Resistance to osimertinib in advanced EGFR-mutated NSCLC: a prospective study of molecular genotyping on tissue and liquid biopsies

BACKGROUND

Resistance to osimertinib in advanced EGFR-mutated non-small cell lung cancer (NSCLC) constitutes a significant challenge for clinicians either in terms of molecular diagnosis and subsequent therapeutic implications.

METHODS

This is a prospective single-centre study with the primary objective of characterising resistance mechanisms to osimertinib in advanced EGFR-mutated NSCLC patients treated both in first- and in second-line. Next-Generation Sequencing analysis was conducted on paired tissue biopsies and plasma samples. A concordance analysis between tissue and plasma was performed.

RESULTS

Sixty-five advanced EGFR-mutated NSCLC patients treated with osimertinib in first- (n = 56) or in second-line (n = 9) were included. We managed to perform tissue and liquid biopsies in 65.5% and 89.7% of patients who experienced osimertinib progression, respectively. Acquired resistance mechanisms were identified in 80% of 25 patients with post-progression samples, with MET amplification (n = 8), EGFR C797S (n = 3), and SCLC transformation (n = 2) the most frequently identified. The mean concordance rates between tissue and plasma for the EGFR activating mutation and for the molecular resistance mechanisms were 87.5% and 22.7%, respectively.

CONCLUSIONS

Resistance to osimertinib demonstrated to be highly heterogeneous, with MET amplification the main mechanism. Plasma genotyping is a relevant complementary tool which might integrate tissue analysis for the study of resistance mechanisms.

Notch-Jagged1 signaling and response to bevacizumab therapy in advanced colorectal cancer: A glance to radiomics or back to physiopathology?

Introduction

The Notch intracellular domain (NICD) and its ligands Jagged-1(Jag1), Delta-like ligand (DLL-3) and DLL4 play an important role in neoangiogenesis. Previous studies suggest a correlation between the tissue levels of NICD and response to therapy with bevacizumab in colorectal cancer (CRC). Another marker that may predict outcome in CRC is radiomics of liver metastases. The aim of this study was to investigate the expression of NICD and its ligands and the role of radiomics in the selection of treatment-naive metastatic CRC patients receiving bevacizumab.

Methods

Immunohistochemistry (IHC) for NICD, Jag1 and E-cadherin was performed on the tissue microarrays (TMAs) of 111 patients with metastatic CRC treated with bevacizumab and chemotherapy. Both the intensity and the percentage of stained cells were evaluated. The absolute number of CD4+ and CD8+ lymphocytes was counted in three different high-power fields and the mean values obtained were used to determine the CD4/CD8 ratio. The positivity of tumor cells to DLL3 and DLL4 was studied. The microvascular density (MVD) was assessed in fifteen cases by counting the microvessels at 20x magnification and expressed as MVD score. Abdominal CT scans were retrieved and imported into a dedicated workstation for radiomic analysis. Manually drawn regions of interest (ROI) allowed the extraction of radiomic features (RFs) from the tumor.

Results

A positive association was found between NICD and Jag1 expression (p < 0.001). Median PFS was significantly shorter in patients whose tumors expressed high NICD and Jag1 (6.43 months vs 11.53 months for negative cases; p = 0.001). Those with an MVD score ≥5 (CD31-high, NICD/Jag1 positive) experienced significantly poorer survival. The radiomic model developed to predict short and long-term survival and PFS yielded a ROC-AUC of 0.709; when integrated with clinical and histopathological data, the integrated model improved the predictive score (ROC-AUC of 0.823).

Discussion

These results show that high NICD and Jag1 expression are associated with progressive disease and early disease progression to anti VEGF-based therapy; the preliminary radiomic analyses show that the integration of quantitative information with clinical and histological data display the highest performance in predicting the outcome of CRC patients.

Multicenter Observational Study on Metastatic Non-Small Cell Lung Cancer Harboring BRAF Mutations: Focus on Clinical Characteristics and Treatment Outcome of V600E and Non-V600E Subgroups

Simple Summary

Around 2–4% of lung adenocarcinoma harbors BRAF mutations. Dabrafenib and Trametinib represent the first treatment-choice for BRAF V600E^mut NSCLC, regardless of the line of therapy, while non-V600E^mut receive standard immunotherapy or chemo-immunotherapy. Our real-life multicenter study on 44 BRAF mutant NSCLC responds to the urgent need to characterize this subset of patients in-depth, potentially offering new valuable biological and clinical insights. We specifically focused on similarities/discrepancies between V600E and non-V600E populations, providing consistent data about clinicopathologic characteristics, treatment response, and survival outcome.

Abstract

Introduction: BRAF mutation involved 2–4% of lung adenocarcinoma. Differences in clinicopathologic features and patient outcome exist between V600E and non-V600E BRAF mutated NSCLC. Thus, we sought to assess the frequency and clinical relevance of BRAF mutations in a real-life population of advanced-NSCLC, investigating the potential prognostic significance of distinct genetic alterations. Materials and Methods: The present multicenter Italian retrospective study involved advanced BRAF mutant NSCLC. Complete clinicopathologic data were evaluated for BRAF V600E and non-V600E patients. Results: A total of 44 BRAF^mut NSCLC patients were included (V600E, n = 23; non-V600E, n = 21). No significant differences in survival outcome and treatment response were documented, according to V600E vs. non-V600E mutations, although a trend towards prolonged PFS was observed in the V600E subgroup (median PFS = 11.3 vs. 6.0 months in non-V600E). In the overall population, ECOG PS and age significantly impacted on OS, while bone lesions were associated with shorter PFS. Compared to immunotherapy, first-line chemotherapy was associated with longer OS in the overall population, and especially in the BRAF V600E subtype. Conclusions: Here, we report on real-life data from a retrospective cohort of advanced-NSCLC harboring BRAF alterations. Our study offers relevant clues on survival outcome, therapeutic response, and clinicopathologic correlations of BRAF-mutant NSCLC.

YES1 and MYC amplifications as synergistic resistance mechanisms to different generation ALK-TKIs in advanced NSCLC: brief report of clinical and preclinical proofs

Introduction

ALK tyrosine kinase inhibitors (TKIs) are the standard treatment for advanced ALK-positive NSCLC. Nevertheless, drug resistance inevitably occurs. Here, we report a case of a patient with metastatic ALK-positive lung adenocarcinoma with an impressive resistance to sequential treatment with ALK TKIs mediated by YES1 and MYC amplification in a contest of epithelial-to-mesenchymal transition and high progressive chromosomal instability.

Methods

The patient received, after chemotherapy and 7 months of crizotinib, brigatinib and lorlatinib with no clinical benefit to both treatments. A study of resistance mechanisms was performed with whole exome sequencing on different biological samples; primary cell lines were established from pleural effusion after lorlatinib progression.

Results

At whole exome sequencing analysis, YES1 and MYC amplifications were observed both in the pericardial biopsy and the pleural effusion samples collected at brigatinib and lorlatinib progression, respectively. Increasing chromosomal instability from diagnostic biopsy to pleural effusion was also observed. The addition of dasatinib to brigatinib or lorlatinib restored the sensitivity in primary cell lines; data were confirmed also in H3122_ALK-positive model overexpressing both YES1 and MYC.

