Marian Hajduch

Non-small cell lung cancer - genetic predictors

BACKGROUNDnNon-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer that is the leading cause of cancer-related mortality worldwide. Several predictive markers have been found in NSCLC patients to date but only a few are currently used for tailored therapy.nnnMETHODS AND RESULTSnPubMed and Web of Science online databases were used to search review and original articles on the most important predictive markers in NSCLC.nnnCONCLUSIONnEGFR activating mutations (exons 18 to 21) and EML4-ALK rearrangement are clinically important markers able to select NSCLC patients which benefit from EGFR or ALK tyrosine kinase inhibitors (gefitinib, erlotinib, crizotinib). Other markers, such as KRAS mutation, EGFR T790M mutation and C-MET amplification, are responsible for resistance to these inhibitors. Overcoming of this resistance as well as discovery of new potential markers and inhibitors is the main goal of ongoing research and clinical trials in NSCLC.

Resection versus biopsy of glioblastomas in eloquent brain areas

AIMnThe aim of this study was to compare resection and biopsy of glioblastoma (GBM) in eloquent brain areas (EBA).nnnMETHODSnThis was a prospective evaluation of 38 patients with GBM in EBA. 22 were treated by surgical resection and 16 by biopsy. Preoperative KPS, neurological status and size of lesion on MRI were assessed. One week and three months postoperatively KPS, neurological status and Performance Status (PS) WHO were evaluated. Extent of resection (EOR) and overall survival (OS) were described. Overall mean age of the patients was 64.3 years, the mean lesion size in the resection group was 47.7 mm and in the biopsy group 51.0 mm.nnnRESULTSnWorsening or development of permanent neurological deficits 3 months after surgery were significantly lower in the resection group (23%), than the biopsy group (94%). In the resection group the median pre and postoperative KPS three months after surgery was 80.0. In the biopsy group the median pre and postoperative KPS was 68.1 one week after the procedure. In the resection group, 3 months after surgery, the median PS was 1, in the biopsy group one week after surgery the median PS was 2. The difference was statistically insignificant. The mean OS after resection was 12.2 months, and after biopsy 3.5 months. The difference was highly statistically significant. The mean EOR was 90%.nnnCONCLUSIONnThis is the first prospective study, to our knowledge, that compares the results of resection and biopsy of primary GBM in EBA. For patients in good clinical condition with tumors in or near EBA, recommended is as radical resection of GBM as possible.

Occult tumour cells in peritoneal lavage are a negative prognostic factor in pancreatic cancer

AIMSnThe aim of this study was to test the hypothesis that occult tumour cells in peritoneal lavage are a negative prognostic factor in pancreatic adenocarcinoma.nnnMETHODSnReal-time RT-PCR analysis of CEA, EGFR and hTERT transcript levels was used to identify occult tumour cells in peritoneal lavage samples from 96 pancreatic cancer patients.nnnRESULTSnWe found significant association between CEA expression levels in peritoneal lavage and clinical stage. We also found that EGFR transcript levels were higher in peritoneal lavage samples from patients with high grade tumours than in samples from patients with low grade tumours. Detection of CEA and/or EGFR occult tumour cell markers in the peritoneal lavage was associated with significantly shorter overall survival and increased hazard ratio for disease recurrence.nnnCONCLUSIONSnThe results show that the presence of occult tumour cells in peritoneal lavage is a negative prognostic factor for survival in pancreatic cancer patients, and that detection of occult tumour cells using PCR-based methods can identify patients with advanced disease for whom radical surgery is likely to have little benefit.

Isocitrate Dehydrogenase Mutations are Better Prognostic Marker than O6-methylguanine-DNA Methyltransferase Promoter Methylation in Glioblastomas – a Retrospective, Single-centre Molecular Genetics Study of Gliomas

BACKGROUNDnMutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) are a promising prognostic biomarker of gliomas. The purpose of our study was to examine the clinical prognostic properties of IDH1/2 mutations in a glioma patient cohort from the Czech Republic using an improved platform for simple and reliable IDH genotyping.nnnMATERIAL AND METHODSnWe retrospectively analyzed a group of 145 glioma patients by testing for the three most frequent IDH mutations, IDH1 R132H, IDH1 R132C, and IDH2 R172K, through the competitive amplification of differentially melting amplicons (CADMA) polymerase chain reaction (PCR). O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, copy number of EGFR, p53, RB1, MDM2, CDKN2A genes, and deletions in 1p, 19q and 10p chromosomal regions were also analyzed and correlated with clinical characteristics.nnnRESULTSnOf 145 gliomas, 36 harbored IDH1 R132H mutation and 1 IDH1 R132C mutation. We did not detect any IDH2 R172K mutation. IDH1 mutations were positively associated with MGMT methylation (OR 3.08, 95% CI 1.387-7.282; p = 0.007), 1p/19q co-loss (OR 8.85, 95% CI 2.367-42.786; p = 0.002) and negatively associated with epidermal growth factor receptor amplification (OR 0.12, 95% CI 0.019-0.437; p = 0.006) and 10p loss (OR 0.09, 95% CI 0.005-0.436; p = 0.019). The overall survival of IDH-mutant was 25 months, but only 9 months in IDH-wild type gliomas (p = 0.035); at the same time, survival associated with methylated vs. unmethylated MGMT promoter did not significantly differ (p = 0.166).nnnCONCLUSIONnDespite IDH1 mutations being closely associated with MGMT methylation in glioma patients, IDH1 mutations in glioblastoma patients are stronger marker of overall survival than MGMT methylation and should be the marker of choice, especially when using genotyping by CADMA PCR.Key words: isocitrate dehydrogenase - polymerase chain reaction - glioma - glioblastoma.

