Subsequent Metastasis Research Articles

Role of Cytokines and Chemokines in NSCLC Immune Navigation and Proliferation.

With over a million deaths every year around the world, lung cancer is found to be the most recurrent cancer among all types. Nonsmall cell lung carcinoma (NSCLC) amounts to about 85% of the entire cases. The other 15% owes it to small cell lung carcinoma (SCLC). Despite decades of research, the prognosis for NSCLC patients is poorly understood with treatment options limited. First, this article emphasises on the part that tumour microenvironment (TME) and its constituents play in lung cancer progression. This review also highlights the inflammatory (pro- or anti-) roles of different cytokines (ILs, TGF-β, and TNF-α) and chemokine (CC, CXC, C, and CX3C) families in the lung TME, provoking tumour growth and subsequent metastasis. The write-up also pinpoints recent developments in the field of chemokine biology. Additionally, it covers the role of extracellular vesicles (EVs), as alternate carriers of cytokines and chemokines. This allows the cytokines/chemokines to modulate the EVs for their secretion, trafficking, and aid in cancer proliferation. In the end, this review also stresses on the role of these factors as prognostic biomarkers for lung immunotherapy, apart from focusing on inflammatory actions of these chemoattractants.

SLC34A2 Up-regulation And SLC4A4 Down-regulation Correlates With Invasion, Metastasis, And The MAPK Signaling Pathway In Papillary Thyroid Carcinomas.

Papillary thyroid carcinoma (PTC) is one of the fastest growing endocrine system malignant carcinomas detected over the past decade. Unfortunately, more than 25% of PTC patients are characterized by their aggressiveness and subsequent metastasis; these characteristics usually indicate poor prognosis. Recently, increasing evidence has suggested that solute carrier (SLC) transporters may play a pivotal role in the initiation, invasion and metastasis of human carcinoma. However, the expression and clinicopathological significance of SLC transporters in patients with PTC remains undetermined. In this study, we aimed to elucidate how the differential expression of SLC transporters affects clinicopathological features, as well as determine the possible regulatory signaling pathways involved. Three differentially expressed SLC transporters were screened from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database using a bioinformatics approach. The results indicated that high SLC34A2 and low SLC4A4 protein expression exhibited a higher percentage of capsular invasion and extra-thyroid metastasis in patients. Logistic regression analysis showed that high SLC34A2 expression in tumors was identified as an independent risk factor for capsular invasion [odds ratio (OR)=11.400, 95% confidence interval (CI)=1.733-74.995, P=0.011] and extra-thyroid metastasis (OR=4.920, 95%CI=1.234-19.623, P=0.024), while low SLC4A4 expression in tumors was only identified as independent risk factors for extra-thyroid metastasis (OR=8.568, 95%CI =1.186-61.906, P=0.033). Specifically, for tumors with capsular invasion and extra-thyroid metastasis, the protein expression staining of SLC34A2 was markedly enhanced in the cytoplasm of follicular epithelial cells, contrastingly, SLC4A4 expression was notably weakened in the cytomembrane and nucleus. Intriguingly, both high SLC34A2 and low SLC4A4 protein expression were significantly linked to a high urinary iodine concentration in patients with PTC. Mechanistically, compared with adjacent normal thyroids, p-ERK was significantly up-regulated by 17.8% in the invading tumor; p-ERK, p-JNK, and p-P38 were markedly up-regulated by 29.2%, 67.1%, and 38.9% for metastatic tumors, respectively. Importantly, SLC4A4 negatively correlated with p-JNK (r=-0.696, P= 0.004) and p-P38 (r=-0.534, P=0.049). In conclusion, we suggest that up-regulated SLC34A2 (mainly in the cytoplasm) and down-regulated SLC4A4 (mainly in the cytomembrane and nucleus), which might be attributed to excess iodine intake, were closely linked to extra-thyroid metastasis in PTCs. Furthermore, this effect of SLC4A4 may be through the activation of JNK/P38 MAPK signaling pathway. Future in vivo and in vitro gain- or loss-of-function experiments are needed to verify these findings and further elucidate the deeper molecular mechanisms.