Conclusions

In conclusion, YES1 and MYC amplifications are candidates to justify a rapid acquired resistance to crizotinib entailing primary brigatinib and lorlatinib resistance. In this context, a combination strategy of ALK TKI with dasatinib could be effective to overcome a rapid resistance.

miR-21 antagonism reprograms macrophage metabolism and abrogates chronic allograft vasculopathy

Despite much progress in improving graft outcome during cardiac transplantation, chronic allograft vasculopathy (CAV) remains an impediment to long-term graft survival. MicroRNAs (miRNAs) emerged as regulators of the immune response. Here, we aimed to examine the miRNA network involved in CAV. miRNA profiling of heart samples obtained from a murine model of CAV and from cardiac-transplanted patients with CAV demonstrated that miR-21 was most significantly expressed and was primarily localized to macrophages. Interestingly, macrophage depletion with clodronate did not significantly prolong allograft survival in mice, while conditional deletion of miR-21 in macrophages or the use of a specific miR-21 antagomir resulted in indefinite cardiac allograft survival and abrogated CAV. The immunophenotype, secretome, ability to phagocytose, migration, and antigen presentation of macrophages were unaffected by miR-21 targeting, while macrophage metabolism was reprogrammed, with a shift toward oxidative phosphorylation in naïve macrophages and with an inhibition of glycolysis in pro-inflammatory macrophages. The aforementioned effects resulted in an increase in M2-like macrophages, which could be reverted by the addition of L-arginine. RNA-seq analysis confirmed alterations in arginase-associated pathways associated with miR-21 antagonism. In conclusion, miR-21 is overexpressed in murine and human CAV, and its targeting delays CAV onset by reprogramming macrophages metabolism.

Emergence of a HER2-amplified clone during disease progression in an ALK-rearranged NSCLC patient treated with ALK-inhibitors: a case report

Anaplastic lymphoma kinase tyrosine kinase inhibitors (ALK-TKIs) are the standard treatment for advanced ALK-positive non-small cell lung cancer (NSCLC) allowing survivals up to 5 years. However, duration of responses is limited by the almost certain occurrence of drug resistance. Here, we report a case of a never smoker, 59-year-old female with metastatic ALK-positive adenocarcinoma, solid and signet ring patterns, who developed resistance to alectinib, a second-generation ALK-TKI, mediated by HER2 gene amplification. The patient received 22 months of crizotinib as first-line and subsequently 1-year of alectinib therapy. A study of resistance mechanism was performed with next generation sequencing (NGS) on tissue re-biopsy. A HER2-amplified emerging clone was identified by NGS in a liver metastasis and confirmed by fluorescent in situ hybridization (FISH) analysis. The resistant clone was detectable 2 months before disease progression in plasma cell-free DNA (cfDNA) using digital droplet PCR (ddPCR) copy number variation (CNV) assay and it was retrospectively traced in rare cells of the lung primary by FISH. To our best knowledge, this is first evidence of HER2 gene amplification as a resistance mechanism to ALK-TKI in a NSCLC. Future strategies against oncogene-addicted NSCLC might benefit of combined drug treatments, such as ALK and HER2 inhibition.

Optimizing PD-L1 evaluation on cytological samples from advanced non-small-cell lung cancer

Aim: Programmed cell death-ligand 1 (PD-L1) predicts response to immune checkpoint inhibitors in non-small-cell lung cancer (NSCLC) patients. Most NSCLCs are diagnosed at an advanced stage and using minimally invasive diagnostic procedures that yield small biopsies or cytological samples. Methods: Cytological smears and paired histological samples from 52 advanced NSCLC patients were tested for PD-L1 expression by immunocyto/histochemistry (ICC/IHC) and for PD-L1 gene status by FISH. Results: PD-L1 was overexpressed in 9/52 (17%) cytological samples and in seven (13.5%) matched biopsies. The concordance between immunocytochemistry and IHC was 92.3% (48/52; p < 0.001). The concordance between PD-L1 gene status on cytology and histology was 69.2% (18/26; p < 0.001). No correlation between IHC and fluorescence in situ hybridization results was found. Conclusion: Our data support the feasibility and reliability of PD-L1 protein and PD-L1 gene assessment on direct cytological smears from NSCLC patients whenever histological sample are inadequate.

Correlations between tumor-infiltrating and circulating lymphocyte subpopulations in advanced renal cancer patients treated with nivolumab

BACKGROUND

In clinical trials with immunotherapy, histological features such as tumor-infiltrating lymphocytes (TILs) are investigated as potential predictive biomarkers, with the limit of an outdated parameter for a typically dynamic element.

METHODS

This explorative study compared, in metastatic renal cell carcinoma (mRCC) patients, basal pathological data about TILs on diagnostic histological specimens with circulating lymphocyte subpopulations measured before and during therapy with nivolumab.

RESULTS

Of 11 mRCC patients, 5 had low presence of TILs (L-TILs), 3 moderate amount (M-TILs) and 3 high number (H-TILs). Overall, 8 patients had low intratumoral pathological CD4+/CD8+ ratio (LIPR) ≤1 and 3 cases high intratumoral pathological ratio (HIPR) ≥2. Of 8 patients with LIPR, only 2 matched with low circulating CD4+/CD8+ ratio (LCR) ≤1; 5 had high circulating ratio (HCR) ≥2. All 3 cases with HIPR (≥2) conversely had LCR (≤1). Circulating CD4+/CD8+ ratio remained unchanged during therapy (mean -0.12 in 8 weeks). The respective percentage values of CD4+ and CD8+ circulating T cells also remained stable (variation 0%); the absolute value of CD4+ was more likely to increase (mean +46.3/mm3); the level of CD8+ tended to slightly decrease (mean -6.5/mm3). No correlation of lymphocyte subpopulations with treatment outcome was found. Of note, we did not evidence correspondence between histopathological and circulating findings in terms of T-lymphocyte subpopulations, also suggesting the inconsistency of circulating data in terms of relative variations.

CONCLUSIONS

Considering the likely high dynamism of TILs, rebiopsy before therapy might be proposed to assess the utility of TILs characterization for predictive purpose. (www.actabiomedica.it).

