Lung cancer management: monitoring and treating resistance development in third-generation EGFR TKIs.

INTRODUCTION: Patients treated with third-generation EGFR TKIs will develop resistance to treatment at a certain point. Early detection of resistance occurrence could allow more options for treatment. AREAS COVERED: We discuss the development of third-generation EGFR TKIs, focusing on osimertinib and discuss the most common resistance mechanisms under evaluation. We also debate how this resistance can be detected; particularly we review the possible application of liquid biopsy in this scenario. Lastly we discuss available treatment options when resistance occurs, with an eye on ongoing trials and possible future developments. EXPERT OPINION: As resistance will ultimately develop, a strict instrumental follow-up as per international guidelines is required with the aim of detecting this resistance in an early phase. Detecting an oligoprogression could allow the integration of local ablative therapies while further delaying the need for a systemic therapy change. By exploiting the increasing potentiality of liquid biopsy, in the near future, physicians could be able to understand why a patient develops resistance and therefore can choose the best possible individualized treatment option.

The use of radiation therapy for oligoprogressive/oligopersistent oncogene-driven non small cell lung cancer: State of the art.

Oncogene-driven non small cell lung cancer (NSCLC) is a distinct entity in thoracic oncology. The availability of effective target therapies, like EGFR inhibitors or ALK inhibitors, have revolutionized the prognosis of these patients. However, despite an initial response in the majority of patients, drug resistance ultimately occurs. In some cases, this resistance develops in few clonal cells (oligoprogression), so that a local ablation of these resistant deposits could allow to maintain the same systemic therapy and possibly to prolong patients' survival. For these purposes, stereotactic body radiation therapy (SBRT) is an ideal local ablative treatment, because it is effective, non invasive and with limited side effects. In this review, we aim to analyze available clinical data to verify whether SBRT can allow these patients to continue with existing target therapy longer, delay the switch to other systemic therapies and improve their outcome modifying the natural history of the disease.

Clinical Outcome of Stereotactic Ablative Body Radiotherapy for Lung Metastatic Lesions in Non-small Cell Lung Cancer Oligometastatic Patients.

AIMS: The aim of this observational study was the evaluation of toxicity, local control and overall survival in non-small cell lung cancer (NSCLC) oligometastatic patients who had undergone stereotactic ablative body radiotherapy (SABR) for lung metastatic lesions. MATERIALS AND METHODS: SABR was carried out in oligometastatic patients with controlled primary tumour (adequate pulmonary function). We adopted the following dose prescriptions according to the site and the maximum diameter of the lung lesions: 60 Gy in three fractions for peripheral lesions with diameter ≤ 2 cm, 48 Gy in four fractions for peripheral lesions between 2 and 5 cm and 60 Gy in eight fractions for central lesions. A radiological response was defined according to RECIST criteria. Toxicity was recorded according to the Common Toxicity Criteria version 4.0. RESULTS: Between October 2010 and December 2014, 60 NSCLC patients with 90 lung lesions in total were treated at our institution. A radiological response was obtained in most patients. No pulmonary toxicity grade 4, chest pain or rib fracture occurred. The median follow-up from diagnosis was 28 months (range 5.4-104.5 months). The local control at 2 years was 88.9%. Overall survival at 1 and 2 years was 94.5 and 74.6%, respectively. CONCLUSION: SABR is well tolerated with a good radiological response and toxicity profile. Discussion within a multidisciplinary team is crucial to identify the oligometastatic patients who would probably benefit from ablative local therapy.

Advanced MRI may complement histological diagnosis of lower grade gliomas and help in predicting survival.

