Update of the recommendations for the determination of biomarkers in colorectal carcinoma: National Consensus of the Spanish Society of Medical Oncology and the Spanish Society of Pathology

In this update of the consensus of the Spanish Society of Medical Oncology (Sociedad Española de Oncología Médica—SEOM) and the Spanish Society of Pathology (Sociedad Española de Anatomía Patológica—SEAP), advances in the analysis of biomarkers in advanced colorectal cancer (CRC) as well as susceptibility markers of hereditary CRC and molecular biomarkers of localized CRC are reviewed. Recently published information on the essential determination of KRAS, NRAS and BRAF mutations and the convenience of determining the amplification of human epidermal growth factor receptor 2 (HER2), the expression of proteins in the DNA repair pathway and the study of NTRK fusions are also evaluated. From the pathological point of view, the importance of analysing the tumour budding and poorly differentiated clusters, and its prognostic value in CRC is reviewed, as well as the impact of molecular lymph node analysis on lymph node staging in CRC. The incorporation of pan-genomic technologies, such as next-generation sequencing (NGS) and liquid biopsy in the clinical management of patients with CRC is also outlined. All these aspects are developed in this guide, which, like the previous one, will remain open to any necessary revision in the future.

In vitro-acquired resistance gene expression profile and in vivo response to oxaliplatin-based treatment

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Background: Resistance to oxaliplatin is one of the main problems of colorectal cancer (CRC) treatment success. It is not clear if intrinsic and acquired resistance processes are developed by related mechanisms. In a previous work (Martinez-Cardús et al. Mol Cancer Ther, January 2009), we determined a profile of oxaliplatin-acquired resistance related genes by using an in vitro model. In the present work, we analyzed this genetic profile in paraffin-embedded primary adenocarcinomas from CRC patients treated with oxaliplatin-fluoropyrimidine. mRNA expression data was correlated with response rate and time to progression (TTP) in order to determine the role of these genes as markers of resistance to oxaliplatin-based treatment. Material and Method: mRNA levels were analyzed by using Real Time PCR. β-actin and 18s were used as housekeeping genes and, as a reference sample, we used commercial pool of mRNA from different human tumours. Chi- square and Fisher test were used in order to value differences in response rate to treatment. TTP was studied by using Kaplan Meyer curves and Log rank test. Median and percentile 33 and 66 were used as threshold values to determine both high and low expression level groups for each gene analyzed. We considered statistically significant a two-sided p-value lower than 0.05. Results: Forty-four advanced CRC patients treated with fluoropyrimidine plus oxaliplatin were analyzed. 54.5% of them were males; primary tumour was localized in colon in a 65.9% of cases. According to qRT-PCR analysis, the in vitro oxaliplatin acquired resistance related genes could be detected in the tumours but the expression of any of them correlated significantly with in vivo resistance to oxaliplatin-based treatment by using the three different threshold values to define groups. Conclusions: According to our results, these genes could not be used as markers of resistance to oxaliplatin-based treatment in non-treated tumours. Thereby, oxaliplatin resistance acquisition genes seems not to be involved in intrinsic drug resistance probably due to the fact that acquired and intrinsic oxaliplatin resistance are not related mechanisms. Further studies to typify oxaliplatin intrinsic resistance potential markers are guaranteed.

No significant financial relationships to disclose.

Gastrointestinal stromal tumors

BACKGROUND

We reviewed radiologic features of gastrointestinal stromal tumors (GISTs) and correlated them with clinical and pathologic findings.

METHODS

We investigated a series of 39 c-Kit-positive GISTs. Clinical and radiologic findings and management of these patients were recorded.

RESULTS

Twenty women and 19 men (mean age 64 years) had histologically proved GIST. Tumor locations were the small bowel (n = 20), stomach (n = 14), rectum (n = 4), and omentum (n = l). Symptoms at presentation were most frequently gastrointestinal bleeding (n = 14) and abdominal pain (n = l1). Tumors were classified as very low risk (n = 2), low risk (n = 10), intermediate risk (n = 12), and high risk (n = 11). Ultrasonography, computed tomography, magnetic resonance, digital subtraction angiography, and barium series were used in the evaluation of these tumors. Most tumors were seen as well-delineated soft tissue masses with heterogeneous contrast enhancement. Necrosis, calcification, and ulceration were most commonly seen in large tumors that presented a more aggressive behavior.

CONCLUSION

GISTs can arise anywhere in the gastrointestinal tract and present a great variety of clinical and radiologic features, depending mostly on size and location.

[Cecal cytomegalovirus infection following appendicectomy in a patient with ulcerative colitis]

We report a patient who, 3 months after being diagnosed with ulcerative colitis, was admitted to hospital because of malaise and right lower abdominal pain. An open appendectomy was performed. Histological study showed ulcerative colitis affecting the appendix. After surgery, the patient presented a refractory outbreak of ulcerative colitis requiring treatment with steroids and cyclosporin A. Despite this treatment, the patient continued to pass abundant fresh blood associated with severe anemia. Colonoscopy showed only granular and congestive cecal mucosa. Biopsies showed intracytoplasmic inclusion bodies with immunohistochemical stains positive for cytomegalovirus (CMV) infection. Rectorrhagia and anemia quickly disappeared after beginning treatment with ganciclovir. Appendicular ulcerative colitis is not uncommonly associated with distal colitis. In addition, diffuse CMV infection complicating ulcerative colitis treatment is not unusual. By contrast, isolated, segmentary infection by CMV in the proximal colon is extremely rare. Until now, only three patients with localized CMV infection have been described, and all three cases occurred in the context of ileoanal anastomosis.