MicroRNA-128 Confers Anti-Endothelial Adhesion and Anti-Migration Properties to Counteract Highly Metastatic Cervical Cancer Cells' Migration in a Parallel-Plate Flow Chamber.

Despite the distant metastasis of cervical cancer cells being a prominent cause of mortality, neither the metastasis capacity nor the in vitro conditions mimicking adhesion of cervical cancer cells to endothelial cells have been fully elucidated. Circulating metastatic cancer cells undergo transendothelial migration and invade normal organs in distant metastasis; however, the putative molecular mechanism remains largely uncertain. In this study, we describe the use of an in vitro parallel-plate flow chamber to simulate the dynamic circulation stress on cervical cancer cells and elucidate their vascular adhesion and metastasis. We isolate the viable and shear stress-resistant (SSR) cervical cancer cells for mechanistic studies. Remarkably, the identified SSR-HeLa and SSR-CaSki exhibited high in vitro adhesive and metastatic activities. Hence, a consistently suppressed miR-128 level was revealed in SSR cell clones compared to those of parental wild-type (WT) cells. Overexpressed miR-128 attenuated SSR-HeLa cells’ adherence to human umbilical cord vein endothelial cells (HUVECs); in contrast, suppressed miR-128 efficiently augmented the static adhesion capacity in WT-HeLa and WT-CaSki cells. Hence, amplified miR-128 modestly abolished in vitro SSR-augmented HeLa and CaSki cell movement, whereas reduced miR-128 aggravated the migration speed in a time-lapse recording assay in WT groups. Consistently, the force expression of miR-128 alleviated the SSR-enhanced HeLa and CaSki cell mobility in a wound healing assay. Notably, miR-128 mediated SSR-enhanced HeLa and CaSki cells’ adhesion and metastasis through suppressed ITGA5, ITGB5, sLex, CEACAM-6, MMP9, and MMP23 transcript levels. Our data provide evidence suggesting that miR-128 is a promising microRNA that prevented endothelial cells’ adhesion and transendothelial migration to contribute to the SSR-enhanced adhesion and metastasis progression under a parallel-plate flow chamber system. This indicates that the nucleoid-based miR-128 strategy may be an attractive therapeutic strategy to eliminate tumor cells resistant to circulation shear flow, prevent vascular adhesion, and preclude subsequent transendothelial metastasis.

Abstract IA20: Lymph protects metastasizing melanoma cells from ferroptosis

Abstract Cancer cells, including melanoma, often metastasize regionally through lymphatics before metastasizing systemically through the blood; however, the reason for this is unclear. We discovered that melanoma cells in lymph experience less oxidative stress and form more metastases than melanoma cells in blood. Immunocompromised mice with patient-derived melanomas and immunocompetent mice with mouse melanomas had more melanoma cells per microliter of tumor-draining lymph than tumor-draining blood. Cells metastasizing through blood, but not lymph, became dependent on the ferroptosis inhibitor GPX4. Cells pre-treated with chemical ferroptosis inhibitors formed more metastases than untreated cells after intravenous, but not intralymphatic, injection. We observed multiple differences between lymph fluid and blood plasma that may contribute to decreased oxidative stress and ferroptosis in lymph, including higher levels of glutathione and oleic acid, and less free iron, in lymph. Oleic acid protected melanoma cells from ferroptosis in an Acsl3-dependent manner and increased their capacity to form metastatic tumors. Melanoma cells from lymph nodes were more resistant to ferroptosis and formed more metastases after intravenous injection than melanoma cells from subcutaneous tumors. Exposure to the lymphatic environment thus protects melanoma cells from ferroptosis and increases their ability to survive during subsequent metastasis through the blood. Citation Format: Sean J. Morrison. Lymph protects metastasizing melanoma cells from ferroptosis [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr IA20.

