Reactive oxygen species and antioxidant mechanisms in human tissues and their relation to malignancies

Reactive oxygen species (ROS) are formed in mammalian cells as a consequence of aerobic respiration. Despite multiple conserved redox modulating systems, a given proportion of ROS continuously escape from the mitochondrial respiratory chain, being sufficiently potent to damage cells in various ways, including numerous carcinogenic DNA mutations. Oxidative stress resulting from an imbalanced ratio between ROS production and detoxification may also disturb physiological signal transduction, lead to chain reactions in lipid layers, and damage DNA repair enzymes. The significance of ROS and antioxidant systems in carcinogenesis is still complicated and in many ways contradictory. Enhanced antioxidant mechanisms in tumor cells in vivo have been implicated in chemoresistance and lead to poor prognosis, whereas most in vitro studies have reported tumor-suppressing properties of antioxidant enzymes. The present review aims to clarify the significance of oxidative stress and the role of cell redox state modulating systems in human malignancies in light of the current literature.

Reactive Oxygen Species-Mediated Mechanisms of Action of Targeted Cancer Therapy

Targeted cancer therapies, involving tyrosine kinase inhibitors and monoclonal antibodies, for example, have recently led to substantial prolongation of survival in many metastatic cancers. Compared with traditional chemotherapy and radiotherapy, where reactive oxygen species (ROS) have been directly linked to the mediation of cytotoxic effects and adverse events, the field of oxidative stress regulation is still emerging in targeted cancer therapies. Here, we provide a comprehensive review regarding the current evidence of ROS-mediated effects of antibodies and tyrosine kinase inhibitors, use of which has been indicated in the treatment of solid malignancies and lymphomas. It can be concluded that there is rapidly emerging evidence of ROS-mediated effects of some of these compounds, which is also relevant in the context of drug resistance and how to overcome it.

8-Hydroxydeoxyguanosine: a new potential independent prognostic factor in breast cancer

BACKGROUND

8-Hydroxydeoxyguanosine (8-oxodG) is the commonly used marker of oxidative stress-derived DNA damage. 8-OxodG formation is regulated by local antioxidant capacity and DNA repair enzyme activity. Earlier studies have reported contradictory data on the function of 8-oxodG as a prognostic factor in different cancer types.

METHODS

We assessed pre-operative serum 8-oxodG levels with an enzyme-linked immunosorbent assay in a well-defined series of 173 breast cancer patients. 8-OxodG expression in the nuclei of cancer cells from 150 of these patients was examined by immunohistochemistry.

RESULTS

The serum 8-oxodG levels and immunohistochemical 8-oxodG expression were in concordance with each other (P<0.05). Negative 8-oxodG immunostaining was an independent prognostic factor for poor breast cancer-specific survival according to the multivariate analysis (P<0.01). This observation was even more remarkable when ductal carcinomas only (n=140) were considered (P<0.001). A low serum 8-oxodG level was associated statistically significantly with lymphatic vessel invasion and a positive lymph node status.

CONCLUSIONS

Low serum 8-oxodG levels and a low immunohistochemical 8-oxodG expression were associated with an aggressive breast cancer phenotype. In addition, negative 8-oxodG immunostaining was a powerful prognostic factor for breast cancer-specific death in breast carcinoma patients.

Combined Strategies with Poly (ADP-Ribose) Polymerase (PARP) Inhibitors for the Treatment of Ovarian Cancer: A Literature Review