High levels of Notch intracellular cleaved domain are associated with stemness and reduced bevacizumab efficacy in patients with advanced colon cancer

δ‑like ligand 4 (DLL4)‑Notch signaling is associated with tumor resistance to anti‑vascular endothelial growth factor (VEGF) therapy. Furthermore, Notch signaling is critical for the maintenance of colon cancer stem cells (CSCs), which are relevant in drug resistance and tumor angiogenesis. CD44 is a transmembrane glycoprotein and is considered a putative marker of CSCs. To assess the association of Notch intracellular cleaved domain (NICD), DLL4 and CD44 expression with the efficacy of anti‑angiogenic drugs, a series of samples derived from patients with advanced colon cancer enrolled in prospective clinical trials were analyzed. Histological samples from 51 primary tumors that originated from patients treated with bevacizumab‑based first‑line chemotherapy were analyzed by immunohistochemistry for NICD, DLL4 and CD44 expression, and CD31 for microvessel count. The expression levels of genes relevant for angiogenesis [angiopoietin (ANGPT)1, ANGPT2, fibroblast growth factor (FGF)1, FGF2, epidermal growth factor, placental growth factor, VEGFA and DLL4] were detected by reverse transcription‑quantitative PCR using RNA extracted from the frozen tissues of four tumors with low and four tumors with high NICD expression. Strong NICD levels were observed in 12/51 (24%) of the patients, whereas 16/51 (31%) of the colon cancer subjects exhibited high CD44 expression. Strong CD44 staining was associated with high NICD levels compared with the CD44 expression levels noted in samples with low NICD levels (67 vs. 20%, P=0.005). No association was observed with regards to the expression levels of NICD, CD44 and the other aforementioned biomarkers. High expression levels of NICD and CD44 predicted reduced progression‑free survival (P<0.001) and overall survival (P=0.002). No significant differences in the expression of angiogenesis‑related genes were detected between low and high NICD‑expressing tumors. In conclusion, NICD and CD44 tissue levels exhibited an association and may be related to a reduced survival rate in patients with advanced colon cancer treated with bevacizumab.

From the beginning to resistance: Study of plasma monitoring and resistance mechanisms in a cohort of patients treated with osimertinib for advanced T790M-positive NSCLC

INTRODUCTION

Analysis of circulating tumor DNA (ctDNA) for the identification of T790M mutation in advanced EGFR-mutated NSCLC patients can replace tissue re-biopsy for resistance characterization and, being non-invasive, may be applied for disease monitoring. We analysed ctDNA during osimertinib treatment to correlate mutational levels with clinical outcome and to predict pattern of resistance.

MATERIALS AND METHODS

Forty patients with advanced NSCLC receiving osimertinib for T790M + disease after previous EGFR-TKI were enrolled in a pilot study to collect plasma at baseline and every 12 weeks until progression. Molecular analysis of ctDNA was performed by ddPCR and Therascreen®. When feasible at progression, tissue re-biopsy and NGS analysis were performed.

RESULTS

Thirty-eight patients had baseline plasma samples suitable for molecular analysis. Patients with low levels of the EGFR activating mutation in ctDNA [< 2200 copies/mL or allele frequency (AF) < 6.1%] showed better progression-free survival (17.8 or 17.8 months vs. 4.3 or 2.7, p = 0.022 or p = 0.018, respectively) and overall survival (23.6 or 23.6 vs. 7.7 or 7.3, p = 0.016 or p = 0.013, respectively) than patients with high levels (≥ 2200 copies/mL or AF ≥ 6.1%). Patients with detectable EGFR mutations in plasma (shedders) presented worse outcome than negative subjects (non-shedders). Low levels of T790M, higher T790M/activating mutation ratio and complete clearance after 2 months were associated with a trend towards better outcome. Tissue re-biopsy at resistance showed 3 patients with EGFR C797S, 1 with MET amplification, 1 with MYC amplification, 1 with PTEN loss, 3 with SCLC transformation.

CONCLUSIONS

The mutational analysis performed on plasma plays a significant role in prognostic stratification, especially for the EGFR activating mutation, since patients with absence or low levels of mutations presented a better outcome to osimertinib. At progression, tissue re-biopsy remains a crucial issue for the identification of resistance mechanisms.

Impact of laterality and mucinous histology on relapse-free and overall survival in a registry-based colon cancer series

Recent data suggest that tumor laterality and mucinous histology may be clinically relevant. We investigated how both variables impact on the prognosis and the response to therapies in a large population-based cohort of cancer patients. Incidence data, clinical and pathological features, and outcome were systematically collected from the Tumor Registry of Parma over the years 2004–2009. Survival data were modeled by multivariable analysis. 1358 patients affected by stage I–IV colon cancer were considered; 661 (49%) had right-sided and 697 (51%) left-sided tumors. 144 (11%) had mucinous (MAC) and 1214 (89%) non-mucinous (NMAC) histology. MACs and NMACs of the right colon showed no difference in stage distribution, whereas left colon MACs were more frequently in an advanced stage (stage IV) (p = 0.008). Stage IV right colon tumors had a poorer overall survival than stage IV left-sided colon cancers (75^th percentile 20 vs 34 months, p < 0.001). At relapse, MACs were less responsive to systemic therapy and had worse survival compared with NMACs regardless of tumor side (7.1 vs 13.1 months, p = 0.018). Right-sided colon cancers had poorer survival compared to left-sided tumors; the effect was mainly attributable to NMACs. At relapse, MACs had unfavorable prognosis regardless of the primary tumor-side.

Potential predictive biomarkers in locally advanced rectal cancer treated with preoperative chemo-radiotherapy

Fluorouracil-based preoperative chemoradiotherapy represents a standard option for the treatment of locally advanced rectal cancer. Randomized clinical trials have shown that fluorouracil concomitant to preoperative radiation enhances tumor shrinkage (with 10% to 15% of the patients showing a complete pathological tumor response) compared with preoperative radiation alone. A high response rate is of clinical importance in rectal cancer, since patients who achieve a complete pathological response may experience improved long-term survival. Adding oxaliplatin to fluorouracil-based preoperative chemoradiotherapy has no effect on response of the primary rectal tumor and single-agent fluoropyrimidine remains the standard chemotherapy in this setting. Despite novel biological insights and therapeutic advances, little is known about potential biological markers able to predict pathological tumor response before treatment and to subsequently impact patients' prognosis. This review focuses on the current available data on main molecular markers and molecular subtypes and the possible upcoming introduction of such analyses in the clinical setting.

Microsatellite instability in colorectal cancer

Microsatellites are short tandem repeat DNA sequences of one to tetra base pairs distributed throughout the human genome, both in coding and non-coding regions. Owing to their repeated structure, microsatellites are particularly prone to replication errors that are normally repaired by the Mismatch Repair (MMR) system. MMR is a very highly conserved cellular process, involving many proteins, resulting in the identification, and subsequent repair of mismatched bases, likely to have arisen during DNA replication, genetic recombination or chemical or physical damage. Proteins within the MMR system include MLH1, PMS2, MSH2, MSH6, MLH3, MSH3, PMS1, and Exo1. Deficient MMR (dMMR) results in a strong mutator phenotype known as microsatellite instability (MSI), characterized by widespread length polymorphisms of microsatellite sequences due to DNA polymerase slippage. MSI is recognized as one of the major carcinogenetic pathways of colorectal cancer (CRC): it represents a molecular hallmark of hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome (LS); moreover it is detected in 15% of sporadic colorectal cancers, more often due to an epigenetic inactivation of MLH1. Identification of MSI CRC is important, as MSI may serve as a screening tool for detecting LS, a prognostic marker for patient outcome, and a predictive marker for response to chemotherapy and to immunotherapy. (www.actabiomedica.it)

Loss of heterozygosity of key tumor suppressor genes in advanced renal cancer patients treated with nivolumab

AIM

We studied the possible clinical significance of loss of heterozygosity (LOH) at key tumor suppressor genes loci in advanced renal cancer patients treated with nivolumab.

METHODS

LOH study was performed on 3p14.2 (FHIT gene); 3p21.3-21.2; 9p21 (BDMF gene); 9p22 (SH3GL2 gene).