Inhomogeneities in 3D Collagen Matrices Impact Matrix Mechanics and Cancer Cell Migration.

Cell motility under physiological and pathological conditions including malignant progression of cancer and subsequent metastasis are founded on environmental confinements. During the last two decades, three-dimensional cell migration has been studied mostly by utilizing biomimetic extracellular matrix models. In the majority of these studies, the in vitro collagen scaffolds are usually assumed to be homogenous, as they consist commonly of one specific type of collagen, such as collagen type I, isolated from one species. These collagen matrices should resemble in vivo extracellular matrix scaffolds physiologically, however, mechanical phenotype and functional reliability have been addressed poorly due to certain limitations based on the assumption of homogeneity. How local variations of extracellular matrix structure impact matrix mechanics and cell migration is largely unknown. Here, we hypothesize that local inhomogeneities alter cell movement due to alterations in matrix mechanics, as they frequently occur in in vivo tissue scaffolds and were even changed in diseased tissues. To analyze the effect of structural inhomogeneities on cell migration, we used a mixture of rat tail and bovine dermal collagen type I as well as pure rat and pure bovine collagens at four different concentrations to assess three-dimensional scaffold inhomogeneities. Collagen type I from rat self-assembled to elongated fibrils, whereas bovine collagen tended to build node-shaped inhomogeneous scaffolds. We have shown that the elastic modulus determined with atomic force microscopy in combination with pore size analysis using confocal laser scanning microscopy revealed distinct inhomogeneities within collagen matrices. We hypothesized that elastic modulus and pore size govern cancer cell invasion in three-dimensional collagen matrices. In fact, invasiveness of three breast cancer cell types is altered due to matrix-type and concentration indicating that these two factors are crucial for cellular invasiveness. Our findings revealed that local matrix scaffold inhomogeneity is another crucial parameter to explain differences in cell migration, which not solely depended on pore size and stiffness of the collagen matrices. With these three distinct biophysical parameters, characterizing structure and mechanics of the studied collagen matrices, we were able to explain differences in the invasion behavior of the studied cancer cell lines in dependence of the used collagen model.

Assessment of circulating HISLA as a potential biomarker for breast cancer diagnosis and prognosis.

Breast cancer (BC) is the most frequently encountered and aggressive type of malignant tumor and affects the health of females across the globe. Approximately 30% of patients that are newly diagnosed have a high risk of subsequent metastasis and relapse. HIF-1α-stabilizing long noncoding RNA (HISLA) packaged in exosome has been recently identified and revealed as an important oncogenic gene in promoting BC progress. Thus, we sought to investigate whether serum circulating HISLA was involved in dynamics underlying its applicability for the diagnosis and prognosis of BC. We assessed serum HISLA expression in 40 patients with BC and 20 healthy controls to investigate its roles in BC using quantitative real-time polymerase chain reaction (qRT-PCR). We also assessed measures of correlation of clinical and pathological parameters with prognoses of BC patients. Our findings suggested that serum HISLA expression in BC patients was significantly higher than in healthy controls. Furthermore, high expression of serum HISLA was positively associated with advanced stage lymph node metastasis. Expression of HISLA was reduced in postoperative BC patients' serum samples, compared with preoperative serum samples. Pearson correlation assessments indicated significant correlation between serum HISLA expression and the tissue sample HISLA expression in BC patients. Our findings suggested that serum HISLA may serve as newfound biomarker which could help to improve diagnoses and prognoses for BC-afflicted patients.