MRI grading of grade II and III gliomas may have an important impact on treatment decisions. Occasionally,both conventional MRI (cMRI) and histology fail to clearly establish the tumour grade. Three cMRI features(no necrosis; no relevant oedema; absent or faint contrast enhancement) previously validated in 196 patients with supratentorial gliomas directed our selection of 68 suspected low-grade gliomas (LGG) that were also investigated by advanced MRI (aMRI), including perfusion weighted imaging (PWI), diffusion weighted imaging(DWI) and spectroscopy. All the gliomas had histopathological diagnoses. Sensitivity and specificity of cMRI preoperative diagnosis were 78.5 and 38.5 %, respectively, and 85.7 and 53.8 % when a MRI was included, respectively. ROC analysis showed that cut-off values of 1.29 for maximum rCBV, 1.69 for minimum rADC, 2.1 for rCho/Cr ratio could differentiate between LGG and HGG with a sensitivity of 61.5, 53.8, and 53.8 % and a specificity of 54.7, 43 and 64.3 %, respectively. A significantly longer OS was observed in patients with a maximum rCBV<1.46 and minimum rADC>1.69 (80 vs 55 months, p = 0.01; 80 vs 51 months, p = 0.002, respectively). This result was also confirmed when cases were stratified according to pathology (LGG vs HGG). The ability of a MRI to differentiate between LGG and HGG and to predict survival improved as the number of a MRI techniques considered increased. In a selected population of suspected LGG,classification by cMRI underestimated the actual fraction of HGG. aMRI slightly increased the diagnostic accuracy compared to histopathology. However, DWI and PWI were prognostic markers independent of histological grade.

TERT promoter mutations in gliomas, genetic associations and clinico-pathological correlations.

BACKGROUND: The role of telomerase reverse transcriptase (TERT) in gliomagenesis has been recently further strengthened by the frequent occurrence of TERT promoter mutations (TERTp-mut) in gliomas and evidence that the TERT SNP genetic rs2736100 influences glioma risk. TERTp-mut creates a binding site for Ets/TCF transcription factors, whereas the common rs2853669 polymorphism disrupts another Ets/TCF site on TERT promoter. METHODS: We sequenced for TERTp-mut in 807 glioma DNAs and in 235 blood DNAs and analysed TERT expression by RT-PCR in 151 samples. TERTp-mut status and TERTp polymorphism rs2853669 were correlated with histology, genomic profile, TERT mRNA expression, clinical outcome and rs2736100 genotype. RESULTS: TERTp-mut identified in 60.8% of gliomas (491 out of 807) was globally associated with poorer outcome (Hazard ratio (HR)=1.50). We defined, based on TERTp-mut and IDH mutation status, four prognostic groups: (1) TERTp-mut and IDH-mut associated with 1p19q codeletion, overall survival (OS)>17 years; (2) TERTp-wt and IDH-mut, associated with TP53 mutation, OS=97.5 months; (3) TERTp-wt and IDH-wt, with no specific association, OS=31.6 months; (4) TERTp-mut and IDH-wt, associated with EGFR amplification, OS=15.4 months. TERTp-mut was associated with higher TERT mRNA expression, whereas the rs2853669 variant was associated with lower TERT mRNA expression. The mutation of CIC (a repressor of ETV1-5 belonging to the Ets/TCF family) was also associated with TERT mRNA upregulation. CONCLUSIONS: In addition to IDH mutation status, defining the TERTp-mut status of glial tumours should afford enhanced prognostic stratification of patients with glioma. We also show that TERTp-mut, rs2853669 variant and CIC mutation influence Tert expression. This effect could be mediated by Ets/TCF transcription factors.

Neutrophil-tumor cell phagocytosis (cannibalism) in human tumors: an update and literature review.

The recognition and removal of apoptotic cells by tissue macrophages and nonprofessional phagocytes, in a process called efferocytosis, is critical for development, tissue homeostasis and resolution of inflammation. Apoptotic bodies arising in tumor tissue are ingested by viable neoplastic cells and by resident macrophages. We described tumor cell phagocytosis of apoptotic neutrophils in human gastric carcinomas. This phenomenon is analogous to neutrophil efferocytosis performed by macrophages and by nonprofessional phagocytes during inflammatory reaction but is distinct by other types of cell-in-cell phenomena including emperipolesis and entosis both cytologically and biologically. In this review, we discussed them in their ultrastructural morphology, physiological roles, and clinicopathologic implications. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later".

