Publications by authors named "Koukourakis Michael"

The tumor microenvironment has a significant input on prognosis and also for predicting clinical outcomes in various types of cancers. However, tumor tissue is not always available, thus, rendering peripheral blood a preferable alternative in the search for prognostic and predictive gene signatures. Head and neck squamous cell carcinoma (HNSCC) constitutes a quite heterogeneous disease characterized by poor prognosis.

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Background/aim: The prognostic role of tissue PD-L1 expression in endometrial cancer (EC) remains controversial. Moreover, its value in guiding anti-PD1/PD-L1 immunotherapy is questionable. The eventual role of soluble PD-L1 (sPD-L1), released by cancer tissue and circulating immune cells, is largely unexplored.

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Radiotherapy (RT)-induced lymphopenia may hinder the anti-tumor immune response. Preoperative RT or chemo-RT (CRT) for locally advanced rectal cancer is a standard therapeutic approach, while immunotherapy has been approved for mismatch repair-deficient rectal tumors. We retrospectively analyzed 98 rectal adenocarcinoma patients undergoing neoadjuvant CRT with VMAT (groups A, B, C) or IMRT (group D) techniques, with four different RT schemes: group A (n = 24): 25 Gy/5 Gy/fraction plus a 0.

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Background/objectives: Immune checkpoint inhibitors have an established role in non-small cell lung cancer (NSCLC) therapy. The loss of HLA-class-I expression allows cancer cell evasion from immune surveillance, disease progression, and failure of immunotherapy. The restoration of HLA-class-I expression may prove to be a game-changer in current immunotherapy strategies.

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Article Synopsis
  • Mismatch repair deficiency, immunological fertility, and PD-L1 status are crucial factors for understanding how rectal cancer tumors respond to immunotherapy and their overall prognosis.
  • In a study of advanced rectal cancer patients, higher tumor-infiltrating lymphocyte (TIL) density correlated with better survival outcomes, while cancer cell PD-L1 expression presented mixed effects on prognosis.
  • The findings suggest that patients with high TIL density combined with high PD-L1 expression might benefit from targeting anti-PD-1/PD-L1 therapies, along with those with mismatch repair deficiency.
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The IFN-type-I pathway is involved in radiotherapy (RT)-mediated immune responses. Large RT fractions have been suggested to potently induce this pathway. Neoadjuvant hypofractionated short-course (scRT) and conventional long-course (lcRT) RT applied for the treatment of locally advanced rectal adenocarcinoma patients provides a unique model to address the immuno-stimulatory properties of RT on a systemic level.

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Loss of HLA-class-I molecule expression by cancer cells is a frequent event in human tumors that may lead to immune evasion from cytotoxic T-cells. We examined the expression patterns of HLA-class-I molecules in a series of 175 patients with operable breast cancer (BCa). Extensive loss of BCa cell HLA-class-I expression was noted 76.

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Introduction: The role of the immune system in the efficacy of radiotherapy (RT) has been well established. We examined the role of neoplasia-related and treatment-induced lymphopenia in the outcome of RT or chemoradiotherapy (CRT) in squamous cell laryngeal cancer.

Materials And Methods: We retrospectively analyzed a series of 135 laryngeal carcinomas treated with radical or postoperative RT/CRT.

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Studying the levels of cytokines in the plasma of patients could be valuable in guiding immunotherapy policies. We assessed the plasma levels of 4 major cytokines [interferon (IFN)-β, interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β)] collected from 19 patients with ductal breast cancer (BCa), before surgery (BS) and 5 days after surgery (AS). The ratio AS/BS was also calculated and correlated with histopathological variables and tumor-infiltrating lymphocyte (TIL) density.

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Large fractions of radiotherapy of 8 Gy (ultra-hypofractionated RT, ultra-hypoRT) promote anti-tumor immune responses that have been clinically substantiated in combination trials with immune checkpoint inhibitors (ICIs). In the current study, we postulated that ultra-hypoRT in combination with ICIs may enhance tumor clearance in NSCLC patients with locoregional relapse after radical chemo-RT. Between 2019 and 2021, eleven patients received re-irradiation with one or two fractions of 8 Gy concurrently with anti-PD1 immunotherapy (nivolumab or pembrolizumab).

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Using next-generation sequencing (NGS), we investigated DNA mutations in the plasma tumor cell-free circulating DNA (ctDNA) of 38 patients with inoperable squamous cell head neck cancer (SCHNC) before and after the completion of chemoradiotherapy (CRT). Baseline mutations of the were recorded in 10/38 (26.3%) and persisted in 4/10 patients after CRT.

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Purpose: In contemporary radiotherapy, patient positioning accuracy relies on kV imaging. This study aims at optimizing planar kV image acquisition protocols regarding patient dose without degrading image quality.

Materials And Methods: An image quality test-object was placed in-between PMMA plates, suitably arranged to model head or pelvis.