DCC and SMAD4 alterations in human colorectal and pancreatic tumor dissemination

Chromosome 18q is lost a high proportion of colorectal and pancreatic cancers. Three candidate tumor suppressor genes, DCC, Smad4 and Smad2 have been identified in this chromosome region. DCC and Smad4 aberrations have been previously identified in pancreatic and colorectal tumors. The aim of this study was to compare the presence of concurrent genetic aberrations in DCC and neighboring Smad4 and Smad2 genes during colorectal and pancreatic distal dissemination. We have used a panel of orthotopically implanted colorectal and pancreatic xenografts and corresponding metastases. We have shown that while LOH at DCC locus occurred at a similar frequency in both tumors, diminished DCC protein expression was exclusively present in colorectal tumors harboring intragenic DCC LOH. In contrast, in pancreatic xenografts loss of DCC protein and mRNA expression was restricted to metastases. Smad4 gene aberrations were detected at a similar frequency in both tumors and were selected for during distal dissemination. Acquisition of alterations in both genes occurred independently. Our results suggest that both DCC and Smad4 contribute to pancreatic and colorectal distal dissemination. However, the role of DCC may differ between both tumor types.

Hyperechoic liver nodules: characterization with proton fat-water chemical shift MR imaging

PURPOSE

To evaluate proton fat-water chemical shift fast low-angle shot magnetic resonance (MR) imaging for differentiation of fat-containing hyperechoic liver nodules from hyperechoic liver nodules without a fatty component.

MATERIALS AND METHODS

T1-weighted fast low-angle shot fat-water chemical shift gradient-echo MR imaging was performed in 96 patients without cirrhosis with 138 hyperechoic liver nodules. In-phase and opposed-phase breath-hold images were acquired. The percentage of signal intensity variation between in-phase and opposed-phase images and the spleen-to-lesion contrast ratio were used to differentiate liver nodules.

RESULTS

Chemical shift MR images showed fat in 15 (11%) hyperechoic nodules (two angiomyolipomas and 13 nodular fatty infiltrations of the liver). The mean percentage of signal intensity variation between in-phase and opposed-phase images was 156% (standard error, 43.5%) in nodules with fat and -0.16% (standard error, 0.96%) in nodules without fat (P = .003). Spleen-to-lesion contrast was similar on in- and opposed-phase images in lesions without fat (mean difference, -0.0107; standard error, 0.012), whereas the mean difference in fat-containing nodules was 0.805 (standard error, 0.225; P = .003). The area under the receiver operating characteristic curve was 0.97 for signal intensity variation.

CONCLUSION

Hyperechogenicity in certain liver nodules is caused by fat. Chemical shift MR imaging allows accurate differentiation between these and other hyperechoic lesions with no fat component.

Mycosis fungoides associated with unusual epidermal hyperplasia

A 58-year-old white woman presented with widespread pruritic brownish plaques and hyperpigmented flexural lesions with a velvety appearance. On histopathological examination, the macules were diagnostic of mycosis fungoides, plaque stage, and the flexural lesions showed epidermal hyperplasia with a seborrhoeic keratosis-like appearance. There was intense mucin deposition and marked reduction of elastic fibres in the papillary dermis, as well as a moderately dense dermal lymphoid infiltrate composed of CD4+ T cells with occasional atypia and focal epidermotropism. The clinical and pathological manifestations of cutaneous T-cell lymphomas, including mycosis fungoides (MF), may show considerable variation. Apart from the three classic stages, a number of unusual clinical presentations and a broad spectrum of histopathological findings have been reported in the literature. In this report, a case of MF, plaque stage, with flexural lesions clinically reminiscent of (pseudo)acanthosis nigricans is presented. On histopathological examination, there was epidermal hyperplasia with a seborrhoeic keratosis-like appearance, with intense deposition of mucin and marked reduction of elastic fibres in the papillary dermis, together with a lymphoid infiltrate composed mainly of CD4+ cells with occasional atypia and epidermotropism. Cytokines produced by the lymphocytes in the infiltrate might account for the epithelial and dermal changes that characterize this peculiar variant of MF.

Role of CD44 in the invasiveness of glioblastoma multiforme and the noninvasiveness of meningioma: an immunohistochemistry study

CD44 is a polymorphic family of cell adhesion molecules that seems to be instrumental in the mechanism of tumor invasion and metastasis. Tumor cell expression of CD44, or lack thereof, may be one of the factors conditioning the highly disparate ability to penetrate the brain extracellular matrix (ECM) exhibited by glioblastoma multiforme (GM) and conventional meningioma. To assess the presence of CD44 in these two tumor types we have immunohistochemically investigated the expression of CD44 standard form (CD44s) and the variant isoforms containing the domain encoded by variant exon 3 (CD44v3) and variant exon 6 (CD44v6) in paraffin-embedded tissue from 10 conventional meningiomas and 10 GMs. A CD44s-/CD44v-phenotype was discerned in the meningioma cases, whereas GMs featured a CD44s+/CD44v- expression profile. Consequently, the growth patterns of meningioma and GM seem to be, at least in part, a reflection of their CD44 expression status. Paucity of CD44 in meningioma cells would render them unable to infiltrate the brain ECM, whereas CD44-rich glioma cells would successfully migrate through it. Conversely, lack of CD44v expression would contribute to explain the lack of metastatic potential characterizing both conventional meningioma and GM.

Pigmented epidermotropic ductal carcinoma of the breast in a male. Ultrastructural evidence of melanocytic colonization and melanin transfer to the tumor

The first case of pigmented epidermotropic breast carcinoma in a male, presenting as a pigmented lesion of the areola and nipple, is described. Immunohistochemical and ultrastructural studies demonstrated that the pigmentation was found to be primarily due to colonization of tumor nests by melanocytes, with numerous melanophages interspersed in the desmoplastic stroma and only occasional compound melanosomes within the epithelial tumor cells.