CT and MRI of brain tumors.

Imaging plays a crucial role in the management of patients with brain tumors. The technical improvement of computed tomography (CT) and magnetic resonance (MRI) with the development of, new imaging techniques strongly improved the detection and characterization of brain tumors. For the optimal therapeutic management of the oncologic patient not only the recognition of the lesion is needed, but also the exclusion of other diseases that can mimic brain tumors. The preoperative assessment of malignancy and of relationships of the tumor with surrounding eloquent structures are also necessary to allow the correct choice of therapy and to warn surgeons of possible risks of the surgical approach. This article is an overview of the current state of neuroimaging of the most frequent brain tumors including CT and MRI, perfusion weighted imaging (PWI), diffusion weighted imaging (DWI), diffusion tensor imaging (DTI), proton magnetic resonance spectroscopy (1H-MRS) and functional MRI based on blood oxygen level (fMRI BOLD). Indeed, in the last years, a transition took place from a purely anatomy-based radiology to one that incorporates functional, hemodynamic, metabolic, cellular, and cytoarchitectural alterations. Neuroimaging has evolved into a comprehensive diagnostic tool that allows the characterization of morphologic as well as biologic alterations to diagnose and grade brain tumors and to monitor and assess treatment response and patient prognosis.

Enhancer of Zeste 2 (EZH2) is up-regulated in malignant gliomas and in glioma stem-like cells.

AIMS: Proteins of the Polycomb repressive complex 2 (PRC2) are epigenetic gene silencers and are involved in tumour development. Their oncogenic function might be associated with their role in stem cell maintenance. The histone methyltransferase Enhancer of Zeste 2 (EZH2) is a key member of PRC2 function: we have investigated its expression and function in gliomas. METHODS: EZH2 expression was studied in grade II-IV gliomas and in glioma stem-like cells (GSC) by quantitative PCR and immunohistochemistry. Effects of EZH2 down-regulation were analysed by treating GSC with the histone deacetylase (HDAC) inhibitor suberoylanide hydroxamic acid (SAHA) and by shRNA. RESULTS: DNA microarray analysis showed that EZH2 is highly expressed in murine and human GSC. Real-time PCR on gliomas of different grade (n = 66) indicated that EZH2 is more expressed in glioblastoma multiforme (GBM) than in low-grade gliomas (P = 0.0013). This was confirmed by immunohistochemistry on an independent set of 106 gliomas. Treatment with SAHA caused significant up-regulation of PRC2 predicted target genes, GSC disruption and decreased expression of EZH2 and of the stem cell marker CD133. Inhibition of EZH2 expression by shRNA was associated with a significant decrease of glioma proliferation. CONCLUSION: The data suggest that EZH2 plays a role in glioma progression and encourage the therapeutic targeting of these malignancies by HDAC inhibitors.

TLR4 and NOD2/CARD15 genetic polymorphisms and their possible role in gastric carcinogenesis.

UNLABELLED: The aim of this study was to evaluate the role of TLR4 and NOD2/CARD15 genes in gastric carcinogenesis. PATIENTS AND METHODS: We investigated the allelic frequencies of TLR4 (D299G and T399I) and NOD2/CARD15 (R702W, G908R, and L1007finsC) SNPs in 87 asymptomatic serologically H. pylori-positive individuals (Group I), in 63 patients with antrum-predominant gastritis (Group II) and in 60 patients with corpus-predominant gastritis or pangastritis (Group III). RESULTS: There was significant difference in allelic frequencies of TLR4 D299G SNP in Group II (p=0.02; OR 2.97) as well as in Group III (p=0.001; OR 4.80). Significant difference of T399I SNP allele frequency was only found in Group III (p=0.009; OR 3.73). The allele frequencies of NOD2/CARD15 G908R and of L1007insC SNP were higher in Group III (p=0.003, OR 5.18; p=0.03; OR 3.66, respectively). CONCLUSION: TLR4 and NOD2/CARD15 genes are associated with high risk Group III patients and, therefore, they appear to play a role in gastric carcinogenesis.