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Background/aim: The plasma levels of cell-free DNA (cfDNA) in cancer patients increase due to rapid cancer cell proliferation and death. Therefore, cfDNA can be used to study specific tumor-DNA features. In addition, the non-specific cfDNA concentration may be an important biomarker of cancer prognosis.

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Circulating cell-free DNA (cfDNA) in the blood of cancer patients contains tumor-specific mutated genes and viral genome that can be identified and quantified as 'tumor-specific cfDNA' (circulating tumor DNA, ctDNA). Various technologies are available that offer reliable detection of ctDNA at a low concentration. Quantitative and qualitative analysis of ctDNA may be of prognostic and predictive value in oncology.

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The Interferon (ΙFN) Type-I pathway has an important role in the activation of an anti-tumor immune response. We investigated the effects of two different dose fractionations of radiation (3 daily 8 Gy fractions vs. one fraction of 20 Gy) on the activation of the Type-I IFN-pathway in three hormone-dependent (22Rv1) and independent (DU145, PC3), prostate cancer (PC) cell lines.

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Purpose: Non-small cell lung cancer (NSCLC) is one of the most lethal tumors in humans. Immunotherapy with immune checkpoint inhibitors (ICIs) has revolutionized the treatment of patients with advanced diseases. Tumor microenvironment conditions like hypoxia and low pH may compromise the efficacy of ICIs.

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PD-L1/PD-1 pathway is a major pathway exploited by human cancer types, which is a target for current immunotherapy. We investigated tumor microenvironmental factors involved in PD-L1 induction in prostate cancer (PC). We studied the expression of PD-L1 in a series of 66 PCs, in parallel with the expression of hypoxia- and acidity-related immunohistochemical markers (Hypoxia-inducible factor HIF1α, and lactate dehydrogenase LDHA) and tumor-infiltrating lymphocyte TIL density.

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Introduction: Patients with recurrent inoperable squamous-cell head-neck cancer (HNSCC) after chemo-radiotherapy have an ominous prognosis. Re-irradiation can be applied with some efficacy and high toxicity rates. Anti-PD-1 immunotherapy is effective in 25% of patients.

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Tumor-infiltrating lymphocytes (TILs) play a significant role in cancer progression and prognosis of patients. The tumor microenvironment (TME) may affect the anti-tumor immune response. We examined the TIL and tertiary lymphoid structure (TLS) density in the invading front and inner tumor stroma, and the lymphocyte subpopulation (CD8, CD4, FOXP3) density in 60 squamous cell carcinomas of the lip.

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A set of arylazo sulfones, known to undergo N-S bond cleavage upon light exposure, has been synthesized, and their activity in the dark and upon irradiation towards DNA has been investigated. Their interaction with calf-thymus DNA has been examined, and the significant affinity observed (most probably due to DNA intercalation) was analyzed by means of molecular docking "in silico" calculations that pointed out polar contacts, mainly via the sulfonyl moiety. Incubation with plasmid pBluescript KS II revealed DNA cleavage that has been studied over time and concentration.

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Background: The presence and activity of tumor-infiltrating lymphocytes (TILs) is a key parameter related to the antitumor immune response. A large number of studies reveal TIL density as a prognostic marker and predictor of response to radiotherapy, chemotherapy, and immunotherapy.

Methods: We examined the TIL and tertiary lymphoid structure TLS density in the invading front and inner tumor stroma, in a 33 squamous cell laryngeal carcinomas (LSCC) treated with laryngectomy.

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We assessed the presence of 'tertiary lymphoid structures' (TLS) in a series of surgically treated non-small cell lung carcinomas (NSCLC). The TLS-density in the tumor periphery (pTLS) ranged from 0 to 1.8 (median 0.

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Chemo-radiotherapy is the standard treatment for locally advanced head-neck cancer (LA-HNC). However, about 30% of tumors do not respond or even progress shortly after the completion of radiotherapy. We investigated whether anti-PD1 immunotherapy can eradicate the irradiated tumor and reverse the ominous prognosis of these patients.

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Purpose: Lung cancer is considered as one of the most frequent malignancies worldwide. Radiotherapy is the main treatment modality applied for locally advanced disease, but remnant surviving cancer tissue results in disease progression in the majority of irradiated lung carcinomas. Metabolic reprogramming is regarded as a cancer hallmark and is associated with resistance to radiation therapy.

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Article Synopsis
  • The study looks at a new way to treat high-risk prostate cancer using a method called hypofractionated radiotherapy (HypoAR), which gives larger doses of radiation in fewer sessions.
  • Researchers treated 22 patients and found that HypoAR had very low side effects, with no serious issues reported after an average follow-up of 30 months.
  • The results showed that HypoAR is not only safer but also effective compared to traditional methods, making it a promising option for treating this type of cancer.
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