Brief research report pesticide occupational exposure leads to significant inflammatory changes in normal mammary breast tissue.

Studies have documented the high occurrence of several tumors, including female breast cancer, in populations occupationally exposed to pesticides worldwide. It is believed that in addition to direct DNA damage, other molecular alterations that indicate genomic instability are associated, such as epigenetic modifications and the production of inflammation mediators. The present study characterized the profile of inflammatory changes in the breast tissue of women without cancer occupationally exposed to pesticides. In samples of normal breast tissue collected during biopsy and evaluated as negative for cancer by a pathologist, oxidative stress levels were assessed as inflammatory markers through measurements of lipoperoxides and total antioxidant capacity of the sample (TRAP) by high-sensitivity chemiluminescence, as well as levels of nitric oxide (NOx) metabolites. The levels of inflammation-modulating transcription factors PPAR-γ (peroxisome proliferator-activated receptor gamma) and NF-κB (nuclear factor kappa B) were also quantified, in addition to the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin 12 (IL-12). The levels of lipoperoxides, TRAP, and NOx were significantly lower in the exposed group. On the other hand, PPAR-γ levels were increased in the breast tissue of exposed women, with no variation in NF-κB. There was also a rise of TNF-α in exposed women samples without significant variations in IL-12 levels. These findings suggest an inflammatory signature of the breast tissue associated with pesticide exposure, which may trigger mechanisms related to mutations and breast carcinogenesis.

The Expression of CTLA-4 in Breast Tumors and Tumor-Infiltrating Leukocytes Affects Patients' Systemic Inflammatory Status and Varies According to Their Molecular Subtypes.

Recent evidence has pointed out that the cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) expression is a poor prognosis factor. However, the implications of CTLA-4 expression on circulating inflammatory mediators are unclear for breast cancer. Tumor biopsies and blood samples were collected from 117 breast cancer patients. Oxidative stress parameters were evaluated in plasma samples by measuring the lipoperoxidation profile and nitric oxide metabolites (NOx). Interleukins 12 (IL-12) and 4 (IL-4) were assessed by ELISA. CTLA-4 expression was determined by immunofluorescence assessed by its labeling in tumor-infiltrating leukocytes (TILs) or breast tumors. Correlations between CTLA-4 expression in breast tumors with TCD4/TCD8 infiltrating lymphocyte and inflammation-related genes were performed using data from TIMER 2.0/TCGA databases (n = 2160). CTLA-4 expression in TILs significantly correlated to triple-negative breast tumors. Patients carrying CTLA-4-positive tumors exhibited lower plasmatic NOx levels, and those expressing CTLA-4 in TILs had reduced levels of IL-12 in plasma. No changes in either IL-4 or lipid peroxidation profiles were detected concerning any CTLA4 status. Compared to the Luminal A ones, oxidative stress parameters and cytokines were observed in patients bearing triple-negative tumors. CTLA-4 expression in all breast cancer subtypes positively correlated to TCD4/TCD8 lymphocyte infiltrates, as well as to the pro-inflammatory genes IL12A, IL4, NFKB1, NFKB2, NOS1, NOS2, and NOS3. CTLA-4 expression in both tumor and TILs can affect the systemic inflammatory status of breast cancer patients, especially antitumor molecules such as IL-12 and NOx that correlate to more aggressive disease.

Occupational Exposure to Pesticides Affects Pivotal Immunologic Anti-Tumor Responses in Breast Cancer Women from the Intermediate Risk of Recurrence and Death.

