The tumour microenvironment consists of a complex mixture of non‐neoplastic cells, including fibroblasts, immune cells and endothelial cells embedded in the proteins of the extracellular matrix. The ...tumour microenvironment plays an active role in tumour behaviour. By interacting with cancer cells, it influences disease progression and the metastatic capacity of the tumour. Tumours with a high amount of stroma correspond to poor patient prognosis. The tumour–stroma ratio (TSR) is a strong independent prognostic tool in colon cancer and provides additional value to the current clinically used tumour–node–metastasis classification. The TSR is assessed on conventional haematoxylin and eosin‐stained paraffin sections at the invasive front of the tumour. Here we review studies demonstrating the prognostic significance of the TSR in solid epithelial tumours with a focus on colon cancer. Moreover, the biological role of the tumour microenvironment during tumour progression and invasion will be discussed, as well as the attempts to target the tumour stroma for therapeutic purposes. We suggest that the TSR can be implemented with little effort and without additional costs in current routine pathology diagnostics owing to its simplicity and reliability.
Lynch syndrome patients are susceptible to colorectal and endometrial cancers owing to inactivating germline mutations in mismatch repair genes, including MSH2 (ref. 1). Here we describe patients ...from Dutch and Chinese families with MSH2-deficient tumors carrying heterozygous germline deletions of the last exons of TACSTD1, a gene directly upstream of MSH2 encoding Ep-CAM. Due to these deletions, transcription of TACSTD1 extends into MSH2. The MSH2 promoter in cis with the deletion is methylated in Ep-CAM positive but not in Ep-CAM negative normal tissues, thus revealing a correlation between activity of the mutated TACSTD1 allele and epigenetic inactivation of the corresponding MSH2 allele. Gene silencing by transcriptional read-through of a neighboring gene in either sense, as demonstrated here, or antisense direction, could represent a general mutational mechanism. Depending on the expression pattern of the neighboring gene that lacks its normal polyadenylation signal, this may cause either generalized or mosaic patterns of epigenetic inactivation.
The genetic cause underlying the development of multiple colonic adenomas, the premalignant precursors of colorectal cancer (CRC), frequently remains unresolved in patients with adenomatous ...polyposis. Here we applied whole-exome sequencing to 51 individuals with multiple colonic adenomas from 48 families. In seven affected individuals from three unrelated families, we identified a homozygous germline nonsense mutation in the base-excision repair (BER) gene NTHL1. This mutation was exclusively found in a heterozygous state in controls (minor allele frequency of 0.0036; n = 2,329). All three families showed recessive inheritance of the adenomatous polyposis phenotype and progression to CRC in at least one member. All three affected women developed an endometrial malignancy or premalignancy. Genetic analysis of three carcinomas and five adenomas from different affected individuals showed a non-hypermutated profile enriched for cytosine-to-thymine transitions. We conclude that a homozygous loss-of-function germline mutation in the NTHL1 gene predisposes to a new subtype of BER-associated adenomatous polyposis and CRC.
The diagnosis of nodal marginal zone lymphoma is one of the remaining problem areas in hematopathology. Because no established positive markers exist for this lymphoma, it is frequently a diagnosis ...of exclusion, making distinction from other low-grade B-cell lymphomas difficult or even impossible. This systematic review summarizes and discusses the current knowledge on nodal marginal zone lymphoma, including clinical features, epidemiology and etiology, histology, and cytogenetic and molecular features. In particular, recent advances in diagnostics and pathogenesis are discussed. New immunohistochemical markers have become available that could be used as positive markers for nodal marginal zone lymphoma. These markers could be used to ensure more homogeneous study groups in future research. Also, recent gene expression studies and studies describing specific gene mutations have provided clues to the pathogenesis of nodal marginal zone lymphoma, suggesting deregulation of the nuclear factor kappa B pathway. Nevertheless, nodal marginal zone lymphoma remains an enigmatic entity, requiring further study to define its pathogenesis to allow an accurate diagnosis and tailored treatment. However, recent data indicate that it is not related to splenic or extranodal lymphoma, and that it is also not related to lymphoplasmacytic lymphoma. Thus, even though the diagnosis is not always easy, it is clearly a separate entity.
