Genetic abnormalities as diagnostic and prognostic markers in B cell lymphomas: role of new molecular technologies in personalized medicine for extranodal diffuse large B cell lymphoma (EN-DLBCL) and follicular lymphoma (FL)

A plethora of molecular biomarkers are available nowadays in the field of cancer research. However, it is crucial to understand when and how they can be integrated into the clinical setting, translating experimental results from bench to bedside, with the aim of improving patients\u2019 care. We decided to investigate the role of some of these biomarkers in two subtypes of non-Hodgkin lymphoma which still represent a challenge for both researchers and clinicians. We started from diffuse large B cell lymphomas (DLBCLs), investigating a multicentric series of primary extranodal DLBCLs. Overall, data analysis provided strong evidence that the distribution of immunophenotypic, cytogenetic and survival characteristics is site-dependent. We next moved to follicular lymphoma (FL). The translocation (14;18), leading to BCL2 protein overexpression, is considered the genetic hallmark of FL. We tested the incidence of BCL2 negative FLs in a series of Italian patients from the Insubric region, concluding that BCL2 rearrangement in FL is not as frequent as generally reported and that the genetic landscape of FL is more complex than previously thought. What we learned is that even within an individual clinical entity, there is considerable heterogeneity with respect to genetic alterations, expression of commonly assayed markers and, most important, outcome. The personalized approach acknowledges this complexity and gives us tools for the continuous improvement of patients\u2019 care

Aberrant DNA methylation profiles of inherited and sporadic colorectal cancer

Background: Aberrant DNA methylation has been widely investigated in sporadic colorectal carcinomas (CRCs), and extensive work has been performed to characterize different methylation profiles of CRC. Less information is available about the role of epigenetics in hereditary CRC and about the possible clinical use of epigenetic biomarkers in CRC, regardless of the etiopathogenesis. Long interspersed nucleotide element 1 (LINE-1) hypomethylation and gene-specific hypermethylation of 38 promoters were analyzed in multicenter series of 220 CRCs including 71 Lynch (Lynch colorectal cancer with microsatellite instability (LS-MSI)), 23 CRCs of patients under 40 years in which the main inherited CRC syndromes had been excluded (early-onset colorectal cancer with microsatellite stability (EO-MSS)), and 126 sporadic CRCs, comprising 28 cases with microsatellite instability (S-MSI) and 98 that were microsatellite stable (S-MSS). All tumor methylation patterns were integrated with clinicopathological and genetic characteristics, namely chromosomal instability (CIN), TP53 loss, BRAF, and KRAS mutations. Results: LS-MSI mainly showed absence of extensive DNA hypo-and hypermethylation. LINE-1 hypomethylation was observed in a subset of LS-MSI that were associated with the worse prognosis. Genetically, they commonly displayed G:A transition in the KRAS gene and absence of a CIN phenotype and of TP53 loss. S-MSI exhibited a specific epigenetic profile showing low rates of LINE-1 hypomethylation and extensive gene hypermethylation. S-MSI were mainly characterized by MLH1 methylation, BRAF mutation, and absence of a CIN phenotype and of TP53 loss. By contrast, S-MSS showed a high frequency of LINE-1 hypomethylation and of CIN, and they were associated with a worse prognosis. EO-MSS were a genetically and epigenetically heterogeneous group of CRCs. Like LS-MSI, some EO-MSS displayed low rates of DNA hypo-or hypermethylation and frequent G:A transitions in the KRAS gene, suggesting that a genetic syndrome might still be unrevealed in these patients. By contrast, some EO-MSS showed similar features to those observed in S-MSS, such as LINE-1 hypomethylation, CIN, and TP53 deletion. In all four classes, hypermethylation of ESR1, GATA5, and WT1 was very common. Conclusions: Aberrant DNA methylation analysis allows the identification of different subsets of CRCs. This study confirms the potential utility of methylation tests for early detection of CRC and suggests that LINE-1 hypomethylation may be a useful prognostic marker in both sporadic and inherited CRCs