Induction, regulation and roles of neural adhesion molecule L1CAM in cellular senescence

Aging involves tissue accumulation of senescent cells (SC) whose elimination through senolytic approaches may evoke organismal rejuvenation. SC also contribute to aging-associated pathologies including cancer, hence it is imperative to better identify and target SC. Here, we aimed to identify new cell-surface proteins differentially expressed on human SC. Besides previously reported proteins enriched on SC, we identified 78 proteins enriched and 73 proteins underrepresented in replicatively senescent BJ fibroblasts, including L1CAM, whose expression is normally restricted to the neural system and kidneys. L1CAM was: 1) induced in premature forms of cellular senescence triggered chemically and by gamma-radiation, but not in Ras-induced senescence; 2) induced upon inhibition of cyclin-dependent kinases by p16INK4a; 3) induced by TGFbeta and suppressed by RAS/MAPK(Erk) signaling (the latter explaining the lack of L1CAM induction in RAS-induced senescence); and 4) induced upon downregulation of growth-associated gene ANT2, growth in low-glucose medium or inhibition of the mevalonate pathway. These data indicate that L1CAM is controlled by a number of cell growth- and metabolism-related pathways during SC development. Functionally, SC with enhanced surface L1CAM showed increased adhesion to extracellular matrix and migrated faster. Our results provide mechanistic insights into senescence of human cells, with implications for future senolytic strategies.

Detection of minimal residual disease in lung cancer

BACKGROUNDnEven after successful radical treatment of lung cancer, patients in stages I and II of the TNM system very frequently suffer recurrence, which end lethally. Detection of subclinical residual disease after surgery is thus one of the most important emerging diagnostic methods. Minimal residual disease (MRD) is defined as the presence of isolated tumor cells or circulating cells in a patient after curative primary tumor removal and at the same time, no clinical signs of cancer. Conventional methods cannot detect minimal residual disease and hence there is a need for detection using new molecular biological methods.nnnMETHODSnWe searched the PubMed database for original and review articles on minimal residual disease in lung cancer. Search words were lung cancer, minimal residual disease and detection of minimal residual disease. The publications we found were compared with the results of our own studies on the detection of minimal residual disease in lung cancer and the personal experiences are described. Examination of blood samples from 98 healthy volunteers and bone marrow from 12 patients with non inflammatory and non tumour illness, were used to determine cut-off values for specific markers in the compartments. Subsequently, expression of selected markers in tumor tissue was analysed in a pilot sample of 50 patients with lung cancer and the presence of MRD was measured as expression of values of the tested markers correlated with clinico-pathological characteristics.nnnCONCLUSIONSnRecent studies on other malignancies apart from lung cancer have shown the importance of MRD detection in the determination of disease progression and prognosis. The methods of MRD diagnostics are based on detection of specific tumor markers. Of these, the most specific for lung cancer, appears to be the LunX protein. The best method for determining MRD is probably RT-PCR. Further studies should expand knowledge in this area: to refine understanding of the importance of tumor markers for prognosis, as well as to confirm the significance of these findings in clinical practice.

Combination of prednisolone and low dosed dexamethasone exhibits greater in vitro antileukemic activity than equiactive dose of prednisolone and overcomes prednisolone drug resistance in acute childhood lymphoblastic leukemia

INTRODUCTIONnGlucocorticoids, particularly prednisone/ prednisolone and dexamethasone, play a prominent role in the treatment of pediatric patients with acute lymphoblastic leukemia due to their ability to induce apoptosis in susceptible cells. Current therapeutic protocols use prednisone for both the prophase and the induction phase of the therapy because the greater antileukemic activity of dexamethasone is compromised by its high frequency of serious adverse reactions.nnnAIMnTo compare, for the first time, the in vitro antileukemic activity of prednisolone alone to that of a combination of prednisolone and dexamethasone using dexamethasone at a very low and presumably safe dosage (1/50 w/w).nnnMETHODSnLymphoblasts were isolated from bone marrow and/or blood samples from children with newly diagnosed acute lymphoblastic leukemia. The cytotoxic activity of prednisolone, dexamethasone and the prednisolone/dexamethasone combination against isolated leukemia cells was analyzed using the MTT cytotoxicity assay.nnnRESULTSnWe observed differences in the in vitro antileukemic activity of prednisolone and dexamethasone in 21% of the tested patients. 3% of the children were prednisolone sensitive but dexamethasone resistant, while 18% were prednisolone resistant and dexamethasone sensitive. 32% were sensitive to both glucocorticoids and 18% were resistant to both. Cells from patients with good in vivo responses to prednisone monotherapy were more responsive to prednisolone in vitro than were cells from patients with poor prednisone responses (P<0.07). Importantly, we demonstrated that the use of even a minimal dose (1/50 w/w) of dexamethasone with prednisolone dramatically increases the in vitro anti-leukemic activity of prednisolone (P<0.0006).nnnCONCLUSIONnThe high inter-individual variability of acute lymphoblastic leukemia responses to glucocorticoids suggest that either patients should be selected for prednisone or dexamethasone treatment on the basis of predictive biomarkers or that prednisone should be used directly in combination with a very low and safe dose of dexamethasone to potentiate its antileukemic activity. The latter option is likely to be cheaper and more efficient, and therefore warrants further clinical investigation to assess its efficacy and safety in treating childhood acute lymphoblastic leukemia.