were enrolled, median age at diagnosis was 66 (range 44-88) years; 45% were de novo metastatic and 44% were high- very high and 10% were intermediate risk group. Four (2%) had a pathogenic germline variant; one each of the following genes: ATM, CHEK2, BRIP1, and MUTYH (all monoallelic). Younger men at diagnosis were more likely to carry a PV than older age at diagnosis (56.7 vs. 66.4 years, P = .01).

CONCLUSION

Our results showed a low prevalence of known prostate cancer associated PVs and no BRCA PVs in Mexican men with prostate cancer. This suggests that the genetic and/or epidemiologic risk factors for prostate cancer are not well characterized in this specific population.

Radiation therapy for prostate cancer in Syrian refugees: facing the need for change

Purpose

To report the utilization of radiation therapy in Syrian refugee patients with prostate cancer residing in Turkey.

Methods and materials

A multi-institutional retrospective review including 14 cancer centers in Turkey was conducted to include 137 Syrian refugee patients with prostate cancer treated with radiation therapy (RT). Toxicity data was scored using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Noncompliance was defined as a patient missing two or more scheduled RT appointments.

Results

Advanced disease, defined as stage III or IV, was reported in 64.2% of patients while androgen deprivation therapy (ADT) was only administrated to 20% of patients. Conventionally fractionated RT with a median number of 44 fractions was delivered to all patients with curative intent (n = 61) while palliative RT (n = 76) was delivered with a median number of 10 fractions. The acute grade 3-4 toxicity rate for the entire cohort was 16%. Noncompliance rate was 42%.

Conclusion

Most Syrian refugee prostate cancer patients presented with advanced disease however ADT was seldom used. Despite the low treatment compliance rate, conventional fractionation was used in all patients. Interventions are critically needed to improve screening and increase the use of standard-of-care treatment paradigms, including hypofractionated RT and ADT.

Preservation of Proteins in Human Plasma through Metal-Organic Framework Encapsulation

Traditional cold chain systems of collection, transportation, and storage of biofluid specimens for eventual analysis pose a huge financial and environmental burden. These systems are impractical in pre-hospital and resource-limited settings, where refrigeration and electricity are not reliable or even available. Here, we develop an innovative technology using metal-organic frameworks (MOFs), a novel class of organic-inorganic hybrids with high thermal stability, as encapsulates for preserving the integrity of protein biomarkers in biofluids under ambient or non-refrigerated storage conditions. We encapsulate prostate-specific antigen (PSA) in whole patient plasma using hydrophilic zeolitic imidazolate framework-90 (ZIF-90) for preservation at 40 °C for 4 weeks and eventual on-demand reconstitution for antibody-based assays with recovery above 95% compared to storage at -20 °C. Without ZIF-90 encapsulation, only 10-30% of the PSA immunoactivity remained. Furthermore, we demonstrate encapsulation of multiple cancer biomarker proteins in whole patient plasma using ZIF-8 or ZIF-90 encapsulants for eventual on-demand reconstitution and analysis after 1 week at 40 °C. Overall, MOF encapsulation of patient biofluids is important as climate change may be affecting the stability and increase costs of maintaining biospecimen cold chain custody for the collection, transportation, and storage of biospecimens prior to analysis or for biobanking regardless of any countries' affluence.

Prostate Cancer Disparities and Management in Southern Africa: Insights into Practices, Norms and Values

Prostate cancer (PCa) is a leading cause of mortality in men of African origin. While men of African descent in high-income countries (HICs) demonstrate poor prognosis compared to their European counterparts, African men on the African continent, particularly Southern Africa have shown even higher PCa mortality rates. Extrinsic factors such as the socioeconomic status, education level, income level, geographic location and race contribute to PCa patient outcome. These are further deepened by the African norms which are highly esteemed and may have detrimental effects on PCa patients' health. Insights into African cultures and social constructs have been identified as key elements towards improving men's health care seeking behaviour which will in turn improve PCa patients' outcome. Compared to Southern Africa, the Eastern, Western and Central African regions have lower PCa incidence rates but higher mortality rates. The availability of cancer medical equipment has also been reported to be disproportionate in Africa, with most cancer resources in Northern and Southern Africa. Even within Southern Africa, cancer management resources are unevenly available where one country must access PCa specialised care in the neighbouring countries. While PCa seems to be better managed in HICs, steps towards effective PCa management are urgently needed in Africa, as this continent represents a significant portion of low-middle-income countries (LMICs). Replacing African men in Africa with African American men may not optimally resolve PCa challenges in Africa. Adopting western PCa management practices can be optimised by integrating improved core-African norms. The aim of this review is to discuss PCa disparities in Africa, deliberate on the significance of integrating African norms around masculinity and discuss challenges and opportunities towards effective PCa care in Africa, particularly in Southern Africa.