Poly (ADP-ribose) polymerase (PARP) inhibitors are the first clinically approved drugs designed to exploit synthetic lethality, and were first introduced as a cancer-targeting strategy in 2005. They have led to a major change in the treatment of advanced ovarian cancer, and altered the natural history of a disease with extreme genetic complexity and defective DNA repair via homologous recombination (HR) pathway. Furthermore, additional mechanisms apart from breast related cancer antigens 1 and 2 (BRCA1/2) mutations can also result in HR pathway alterations and consequently lead to a clinical benefit from PARP inhibitors. Novel combinations of PARP inhibitors with other anticancer therapies are challenging, and better understanding of PARP biology, DNA repair mechanisms, and PARP inhibitor mechanisms of action is crucial. It seems that PARP inhibitor and biologic agent combinations appear well tolerated and clinically effective in both BRCA-mutated and wild-type cancers. They target differing aberrant and exploitable pathways in ovarian cancer, and may induce greater DNA damage and HR deficiency. The input of immunotherapy in ovarian cancer is based on the observation that immunosuppressive microenvironments can affect tumour growth, metastasis, and even treatment resistance. Several biologic agents have been studied in combination with PARP inhibitors, including inhibitors of vascular endothelial growth factor (VEGF; bevacizumab, cediranib), and PD-1 or PD-L1 (durvalumab, pembrolizumab, nivolumab), anti-CTLA4 monoclonal antibodies (tremelimumab), mTOR-(vistusertib), AKT-(capivasertib), and PI3K inhibitors (buparlisib, alpelisib), as well as MEK 1/2, and WEE1 inhibitors (selumetinib and adavosertib, respectively). Olaparib and veliparib have also been combined with chemotherapy with the rationale of disrupting base excision repair via PARP inhibition. Olaparib has been investigated with carboplatin and paclitaxel, whereas veliparib has been tested additionally in combination with temozolomide vs. pegylated liposomal doxorubicin, as well as with oral cyclophosphamide, and topoisomerase inhibitors. However, overlapping myelosuppression observed with PARP inhibitor and chemotherapy combinations requires further investigation with dose escalation studies. In this review, we discuss multiple clinical trials that are underway examining the antitumor activity of such combination strategies.

Prognostic and predictive role of tumour-associated macrophages in HER2 positive breast cancer

Disease outcomes of HER2+ breast cancers have dramatically improved after targeted therapies, such as trastuzumab became available. The main mechanism of action of trastuzumab depends on immunoactivation, while immunosuppressive tumour phenotype has been linked to adverse outcomes. Current study included metastatic HER2+ breast cancer patients treated with trastuzumab (n = 40). Immunohistochemistry was conducted to detect nitric oxide synthase 2 (iNOS) expressing M1 polarized and CD163+ M2 polarized macrophages, FoxP3+ regulatory T-cells (Tregs), CD47 and indoleamine 2,3-dioxygenase 1 (IDO1). High number of iNOS+ M1-like macrophages, both in the center of the tumour (CT) and invasive margin (IM), was significantly associated with improved survival (p = 0.009) while high expression of IDO1 or CD47 in the malignant cells was associated with worsened prognosis (p = 0.018, p = 0.046). High number of CD163+ M2-like macrophages in the CT, but not in the IM, and high number of FoxP3+ Tregs in both locations showed non-significant tendencies towards poor prognosis. Moreover, high number of iNOS+ M1-like macrophages combined with high number of CD8+ T-cells in the CT was significantly associated with improved survival (p = 0.0003), and this combined marker predicted patient's ability to remain progression-free without trastuzumab after responding to the therapy (p = 0.003). Current study highlights the role of M1 polarized macrophages alone and in combination with CD8+ cells in HER2+ breast cancer.

Oxidative stress and counteracting mechanisms in hormone receptor positive, triple-negative and basal-like breast carcinomas

Background

Triple-negative breast cancer (TNBC) and basal-like breast cancer (BLBC) are breast cancer subtypes with an especially poor prognosis. 8-Hydroxydeoxyguanosine (8-OHdG) is a widely used marker of oxidative stress and the redox-state-regulating enzymes peroxiredoxins (PRDXs) are efficient at depressing excessive reactive oxygen species. NF-E2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) are redox-sensitive transcription factors that regulate PRDX expression. This is the first study to assess oxidative stress and or cell redox state-regulating enzymes in TNBC and BLBC.

Methods

We assessed immunohistochemical expression of 8-OHdG, Nrf2, Keap1, PRDX III and PRDX IV in 79 women with invasive ductal breast carcinomas. Of these tumors, 37 represented TNBC (grade II-III tumors with total lack of ER, PR and human epidermal growth factor receptor 2 [HER2] expression). Control cases (n = 42) were ER-positive, PR-positive and HER2-negative. Of the 37 TNBCs, 31 had BLBC phenotype (TNBC with expression of cytokeratin 5/6 or epidermal growth factor receptor 1).

Results

Patients with TNBC had worse breast cancer-specific survival (BCSS) than the control group (p = 0.015). Expression of 8-OHdG was significantly lower in TNBC than in the non-TNBC group (p < 0.005). 8-OHdG immunostaining was associated with better BCSS (p = 0.01), small tumor size (p < 0.0001) and low grade (p < 0.0005). Keap1 overexpression was observed in the TNBC cohort (p = 0.001) and Keap1-positive patients had worse BCSS than Keap1-negative women (p = 0.014). PRDX IV was overexpressed in the TNBC vs. the non-TNBC group (p = 0.022).