RESULTS

Of 12 patients, 8 (67%) had LOH. The most affected gene was FHIT. All five patients with LOH at FHIT locus had good outcome, mean progression free survival of 6.8 months. The patients LOH negative at FHIT locus had mean progression free survival of 4 months, 67% were treatment refractory. Overall, 75% of patients with LOH of at least one gene had benefit; 75% of LOH negative cases were refractory.

CONCLUSION

LOH at key tumor suppressor genes should be further investigated as predictive for immunotherapy.

Primary resistance to osimertinib due to SCLC transformation: Issue of T790M determination on liquid re-biopsy

OBJECTIVES

EGFR T790M mutation is the most common mechanism of resistance to first-/second-generation EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) and could be overcome by third-generation EGFR-TKIs, such as osimertinib. Liquid biopsy, a non-invasive technique used to test the presence of the resistant mutation, may help avoiding tissue re-biopsy. However, analysing only circulating-free DNA, information about other less frequent and coexisting resistance mechanisms may remain unrevealed.

MATERIALS AND METHODS

All patients reported in this series participated in the ASTRIS trial, a real world treatment study testing the efficacy of osimertinib (80mg os die) in advanced T790M-positive NSCLC progressed to prior EGFR-TKI. Patients were considered eligible to osimertinib if T790M positive on tissue or plasma samples. In our patients, EGFR molecular testing on blood sample was conducted with digital droplet PCR (ddPCR).

RESULTS

We report our experience of five patients treated with osimertinib after T790M detection on liquid biopsy that presented a disease progression at first tumor assessment mediated by SCLC transformation, as evidenced at tissue re-biopsies. All patients showed low ratio T790M/activating mutation in the blood before osimertinib (lower than 0.03). For three patients, EGFR mutational analysis was T790M-negative when re-assessed by using a less sensitive method (therascreen^®) on the same liquid biopsy sample analysed by ddPCR before osimertinib therapy.

CONCLUSION

Although liquid biopsy is a relevant tool to diagnose T790M presence in NSCLC patients resistant to EGFR-TKI, in case of a low ratio T790M/activating mutation, tissue biopsy should be considered to exclude the presence of SCLC transformation and/or other concomitant resistance mechanisms.

Surgical treatment of multiple sporadic colorectal carcinoma

Aim: Many aspects of the surgical management of multiple sporadic colorectal cancer syndrome, either synchronous and metachronous, remain to be cleared, in particular the prognostic influence of the extent of surgical resection. Method: A retrospective review was performed of patients diagnosed with multiple colorectal cancer from 1982 to May 2010. Clinical and pathologic data were collected and reviewed. Survival analysis was performed. Results: We identified 23 patients with multiple sporadic colorectal cancers, of which 8 had synchronous (SC) and 15 metachronous cancers (MC). Of the MC patients, 2 (13%) had the second cancer within 2 years, 4 (27%) in the time period of 2-5 years and 9 (60%) after 5 years. Twenty-one patients underwent multiple segmental resections; 2 patients underwent subtotal colectomy. The 5-year overall survival rate of SC and MC patients was 100% and 87% (p<0.001) respectively. The 5-year overall survival rate of multiple segmental resection patients and subtotal colectomy was 94% and 75% (p=0.655) respectively. Conclusion: Either synchronous and metachronous MSCRC patients showed good prognosis independently from to the extent of resection. Our results support a less aggressive biological behaviour allowing a more conservative management. Multiple segmental colorectal resections seem appropriate from an oncologic point of view in MSCRC patients. (www.actabiomedica.it)

Correlations between tumor-infiltrating and circulating lymphocyte subpopulations in mRCC patients treated with immune-checkpoint inhibitors

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Background: In clinical trials with immune-checkpoint inhibitors (CKI), histological features such as tumor-infiltrating lymphocites (TILs) are investigated as potential predictive biomarkers, with the possible limit of an outdated parameter for a typically dynamic element. Methods: This explorative study compared, in metastatic renal cell carcinoma (mRCC) patients, basal pathological data about TILs on diagnostic histological specimens with circulating lymphocyte subpopulations measured before and during therapy with nivolumab, with the primary aim to assess their concordance. Secondarily, with the limit of a small sample size, a possible relation with treatment outcome was explored. Results: Of 11 mRCC patients, 5 had low presence of TILs (L-TILs), 3 moderate amount (M-TILs), and 3 high number (H-TILs). Overall, 8 patients had low intratumoral pathological CD4+/CD8+ ratio (LIPR) ≤ 1 and 3 cases high intratumoral pathological ratio (HIPR) ≥ 2. Of 8 patients with LIPR, only 2 cases matched with low circulating CD4+/CD8+ ratio (LCR) ≤1, whilst 5 cases had high circulating ratio (HCR) ≥ 2 (1 undetermined). All 3 cases with HIPR (≥ 2) conversely had LCR (≤ 1). Unexpectedly, independently from the clinical outcome, circulating CD4+/CD8+ ratio remained unchanged during therapy with CKI in each patient, maintaining the same value after 8 weeks (mean -0.12). The respective percentage values of CD4+ and CD8+ circulating T cells also remained stable during treatment (mean variation 0%); the absolute value of CD4+ was more likely to increase (mean +46.3/mm3); the level of CD8+ tended to slightly decrease (mean -6.5/mm3). No correlation of lymphocyte subpopulations with treatment outcome was found. Conclusions: Of note, this study did not evidence any correspondence between histopathological and circulating findings in terms of T-lymphocyte subpopulations in mRCC patients undergoing treatment with CKI, also suggesting the inconsistency of circulating data in terms of relative variations. Considering the likely high dynamism of TILs, rebiopsy before CKI therapy might be the most reliable way to assess the utility of TILs characterization for predictive purpose.

Anastomotic recurrence of colon cancer: Genetic analysis challenges the widely held theories of cancerous cells' intraluminal implantation and metachronous carcinogenesis

BACKGROUND AND OBJECTIVES

Anastomotic recurrence (AR), whose etiopathogenesis is attributed to intraluminal implantation of cancerous cells or metachronous carcinogenesis, is a major issue for patients undergoing colon cancer (CC) resection. The objective of the study is to throw some light on AR etiopathogenesis and to identify risk factors of AR in selecting patients to undergo early endoscopy.

METHODS

An analysis of clinical and histopathological parameters, including MSI and LOH of seven sites (Myc-L, BAT26, BAT40, D5S346, D18S452, D18S64, D16S402) was performed in primary CC and AR of 18 patients. They were then compared to 36 controls not developing AR.

RESULTS

A genetic instability was present in 16/18 patients, with distinct genetic patterns between primaries and ARs. LOH at 5q21 and/or 18p11.23 were found in both primary and AR in >50% of cases, but this rate was no different from control population. CEA resulted as associated with AR (P = 0.03), whereas N status presented a borderline result (P = 0.08).

CONCLUSIONS

Our findings challenge present theories about AR development. No "genetic marker" has been found. CEA and, to a lesser extent, N status, appear associated with AR. Rectal washout is seemingly meaningless. Iterative resection should be recommended since a long survival may be expected. J. Surg. Oncol. 2016;114:228-236. © 2016 Wiley Periodicals, Inc.