SNAIL Transctiption factor in prostate cancer cells promotes neurite outgrowth

Neurite outgrowth involves reciprocal signaling interactions between tumor cells and nerves where invading tumor cells have acquired the ability to respond to pro-invasive signals within the nerve environment. Neurite outgrowth could serve as a mechanism leading to invasion of cancer cells into the nerve sheath and subsequent metastasis. Snail transcription factor can promote migration and invasion of prostate cancer cells. We hypothesized that prostate cancer cell interaction with nerve cells will be mediated by Snail expression within prostate cancer cells. For this study we utilized various prostate cancer cell lines: C4-2 non-silencing (NS, control); C4-2 Snail shRNA, (stable Snail knockdown); LNCaP Neo (empty vector control) and LNCaP Snail (stably over-expressing Snail). Cancer cell adhesion and migration towards nerve cells (snF96.2 or NS20Y) was examined by co-culture assays. Conditioned media (CM) collected from C4-2 cells was cultured with nerve cells (PC-12 or NS20Y) for 48 h followed by qualitative or quantitative neurite outgrowth assay. Our results showed that cancer cells expressing high levels of Snail (LNCaP Snail/C4-2 NS) displayed significantly higher migration adherence to nerve cells, compared to cells with lower levels of Snail (LNCaP Neo/C4-2 Snail shRNA). Additionally, LNCaP Snail or C4-2 NS (Snail-high) CM led to a higher neurite outgrowth compared to the LNCaP Neo or C4-2 Snail shRNA (Snail-low). In conclusion, Snail promotes migration and adhesion to nerve cells, as well as neurite outgrowth via secretion of soluble factors. Therefore, targeting cancer cell interaction with nerves may contribute to halting prostate cancer progression/metastasis.

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

A risk stratification model for predicting brain metastasis and brain screening benefit in patients with metastatic triple-negative breast cancer.

BackgroundPatients with metastatic triple‐negative breast cancer (mTNBC) frequently experience brain metastasis. This study aimed to identify prognostic factors and construct a nomogram for predicting brain metastasis possibility and brain screening benefit in mTNBC patients.MethodsPatients with mTNBC treated at our institution between January 2011 and December 2018 were retrospectively analyzed. Fine and Gray's competing risks model was used to identify independent prognostic factors. By integrating these prognostic factors, a competing risk nomogram and risk stratification model were developed and evaluated with concordance index (C‐index) and calibration curves.ResultsA total of 472 patients were retrospectively analyzed, including 305 patients in the training set, 78 patients in the validation set I and 89 patients in the validation set II. Four clinicopathological factors were identified as independent prognostic factors in the nomogram: lung metastasis, number of metastatic organ sites, hilar/mediastinal lymph node metastasis and KI‐67 index. The C‐indexes and calibration plots showed that the nomogram exhibited a sufficient level of discrimination. A risk stratification was further generated to divide all the patients into three prognostic groups. The cumulative incidence of brain metastasis at 18 months was 5.3% (95% confidence interval [CI], 2.5%‐9.7%) for patients in the low‐risk group, while 14.3% (95% CI, 9.3%‐20.4%) for patients with intermediate risk and 34.3% (95% CI, 26.8%‐41.9%) for patients with high risk. Routine brain MRI screening improved overall survival in high‐risk group (HR 0.67, 95% CI 0.46‐0.98, P = .039), but not in low‐risk group (HR 0.93, 95% CI 0.57‐1.49, P = .751) and intermediate‐risk group (HR 0.83, 95% CI 0.55‐1.27, P = .386).ConclusionsWe have developed a robust tool that is able to predict subsequent brain metastasis in mTNBC patients. Our model will allow selection of patients at high risk for brain metastasis who might benefit from routine bran MRI screening.

CPEB3-mediated MTDH mRNA translational suppression restrains hepatocellular carcinoma progression