Conclusions

Cellular redox state markers may be promising targets when elucidating the pathogenesis of TNBC.

Low TLR9 expression defines an aggressive subtype of triple-negative breast cancer

Toll-like receptor-9 (TLR9) is a DNA receptor widely expressed in cancers. Although synthetic TLR9 ligands induce cancer cell invasion in vitro, the role of TLR9 in cancer pathophysiology is unclear. We discovered that low tumor TLR9 expression is associated with significantly shortened disease-specific survival in patients with triple negative but not with ER+ breast cancers. A likely mechanism of this clinical finding involves differential responses to hypoxia. Our pre-clinical studies indicate that while TLR9 expression is hypoxia-regulated, low TLR9 expression has different effects on triple negative and ER+ breast cancer invasion in hypoxia. Hypoxia-induced invasion is augmented by TLR9 siRNA in triple negative, but not in ER+ breast cancer cells. This is possibly due to differential TLR9-regulated TIMP-3 expression, which remains detectable in ER+ cells but disappears from triple-negative TLR9 siRNA cells in hypoxia. Our results demonstrate a novel role for this innate immunity receptor in cancer biology and suggest that TLR9 expression may be a novel marker for triple-negative breast cancer patients who are at a high risk of relapse. Furthermore, these results suggest that interventions or events, which induce hypoxia or down-regulate TLR9 expression in triple-negative breast cancer cells may actually induce their spread.

Nuclear Nrf2 expression is related to a poor survival in pancreatic adenocarcinoma

The aim of this study was to investigate the expression of Nrf2, sulfiredoxin and DJ1 in pancreatic cancer. The expression of Nrf2, sulfiredoxin and DJ1 was studied immunohistochemically in a large set of pancreatic adenocarcinomas consisting of 103 cases. Eighty six percent of the cases showed cytoplasmic Nrf2 and 24% nuclear Nrf2 positivity. Sulfiredoxin positivity was observed in 54% and DJ1 positivity in all cases. Nuclear Nrf2 positivity had an association with sulfiredoxin (p=0.019) and was associated with a poor survival (p=0.010). Stage IV tumors tended to have a more nuclear Nrf2 expression (p=0.080). DJ1 expression was more often found in well-differentiated tumors (p=0.012), and DJ1 expression was associated with better survival (p=0.020). According to the results, nuclear Nrf2 expression predicts a worse survival in pancreatic adenocarcinoma, which is in keeping with its protection of cells against oxidative or xenobiotic stress. In accordance with Nrf2's regulation of the synthesis of sulfiredoxin, there was an association between them (p=0.019). DJ1 had no association with Nrf2, and its expression predicted a better survival of patients.

Wise Management of Ovarian Cancer: On the Cutting Edge

Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer mortality among women. Two-thirds of patients present at advanced stage at diagnosis, and the estimated 5 year survival rate is 20-40%. This heterogeneous group of malignancies has distinguishable etiology and molecular biology. Initially, single-gene sequencing was performed to identify germline DNA variations associated with EOC. However, hereditary EOC syndrome can be explained by germline pathogenic variants (gPVs) in several genes. In this regard, next-generation sequencing (NGS) changed clinical diagnostic testing, allowing assessment of multiple genes simultaneously in a faster and cheaper manner than sequential single gene analysis. As we move into the era of personalized medicine, there is evidence that poly (ADP-ribose) polymerase (PARP) inhibitors exploit homologous recombination (HR) deficiency, especially in breast cancer gene 1 and 2 (BRCA1/2) mutation carriers. Furthermore, extensive preclinical data supported the development of aurora kinase (AURK) inhibitors in specific tumor types, including EOC. Their efficacy may be optimized in combination with chemotherapeutic or other molecular agents. The efficacy of metformin in ovarian cancer prevention is under investigation. Certain mutations, such as ARID1A mutations, and alterations in the phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR pathway, which are specific in ovarian clear cell carcinoma (OCCC) and endometrioid ovarian carcinoma (EnOC), may offer additional therapeutic targets in these clinical entities. Malignant ovarian germ cell tumors (MOGCTs) are rare and randomized trials are extremely challenging for the improvement of the existing management and development of novel strategies. This review attempts to offer an overview of the main aspects of ovarian cancer, catapulted from the molecular mechanisms to therapeutic considerations.