Isolation and Characterization of Circulating Tumor Cells in Squamous Cell Carcinoma of the Lung Using a Non-EpCAM-Based Capture Method

INTRODUCTION

The exclusion of circulating tumor cells (CTCs) that have lost epithelial antigens during the epithelial-to-mesenchymal transition (EMT) process by using Epithelial Cell Adhesion Molecule (EpCAM) based capture methods is still a matter of debate. In this study, cells obtained after depletion procedure from blood samples of squamous cell lung cancer (SQCLC) patients were identified based on morphology and characterized with the combination of FISH assessment and immunophenotypic profile.

MATERIALS AND METHODS

Five mL blood samples, collected from 55 advanced SQCLC patients, were analyzed by a non-EpCAM-based capture method. After depletion of leukocytes and erythroid cells, the negative fraction was characterized by both FISH using a fibroblast growth factor receptor 1 (FGFR1) probe and by immunocytochemistry. Thirty healthy donors were also tested.

RESULTS

Based on morphology (nuclear dimension ≥10 μm, shape and hypercromatic aspect) suspicious circulating cells clearly distinguishable from contaminant leukocytes were observed in 49/55 (89%) SQCLC patients. Thirty-four of the 44 (77%) samples evaluable for FGFR1 FISH showed ≥ 6 FGFR1 gene copy number on average per cell. Vimentin expression involved 43% (18/42) of pooled circulating SQCLC cells, whereas only 29% (14/48) were EpCAM positive. Confocal microscopy confirmed the localization of FGFR1 probe in suspicious circulating cells. Suspicious circulating elements were also observed in healthy donors and did not show any epithelial associated antigens. A significantly lower number of suspicious circulating cells in healthy donors compared to SQCLC patients was found.

CONCLUSIONS

Among the heterogeneous cell population isolated by depletion procedure, the coexistence of cells with epithelial and/or mesenchymal phenotype suggests that EMT may participate to transendothelial invasion and migration of tumor cells in advanced SQCLC. The finding of cells with neither EpCAM or EMT phenotype, retrieved after non-EpCAM-based systems, underlines the presence of suspicious elements in the blood of both SQCLC patients and healthy donors. Further phenotyping and molecular analyses are necessary to fully characterize these circulating elements.

Strong Notch activation hinders bevacizumab efficacy in advanced colorectal cancer

AIM

To assess the role of Notch activation in predicting bevacizumab efficacy in colorectal cancer (CRC).

MATERIALS & METHODS

Notch activation was evaluated by immunohistochemistry (IHC) on 65 CRC enrolled within randomized clinical trials assessing first-line bevacizumab-based chemotherapy and on 21 CRC treated with chemotherapy alone.

RESULTS

Strong Notch (IHC 3+) activation was negatively associated with response (18 vs 62% in low Notch cases [IHC 0, 1, 2+]; p = 0.016), progression-free survival (4.9 vs 12.1 months; p = 0.002) and overall survival (19.3 vs 30.4 months; p = 0.039). No correlation was found between Notch activation and clinical outcome in CRC treated with chemotherapy alone.

CONCLUSION

A potential role of Notch activation in the antitumor activity of bevacizumab could be hypothesized.

Notch expression and bevacizumab efficacy in colorectal cancer patients

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Background: Antiangiogenic therapies represent a well established additional treatment to standard chemotherapy, nevertheless no markers are available to suggest a successful outcome linked to the use of bevacizumab. To investigate potential mechanisms of resistance to angiogenesis inhibitor bevacizumab, Notch expression was correlated with response and survival in a series of bevacizumab treated advanced colorectal cancer (CRC) patients. Methods: Notch expression was evaluated by immunohistochemistry (IHC) on 65 primary CRC enrolled within 6 randomized clinical trials assessing first-line bevacizumab plus chemotherapy. Notch IHC was conducted using a polyclonal antibody to Cleaved Notch1 (Cell Signaling Technology, Danvers, MA). Notch expression was scored based on intensity of staining (0: none, 1+: weak, 2+: moderate; 3+: strong) and on percentage of immunostained cells. A control series of 21 advanced CRC treated with chemotherapy alone was also examined. Results: Notch positivity was localized to the cytoplasm or nucleus of malignant epithelial cells. In all, 11 of 61 (18%) evaluable primary tumours had a high Notch expression (IHC 3+). Six of the 11 cases (55%) with high Notch expression (IHC 3+) experienced progressive disease compared with 5 of 50 (10%) low Notch expression cases (IHC 0 1+ 2+) (p = 0.003). A high Notch expression also demonstrated an inferior median PFS (4.9 vs. 12.1 months; HR = 2.51; 95% CI, 0.96 to 6.58; p = 0.007) and OS (19.3 vs. 30.4 months; HR = 2.21; 95% CI, 0.79 to 6.15; p = 0.039) compared with low Notch expression cases. When the groups were further analyzed considering VEGF expression, the best outcome was found in low Notch (IHC 0 1 +) and high VEGF expressing tumors (IHC 2+ 3+) (response rate 9 of 11, 82 % vs. 1 of 5, 20%, in patients with high levels of Notch and VEGF expression, respectively). No correlation was found between Notch expression and clinical response in the series of patients treated with chemotherapy without bevacizumab. Conclusions: Notwithstanding the limited power of the present analysis, these data seem to suggest that low Notch expression might be a marker for successful bevacizumab treatment.

Adenomatous polyposis coli gene involvement in ileal enterochromaffin cell neuroendocrine neoplasms

The adenomatous polyposis coli gene is a key tumor suppressor gene. Alterations in this gene have been found in most sporadic colon cancers; associated with familial adenomatous polyposis; and found in neoplasms of other organs, such as the liver, stomach, lung, breast, and cerebellar medulloblastoma. In the heterogeneous group of neuroendocrine neoplasms of the gastrointestinal tract, the involvement of adenomatous polyposis coli is debated, and only occasional reports found adenomatous polyposis coli alterations in foregut and midgut neuroendocrine neoplasms, with adenomatous polyposis coli mutations only in the latter. To elucidate the penetrance of adenomatous polyposis coli alterations in ileal neuroendocrine neoplasms, we performed DNA fragment analysis (loss of heterozygosity for 5q22-23 and 5q23) and sequencing on the mutation cluster region of the adenomatous polyposis coli gene on 30 ileal enterochromaffin cell neuroendocrine neoplasms. Adenomatous polyposis coli gene mutations were detected in 23% of cases (7/30); in particular, 57% were missense and 14%, nonsense/frameshift, all novel and different from those reported in colorectal or other cancers. Loss of heterozygosity analysis demonstrated a deletion frequency of 15% (4/27). No association was found with features of tumor progression. Our observations support the involvement of somatic adenomatous polyposis coli alterations in tumorigenesis of ileal enterochromaffin cell neuroendocrine neoplasms; the mechanisms of adenomatous polyposis coli gene inactivation appear to be different from those reported in other tumor types.

Thymidylate synthase, topoisomerase-1 and microsatellite instability: relationship with outcome in mucinous colorectal cancer treated with fluorouracil

BACKGROUND

Mucinous colorectal cancer (CRC) exhibits distinct clinical and pathological features, including poorer response to fluorouracil (FU) compared with non-mucinous tumours.