Cytoplasmic polyadenylation element-binding protein 3 (CPEB3) is a sequence-specific RNA-binding protein. We had reported that CPEB3 is involved in hepatocellular carcinoma (HCC) progression. However, the underlying mechanisms of CPEB3 in HCC remain unclear. In this study, we firstly performed RNA immunoprecipitation to uncover the transcriptome-wide CPEB3-bound mRNAs (CPEB3 binder) in HCC. Bioinformatic analysis indicates that CPEB3 binders are closely related to cancer progression, especially HCC metastasis. Further studies confirmed that metadherin (MTDH) is a direct target of CPEB3. CPEB3 can suppress the translation of MTDH mRNA in vivo and in vitro. Besides, luciferase assay demonstrated that CPEB3 interacted with 3′-untranslated region of MTDH mRNA and inhibited its translation. Subsequently, CPEB3 inhibited the epithelial–mesenchymal transition and metastasis of HCC cells through post-transcriptional regulation of MTDH. In addition, cpeb3 knockout mice are more susceptible to carcinogen-induced hepatocarcinogenesis and subsequent lung metastasis. Our results also indicated that CPEB3 was a good prognosis marker, which is downregulated in HCC tissue. In conclusion, our results demonstrated that CPEB3 played an important role in HCC progression and targeting CPEB3-mediated mRNA translation might be a favorable therapeutic approach.

Lymph protects metastasizing melanoma cells from ferroptosis.

Cancer cells, including melanoma, often metastasize regionally through lymphatics before metastasizing systemically through the blood1–4; however, the reason for this is unclear. Here we show that melanoma cells in lymph experience less oxidative stress and form more metastases than melanoma cells in blood. Immunocompromised mice with patient-derived melanomas and immunocompetent mice with mouse melanomas had more melanoma cells per microliter of tumor-draining lymph than tumor-draining blood. Cells metastasizing through blood, but not lymph, became dependent on the ferroptosis inhibitor GPX4. Cells pre-treated with chemical ferroptosis inhibitors formed more metastases than untreated cells after intravenous, but not intralymphatic, injection. We observed multiple differences between lymph fluid and blood plasma that may contribute to decreased oxidative stress and ferroptosis in lymph, including higher levels of glutathione and oleic acid, and less free iron, in lymph. Oleic acid protected melanoma cells from ferroptosis in an Acsl3-dependent manner and increased their capacity to form metastatic tumors. Melanoma cells from lymph nodes were more resistant to ferroptosis and formed more metastases after intravenous injection than melanoma cells from subcutaneous tumors. Exposure to the lymphatic environment thus protects melanoma cells from ferroptosis and increases their ability to survive during subsequent metastasis through the blood.

Molecular evolutionary mechanisms underlying tumorigenesis, tumor development, and metastasis

Tumorigenesis and the subsequent development and metastasis of tumors are continuous evolutionary processes that are a result of several molecular evolutionary events. During these processes, the tumor cells gradually gain advantages of survival and proliferation and promote tumor heterogeneity. An in-depth understanding of the mechanism underlying the molecular evolution of tumor cells will help us understand the intrinsic mechanism of tumorigenesis, tumor development, and metastasis. This in turn will aid in the development of targeted treatment strategies for blocking tumor development and metastasis as well as improve the therapeutic effects of these strategies. This review systematically summarizes the molecular evolutionary events, such as gene mutation, gene copy number variation, the generation of de novo genes, and chromosome abnormality, during the process of tumorigenesis, tumor development, and metastasis as well as their relationship with tumor development. This review summarizes the main theoretical models of molecular evolution in tumor cells and discusses future research trends and prospects. Furthermore, it provides valuable reference information for additional in-depth theoretical and applied research in this field in the future.

Squalene synthase promotes the invasion of lung cancer cells via the osteopontin/ERK pathway

Cholesterol is the major component of lipid rafts. Squalene synthase (SQS) is a cholesterol biosynthase that functions in cholesterol biosynthesis, modulates the formation of lipids rafts and promotes lung cancer metastasis. In this study, we investigated the lipid raft-associated pathway of SQS in lung cancer. Gene expression microarray data revealed the upregulation of secreted phosphoprotein 1 (SPP1; also known as osteopontin, OPN) in CL1-0/SQS-overexpressing cells. Knockdown of OPN in SQS-overexpressing cells inhibits their migration and invasion, whereas an OPN treatment rescues the migration and invasion of SQS knockdown cells. High OPN expression is associated with lymph node status, advanced stage and poor prognosis in patients with lung cancer. Moreover, patients with high SQS expression and high OPN expression show poor survival compared with patients with low SQS expression and low OPN expression. SQS induces the phosphorylation of Src and ERK1/2 via OPN, resulting in increased expression of MMP1 and subsequent metastasis of lung cancer cells. Based on our findings, SQS expression increases the expression of OPN and phosphorylation of Src through cholesterol synthesis to modulate the formation of lipid rafts. SQS may represent a therapeutic strategy for lung cancer.