Socioeconomic inequalities in prostate cancer screening in low- and middle-income countries: An analysis of the demographic and health surveys between 2010 and 2019

INTRODUCTION

Prostate cancer screening is a valuable public health tool in the early detection of prostate cancer. In this study, we aimed to determine the socioeconomic inequalities in the coverage of prostate cancer screening in Low and Middle-Income Countries (LMICs).

METHODS

This was a retrospective analysis of men's recode data files that were collected by the Demographic and Health Surveys (DHS) in LMICs (Armenia, Colombia, Honduras, Kenya, Namibia, Dominican Republic, and the Philippines). We included surveys that were conducted from 2010 to 2020 and measured the coverage of prostate cancer screening and the study population was men aged 40 years or older. Socioeconomic inequality was measured using the Concertation Index (CIX) and the Slope Index of Inequality (SII).

RESULTS

Eight surveys from seven countries were included in the study with a total of 47,863 men. The coverage of prostate cancer screening was below 50% in all the countries with lower rates in the rural areas compared to the urban areas. The pooled estimate for the coverage of screening was 10.4% [95% CI, 7.9-12.9%). Inequalities in the coverage of prostate cancer screening between the wealth quintiles were observed in the Democratic Republic, Honduras, and Namibia. Great variation in inequalities in the coverage of prostate cancer screening between rural and urban residents was observed in Colombia and Namibia.

CONCLUSION

The coverage of prostate cancer screening was low in LMICs with variations in the coverage by the quintile of wealth (pro-rich) and type of place of residence (pro-urban).

POLICY SUMMARY

To achieve the desired impact of prostate cancer screening services in LMICs, it is important that the coverage of screening programs targets men living in rural areas and those in low wealth quintiles.

Incidence, Mortality, and Trends of Prostate Cancer in Mexico from 2000 to 2019: Results from the Global Burden of Disease Study 2019

Simple Summary

Worldwide, prostate cancer (PC) causes high morbidity and mortality. Thus, developing effective strategies for the prevention, diagnosis, and control of this disease is fundamental to providing updated and reliable estimations of the PC burden both nationally and subnationally. Herein, we analyzed data from the Global Burden of Disease study to estimate PC incidence and mortality, and their trends in Mexico at the national and subnational levels from 2000 to 2019. Our results show that PC was the top ranked cause of death among malign neoplasms in males from Mexico during 2019. Males from 70 to 79 years of age were the most affected by PC, and there was an increasing trend in the burden of this cancer. There was substantial subnational heterogeneity that suggested differential geographical patterns of change. These results provide both comprehensive and comparable estimates to assist the effort to reduce health loss due to PC.

Abstract

In 2019, the Global Burden of Disease (GBD) estimated that prostate cancer (PC) was the 16th most common cause of death globally in males. In Mexico, PC epidemiology has been studied by a number of metrics and over various periods, although without including the most up-to-date estimates. Herein, we describe and compare the burdens and trends of PC in Mexico and its 32 states from 2000 to 2019. For this study, we extracted online available data from the GBD 2019 to estimate the crude and age-standardized rates (ASR per 100,000 people) of the incidence and mortality of PC. In Mexico, PC caused 27.1 thousand (95% uncertainty intervals, 20.6–36.0 thousand) incident cases and 9.2 thousand (7.7–12.7 thousand) deaths in males of all ages in 2019. Among the states, Sinaloa had the greatest ASR of incidence, and Guerrero had the highest mortality. The burden of PC showed an increasing trend, although the magnitude of change differed between metrics and locations. We found both an increasing national trend and subnational variation in the burden of PC. Our results confirm the need for updated and timely estimates to design effective diagnostic and treatment campaigns in locations where the burden of PC is the highest.

Evaluation of Prostate Cancer Screening Strategies in a Low-Resource, High-risk Population in the Bahamas

Importance

The benefit of prostate-specific antigen screening may be greatest in high-risk populations, including men of African descent in the Caribbean. However, organized screening may not be sustainable in low- and middle-income countries.