Noonan syndrome (NS) is characterized by short stature, facial dysmorphisms and congenital heart defects. PTPN11 mutations are the most common cause of NS. Patients with NS have a predisposition for ...leukemia and certain solid tumors. Data on the incidence of malignancies in NS are lacking. Our objective was to estimate the cancer risk and spectrum in patients with NS carrying a PTPN11 mutation. In addition, we have investigated whether specific PTPN11 mutations result in an increased malignancy risk. We have performed a cohort study among 297 Dutch NS patients with a PTPN11 mutation (mean age 18 years). The cancer histories were collected from the referral forms for DNA diagnostics, and by consulting the Dutch national registry of pathology and the Netherlands Cancer Registry. The reported frequencies of cancer among NS patients were compared with the expected frequencies using population-based incidence rates. In total, 12 patients with NS developed a malignancy, providing a cumulative risk for developing cancer of 23% (95% confidence interval (CI), 8-38%) up to age 55 years, which represents a 3.5-fold (95% CI, 2.0-5.9) increased risk compared with that in the general population. Hematological malignancies occurred most frequently. Two malignancies, not previously observed in NS, were found: a malignant mastocytosis and malignant epithelioid angiosarcoma. No correlation was found between specific PTPN11 mutations and cancer occurrence. In conclusion, this study provides first evidence of an increased risk of cancer in patients with NS and a PTPN11 mutation, compared with that in the general population. Our data do not warrant specific cancer surveillance.
Cellular angiofibroma represents a rare benign mesenchymal tumor, occurring mainly in the superficial soft tissue of the genital region. The involvement of 13q14 in some cases confirmed the ...morphological suggested link with spindle cell lipoma and mammary-type myofibroblastoma. We analyzed the clinicopathological and immunohistochemical features of 25 cases, and performed in a number of cases additional molecular studies. There were 17 female and 8 male patients (age ranged from 27 to 83 years); females tended to be younger. A marked predilection for the vulva (n=13) was observed, and neoplasms in males were predominantly located in the inguinal region (n=4), and one case each in the scrotum, perianal, the knee, and the upper eyelid. The tumors arose most commonly in the superficial soft tissue and were well circumscribed in all but two cases. The tumor size ranged from 1 to 9 cm. All lesions were composed of spindle-shaped cells associated with numerous small- to medium-sized blood vessels; however, a broad morphological variation with foci of lipogenic differentiation in nine cases and sarcomatous transformation in one case was found. By immunohistochemistry, 11 out of 22 cases expressed CD34. A focal reaction for α-smooth muscle actin was observed in 9 out of 22 cases, and two cases each stained weak and focally positive for epithelial membrane antigen and CD99. In all seven cases tested, a monoallelic deletion of RB1 was detected by FISH analysis. Follow-up, available in 14 patients, showed neither local recurrence nor metastasis. In conclusion, we affirm the link between cellular angiofibroma, spindle cell lipoma, and mammary-type myofibroblastoma, showing a spectrum of one entity with morphological variations dependent on anatomic location.
Short-term preoperative radiotherapy and total mesorectal excision have each been shown to improve local control of disease in patients with resectable rectal cancer. We conducted a multicenter, ...randomized trial to determine whether the addition of preoperative radiotherapy increases the benefit of total mesorectal excision.
We randomly assigned 1861 patients with resectable rectal cancer either to preoperative radiotherapy (5 Gy on each of five days) followed by total mesorectal excision (924 patients) or to total mesorectal excision alone (937 patients). The trial was conducted with the use of standardization and quality-control measures to ensure the consistency of the radiotherapy, surgery, and pathological techniques.
Of the 1861 patients randomly assigned to one of the two treatment groups, 1805 were eligible to participate. The overall rate of survival at two years among the eligible patients was 82.0 percent in the group assigned to both radiotherapy and surgery and 81.8 percent in the group assigned to surgery alone (P=0.84). Among the 1748 patients who underwent a macroscopically complete local resection, the rate of local recurrence at two years was 5.3 percent. The rate of local recurrence at two years was 2.4 percent in the radiotherapy-plus-surgery group and 8.2 percent in the surgery-only group (P<0.001).
Short-term preoperative radiotherapy reduces the risk of local recurrence in patients with rectal cancer who undergo a standardized total mesorectal excision.
