Cadmium (Cd), a heavy metal with strong carcinogenic properties has been linked with breast cancer risk. Epidemiological data on the association between Cd exposure and breast cancer are not consistent and suggest that this relationship may be modulated by a number of different factors. The mechanisms of action underlying the molecular effects of Cd, especially in terms of its carcinogenicity, are generally not well understood. Specifically, in the mammary gland, the effects of Cd are considered to be related mainly to its oestrogenic potential, however, several other mechanisms have also been suggested, such as epigenetic alterations, inhibition of DNA repair pathways, induction of oxidative stress, interference with metallothioneins, cadherins and integrins, as well as interactions with xenobiotics. This review summarizes the current state of knowledge in this field, including potential mechanisms of action of Cd in breast cancer initiation and progression, as well as possible ways of protection against its toxicity. Importantly, there are many research gaps in this area since limited evidence is available from experimental studies. Important issues to be further investigated concern exact molecular mechanisms of Cd accumulation in the tissues and Cd-induced activation of eostrogen receptors. Impact on DNA damage and epigenome upon Cd exposure in breast cancer development remains still highly unexplored area and should gain more interest.

Oncologists now favor more personalized treatment strategies in breast cancer patients. Gene expression analysis has been widely used, but less is known about epigenetic factors, for example, microRNAs (miRNAs). The aim of this study was to determine the relationship between selected miRNAs and receptor status in core biopsies sampled before preoperative chemotherapy in stage III locally advanced breast cancer (LABC) patients. In 37 LABC core biopsies, three miRNAs per sample were analyzed: hsa-miR-93-5p, hsa-miR-190a, and hsa-miR-200b-3p, and hsa-miR-103a-3p as an endogenous control (TaqMan(®) RT-PCR; Applied Biosystems). Receptor status was determined by a dedicated pathologist. The Mann-Whitney U, Shapiro-Wilk, and Levene's tests were used to compare related samples. Levels of miRNA-93 differed significantly in core biopsies of LABC patients with different expressions of ER (estrogen receptor) and PR (progesterone receptor). Higher levels of miRNA-93 were found in ER-negative (p=0.0027) and PR-negative patients (p=0.0185). Levels of miRNA-190 and 200b did not differ significantly in core biopsies of LABC patients who expressed ER and PR differently (p=0.7727, p=0.9434, p=0.6213, and p=0.1717). Levels of miRNA-93, 190, and 200b were not significantly different in core biopsies of LABC patients with different HER2 (human epidermal growth factor 2) expressions (p=0.8013, p=0.2609, and p=0.3222). The assessment of core biopsy miRNA profiles and receptor-based subtypes may identify new signaling pathways for improved breast cancer classification.

Immune checkpoints refer to a plethora of inhibitory pathways built into the immune system, and recent studies have emphasized the role of these checkpoints in carcinogenesis. The aim of the present study was to evaluate two major immune checkpoints, the cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1), in the serum of 35 patients with stage I and II breast cancer. Serum concentrations of CTLA-4 and PD-1 were measured at three time points: i) Preoperatively; ii) during anesthesia following the harvesting of sentinel nodes (SNs); and iii) 24 h postoperatively. Control samples were obtained from 25 healthy, age-matched females. Assessment of CTLA-4 and PD-1 expression levels was conducted using flow cytometry. A statistically significant difference in PD-1 expression was identified between breast cancer patients preoperatively and healthy controls (26.31±11.87 vs. 12.72±8.15; P<0.0001). In addition, a statistically significant association was found between CTLA-4 and PD-1 levels prior to surgery (P=0.0084). In addition, CTLA-4 expression was associated with age (P=0.0453), with elevated levels of CTLA-4 detected in older breast cancer patients. Higher PD-1 expression levels were observed in T2 tumors compared with T1 tumors prior to surgery and intraoperatively; however, the differences were not statistically significant. Furthermore, a decrease in PD-1 levels was observed subsequent to harvesting SNs with metastasis, but not in SN-negative patients (P=0.05). A negative correlation was also observed between PD-1 expression and progesterone receptor (PR) status following surgery (P=0.024). These results provided a basis for further investigation of immune checkpoints in breast cancer. Breast cancer patients exhibit an altered profile of immune checkpoint markers, with higher concentrations of PD-1 observed in larger, PR-negative tumors.

(1) Introduction: In response to patient concerns about breast cancer recurrence, increased use of breast magnetic resonance imaging and genetic testing, and advancements in breast reconstruction techniques, mastectomy rates have been observed to rise over the last decade. The aim of the study is to compare the outcomes of prepectoral and subpectoral implants and long-term, dual-stage resorbable mesh-based breast reconstructions in mutation carriers (prophylactic surgery) and breast cancer patients. (2) Patients and methods: This retrospective, two-center study included 170 consecutive patients after 232 procedures: Prepectoral surgery was performed in 156 cases and subpectoral was performed in 76. (3) Results: Preoperative chemotherapy was associated with more frequent minor late complications (p < 0.001), but not major ones (p = 0.101), while postoperative chemotherapy was related to more frequent serious (p = 0.005) postoperative complications. Postoperative radiotherapy was associated with a higher rate of minor complications (31.03%) than no-radiotherapy (12.21%; p < 0.001). Multivariate logistic regression found complications to be significantly associated with an expander (OR = 4.43), skin-reducing mastectomy (OR = 9.97), therapeutic mastectomy vs. risk-reducing mastectomy (OR = 4.08), and postoperative chemotherapy (OR = 12.89). Patients in whom prepectoral surgeries were performed demonstrated significantly shorter median hospitalization time (p < 0.001) and lower minor complication rates (5.77% vs. 26.32% p < 0.001), but similar major late complication rates (p = 0.915). (4) Conclusions: Implant-based breast reconstruction with the use of long-term, dual-stage resorbable, synthetic mesh is a safe and effective method of breast restoration, associated with low morbidity and good cosmesis. Nevertheless, prospective, multicenter, and long-term outcome data studies are needed to further evaluate the benefits of such treatments.

Introduction: The evaluation of lymph nodes (LNs) in patients with suspected oncological disease is a crucial factor influencing further diagnostics and management. However, there is a lack of a dedicated system for the precise and comprehensive assessment of LNs. To address this gap, we developed the Lymph Node Reporting and Data System (LN-RADS). Methods: This retrospective multiparametric analysis included the assessment of 719 LNs in 489 patients. The images were evaluated by three radiologists using the LN-RADS scale, assigning each case to one of six group: 1 (normal), 2 (steatotic), 3 (reactive), 4a (low suspicion of malignancy) vs. 4b (high suspicion of malignancy), and 5 (definitely malignant) and were then correlated with histopathological results. The diagnostic performance of LN-RADS was validated. The analysis of 12 morphological features of LNs was performed to identify predictors of malignancy. Results: Histopathological analysis confirmed 389 malignant and 330 benign LNs. LN-RADS achieved 89% sensitivity, 85% specificity, and 87% accuracy in the diagnosis of malignant LN. The observed risk of malignancy by group was 0% for LN-RADS 1, 0% for LN-RADS 2, 2% for LN-RADS 3, 31% for LN-RADS 4a, 77% for LN-RADS 4b, and 97% for LN-RADS 5. Cohen’s kappa statistic indicated substantial inter-reader agreement. Among the evaluated features, the strongest predictor of malignancy was the cortex thickness diameter, with a threshold value of ≥6 mm (82% accuracy; AUC = 0.894). Conclusions: This study demonstrated the high efficacy of the LN-RADS system in distinguishing between benign and malignant lymph nodes and in stratifying malignancy risk. It also showed substantial inter-rater agreement.