Breast cancer risk stratification is a strategy based using on clinical parameters to predict patients' risk of recurrence or death, categorized as low, intermediate, or high risk. Both low and high risk are based on well-defined clinical parameters. However, the intermediate risk depends on more malleable parameters. It means an increased possibility for either suboptimal treatment, leading to disease recurrence, or systemic damage due to drug overload toxicity. Therefore, identifying new factors that help to characterize better the intermediate-risk stratification, such as environmental exposures, is necessary. For this purpose, we evaluated the impact of occupational exposure to pesticides on the systemic profile of cytokines (IL-12, IL-4, IL-17A, and TNF-α) and oxidative stress (hydroperoxides, total antioxidants, and nitric oxide metabolites), as well as TGF-ß1, CTLA-4, CD8, and CD4 expression, investigated in tumor cells. Occupational exposure to pesticides decreased the levels of IL-12 and significantly increased the expression of TGF-ß1 and CTLA-4 in the immune infiltrate. Nevertheless, we observed a decrease in CTLA-4 in tumor samples and CD8 in infiltrating cells of intermediate overweight or obese patients with at least one metastatic lymph node at the diagnosis. These findings indicate that occupational exposure to pesticides changes the molecular behavior of disease and should be considered for intermediate-risk stratification assessment in breast cancer patients.

Corrigendum: Somatic DNA damage response and homologous repair gene alterations and its association with tumor variant burden in breast cancer patients with occupational exposure to pesticides.

[This corrects the article DOI: 10.3389/fonc.2022.904813.].

Somatic DNA Damage Response and Homologous Repair Gene Alterations and Its Association With Tumor Variant Burden in Breast Cancer Patients With Occupational Exposure to Pesticides.

Homologous recombination is a crucial pathway that is specialized in repairing double-strand breaks; thus, alterations in genes of this pathway may lead to loss of genomic stability and cell growth suppression. Pesticide exposure potentially increases cancer risk through several mechanisms, such as the genotoxicity caused by chronic exposure, leading to gene alteration. To analyze this hypothesis, we investigated if breast cancer patients exposed to pesticides present a different mutational pattern in genes related to homologous recombination (BRCA1, BRCA2, PALB2, and RAD51D) and damage-response (TP53) concerning unexposed patients. We performed multiplex PCR-based assays and next-generation sequencing (NGS) of all coding regions and flanking splicing sites of BRCA1, BRCA2, PALB2, TP53, and RAD51D in 158 unpaired tumor samples from breast cancer patients on MiSeq (Illumina) platform. We found that exposed patients had tumors with more pathogenic and likely pathogenic variants than unexposed patients (p = 0.017). In general, tumors that harbored a pathogenic or likely pathogenic variant had a higher mutational burden (p < 0.001). We also observed that breast cancer patients exposed to pesticides had a higher mutational burden when diagnosed before 50 years old (p = 0.00978) and/or when carrying BRCA1 (p = 0.0138), BRCA2 (p = 0.0366), and/or PALB2 (p = 0.00058) variants, a result not found in the unexposed group. Our results show that pesticide exposure impacts the tumor mutational landscape and could be associated with the carcinogenesis process, therapy response, and disease progression. Further studies should increase the observation period in exposed patients to better evaluate the impact of these findings.

Clinical implications of lipid peroxides levels in plasma and tumor tissue in breast cancer patients.

Oxidative stress can promote the oxidation of lipoproteins and polyunsaturated fatty acids present in cell membranes; an event known as lipid peroxidation (LPO). LPO has been associated with carcinogenesis and cancer progression, however, its meaning concerning the clinicopathological aspects of human breast cancer is not clear. This study investigated LPO profiles in tumor and plasma samples from breast cancer patients (n = 140) considering their clinicopathological features (age at diagnosis, menopausal status, body mass index, tumor histological grade, tumor size, ki-67 proliferation index, presence of metastasis, chemotherapy response, the molecular subtype of cancer and overall survival status). LPO levels were estimated by tert-butyl hydroperoxide-initiated chemiluminescence. High LPO levels were found regarding poor prognosis parameters as young age at diagnosis (p = 0.006 in tissue), premenopausal patients (p = 0.012 in tissue), high-grade tumors (p = 0.010 in tissue and p = 0.002 in plasma), metastatic disease (p = 0.046 in tissue), chemoresistant tumors (p = 0.041 in tissue), disease relapse (p = 0.018 in tissue and p = 0.009 in plasma) and overall survival status (p = 0.001 in plasma). Our findings point out the clinical meaning of LPO and highlight it as an oxidative stress event linked to poor prognosis and disease aggressiveness in breast cancer patients.