Divergent behaviour of oxidative stress markers 8-hydroxydeoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal (HNE) in breast carcinogenesis

AIMS

To clarify the role of oxidative stress during breast carcinogenesis by studying the expression of 8-hydroxydeoxyguanosine (8-OHdG) (a marker of oxidative DNA damage) and 4-hydroxy-2-nonenal (HNE) (a marker of lipid peroxidation) during the different phases of breast carcinogenesis.

METHODS AND RESULTS

The study material consisted of a total of 219 patients: 31 with usual ductal hyperplasia (UDH), 25 with atypical ductal hyperplasia (ADH), 30 with ductal carcinoma in situ (DCIS) and 133 with invasive carcinoma. The expression of 8-OHdG and HNE were evaluated immunohistochemically. Both 8-OHdG (77.4%) and HNE (45.8%) expression was already seen in UDH lesions. Interestingly, the trend of these two immunostainings during breast carcinogenesis was diverse. 8-OHdG expression diminished significantly in invasive breast carcinomas compared to non-invasive lesions (P < 0.005 when set against non-invasive cohorts). Also within the same lesions, 8-OHdG expression was the most intensive in benign cells. Conversely, HNE immunostaining was strongest in invasive breast carcinomas (UDH versus invasive cohort, P = 0.015).

CONCLUSIONS

4-hydroxy-2-nonenal as a marker of lipid peroxidation increases during breast carcinogenesis, reflecting the role of oxidative stress in the pathogenesis of breast cancer. However, 8-OHdG shows diminished levels in carcinomas, possibly resulting from the induction of DNA repair in these invasive lesions.

DNA adduct 8-hydroxydeoxyguanosine, a novel putative marker of prognostic significance in ovarian carcinoma

OBJECTIVES

Previous studies have suggested the importance of reactive oxygen species in all the steps of carcinogenesis. Antioxidant enzymes are considered as the most specific and efficient way to protect cells from reactive oxygen species. The purpose of the current study was to identify the role of oxidative stress and major antioxidant enzymes in ovarian carcinomas.

METHODS

The material consisted of 68 invasive ovarian carcinomas which were studied by immunohistochemistry with antibodies to antioxidant enzymes peroxiredoxins (Prxs) I-VI and thioredoxin and oxidative stress markers nitrotyrosine and 8-hydroxydeoxyguanosine (8-OHdG). Both the intensity and the extent of the stainings were assessed, and the nuclear and cytoplasmic expressions were evaluated separately.

RESULTS

The study revealed the hydroxyl radical-derived oxidative stress marker in DNA, 8-OHdG, to be a powerful prognostic factor in ovarian carcinoma (Kaplan-Meier survival log-rank-analysis P = 0.003; risk of death to ovarian carcinoma 2.69; 95% confidence interval 1.35-5.35. 8-OHdG was also associated with poor differentiation (P = 0.053), higher stage (P < 0.001), and non-optimal surgical outcome (P = 0.002). High cytoplasmic Prx IV immunostaining was associated with a better prognosis (P = 0.024), and elevated cytoplasmic expression rates of Prxs V (P = 0.043) and VI (P = 0.032) were associated with a higher stage.

CONCLUSIONS

To conclude, it appears that hydroxyl radical-derived oxidative stress, but not nitric oxide radical-derived oxidative stress, plays a significant role in ovarian carcinogenesis. Immunohistochemical assessment of 8-OHdG could provide a useful prognostic marker in ovarian cancer.

Oxidative stress-induced antioxidant enzyme expression is an early phenomenon in ovarian carcinogenesis