The identification of patients with high-risk stage II colon cancer who may benefit from adjuvant therapy may allow the clinical approach to be tailored for these patients based on an understanding ...of tumour biology. MicroRNAs have been proposed as markers of the prognosis or treatment response in colorectal cancer. Recently, a 2-microRNA signature (let-7i and miR-10b) was proposed to identify colorectal cancer patients at risk of developing distant metastasis. We assessed the prognostic value of this signature and additional candidate microRNAs in an independent, clinically well-defined, prospectively collected cohort of primary colon cancer patients including stage I-II colon cancer without and stage III colon cancer with adjuvant treatment. The 2-microRNA signature specifically predicted hepatic recurrence in the stage I-II group, but not the overall ability to develop distant metastasis. The addition of miR-30b to the 2-microRNA signature allowed the prediction of both distant metastasis and hepatic recurrence in patients with stage I-II colon cancer who did not receive adjuvant chemotherapy. Available gene expression data allowed us to associate miR-30b expression with axon guidance and let-7i expression with cell adhesion, migration, and motility.
The tumour-stroma ratio (TSR) and tumour budding (TB) are two high-risk factors with potential to be implemented in the next TNM classification. The aim of the current study was to evaluate the ...practical application of the two biomarkers based on reproducibility, independency and prognostic value. Patients diagnosed with stage II or III colon cancer who underwent surgery between 2005 and 2016 were included. Both TSR and TB were scored on haematoxylin and eosin-stained tissue sections. The TSR, based on the relative amount of stroma, was scored in increments of 10%. TB was scored following the consensus guidelines; a bud was defined as ≤ 4 tumour cells. For analysis, three categories were used. Cohen’s kappa was used for reproducibility. The prognostic value was determined with survival analysis. In total, 246 patients were included. The TSR distribution was
N
= 137 (56%) stroma-low and
N
= 109 (44%) stroma-high. The TB distribution was TB-low
N
= 194 (79%), TB-intermediate
N
= 35 (14%) and TB-high
N
= 17 (7%). The reproducibility of the TSR was good (interobserver agreement kappa = 0.83 and intraobserver agreement kappa = 0.82), whereas the inter- and intraobserver agreement for scoring TB was moderate (kappa 0.47 and 0.45, respectively). The survival analysis showed an independent prognostic value for disease-free survival for TSR (HR 1.57; 95% CI 1.01–2.44;
p
= 0.048) and for TB-high (HR 2.01; 95% CI 1.02–3.96;
p
= 0.043). Based on current results, we suggest the TSR is a more reliable parameter in daily practice due to better reproducibility and independent prognostic value for disease-free survival.
Clonality analysis in classic Hodgkin lymphoma (cHL) is of added value for correctly diagnosing patients with atypical presentation or histology reminiscent of T cell lymphoma, and for establishing ...the clonal relationship in patients with recurrent disease. However, such analysis has been hampered by the sparsity of malignant Hodgkin and Reed-Sternberg (HRS) cells in a background of reactive immune cells. Recently, the EuroClonality-NGS Working Group developed a novel next-generation sequencing (NGS)-based assay and bioinformatics platform (ARResT/Interrogate) to detect immunoglobulin (IG) gene rearrangements for clonality testing in B-cell lymphoproliferations. Here, we demonstrate the improved performance of IG-NGS compared to conventional BIOMED-2/EuroClonality analysis to detect clonal gene rearrangements in 16 well-characterized primary cHL cases within the IG heavy chain (IGH) and kappa light chain (IGK) loci. This was most obvious in formalin-fixed paraffin-embedded (FFPE) tissue specimens, where three times more clonal cases were detected with IG-NGS (9 cases) compared to BIOMED-2 (3 cases). In total, almost four times more clonal rearrangements were detected in FFPE with IG-NGS (N = 23) as compared to BIOMED-2/EuroClonality (N = 6) as judged on identical IGH and IGK targets. The same clonal rearrangements were also identified in paired fresh frozen cHL samples. To validate the neoplastic origin of the detected clonotypes, IG-NGS clonality analysis was performed on isolated HRS cells, demonstrating identical clonotypes as detected in cHL whole-tissue specimens. Interestingly, IG-NGS and HRS single-cell analysis after DEPArray™ digital sorting revealed rearrangement patterns and copy number variation profiles indicating clonal diversity and intratumoral heterogeneity in cHL. Our data demonstrate improved performance of NGS-based detection of IG gene rearrangements in cHL whole-tissue specimens, providing a sensitive molecular diagnostic assay for clonality assessment in Hodgkin lymphoma.
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