PATIENTS AND METHODS

We compared the expression of thymidylate synthase (TYMS) and topoisomerase-1 (TOPO1) and DNA microsatellite instability (MSI) in 87 patients (35 mucinous and 52 non-mucinous CRCs) enrolled in three randomized trials, evaluating infused FU as first-line treatment.

RESULTS

Mucinous CRCs more frequently had high TOPO1 expression than did non-mucinous tumors (41% vs. 15%, p=0.028). The median overall survival was 14.2 months for patients with mucinous CRC with low TOPO1 expression compared with 9.7 months for high TOPO1-expressing cases (p=0.016). After adjusting for confounding variables, low TOPO1 expression was statistically favourably associated with overall survival (hazard ratio=0.55; p=0.041).

CONCLUSION

Our data suggest the TOPO1 expression levels to be a prognostic marker in patients with mucinous CRC treated with FU. If further verified, these data might redefine therapeutic strategies by identifying categories of patients with a worse prognosis.

Primary squamous cell carcinoma of the endometrium unrelated to human papilloma virus: a molecular study

In this paper we report a molecular study of a case of Primary Endometrial Squamous Carcinoma (PESC), in which a Human Papilloma Virus (HPV) infection had been previously excluded by Polymerase Chain Reaction (PCR). The studies performed in an effort to explain the carcinogenesis included immunohistochemical over-expression of p53 and p16 proteins as previously observed in our own papers, plus microsatellite analysis of D10S1765 at 10q23.3 (PTEN) and TP53 at 17p13.1 (P53) as well as the methylation status of the of BRCA1 and p16 promoters using specific PCRs. In this rare malignancy, we found allelic imbalance (AI) at 17p13.1 (P53). Instead, AI at D10S1765 (PTEN) gene was absent. The genetic alteration of p53, with hyper-expression of p53 protein and an absence of abnormalities in the PTEN gene are consistent with the similarities between Uterine Serous Carcinoma (USC) and our case of PESC. The aberrant methylation of both p16 and BCAR1 promoters was not detected in our case. This finding too could imply that ESC is more similar to Uterine Serous Carcinoma than Uterine Endometrioid Carcinoma (UEC). Moreover, the lack of aberrant methylation of p16, which is in accordance with over-expression of p16 immunoreactivity, in the absence of HPV infection may be related to other unknown genetic alterations. In our opinion, it is hard to reach any definite conclusion concerning the carcinogenesis of PESC, because of its rarity and the very few molecular studies reported in the literature. Further studies with more numerous cases and larger molecular analyses are mandatory for this malignancy, to confirm whether it is more closely related to papillary endometrial cancer than to endometrioid carcinoma.

Reliability of EGFR and KRAS mutation analysis on fine-needle aspiration washing in non-small cell lung cancer

INTRODUCTION

Molecular profiling of advanced non-small cell lung cancer (NSCLC) has become essential for predicting customized medical treatment decision. In light of recent advances in non-invasive diagnostic procedures in NSCLC, we aimed to demonstrate the reliability of assessing molecular tests for epidermal growth factor receptor (EGFR) and KRAS genes on cytological samples by comparing the molecular profile obtained on cells from scraped smears with that on paired needle washing in a series of NSCLC cases.

METHODS

Thirty-two cytological specimens obtained by fine-needle aspiration biopsy procedures from primary or metastatic lesions of NSCLCs were Giemsa stained for a rapid on-site evaluation and, in case of an adequate sampling, the cellular material obtained from needle washing was collected into a saline solution. Scraped smears and needle washings were tested for EGFR and KRAS by polymerase chain reaction followed by direct sequencing.

RESULTS

The concordance between EGFR and KRAS mutational status in 29 paired scraped smears and needle washing was 100%, with 7 paired samples showing the same EGFR mutation (4 L858R mutation, 2 E746_A750 deletion and 1 A767_V769 duplication) and 8 paired samples showing the same KRAS mutations (4 G12D, 1 G12A, 1 G12V and 2 G12C). Three scraped smears, uninformative for poor DNA quality, resulted EGFR mutated on paired needle washings.

CONCLUSIONS

Needle washing obtained in the course of NSCLC non-invasive fine needle diagnostic procedures allows reliable mutation testing and can be regarded as an additional important source of biological material for molecular profiling of advanced NSCLC.

Epidermal growth factor receptor and Kras gene expression: reliability of mutational analysis on cytological samples

Epidermal growth factor receptor (EGFR) and Kras gene mutations are crucial for discriminating patients responsive to anti-EGFR drugs in non-small cell lung cancer (NSCLC) and colorectal cancer (CRC), respectively. The majority of NSCLCs come to clinical attention at an advanced stage when surgery is no longer recommended and a considerable number of them are diagnosed by cytology only. A large number of metastatic CRCs are also diagnosed by imaging and minimally invasive techniques such as fine-needle aspiration biopsy. Here, we report our experience in the mutation analysis of EGFR and Kras on cytological material obtained from superficial and deep lesions of NSCLC and CRC. Our series included 63 cytological specimens from primary or metastatic lesions of 42 NSCLCs and 21 CRCs. The cytological material was adequate for the mutation analysis in 39/42 (93%) NSCLCs and in 20/21(95%) CRCs. EGFR and Kras mutations were found in 9 (23%) and 9 (23%) NSCLC cases, respectively. Kras mutations were found in 9/20 (45%) CRC specimens. Histological samples from the primary tumors were available in 9/42 NSCLCs and in 17/21 CRCs. The agreement of EGFR and Kras mutational status in cytological vs. histological samples was 100% for NSCLC and 88% for CRC. Our results suggest that standard cytology provides adequate material for the assessment of EGFR and Kras mutational status in NSCLC and CRC patients and could be specifically indicated in patients not eligible for surgery but candidate to anti-EGFR therapy.

Repeated anastomotic recurrence of colorectal tumors: Genetic analysis of two cases

AIM: To investigate genetics of two cases of colorectal tumor local recurrence and throw some light on the etiopathogenesis of anastomotic recurrence.

METHODS: Two cases are presented: a 65-year-old female receiving two colonic resections for primary anastomotic recurrences within 21 mo, and a 57-year-old female undergoing two local excisions of recurrent anastomotic adenomas within 26 mo. A loss of heterozygosity (LOH) study of 25 microsatellite markers and a mutational analysis of genes BRAF, K-RAS and APC were performed in samples of neoplastic and normal colonic mucosa collected over the years.

RESULTS: A diffuse genetic instability was present in all samples, including neoplastic and normal colonic mucosa. Two different patterns of genetic alterations (LOH at 5q21 and 18p11.23 in the first case, and LOH at 1p34 and 3p14 in the second) were found to be associated with carcinogenesis over the years. A role for the genes MYC-L (mapping at 1p34) and FIHT (mapping at 3p14.2) is suggested, whereas a role for APC (mapping at 5q21) is not shown.

CONCLUSION: The study challenges the most credited intraluminal implantation and metachronous carcinogenesis theories, and suggests a persistent, patient-specific alteration as the trigger of colorectal cancer anastomotic recurrence.