Objective

To evaluate the expected population outcomes and resource use of conservative prostate-specific antigen screening programs in the Bahamas.

Design Setting and Participants

Prostate cancer incidence from GLOBOCAN and prostate-specific antigen screening data for 4300 men from the Bahamas were used to recalibrate 2 decision analytical models previously used to study prostate-specific antigen screening for Black men in the United States. Data on age and results obtained from prostate-specific antigen screening tests performed in Nassau from 2004 to 2018 and in Freeport from 2013 to 2018 were used. Data were analyzed from January 15, 2021, to March 23, 2022.

Interventions

One or 2 screenings for men aged 45 to 60 years and conservative criteria for biopsy (prostate-specific antigen level >10 ng/mL) and curative treatment (Gleason score ≥8) were modeled. Categories of Gleason scores were 6 or lower, 7, and 8 or higher, with higher scores indicating higher risk of cancer progression and death.

Main Outcomes and Measures

Projected numbers of tests and biopsies, prostate cancer (over)diagnoses, lives saved, and life-years gained owing to screening from 2022 to 2040.

Results

In this decision analytical modeling study, screening histories from 4300 men (median age, 54 years; range, 13-101 years) tested between 2004 and 2018 at 2 sites in the Bahamas were used to inform the models. Screening once at 60 years of age was projected to involve 40 000 to 42 000 tests (range between models) and prevent 500 to 600 of 10 000 to 14 000 prostate cancer deaths. Screening at 50 and 60 years doubled the number of tests but increased lives saved by only 15% to 16%. Among onetime strategies, screening once at 60 years of age involved the fewest tests per life saved (74-84 tests) and curative treatments per life saved (1.2-2.8 treatments).

Conclusions and Relevance

The findings of this decision analytical modeling study of prostate cancer screening in the Bahamas suggest that limited screening offered modest benefits that varied with screening ages and number of tests. The results can be combined with data on capacity constraints and evaluated relative to competing national public health priorities.

Improving prostate biopsy decision making in Mexican patients: Still a major public health concern

BACKGROUND

Prostate cancer screening has reduced its mortality in 21%. However, this has also led to an increased number of biopsies in order to establish the diagnosis, many of them unnecessary. Current screening guidelines prioritize use of prostatic magnetic resonance and new biomarkers to reduce unnecessary biopsies, however, their implementation in developing countries screening programs is mainly limited by its costs.

OBJECTIVE

We aimed to evaluate Prostate Biopsy Risk Collaborative Group (PBCG) and Prostate Cancer Prevention Trial Risk Calculator (PCPTRC) 2.0 predictions accuracy in Mexican patients in order to guide prostate biopsy decision making and reduce unnecessary biopsies.

MATERIALS AND METHODS

We retrospectively analyzed patients between 55 and 90 years old who underwent prostate biopsy in a high-volume center in Mexico between January 2017 and June 2020. Clinical utility of PBCG and PCPTRC 2.0 to predict high-grade prostate cancer (HGPCa) biopsy outcomes was evaluated using decision curve analysis and compared to actual biopsy decision making. Receiver operating characteristics area under the curve (AUC) was used to measure discrimination and external validation.

RESULTS

From 687 patients eligible for prostate biopsy, 433 met selections criteria. One hundred and thirty-five (31.17%) patients were diagnosed with HGPCa, 63 (14.54%) with low-grade disease and 235 (54.27%) had a negative biopsy. PCPTRC 2.0 ≥15% threshold got a standardized net benefit (sNB) of 0.70, while PBCG ≥30% and ≥35% had a sNB of 0.27 and 0.15, respectively. Use of both models for guiding prostate biopsy decision resulted in no statistical difference for HGCPa detection rates, while achieved a significant difference in reducing total and unnecessary biopsies. However, this difference was lower (better) for PCPTRC 2.0, being statistically significative when compared against PBCG thresholds. Both models were well calibrated (AUC 0.79) and achieved external validation compared with international cohorts.

CONCLUSIONS

Our study is the first to effectively validate both PCPTRC 2.0 and PBCG predictions for the Mexican population, proving that their use in daily practice improves biopsy decision making by accurately predicting HGPCa and limit unnecessary biopsies without representing additional costs to screening programs.