Oxidative stress and antioxidant enzymes have been widely investigated in various carcinomas. However, there is only some information about their role in ovarian carcinogenesis or in ovarian carcinomas in vivo. We studied immunohistochemical nuclear and/or cytoplasmic expression of oxidative stress markers 8-hydroxydeoxyguanosine (8-OHdG) and nitrotyrosine, as well as major antioxidative enzymes peroxiredoxins (PRDX) I-VI and thioredoxin (TXN) in ovarian tumours. The material consisted of 20 benign (10 serous, 10 mucinous) and 51 borderline (33 serous, 18 mucinous) epithelial ovarian tumours. The markers of oxidative stress, 8-OHdG and nitrotyrosine, were seen already in benign tumours (in 20% and 45% of the tumours, respectively) and their expression patterns were similar in benign and borderline tumours. The levels of PRDX II, III, IV, V and VI were significantly higher in borderline than in benign tumours (p<0.02 for all). Specifically for PRDX II (for both nuclear and cytoplasmic expression, p<0.00005) and PRDX VI (for cytoplasmic expression, p=0.0003 and for nuclear expression, p=0.0005) the difference between benign and borderline tumours was remarkable. In general, serous benign and borderline tumours expressed higher antioxidant enzyme levels than mucinous ones. Nuclear TXN was expressed more strongly in benign than in borderline tumours (p=0.003). Oxidative stress occurs already in benign ovarian tumours and the levels are comparable to borderline tumours. However, some of the antioxidant enzymes, especially PRDX II and VI, are more profoundly induced in borderline ovarian tumours, reflecting their possible role as cancer preventers. This difference could also offer a potential tool for differential diagnosis between benign and borderline epithelial ovarian tumours.

Thioredoxin is associated with proliferation, p53 expression and negative estrogen and progesterone receptor status in breast carcinoma

We investigated the expression of thioredoxin and thioredoxin reductase in a large set of breast invasive and in situ carcinomas by immunohistochemistry. Additionally, NF-kappa B, p53 and proliferating cell nuclear antigen (PCNA) expression was studied. Thioredoxin and thioredoxin reductase expression was located in both cytoplasmic and nuclear compartments of the cell. Cytoplasmic thioredoxin positivity was found in 67 % and nuclear in 59 % of the cases, while thioredoxin reductase was found in 55 % and 6 % of cases, respectively. Ductal carcinomas showed stronger cytoplasmic thioredoxin immunoreactivity than lobular ones. Nuclear thioredoxin positivity was more often found in in situ lesions, and lobular carcinomas were more often negative than ductal ones. Both cytoplasmic and nuclear thioredoxin-positive cases had a high proliferation measured by PCNA staining. Positive nuclear immunostaining was associated with negative estrogen and progesterone receptor status. Cases with high p53 expression showed significantly higher nuclear thioredoxin positivity, but lower thioredoxin reductase positivity. Whilst thioredoxin or thioredoxin reductase was not associated with patient survival, cases showing both cytoplasmic and nuclear thioredoxin reductase-positive tumours had a shorter disease-free interval than those with negative immunostaining.

Oxidative stress markers and mitochondrial antioxidant enzyme expression are increased in aggressive Hodgkin lymphomas

AIMS

Hodgkin lymphoma treatments are largely based on the generation of reactive oxygen species, but increased expression of antioxidant enzymes may contribute to chemoresistance. The aims of this study were: to define the extent and prognostic value of oxidative stress marker and antioxidant enzyme expression in Hodgkin lymphomas; and to investigate a potential association between antioxidant enzymes and chemoresistance.

METHODS AND RESULTS

We immunohistochemically assessed expression of peroxiredoxin (Prx) II, Prx III, Prx V, Prx VI, manganese superoxide dismutase (MnSOD), 8-hydroxydeoxyguanosine (8-OHdG) and nitrotyrosine in 99 cases of uniformly treated Hodgkin lymphoma. Localization of 8-OHdG was assessed using transmission electron microscopy, which demonstrated expression in the cytosol and mitochondria. 8-OHdG expression in Reed-Sternberg (RS) cells was associated with advanced stage (P = 0.006) and a lower International Prognostic Score (P = 0.004). Prx III expression in reactive cellular infiltrate was associated with advanced stage (P = 0.002) and B-symptoms (P = 0.0006). Strong cytoplasmic Prx V immunostaining was associated with a low rate of complete response to chemotherapy (P = 0.043). MnSOD immunostaining in RS cells was related to advanced stage (P = 0.031) and to poorer relapse-free survival (RFS) (P = 0.033). Low 8-OHdG expression in the nuclei of RS cells was a predictor of poorer RFS (P = 0.038). Both 8-OHdG and MnSOD were also significant RFS predictors in multivariate analysis.

CONCLUSIONS

Our results suggest that significant oxidative stress exists in Hodgkin lymphomas, both in RS cells and in reactive cellular infiltrates. Mitochondrial antioxidant enzymes are induced in the most aggressive forms of the disease, and they may play some part in chemoresistance.