Involvement of HER-2/neu and metastasis-related proteins in the development of ileal neuroendocrine tumors

HER-2/neu overexpression and/or gene amplification occurs in several human malignancies, frequently correlates with tumor aggressiveness, and provides the basis for treatment with trastuzumab. Among neuroendocrine neoplasms (NEN) of the gastroenteropancreatic (GEP) tract, ileal neuroendocrine tumors show peculiar features of malignancy with frequent metastases at the diagnosis. We investigated the overexpression and/or amplification of HER-2/neu and the involvement of the metastasis-related proteins c-Met, MTA-1, and VEGF in 24 primary ileal NEN by immunohistochemistry and fluorescence in situ hybridization (FISH). Data were compared with those of 43 GEP endocrine tumors of other sites. All primary ileal NEN showed an intense membranous and cytoplasmic immunostaining for HER-2/neu. According to the breast cancer scoring system, 17% of ileal carcinoids showed a score of 3+ and 71% with a score of 2+ with a significant difference respect the non-ileal GEP endocrine tumors (p < 0.0000). FISH analysis revealed chromosome 17 polysomy in 33% of 2+/3+ ileal tumors but not HER-2/neu gene amplification. The c-Met and MTA-1 but not VEGF were overexpressed in almost all ileal NEN, whereas VEGF presented more frequently a normal staining. The comparisons with the other GEP NEN demonstrated significant differences for all the three proteins (p < 0.0000, p < 0.0002, and p < 0.001, respectively). These findings suggest that in ileal NEN, HER-2/neu overexpression plays a role in the carcinogenetic process and by triggering the altered expression of c-Met and MTA-1, may activate the molecular pathway(s) promoting tumor progression and metastasis development. Ileal HER-2/neu overexpressing neuroendrocrine tumors may constitute potential candidates for target therapy with specific humanized monoclonal antibodies.

Adenomatous polyposis coli alteration in digestive endocrine tumours: correlation with nuclear translocation of beta-catenin and chromosomal instability

The role of Wnt pathway in digestive endocrine tumours is debated. The aim of this work is to investigate key players in Wnt pathway by a multimodal approach. Sixty cases (49 well-differentiated and 11 poorly differentiated) were investigated for methylation of adenomatous polyposis coli (APC) and E-cadherin promoters, the loss of heterozygosity (LOH) at APC locus and beta-catenin and E-cadherin expression by immunohistochemistry. Tumours showing altered beta-catenin localization were tested for beta-catenin and APC mutations. APC promoter methylation was restricted to gastroduodenal tumours (21 out of 59, 36%), prevalent in poorly differentiated carcinomas (P=0.042) and correlating with aggressive features (high histology grade, P<0.02; tumour death, P=0.026; high fractional allelic loss, P=0.002, in turn correlating with short survival, P=0.017). LOH at APC locus was found in 14 out of 53 cases (26%, 10 gastroduodenal and 4 colorectal), prevalent in poorly differentiated carcinomas (P=0.002) and correlating with histology grade (P=0.012). beta-catenin abnormal expression was found in 41 out of 54 cases (76%), with nuclear staining correlating with APC alteration (P=0.047) and short survival (P=0.006). APC, but not beta-catenin, gene mutations were found (7 out of 35 tumours), 4 of which in the midgut. E-cadherin promoter methylation was rarely detected (2 out of 52 cases), with cytoplasmic expression in 18 out of 43 cases (42%), not correlating with any clinico-pathological feature. In conclusion, Wnt pathway alterations, as represented by abnormal beta-catenin localization, are common events in digestive endocrine tumours, but only nuclear expression correlates with tumour aggressiveness. Though with different alteration mechanisms according to anatomical site, APC plays a major role in Wnt pathway activation and in determining the high chromosomal instability observed in aggressive endocrine carcinomas.

Human papilloma virus (HPV) status, p16INK4a, and p53 overexpression in epithelial malignant and borderline ovarian neoplasms

This investigation is the first to evaluate simultaneously human papilloma virus (HPV) status, p16(INK4a), and p53 immunoreactivity in epithelial ovarian neoplasms. The results were analyzed and correlated with histological type, histological grade, and survival of patients. Subtypes considered are papillary serous and mucinous. Polymerase chain reaction (PCR) analysis, performed in our previous study, had already demonstrated a small number of HPV-positive epithelial ovarian neoplasms. No significant correlation was found between the presence of HPV DNA and subtypes of ovarian neoplasms; thus, HPV cannot be considered responsible for epithelial ovarian neoplasm. Since p16 immunoreactivity was present in many other HPV-negative cases of epithelial ovarian neoplasms, this study suggests that p16 overexpression in some neoplasms of the female genital tract is not related to HPV carcinogenesis. A higher p53 expression rate observed between borderline and malignant serous tumors and between serous and mucinous neoplasms can confirm a recent dualistic model of ovarian carcinogenesis. According to this theory, low-grade serous carcinomas (serous intraepithelial carcinomas, serous borderline neoplasm, and ovarian mucinous neoplasms) (type I tumors) develop from mutations of KAS and BRAF, while high-grade serous carcinomas (type II tumors) develop from mutation of p53. In malignant neoplasms, for univariate analysis, patient survival seems to be related to p53, strong and diffuse p16 overexpression, and the stage of development of neoplasms at the diagnosis. In multinomial logistic regression, used to evaluate the role of staging, grading, p16 and p53 immunopositivity as predictor variables of unfavorable outcome of the disease, only p16 positivity was significantly related to the poor prognosis of the cancer.

Sex chromosome alterations associate with tumor progression in sporadic colorectal carcinomas

PURPOSE

The X and Y chromosomes have been associated with malignancy in different types of human tumors. This study attempts to determine the involvement of X chromosome and pseudoautosomal regions (PAR) in sporadic colorectal carcinogenesis.

EXPERIMENTAL DESIGN

An allelotyping of X chromosome in 20 premalignant and 22 malignant sporadic colorectal tumors (CRC) from female patients and an analysis of losses [loss of heterozygosity (LOH)] on PARs from 44 CRCs and 12 adenomas of male patients were carried out. In male tumors, a fluorescence in situ hybridization analysis was done to identify which sex chromosome was possibly lost.

RESULTS

The LOH frequency in female CRCs was 46% with higher incidence in patients with tumor recurrence than in those who were disease-free (P < 0.01) and with a significant difference from adenomas (11%; P < 0.0001). The LOH rate of PARs in male CRCs was 37% with a frequency significantly higher in patients with recurrence (P < 0.03). These results were maintained also when data from PARs of all 66 male and female patients were cumulated (P < 0.05). LOH in PARs was significantly correlated with LOH at 5q (P < 0.01) and 18q (P < 0.01), early and late events, respectively, in colorectal carcinogenesis. Fluorescence in situ hybridization analysis in male patients with extensive PAR LOH revealed a preferential loss of the Y chromosome.

CONCLUSIONS

Our data suggest a role for sex chromosome deletions in the malignant progression of sporadic CRCs and support the presence in the PARs of putative tumor suppressor genes involved in the progression of human sporadic CRCs.