Modifications of nuclear envelope in tumour cells of human gastric carcinomas: an ultrastructural study.

BACKGROUND: Various nuclear envelope derivatives, such as the annulate lamellae, the intranuclear tubules as well as the nuclear projections and pockets may be observed electron microscopically in tumour cells. PATIENTS AND METHODS: In a series of eight gastric adenocarcinomas, ultrastructural features of nuclear envelope changes were analyzed and correlated to the biology of the tumours. RESULTS: Histologically, three tumours were intestinal-type adenocarcinomas and showed annulate lamellae in the cytoplasm of some tumor cells. Five tumors were mixed-type adenocarcinomas, with a solid growth pattern; two of these tumours were characterized by the presence of intranuclear tubules, whereas the remaining three tumours exhibited nuclear pockets and projections. Seven out of eight patients died due to metastatic disease during the follow-up period (median 31 months). CONCLUSION: Ultrastructural evaluation of pleomorphism of the nuclear envelope may be an ancillary method for the pathologist in the study of nuclear grading of gastric carcinomas.

Insulin-like growth factor receptor 1 (IGF1R) expression and survival in surgically resected non-small-cell lung cancer (NSCLC) patients.

BACKGROUND: The purpose of this study is to investigate the prognostic role of insulin-like growth factor receptor 1 (IGF1R) expression in surgically resected non-small-cell lung cancer (NSCLC). Patient characteristics and methods: This retrospective study was conducted in 369 stage I-II-IIIA, surgically resected, NSCLC patients. Patients exposed to anti-epidermal growth factor receptor (EGFR) agents were excluded. IGF1R expression was evaluated by immunohistochemistry in tissue microarray sections. RESULTS: A positive IGF1R expression (score > or = 100) was observed in 282 cases (76.4%) and was significantly associated with squamous cell histology (P = 0.04) and with grade III differentiation (P = 0.02). No difference in survival was observed between the positive and negative group when score 100 was used as cut-off for discriminating a positive versus a negative IGF1R result (52 versus 48 months, P = 0.99) or when median value of IGF1R expression was used (45 versus 55 months, P = 0.36). No difference in survival was observed between IGF1R-positive and -negative patients in a subgroup of stage I-II adenocarcinoma (n = 137) with known EGFR mutation and copy number status. CONCLUSIONS: IGF1R expression does not represent a prognostic factor in resected NSCLC patients. Patients with squamous cell carcinoma overexpress IGF1R more frequently than patients with nonsquamous histology, justifying the different sensitivity to anti-IGF1R agents observed in clinical trials.

Granulomatous inflammatory reaction in human gastric adenocarcinomas: a light and electron microscopy study.

Granuloma is a focal, compact collection of inflammatory cells in which mononuclear phagocytes predominate. The authors report 9 cases of papillary-tubular gastric adenocarcinomas characterized by mature granulomas associated with recent microhemorrhages. Mature granulomas were composed of foamy, CD68-positive histiocytes with occasional giant cells. Hemosiderin-containing macrophages were present in the tumor stroma, suggesting phagocytosis of erythrocytes. Under electron microscopy, mature (nonepithelioid) granulomas and clusters containing 1 macrophage and 1-3 eosinophils were found. This study provides morphological examples of skewed type II macrophage infiltration in gastric adenocarcinomas that is involved in scavenging activity, particularly erythrophagocytosis, formation of mature (nonepithelioid granulomas), and heterotypic aggregation with eosinophils.

Ultrastructural descriptions of pericyte/endothelium peg-socket interdigitations in the microvasculature of human gastric carcinomas.