Hyaluronan in Breast Cancer: Correlations With Nitric Oxide Synthases and Tyrosine Nitrosylation

Reactive oxygen species (ROS), including nitric oxide (NO•), are associated with all steps of carcinogenesis. Hyaluronan (HA), a high-molecular-mass glycosaminoglycan over-expressed in a variety of human malignancies also has ROS-scavenging properties. We histochemically studied the level of HA in breast carcinoma cells and their stroma and compared it with the expression of NO• synthases (NOSs), major antioxidant enzymes, and nitrotyrosine. We also assessed whether the level of HA correlates with traditional prognostic factors of breast cancer and survival. Stromal HA level was moderate or high in all the samples studied ( n=185), and 84% of the lesions showed HA-positive carcinoma cells. Intense stromal HA signal was associated with high neuronal NOS expression ( p=0.009), whereas tumor-cell associated HA was inversely correlated with nitrotyrosine expression ( p=0.027). Of the traditional prognostic factors, tumor cell-associated HA was correlated with poor differentiation ( p=0.011), and high stromal HA levels were associated with aggressive features of the carcinomas such as large primary tumor ( p=0.002), poor differentiation ( p=0.019), and estrogen ( p=0.012) and progesterone receptor negativity ( p=0.009). High stromal HA level also significantly predicted poorer survival. The strong positive correlation between neuronal NOS and stromal HA could reflect NO•-stimulated synthesis of HA, an extracellular matrix alteration that favors breast cancer progression. Furthermore, it is suggested that, while acting as a scavenger of NO•-derived radicals, cell-associated HA undergoes partial fragmentation, release from receptors, and further degradation in lysosomes, and thus becomes undetectable in histological sections.

Metformin and ovarian cancer: the evidence

In recent decades, great interest in the off-label use of metformin has arisen as a result of its broad effects on different signaling pathways, with only a few side effects, and low cost. Metformin has been shown to have multiple, dose-dependent preclinical anticancer effects, which can be roughly divided into either direct effects via inhibition of mitochondrial respiratory chain complex I, or indirect effects through lowered glucose, insulin and insulin-like growth factor levels. Further details on in vitro and in vivo anticancer effects specifically in ovarian cancer are continuously reported. Preclinically metformin has clear chemosensitizing effects in ovarian cancer and it is an effective negative regulator of angiogenesis. There are also some epidemiological studies on metformin use in ovarian cancer, but the results of these studies are not as promising as those preclinical studies would indicate. Most preclinical studies have involved metformin concentrations that are many times higher than the pharmacological doses used in patients, which might confound the clinical use of metformin as regards the above-mentioned aspects. In this review we evaluate preclinical and clinical evidence concerning metformin in ovarian cancer treatment.

Oxidative stress and redox state-regulating enzymes have prognostic relevance in diffuse large B-cell lymphoma

Background

Oxidative stress and redox-regulating enzymes may have roles both in lymphomagenesis and resistance to lymphoma therapy. Previous studies from the pre-rituximab era suggest that antioxidant enzyme expression is related to prognosis in diffuse large B-cell lymphoma (DLBCL), although these results cannot be extrapolated to patient populations undergoing modern treatment modalities. In this study we assessed expression of the oxidative stress markers 8-hydroxydeoxyguanosine (8-OHdG) and nitrotyrosine and the antioxidant enzymes thioredoxin (Trx), manganese superoxide dismutase (MnSOD) and glutamate-cysteine ligase (GCL) via immunohistochemistry in 106 patients with DLBCL. All patients were treated with CHOP-like therapy combined with rituximab. Immunostaining results were correlated with progression-free survival, disease-specific survival and traditional prognostic factors of DLBCL.

Results

Strong 8-OHdG immunostaining intensity was associated with extranodal involvement (p = 0.00002), a high International Prognostic Index (p = 0.002) and strong Trx (p = 0.011) and GCL (p = 0.0003) expression. Strong Trx staining intensity was associated with poor progression-free survival (p = 0.046) and poor disease-specific survival (p = 0.015). Strong GCL immunostaining intensity predicted poor progression-free survival (p = 0.049). Patients with either strong Trx or strong nitrotyrosine expression showed significantly poorer progression-free survival (p = 0.003) and disease-specific survival (p = 0.031) compared with the other patients.