Exosomal MicroRNAs and Organotropism in Breast Cancer Metastasis.

Breast cancer is the most frequent malignancy for women in which one in eight women will be diagnosed with the disease in their lifetime. Despite advances made in treating primary breast cancer, there is still no effective treatment for metastatic breast cancer. Consequently, metastatic breast cancer is responsible for 90% of breast cancer-related deaths while only accounting for approximately one third of all breast cancer cases. To help develop effective treatments for metastatic breast cancer, it is important to gain a deeper understanding of the mechanisms by which breast cancer metastasizes, particularly, those underlying organotropism towards brain, bone, and lungs. In this review, we will primarily focus on the roles that circulating exosomal microRNAs (miRNAs) play in organotropism of breast cancer metastasis. Exosomes are extracellular vesicles that play critical roles in intercellular communication. MicroRNAs can be encapsulated in exosomes; cargo-loaded exosomes can be secreted by tumor cells into the tumor microenvironment to facilitate tumor–stroma interactions or released to circulation to prime distant organs for subsequent metastasis. Here, we will summarize our current knowledge on the biogenesis of exosomes and miRNAs, mechanisms of cargo sorting into exosomes, the exosomal miRNAs implicated in breast cancer metastasis, and therapeutic exosomal miRNAs.

IJU this issue

In this issue, a Guideline with Editorial Comment, a Review Article with Editorial Comment, five Original Articles with three Editorial Comments and a Urological Note were published in the International Journal of Urology. Interstitial cystitis/bladder pain syndrome (BPS) bothers both patients and urologists. Homma et al. (Tokyo, Japan) revised the previous guidelines completing articles identified by the PubMed database published from 2016 to 2019. In this article, the authors clearly defined Hunner-type interstitial cystitis (HIC) associated with Hunner’s ulceration and non-Hunner-type BPS featuring glomerulations or bladder bleeding after distension are different entities of disorder in terms of pathophysiology. Interestingly, HIC shows immunological inflammatory reaction accompanied by B-cell clonal expansion, which demonstrates HIC is genetically different from BPS. Urologists should keep in mind that patients should be treated differently based on the diagnosis of HIC or BPS, which requires cystoscopy to determine the presence or absence of Hunner lesions. Malignant ureteral obstruction, defined as either intrinsic or extrinsic compression caused by metastasis, lymphadenopathy or direct extension of the tumors, is an unfortunate finding that most urologists encounter in the daily practice. Tabib et al. (New York, USA) reviewed many types of ureteral stents, including tandem stents or metallic stents that aim for the resolution of malignant ureteral obstruction, and attempted to provide considerations regarding the treatment and management of malignant ureteral obstruction. Ochi et al. (Chiba, Japan) examined the anatomical relationship between the urinary system and perirenal fat using computed tomography images from 50 men, as well as macroscopic imaging in nine cadavers. They found that perirenal fat belongs to the connective tissue of the gonad and the adrenal gland. The urinary system is separated from perirenal fat, and is located on the dorsal side inside the renal fascia. The authors concluded that this anatomical finding might help aid in the isolation of periureteric fat from perinephric fat in retroperitoneoscopic donor nephrectomy. A substantial number of non-classic angiomyolipomas (AML), including fat-poor or epithelioid AML, are encountered in daily practice, and are occasionally difficult to discriminate from renal cell carcinoma. Kaneko et al. (Tokyo, Japan) retrospectively evaluated the incidence of epithelioid AML (17.9%) out of 39 renal tumors diagnosed as non-classical AML. They found that magnetic resonance imaging findings (apparent diffusion coefficient value) are potentially useful to differentiate between epithelioid and fat-poor AML. A recent trend for the treatment of metastatic castration-sensitive prostate cancer (CSPC) is upfront intensification therapy including androgen deprivation therapy (ADT) plus docetaxel, ADT plus abiraterone acetate, ADT plus enzalutamide and ADT plus apalutamide. However, indication is limited in high-risk (LATITUDE criteria) or high-volume (CHARRTED criteria) patients. Hatakeyama et al. (Hirosaki, Japan) retrospectively evaluated 679 patients with metastatic castration-sensitive prostate cancer. They found that the overall survival from the initiation of castration-resistant prostate cancer in patients with low-volume disease and those with high-volume disease was not significantly different, and concluded that upfront intensification therapy might be beneficial to patients with low-volume disease, because approximately half of patients with low-volume disease experienced metastatic castration-resistant prostate cancer progression in real-world practice. The Editorial Comment by Kato (Nagoya, Japan) is worthwhile to correctly evaluate this article. As most of the metastatic spread is reported to be in a hematogenous fashion in renal cell carcinoma, the impact of regional lymph node metastases on subsequent distant metastasis remains unknown. Yang et al. (Rochester, USA) retrospectively evaluated 1049 patients (135 pN1, 914 pN0/x) who were surgically treated at the Mayo Clinic. They found that pN1 nodal status in M0 patients treated with nephrectomy for renal cell carcinoma is associated with more frequent early metastasis to sites conferring poor prognosis when compared with pN0/x in the lung, bone and non-regional lymph nodes. Interestingly, pN1 status did not affect subsequent liver metastasis, one of the most hematogenous metastatic organs. Although this article involves several limitations, their finding might stimulate discussion of the predictive/therapeutic role of regional lymph node dissection during renal cancer surgery. None declared.