BACKGROUND: Angiogenesis requires complex multistep signalling pathways and a high degree of spatial and temporal coordination among endothelial cells and pericytes. The two cell types exhibit numerous contacts in vivo and in vitro, including the occurrence of peg-socket junctions. MATERIALS AND METHODS: Ultrastructural findings in 9 cases of advanced gastric carcinomas were reviewed with special emphasis on endothelium/pericyte peg-socket junctions. RESULTS: The incidence of peg-socket junctions was approximately 8% in 5 out of 9 cases. The remaining 4 cases showed a very low rate, including two cases in whom interactions were totally absent. Peg-socket junctions consisted of cytoplasmic projection from the pericyte protruding into the endothelial indentation. The endothelial cells interacting with pericytes showed ultrastructural signs of partial stabilization such as continuous endothelial lining, regularly constructed interendothelial junctions, more or less integrated pericytes, and multilayered basement membrane. CONCLUSION: Our ultrastructural study confirms previous reports regarding pericyte/endothelial peg-socket interdigitations in murine and human granulation tissues and extends these findings to the microvasculature of human gastric carcinomas.

[Clinical governance and continuous quality improvement in surgical organizations]. / La clinical governance e il miglioramento continuo della qualità in chirurgia.

Recently the awareness had progressively strengthened that the main interest of health care organizations is effectiveness and appropriateness of clinical performance. They have a statutory duty to seek quality improvement through clinical governance. All health care operators are involved in clinical governance implementation, in respect of their organizational positions toward continuous quality improvement. In this way health care organizations, professionals and patients will benefit of outcomes of the change.

MET increased gene copy number and primary resistance to gefitinib therapy in non-small-cell lung cancer patients.

BACKGROUND: MET amplification has been detected in approximately 20% of non-small-cell lung cancer patients (NSCLC) with epidermal growth factor receptor (EGFR) mutations progressing after an initial response to tyrosine kinase inhibitor (TKI) therapy. PATIENTS AND METHODS: We analyzed MET gene copy number using FISH in two related NSCLC cell lines, one sensitive (HCC827) and one resistant (HCC827 GR6) to gefitinib therapy and in two different NSCLC patient populations: 24 never smokers or EGFR FISH-positive patients treated with gefitinib (ONCOBELL cohort) and 182 surgically resected NSCLC not exposed to anti-EGFR agents. RESULTS: HCC827 GR6-resistant cell line displayed MET amplification, with a mean MET copy number >12, while sensitive HCC827 cell line had a mean MET copy number of 4. In the ONCOBELL cohort, no patient had gene amplification and MET gene copy number was not associated with outcome to gefitinib therapy. Among the surgically resected patients, MET was amplified in 12 cases (7.3%) and only four (2.4%) had a higher MET copy number than the resistant HCC827 GR6 cell line. CONCLUSIONS: MET gene amplification is a rare event in patients with advanced NSCLC. The development of anti-MET therapeutic strategies should be focused on patients with acquired EGFR-TKI resistance.

Late-onset sporadic ataxia, pontine lesion, and retroperitoneal fibrosis: a case of Erdheim-Chester disease.

A 60-year-old man with progressive gait ataxia and mild pyramidal signs showed at MRI a pontine lesion with post-contrast enhancement in the left middle cerebellar peduncle. Diagnosis of Erdheim-Chester disease (ECD), a rare non-Langerhans cell histiocytosis, was suggested, further supported by a previously diagnosed retroperitoneal fibrosis. X-ray films demonstrated characteristic bilateral and symmetric osteosclerosis of the long bones of the lower limbs, which at radionuclide studies exhibited a marked increase in technetium-99 uptake. A cerebral 18FDG-PET showed a relevant pontine uptake of the tracer. Re-evaluation of a past retroperitoneal biopsy showed an intense CD68+, CD1a-, and S100- infiltrate of histiocytes with foamy cytoplasm, thus confirming the diagnosis. ECD should be regarded as a rare cause of adult-onset sporadic ataxia, especially when pontine lesions and extraneurological manifestations are present.

Primary resistance to cetuximab therapy in EGFR FISH-positive colorectal cancer patients.