Conclusions

The redox state-regulating enzymes GCL and Trx are promising markers in the evaluation of DLBCL prognosis in the era of modern immunochemotherapy.

High-level cytoplasmic claudin 3 expression is an independent predictor of poor survival in triple-negative breast cancer

Background

The subtype of claudin-low breast cancer can be reliably determined only by gene-expression profiling. Attempts have been made to develop immunohistochemical surrogates, which nearly always focus on membranous claudin expression.

Methods

We assessed the immunohistochemical expression of both membranous and cytoplasmic claudins 3, 4 and 7 in a series of 197 non-metastatic breast cancers, enriched with triple-negative breast cancers (TNBCs; 60%). The expression of epithelial-to-mesenchymal transition-regulating transcription factors Sip1, Zeb1 and vimentin had previously been determined in the same material.

Results

In multivariate analysis, strong cytoplasmic claudin 3 expression was associated with poor relapse-free survival (RFS), disease-free survival, distant disease-free survival, breast cancer-specific survival and overall survival among TNBC patients (for RFS, RR 5.202, 95% CI 1.210–22.369, p = 0.027, vs. T-class, RR 0.663, 95% CI 0.168–2.623, p = 0.558, and N-class, RR 3.940, 95% CI 0.933–16.631, p = 0.062). Cytoplasmic claudin 3 expression was also associated with strong nuclear Sip1 expression (p = 0.000053), TNBC phenotype (p = 0.012) and within them, non-basal-like phenotype (p = 0.026). Cytoplasmic claudin 7 was associated with dismal RFS (RR 6.328, 95% CI 1.401–28.593, p = 0.016, vs. T-class, RR 0.692, 95% CI 0.242–1.982, p = 0.493, and N-class, RR 2.981, 95% CI 1.1016–8.749, p = 0.047). Low cytoplasmic expression of claudins 3, 4 and 7 together also predicted poor RFS (RR 6.070, 95% CI 1.347–27.363, p = 0.019, vs. T-class, RR 0.677, 95% CI 0.237–1.934, p = 0.467, and N-class, RR 3.167, 95% CI 1.079–9.290, p = 0.036).

Conclusions

Immunohistochemical expression levels of cytoplasmic claudins 3 and 7 appear to be novel prognostic factors in TNBC.

Tumor infiltrating CD8+ T lymphocyte count is independent of tumor TLR9 status in treatment naïve triple negative breast cancer and renal cell carcinoma

Toll-like receptor 9 (TLR9) is a cellular DNA-receptor of the innate immune system that is widely expressed in cancers. We demonstrated that low tumor TLR9 expression predicts poor disease-specific survival in triple negative breast cancer (TNBC) and renal cell carcinoma (RCC). We hypothesized that this is because TLR9 expression affects tumor immunophenotype. To begin to test this, we compared the number of tumor infiltrating CD8⁺ T lymphocytes with TLR9 expression in treatment naïve breast cancer (n = 197) and RCC (n = 94) cohorts with known TLR9 expression status. CD8⁺ T lymphocyte counts were assayed with image analysis after immunohistochemistry (IHC). Tumor TLR9 expression was not correlated with CD8⁺ T cell counts in breast cancer or RCC. CD8⁺ T cell counts were significantly associated with tumor proliferation index in TNBC, but not in non-TNBC. CD8⁺ T cell counts were also significantly associated with tumor grade in non-TNBC, but not in TNBC. In RCC, CD8⁺ T cell counts were significantly associated with tumor stage. CD8⁺ T cell counts were significantly associated with prognosis in TNBC and RCC, but the presence of CD8⁺ T cells in these tumors had opposite effects on disease-specific survival: High CD8⁺ counts were associated with better prognosis in TNBC and worse prognosis in RCC. Among TNBC patients, those with low tumor TLR9 and low CD8⁺ T cell counts had the poorest prognosis (log-rank p = 0.0002 vs. high tumor TLR9 and high CD8⁺ T cell count). In conclusion, pre-treatment tumor TLR9 status is not associated with tumor infiltrating CD8⁺ T lymphocytes in TNBC or RCC. The combination of TLR9 and CD8⁺ TIL count might be a novel composite prognostic marker in TNBC.

Primary neuroendocrine breast carcinomas are associated with poor local control despite favourable biological profile: a retrospective clinical study

BACKGROUND

Breast carcinomas with neuroendocrine features (NEBC) are a very rare entity of mammary neoplasms, WHO classification of which has recently been revised. There are very limited data available about the clinical behaviour and treatment options of NEBC.