Cutaneous leiomyosarcoma /
 atypical smooth muscle sarcoma

Relevance: Cutaneous leiomyosarcoma is a rare primary
 dermal neoplasm, accounting for up to 2-3% of all superficial
 sarcomas. It can occur at any age, most likely between the ages
 of 50 and 70 years. This tumor has a high recurrence potential
 in case of insufficiently deep excision. Recurrent tumors are
 more aggressive and characterized by subsequent metastasis.
 The purpose of the study was to demonstrate the results
 of the histopathological examination of a cutaneous leiomyosarcoma / atypical smooth muscle tumor.
 Results: Cutaneous leiomyosarcoma was represented by
 spindle-shaped cells with high cellularity located in bundles
 and growing expansively, surrounded by a capsule. The nuclei
 of the cells were elongated, hyperchromic. Cells with atypical
 abnormal nuclei were present in smaller quantities. The mitoses, including atypical, were numerous. IHC staining for SMA,
 Desmin, H-Caldesmon – diffusely positive on tumor cells. The
 reaction for S100, Myogenin – negative.
 Conclusion: A cutaneous leiomyosarcoma can be finally
 diagnosed only after a pathomorphological examination of
 the specimen and differential diagnostics using additional research methods.

Cutaneous leiomyosarcoma/
 atypical smooth muscle sarcoma

Relevance: Cutaneous leiomyosarcoma is a rare primary dermal neoplasm, accounting for up to 2-3% of all superficial
 sarcomas. It can occur at any age, most likely between the ages of 50 and 70 years. This tumor has a high recurrence potential
 in case of insufficiently deep excision. Recurrent tumors are more aggressive and characterized by subsequent metastasis.
 The purpose of the study was to demonstrate the results of the histopathological examination of a cutaneous
 leiomyosarcoma / atypical smooth muscle tumor.
 Results: Cutaneous leiomyosarcoma was represented by spindle-shaped cells with high cellularity located in bundles
 and growing expansively, surrounded by a capsule. The nuclei of the cells were elongated, hyperchromic. Cells with atypical
 abnormal nuclei were present in smaller quantities. The mitoses, including atypical, were numerous. IHC staining for SMA,
 Desmin, H-Caldesmon – diffusely positive on tumor cells. The reaction for S100, Myogenin – negative.
 Conclusion: A cutaneous leiomyosarcoma can be finally diagnosed only after a pathomorphological examination of the
 specimen and differential diagnostics using additional research methods

The histone deacetylase HDAC1 activates HIF1α/VEGFA signal pathway in colorectal cancer.