Genetic abnormalities as diagnostic and prognostic markers in B cell lymphomas: role of new molecular technologies in personalized medicine for extranodal diffuse large B cell lymphoma (EN-DLBCL) and follicular lymphoma (FL)

A plethora of molecular biomarkers are available nowadays in the field of cancer research. However, it is crucial to understand when and how they can be integrated into the clinical setting, translating experimental results from bench to bedside, with the aim of improving patients’ care. We decided to investigate the role of some of these biomarkers in two subtypes of non-Hodgkin lymphoma which still represent a challenge for both researchers and clinicians. We started from diffuse large B cell lymphomas (DLBCLs), investigating a multicentric series of primary extranodal DLBCLs. Overall, data analysis provided strong evidence that the distribution of immunophenotypic, cytogenetic and survival characteristics is site-dependent. We next moved to follicular lymphoma (FL). The translocation (14;18), leading to BCL2 protein overexpression, is considered the genetic hallmark of FL. We tested the incidence of BCL2 negative FLs in a series of Italian patients from the Insubric region, concluding that BCL2 rearrangement in FL is not as frequent as generally reported and that the genetic landscape of FL is more complex than previously thought. What we learned is that even within an individual clinical entity, there is considerable heterogeneity with respect to genetic alterations, expression of commonly assayed markers and, most important, outcome. The personalized approach acknowledges this complexity and gives us tools for the continuous improvement of patients’ care

ACTH-producing tumor

ACTH-producing pancreatic neuroendocrine tumors (PanNETs) are rare neoplasms, accounting for a minority of all PanNETs. Nevertheless, they are one of the leading non-pulmonary causes of the so-called ectopic ACTH-dependent Cushing's syndrome (ECS). The first ECS-associated PanNET was described in 1950 by Del Castillo and coworkers. Since then, less than 150 cases have been reported in the English literature The diagnosis of ACTH-producing PanNETs may be a clinical challenge, in particular when the presentation of the Cushing\ue2\u80\u99s syndrome is not typical. The milestones of the diagnosis are the detection of high circulating levels of ACTH and cortisol and the discovery of a pancreatic mass. ACTH-producing PanNETs have a female predominance, and the age of the patients is somewhat younger than in other PanNETs. Morphologically, they show the features of well-differentiated neuroendocrine tumors, but they are often larger than other PanNETs and frequently metastatic at the time of the diagnosis. Immunohistochemical staining helps to define the corticotroph phenotype of tumor cells.The prognosis of these tumors is often poor, with patients dying in a few months or years with metastatic disease

Unraveling Tumor Heterogeneity in an Apparently Monolithic Disease: BCL2 and Other Players in the Genetic Landscape of Nodal Follicular Lymphoma

Follicular lymphoma (FL) is the most common form of non-Hodgkin lymphoma in Western countries. Although traditionally considered a well-defined, easy to diagnose lymphoproliferative disorder, in the last few years it has become clear that it is in fact composed of many different clinicopathological entities, encompassing a variegated and complex genetic background. This has led to the inclusion of specific FL variants and separate entities in the latest update of the WHO classification. However, even in the context of classical FL, many aspects of intra- and inter-tumoral heterogeneity have been recognized, with a major influence on diagnosis and clinical practice at different time points during the course of the disease. This review focuses on the molecular cytogenetic heterogeneity in classical FL from precursors and early development to progression and transformation, in terms of both clonal heterogeneity and unusual genetic features. Several factors have been investigated and suggested to contribute to the broad spectrum of clinicopathological, phenotypic, and genetic features observed in otherwise morphologically classical cases. Among them, deregulation of the epigenetic machinery and interactions with tumor microenvironment seem to play a pivotal role, together with genetic aberrations involving well-known molecular pathways and mechanisms physiologically operating in the germinal center. In the era of personalized medicine, precision diagnostics based both on understanding of the complex interplay among all these factors and on novel developments will become crucial to predict the outcome and guide the treatment of FL patients.Follicular lymphoma (FL) is the most common form of non-Hodgkin lymphoma in Western countries. Although traditionally considered a well-defined, easy to diagnose lymphoproliferative disorder, in the last few years it has become clear that it is in fact composed of many different clinicopathological entities, encompassing a variegated and complex genetic background. This has led to the inclusion of specific FL variants and separate entities in the latest update of the WHO classification. However, even in the context of classical FL, many aspects of intra-and inter-tumoral heterogeneity have been recognized, with a major influence on diagnosis and clinical practice at different time points during the course of the disease. This review focuses on the molecular cytogenetic heterogeneity in classical FL from precursors and early development to progression and transformation, in terms of both clonal heterogeneity and unusual genetic features. Several factors have been investigated and suggested to contribute to the broad spectrum of clinicopathological, phenotypic, and genetic features observed in otherwise morphologically classical cases. Among them, deregulation of the epigenetic machinery and interactions with tumor microenvironment seem to play a pivotal role, together with genetic aberrations involving well-known molecular pathways and mechanisms physiologically operating in the germinal center. In the era of personalized medicine, precision diagnostics based both on understanding of the complex interplay among all these factors and on novel developments will become crucial to predict the outcome and guide the treatment of FL patients