METHODS

We collected retrospectively patients with NEBC from Oulu and Helsinki University Hospitals in 2007-2015. There were 43 NEBC cases during the period.

RESULTS

The incidence of NEBC from all breast cancers varied from 0.1% in Helsinki to 1.3% in Oulu. The mean tumor size was 2.2 cm and 23 patients (55.8%) had no lymph node metastases when diagnosed. In total, 4 patients (9.3%) had distant metastases at the time of diagnosis. High estrogen receptor (ER) expression was observed in 41 (97.7%) patients. When non-metastatic NEBC were compared to a prospective set of ductal carcinomas (n = 506), NEBC were more often HER2 negative (p = 0.046), ER positive (p = 0.0062) and the NEBC patients were older (p < 0.0005) than patients with ductal carcinomas. Plasma chromogranin A correlated only to higher age at diagnosis (p = 0.0028). Relapse-free survival (p = 0.0013), disease-free survival (p = 0.024) and overall survival (p = 0.0028) favoured ductal carcinomas compared to NEBC, while no difference was observed in distant disease-free survival or in breast cancer-specific survival.

CONCLUSIONS

There is remarkable variation in the incidence of NEBC in Finland, which is likely to be explained by differences in the use of neuroendocrine marker immunostainings. Poor local control and worse overall survival may be linked to the more aggressive biology of the disease, despite its association with apparently indolent prognostic factors.

Angiogenesis Inhibitors for Head and Neck Squamous Cell Carcinoma Treatment: Is There Still Hope?

Background

Head and neck squamous cell carcinoma (HNSCC) carries poor survival outcomes despite recent progress in cancer treatment in general. Angiogenesis is crucial for tumour survival and progression. Therefore, several agents targeting the pathways that mediate angiogenesis have been developed. We conducted a systematic review to summarise the current clinical trial data examining angiogenesis inhibitors in HNSCC.

Methods

We carried out a literature search on three angiogenesis inhibitor categories—bevacizumab, tyrosine kinase inhibitors and endostatin—from Ovid MEDLINE, Cochrane Library, Scopus and ClinicalTrials.gov database.

Results

Here, we analysed 38 clinical trials, total of 1670 patients, investigating 12 angiogenesis inhibitors. All trials were in phase I or II, except one study in phase III on bevacizumab. Angiogenesis inhibitors were used as mono- and combination therapies together with radio-, chemo-, targeted- or immunotherapy. Among 12 angiogenesis inhibitors, bevacizumab was the most studied drug, included in 13 trials. Although bevacizumab appeared effective in various combinations, it associated with high toxicity levels. Endostatin and lenvatinib were well-tolerated and their anticancer effects appeared promising.

Conclusions

Most studies did not show benefit of angiogenesis inhibitors in HNSCC treatment. Additionally, angiogenesis inhibitors were associated with considerable toxicity. However, some results appear encouraging, suggesting that further investigations of angiogenesis inhibitors, particularly in combination therapies, for HNSCC patients are warranted.

Systematic Review Registration

PROSPERO (https://www.crd.york.ac.uk/prospero/), identifier CRD42020157144.

Increasing oxidative damage and loss of mismatch repair enzymes during breast carcinogenesis

This study examined the expression of oxidative damage markers 8-hydroxydeoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal (HNE) and nitrotyrosine using immunohistochemical techniques. In addition, DNA topoisomerase II binding protein 1 (TopBP1) and mismatch repair proteins 2 and 6 (MSH2 and MSH6) were immunostained in a series of 80 stage I invasive breast tumours, 26 in situ breast carcinomas and 12 benign breast hyperplasias. 8-OHdG, HNE and nitrotyrosine expression were considerably weaker in hyperplasias than in in situ lesions, which, in turn, showed less oxidative damage than T1N0 tumours. Hyperplasias and in situ tumours were all, at least moderately, positive for MSH2, and nearly all were positive for MSH6. Nitrotyrosine expression was associated with HNE (P<0.0005) and 8-OHdG (P=0.041) in the T1N0 cohort. To conclude, there is increasing oxidative stress during the early steps of breast carcinogenesis. On the other hand, a significant reduction in expression of mismatch repair proteins occurs during the progression of in situ lesions to invasive tumours.