High levels of microplastics found in prostate tumors, possibly linked to take-out food

by · News-Medical

The presence of microplastics in prostate tumors points to potential health risks, and researchers are calling for urgent studies to explore how take-out food may be driving this exposure.

The study highlights the strong positive correlation between take-out food consumption and polystyrene abundance, emphasizing the need for safer food packaging alternatives. Furthermore, the presence of microplastics in prostate tissue raises questions about the potential role of environmental factors in the onset or progression of prostate cancer. However, more research is needed to establish causality.

Background

Microplastics (MPs) are minute plastic fragments (<5 mm) that arise from the (usually environmental) degradation of plastic commodities. They are ubiquitous in nature and are easily ingested and assimilated into the tissues of humans and other animals, given their small particle sizes. A growing body of evidence underscores microplastics' negative public health potential, associating these particles with diseases of the placenta, lungs, blood, intestines, and gonads. Microplastics are also observed to be bioaccumulated across food chains, resulting in higher concentrations and physiological damage to higher trophic levels.

Particle shape and size: The microplastics varied in shape, with irregular forms being predominant, and most particle sizes ranged between 20 and 100 μm. Tumor tissues had a higher concentration of larger particles (50-100 μm).

Alarmingly, the global prevalence of plastics (and, by extension, microplastics) continues to rise. The rapid industrial development, population growth, and consumeristic trends of the 21st century have promoted this pattern, resulting in a 230-fold increase in plastic production (2019, 460 metric tons) compared to just 70 years prior (1950, 2 metric tons).

Alongside their particulate (physical) effects, microplastics are known to have a strong affinity for toxic plasticizers, including dibutyl phthalate (DBP) and bisphenol A (BPA), with known hormone-altering, often carcinogenic properties. While the impacts of microplastics on a handful of cancers (e.g., blood and lung) have been extensively characterized, their associations with prostate cancers remain unknown. Given the growing prevalence of prostate-cancer-associated morbidity and mortality worldwide (one of the most common male cancers), elucidating the risk factors in prostate cancer genesis is imperative.

About the study

The present study aims to elucidate the properties, abundance, and main types of MPs in prostate tissue (specifically, para-tumor and tumor). Study data was obtained from Peking University First Hospital patients who underwent robot-assisted radical prostatectomy (RARP) between Jan 2023 and July 2024. However, due to the small sample size (22 patients), the results of this exploratory study may not be generalizable to all prostate cancer populations. Larger, more diverse samples are needed to validate these findings. Exclusion criteria included: 1. Patients who underwent neoadjuvant endocrine therapy, 2. Patients with preexisting prostate cancer at baseline, and 3. Lack of expert supervision during RARP procedures.

Data collection included patient's demographic data and medical histories. Sample collection comprised paired para-tumor and tumor tissue excisions (n = 22 each). To identify and characterize microplastics, two paired samples were used for laser direct infrared (LDIR) imaging and scanning electron microscopy (SEM) analysis. For abundance estimations, the remaining 20 pairs were used for pyrolysis–gas chromatography-mass spectrometry (Py–GC/MS) analysis. The National Institute of Standards and Technology (NIST) mass spectrometry database was referenced for microplastic characteristics.

Study findings

The patient population's median age was 66.8 years, with mean body mass index (BMI) and prostate volume elucidated as 25.4 kg/cm2 and 45.9 mL, respectively. Notably, 50% (n = 11) of patients were smokers, and 36.4% (n = 8) regularly consumed alcohol. Alarmingly, almost all patients were found to frequently consume packaged bottled water (86.4%) and take-out food (77.3%).

LDIR and SEM imaging revealed the presence of four main MPs (PS, PE, PP, and PVC) across both tissue types analyzed. Surprisingly, PS could only be detected from tumor tissue but not para-tumor tissue. All MPs detected ranged in size from 20 to 100 μm, but the majority measured 20 to 50 μm.

Patient correlations: The study found a positive correlation between polystyrene levels in tumor tissues and the frequency of take-out food consumption, further linking lifestyle choices to microplastic exposure.

Conclusions

Notably, participant behavioral investigations revealed frequent utilization of packaged drinking water and take-out food, suggesting potential MP exposure routes and highlighting the safer food packing alternatives.

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