Primary extranodal diffuse large B-cell lymphomas: Many sites, many entities? Clinico-pathological, immunohistochemical and cytogenetic study of 106 cases

We analyzed the clinicopathological, immunohistochemical and cytogenetic features of 106 extranodal (EN) diffuse large B-cell lymphomas (DLBCLs) from stomach (34 cases), intestine (10), cervico-cephalic region (11), central nervous system (13), testes (21), skin (8), and miscellaneous sites (9). Hans\u2019 algorithm and the immunohistochemical double expressor score (DES) for MYC and BCL2 were applied to all cases. A subset of fifty-eight cases were analyzed with fluorescent in situ hybridization (FISH) with specific break apart probes for BCL6, MYC, BCL2, CCND1, BCL10 and MALT1 genes. Clinical records were available for all patients. The immunohistochemical study showed that, in our series of EN-DLBCLs, the Hans\u2019 subgroup and the DES differed significantly according to the site of origin. At FISH analysis, BCL6 and BCL2 were the most commonly rearranged genes in non-GC and in GC cases, respectively. Gastrointestinal lymphomas displayed the highest rate of gene rearrangements, often with MYC involvement. One testicular DLBCL showed BCL2/MYC double hit. At survival analysis, cerebral and testicular origin was associated with poor prognosis. In addition, Hans\u2019 subgroup and other immunohistochemical markers influenced patients\u2019 outcome. In conclusion, our data suggest that immunophenotypic, genetic and survival characteristics of EN-DLBCL are related to the specific primary site of the disease

EBV+ and MSI Gastric Cancers Harbor High PD-L1/PD-1 Expression and High CD8+ Intratumoral Lymphocytes

Both EBV+ and MSI gastric cancers (GCs) have high lymphoid infiltration which is rare in MSS/EBV− cancers. PD-L1/PD-1 interaction leads to a down-regulated immune response and it is one of the most promising targets for gastric cancer immunotherapy. PD-L1/PD-1 and CD8 expression were immunohistochemically investigated in a series of 169 FFPE GCs, including 33 EBV+, 59 MSI and 77 MSS/EBV− cases. PD-L1 membrane immunoreactivity in more than 5% of tumor cells was present in 31/169 GCs and was associated with high levels of CD8 intraepithelial lymphocytes (TILs; p < 0.001). PD-L1+ cases were mainly poorly differentiated (71%), intestinal type (85%) and high lymphoid response (HLR; 90%) tumors. PD-L1 expression was only present in EBV⁺ (46%), MSI (24%) and rare MSS/EBV− (3%) GCs with high CD8+ TILs (p < 0.001). Despite being associated with a better prognosis both in the whole series (p < 0.05) and in the MSI subset, PD-L1 is not an independent prognostic factor. PD-L1 gene amplification was detected in 3/17 cases, including 2/7 EBV+ and 1/8 MSI GC. PD-1⁺ TILs were significantly higher in EBV⁺ than MSI and MSS/EBV− cases. PD-L1/PD-1 pathway is selectively activated in HLR GCs and could be considered an emerging therapeutic target, particularly for EBV and MSI GCs