P16INK4a overexpression independent of Human Papilloma Virus (HPV) infection in rare subtypes of endometrial carcinomas

In the current study, we evaluated p16 expression in rare subtypes of endometrial carcinomas, whose HPV status has been previously examined in order to establish the role of this protein in their pathogenesis. These rare subtypes of endometrial carcinomas are primary squamous endometrial carcinoma (ESCC), endometrial mucinous microglandular adenocarcinoma (EMMA), and endometrial transitional cell carcinoma (ETCC). All tissues, obtained at the time of hysterectomy, were fixed in 10% phosphate-buffered formalin and embedded in paraffin. Serial sections were made for hematoxylin and eosin staining and for immunohistochemistry. Although a previous PCR study has demonstrated that none of these neoplasms showed any signal for HPV DNA, these malignancies did display immunoreactivity for P16(INK4a). In ESCC, P16(INK4a) immunoreactivity was diffuse in 100% of neoplastic cells. In two cases of EMMA, positivity for P16INK4a was zonal. In ETCC, scattered cells were positive for P16INK4a protein. These findings suggest that alteration of p16 could play an etiologic role, without any association to HPV infections, in these rare endometrial carcinomas. However, in our view, other cases of these rare malignancies should be investigated in order to confirm this hypothesis.

Peptide products of the neurotrophin-inducible gene vgf are produced in human neuroendocrine cells from early development and increase in hyperplasia and neoplasia

BACKGROUND

Although the neurotrophin-inducible gene vgf is expressed in mammalian neurons and endocrine cells, limited data is available in man.

AIM

The objective of the study was to map proVGF peptides in human endocrine cells during development, adulthood, hyperplasia, and tumors.

METHODS

Antisera were generated against peptides related to internal cleavage or cleavage-amidation sites (rat proVGF(422-430) and human proVGF(298-306)-NH2) and the proVGF C-terminal ending (human proVGF(607-615)). Developing and normal adult endocrine cells, hyperplastic endocrine lesions (thyroid, parathyroid, lung, and stomach), and 120 tumors (102 endocrine) were studied. Immunogold electron microscopy was performed on normal adult pancreas and gut, and Western blotting was performed on extracts of control tissues and endocrine tumors.

RESULTS

proVGF fragments were revealed in developing pituitary, gut, pancreas, and adrenal medulla from 10 gestational weeks, in normal adult pituitary and adrenal medulla, pancreatic glucagon, and insulin cells and gut serotonin cells, in hyperplastic thyroid calcitonin cells, lung P cells, gastric enterochromaffin-like cells, and gastrin cells, and in 88 of 102 endocrine tumors. At electron microscopy proVGF immunoreactivity was restricted to electron-dense granules. Western blotting revealed large molecular weight forms and cleavage fragments in both control tissues and tumor extracts.

CONCLUSIONS

proVGF-related peptides are present in endocrine cells early during development and adulthood and increase in hyperplasia and tumors, and proVGF fragments could be novel diagnostic tools for endocrine cells and related lesions, including tumors.

Loss of p27 expression and microsatellite instability in sporadic colorectal cancer

BACKGROUND

The role of the loss of p27 protein expression in the oncogenesis of colorectal cancer is still in debate. In this study, we prospectively examined the immunohistochemical expression of p27 in 108 consecutive colorectal cancers, and we analysed the relationship with the results, the clinicopathological data, microsatellite instability (MSI) and other genetic alterations of tumours.

METHODS

Unselected patients (108) who underwent curative colorectal resection for sporadic colorectal cancer in a three-year period were evaluated for MSI using 6 microsatellite markers, and for the presence of p27, p53, Fhit, Mlh1 and Msh2 proteins by means of immunostaining. The relationships between these markers were analysed. p27 protein expression was examined for association with disease recurrences and survival.

RESULTS

Lack of p27 expression was noted in 33 out of 108 (30.5%) colorectal cancer cases (P<0.05). This altered expression was significantly higher in proximal cancers (P<0.05), mucinous tumours (P<0.001), poorly differentiated histology (P<0.01), cancers with MSI (P<0.05), tumours with altered expression of Mlh1 (P<0.01), of Msh2 (P<0.05), and of Fhit (P<0.01). Overall survival was better in the patient group with altered level of phenotypic p27 expression, although the difference does not reach statistical significance (P=0.069). The analysis performed only for patients with tumour at stage II showed significantly better survival when the tumour exhibited altered p27 expression (P<0.02).

CONCLUSIONS

The results of the present study support the hypothesis that altered expression of p27 may be part of the genetic pathway involving MSI, which is responsible for the development of some colorectal cancers.

Distinct molecular patterns based on proximal and distal sporadic colorectal cancer: arguments for different mechanisms in the tumorigenesis

BACKGROUND AND AIMS

Colorectal cancer (CRC) ranks as the fourth most frequently diagnosed cancer worldwide. CRCs that arise proximally or distally to the splenic flexure show differences in epidemiologic incidence, morphology, and molecular alterations, suggesting the existence of two categories of CRC based on the site of origin. The aim of the present work is to investigate the histological and molecular differences between CRCs located proximally and distally to the splenic flexure, and their potential involvement in tumor prognosis and therapeutic strategies.

METHODS

We evaluated 120 patients affected by sporadic CRC for clinicopathologic features, microsatellite instability (MSI), loss of heterozygosity (LOH) of chromosomes 18q, 8p, and 4p; they were also investigated for hMlh1, hMsh2, Fhit, p27, and Cox-2 immunostaining.

RESULTS

The mucinous histotype was more frequent in the proximal than in the distal CRCs (p<0.004). The frequency of MSI phenotype was higher in proximal than in distal tumors (p<0.001); moreover, reduced or absent hMlh1, Fhit, p27 immunohistochemical expressions were more frequent in proximal than in distal tumors (p<0.001 and 0.01 for p27). In contrast, the frequency of LOH in 18q was higher in distal than in proximal tumors (p=0.002). No significant differences were observed between proximal and distal tumors in the frequency of LOH in 8p and altered expression of hMsh2 and p53 protein.

CONCLUSION

These different features may reflect different genetic pathways of carcinogenesis and support the hypothesis of a different mechanism of cancer development between the proximal and the distal colon, with potential implications in the therapeutic approach.

Criteria for malignancy in gastrointestinal endocrine tumors

In contrast with the large amount of data generated from endocrine tumors of the pancreas, sparse and mostly unconfirmed data are available on the criteria for the assessment of malignancy risk and patient outcome in endocrine tumors of the gastrointestinal tract. In these conditions the 2000 WHO classification with its standardized scheme of pathologic report constitutes a framework facilitating the assessment of tumor malignancy and has been regarded as useful for clinical purposes, providing the basis for proper management of the patients and for the design of treatment protocols. The classification is based on a combination of pathological and clinical features with parameters specific for each organ in which the endocrine tumors originate. Three main categories, one further subdivided into two subgroups, are considered: (1) well-differentiated endocrine tumors, further subdivided into tumors with benign and with uncertain behavior; (2) well-differentiated endocrine carcinomas, low grade; and (3) poorly differentiated endocrine carcinomas, high grade. In this review the differential tumor characteristics between the different categories are summarized. Moreover, the relevance of additional features with respect to tumor prognostication, chiefly the Ki-67 proliferation index and malignancy-associated genetic changes, is discussed with emphasis on the discrepancies emerging between tumors of foregut and of midgut origin.