Tumor angiogenesis is a common feature of rapidly growing solid tumors, accelerated by tumor hypoxia. It is associated with subsequent metastasis, progression, poor prognosis, and aggressive phenotype in many types of cancer. The hypoxia-inducible factors/vascular endothelial growth factor 1(HIF1/VEGF) signal pathway plays an important role in tumor angiogenesis. Proteasome-mediated ubiquitin degradation pathway is one of the most important processes involved in regulating the level of cellular HIF-1α. Our study revealed that Histone Deacetylase 1 (HDAC1) directly inhibits the ubiquitination of HIF1α. Additionally, HDAC1 activates HIF1α/VEGFA signaling pathway, promoting s tumor angiogenesis. These findings have enhanced our understanding of the molecular mechanisms of colorectal (CRC) tumor angiogenesis. HDAC1/HIF1α/VEGFA signaling pathway may provide a novel therapeutic window for CRC.

Tumor-infiltrating lymphocytes in ipsilateral breast tumor recurrences predict prognosis.

546 Background: The antitumoral immune response is dynamic and changes with tumor progression. Previous studies show that immunohistochemical (IHC) assessment of TILs in local recurrences can predict prognosis. It is not clear how adjuvant radiotherapy (RT) can alter the local immune response or if gene expression analyses of TILs in recurrences can provide prognostic information. Methods: Matched biopsies from primary tumors and ipsilateral breast tumor recurrences (IBTRs) from the randomized SweBCG91RT trial were assessed for TILs. Analyses were performed using gene expression (86 matched pairs) and IHC assessment (126 matched pairs). Results: The median time to IBTR was 8.0 years among irradiated patients and 3.6 years among unirradiated patients. In the gene expression analyses, higher absolute values of CD8+ T cells, CD4+ effector memory and CD8+ effector memory T cells in the recurrence could significantly predict a decreased risk of subsequent distant metastasis. In addition, a net increase of these cells in the IBTR compared to the primary tumor was associated with a significantly lower risk of metastasis. TILs did not change significantly between the matched tumors for the whole group or among irradiated patients versus unirradiated patients in the gene expression or IHC analyses. Surprisingly, the group with unchanged TILs levels as measured by IHC had the lowest risk of metastasis while an increase or a decrease in TILs was significantly associated with an increased risk. Conclusions: Cytotoxic and memory T cells in the recurrence protect against subsequent distant metastasis although IHC measurement of TILs could not confirm these results. No significant differences in TILs infiltration between irradiated versus unirradiated patients could be determined in the recurrences. Further analyses including changes of subtypes between the primary tumor and the recurrence will be presented.

Omitting surgery for early breast cancer showing clinical complete response to primary systemic therapy

Breast cancer is highly sensitive to systemic therapy. High probability of pathological complete response suggests a clinical question that omitting surgery is an effective alternative to surgery in breast cancer showing clinical complete response to primary systemic therapy. However, the validity of omitting surgery for early breast cancer after primary systemic therapy has not been sufficiently established; thus, even if pathological complete response is expected in patients showing clinical complete response, excision of the primary tumor site remains the standard treatment of breast cancer. Inappropriate omitting surgery increases the incidence of local recurrence, which can be the risk of a subsequent distant metastasis and reduced overall survival. To achieve acceptable local control rate, omitting surgery should be investigated in patients with early breast cancer where a high percentage of pathological complete response, a high concordance rate between clinical complete response and pathological complete response and an acceptable local control rate are expected. This review presents concept and ongoing clinical trials for omitting surgery for patients with breast cancer showing clinical complete response to primary systemic therapy.