The impact of KRAS mutations on cetuximab sensitivity in epidermal growth factor receptor fluorescence in situ hybridisation-positive (EGFR FISH+) metastatic colorectal cancer patients (mCRC) has not been previously investigated. In the present study, we analysed KRAS, BRAF, PI3KCA, MET, and IGF1R in 85 mCRC treated with cetuximab-based therapy in whom EGFR status was known. KRAS mutations (52.5%) negatively affected response only in EGFR FISH+ patients. EGFR FISH+/KRAS mutated had a significantly lower response rate (P=0.04) than EGFR FISH+/KRAS wild type patients. Four EGFR FISH+ patients with KRAS mutations responded to cetuximab therapy. BRAF was mutated in 5.0% of patients and none responded to the therapy. PI3KCA mutations (17.7%) were not associated to cetuximab sensitivity. Patients overexpressing IGF1R (74.3%) had significantly longer survival than patients with low IGF1R expression (P=0.006), with no difference in response rate. IGF1R gene amplification was not detected, and only two (2.6%) patients, both responders, had MET gene amplification. In conclusion, KRAS mutations are associated with cetuximab failure in EGFR FISH+ mCRC, even if it does not preclude response. The rarity of MET and IGF1R gene amplification suggests a marginal role in primary resistance. The potential prognostic implication of IGF1R expression merits further evaluation.

EGFR FISH assay predicts for response to cetuximab in chemotherapy refractory colorectal cancer patients.

BACKGROUND: Standardized conditions to distinguish subpopulations of colorectal cancer (CRC) patients more and less sensitive to cetuximab therapy remain undefined. MATERIALS AND METHODS: We retrospectively analyzed epidermal growth factor receptor (EGFR) copy number by fluorescence in situ hybridization (FISH) in paraffin-embedded tumor blocks from 85 chemorefractory CRC patients treated with cetuximab. Results were analyzed according to different score systems previously reported in colorectal and lung cancers. The primary end point of the study was identification of the EGFR FISH score that best associates with response rate (RR). RESULTS: Using receiver operating characteristic (ROC) analysis, the cut-off that best discriminated responders versus nonresponders to cetuximab was a mean of 2.92 EGFR gene copies per cell. This model showed sensitivity of 58.6% [95% confidence interval (CI) = 47.1-70.1) and specificity of 93.3% (95% CI = 80.6-100). EGFR FISH-positive patients (N = 43, 50.6%) had significantly higher RR (P = 0.0001) and significantly longer time to disease progression (P = 0.02) than EGFR FISH negative (N = 42, 49.4%). Other scoring systems resulted less accurate in discriminating patients with the highest likelihood of response to cetuximab therapy. CONCLUSIONS: CRC patients with high EGFR gene copy number have an increased likelihood to respond to cetuximab therapy. Prospective clinical trials with a careful standardization of assay conditions and pattern interpretation are urgently needed.

Surrogate predictive biomarkers for response to anti-EGFR agents: state of the art and challenges.

The epidermal growth factor receptor (EGFR) plays a key role in cancer development and progression in several human malignancies including non-small cell lung cancer (NSCLC). Several strategies aimed at inhibiting the EGFR have been investigated in the last years, including the use of small tyrosine kinase inhibitors (TKIs) directed against the intracellular domain of the receptor and monoclonal antibodies targeting its extracellular portion. Subgroups of patients who are more likely to respond to TKIs have been identified based on both clinical and biological features. Never-smoking history has emerged as the most relevant clinical characteristic predictive of response to TKIs in NSCLC, while presence of drug-sensitive EGFR mutations and EGFR gene gain represent critical biological variables associated with an improved outcome for patients exposed to these agents. Recent studies have highlighted the existence of biological factors involved in intrinsic and acquired resistance to TKIs, including k-ras, HER-2 and EGFR exon 20 mutations. Increasing knowledge of EGFR biology and drug-receptor interactions will allow to identify individuals who are likely to derive a clinical benefit from the proposed targeted therapy, sparing refractory patients expensive and potentially toxic treatment.