Carcinoma de Células de Merkel Metastático: Relato de Caso / Metastatic Merkel cell Carcinoma: Case Report / Carcinoma de Células de Merkel Metastásico: Relato de Caso

Introdução: O carcinoma de células de Merkel é um raro tumor neuroendócrino cutâneo, que se origina das células responsáveis pela sensibilidade tátil, possui caráter agressivo, evolução rápida e difícil tratamento. Relato do caso: Paciente do sexo masculino, 49 anos, caucasiano, que, ao atendimento dermatológico, apresentou nódulo indolor, infiltrando tecidos profundos, não ulcerado e localizado na região do braço esquerdo. O resultado da biópsia incisional foi positivo para carcinoma de células de Merkel. Após ressecção da lesão, os exames complementares evidenciaram doença metastática na axila e parede torácica. Com o tratamento quimioterápico, houve um benefício inicial com redução tumoral, porém, não durável, uma vez que foram reveladas novas áreas com metástases tumorais em regiões superiores do corpo, sendo submetido a novo procedimento cirúrgico, o qual, após novo regime quimioterápico, não obteve sucesso. Conclusão: Na ocasião do tratamento desse paciente, os anticorpos monoclonais, como o avelumab, não estavam disponíveis. O diagnóstico precoce com cirurgia de exérese da lesão imediata, antes do acometimento de outras regiões, permanece sendo a melhor opção para um prognóstico favorável ao paciente. Contudo, a despeito disso, com as limitações à época do tratamento, o paciente evoluiu a óbito.

Introduction: The Merkel cell carcinoma is a rare cutaneous neuroendocrine tumor that originates from cells responsible for tactile sensitivity, it has an aggressive character, fast evolution and difficult treatment. Case report: 49 years Caucasian male patient, with a painless nodule, infiltrating deep tissue, not ulcerated and located in left arm identified during the dermatological consultation. The result of the incisional biopsy was positive for Merkel cell carcinoma. After resection of the lesion, complementary exams revealed metastatic disease in the axilla and chest wall. The chemotherapy treatment brought an initial improvement with tumor reduction, however, it was not durable, because new areas with tumor metastases in upper regions of the body were revealed, the patient was submitted to an another surgical procedure, after which a new chemotherapy regimen failed. Conclusion:At the time of the treatment of this patient, monoclonal antibodies, such as avelumab, were not available. Early diagnosis with immediate lesion excision surgery, before the involvement of other regions, remains the best option for a better prognosis. However, regardless of this, because of the limitations at the time of the treatment, the patient died.

Introducción: El carcinoma de células de Merkel es un tumor neuroendocrino cutáneo raro, que se origina en células responsables de la sensibilidad táctil, tiene un carácter agresivo, una evolución rápida y un tratamiento difícil. Relato del caso: Paciente masculino, de 49 años, caucásico, que en atención dermatológica encontró nódulo indoloro, infiltrando tejidos profundos, no ulcerados y ubicados en la región del brazo izquierdo. El resultado de la biopsia incisional fue positivo para el carcinoma de células de Merkel. Después de la resección de la lesión, los exámenes complementarios mostraron enfermedad metastásica en la axila y la pared torácica. Con el tratamiento de quimioterapia, hubo un beneficio inicial con la reducción del tumor, sin embargo, no es duradero, ya que se revelaron nuevas áreas con metástasis tumorales en las regiones superiores del cuerpo, que se sometieron a un nuevo procedimiento quirúrgico, que después de un nuevo régimen de quimioterapia no tuvo éxito. Conclusión: En el momento del tratamiento de este paciente, los anticuerpos monoclonales, como avelumab, no estaban disponibles. El diagnóstico temprano con cirugía para la escisión de la lesión inmediata, antes de la participación de otras regiones, sigue siendo la mejor opción para un pronóstico favorable para el paciente. Sin embargo, a pesar de esto, con las limitaciones al momento del tratamiento, el paciente falleció.