Validation of a Nomogram for Non-sentinel Node Positivity in Melanoma Patients, and Its Clinical Implications: A Brazilian-Dutch Study.

BACKGROUND: Non-sentinel node (NSN) positivity impacts the prognosis of melanoma patients; however, the benefits of completion lymph node dissection in patients with positive sentinel nodes (SNs) are limited. OBJECTIVE: We aimed to present a predictive nomogram for NSN positivity in melanoma patients with a positive SN biopsy. METHODS: This retrospective analysis from patients who underwent SN biopsy in a Brazilian institution from 2000 to 2015 was used for the construction and internal validation of the nomogram. This nomogram was then externally validated in a cohort of Dutch patients. RESULTS: The Brazilian cohort comprised 1213 patients, with a mean follow-up of 5.11 years. Breslow thickness (odds ratio [OR] 1.170, 95% confidence interval [CI] 1.043-1.314]; p = 0.008), number of positive SNs (OR 1.092, 95% CI 1.034-1.153; p = 0.001), and largest diameter of the metastatic deposit (OR 3.217, 95% CI 1.551-6.674; p = 0.002) were statistically significant for NSN positivity. Internal validation was performed using a bootstrapping technique. A good performance was observed (Brier score 0.097) and an excellent power of discrimination was achieved (area under the curve [AUC] 0.822). The nomogram was then applied to the Dutch cohort, and its overall performance (Brier score 0.085), calibration (Hosmer-Lemeshow goodness-of-fit test; p = 0.198), and discriminatory power (AUC 0.752, 95% CI 0.615-0.890) were all adequate. CONCLUSIONS: We presented a nomogram for assessing NSN probability that should not only be used for surgical considerations but also for risk stratification and clinical decisions. Internal validation has shown that this is an adequate model, while external validation increases the model's reliability and suggests that it can be globally incorporated.

BAP1 tumor predisposition syndrome case report: pathological and clinical aspects of BAP1-inactivated melanocytic tumors (BIMTs), including dermoscopy and confocal microscopy.

BACKGROUND: BRCA1 associated-protein 1 (BAP1) tumor predisposition syndrome is associated with an increased risk for malignant mesotheliomas, uveal and cutaneous melanomas, renal cell carcinomas, and singular cutaneous lesions. The latter are referred to as BAP1-inactivated melanocytic tumors (BIMTs). When multiple BIMTs manifest, they are considered potential markers of germline BAP1 mutations. CASE PRESENTATION: Here, we report a novel pathogenic BAP1 germline variant in a family with a history of BIMTs, cutaneous melanomas, and mesotheliomas. We also describe singular pathological aspects of the patient's BIMT lesions and their correlation with dermoscopic and reflectance confocal microscopy findings. CONCLUSIONS: This knowledge is crucial for the recognition of BIMTs by dermatologists and pathologists, allowing the determination of appropriate management for high-risk patients, such as genetic investigations and screening for potentially aggressive tumors.

A nomogram to identify high-risk melanoma patients with a negative sentinel lymph node biopsy.

BACKGROUND: Melanoma patients with negative nodes after sentinel lymph node biopsy are a heterogeneous group. Current guidelines fail to adequately stratify surveillance and treatment for this group. Also, there is scarce data on adjuvant treatments for these patients. OBJECTIVE: To create a nomogram including clinical and pathologic characteristics capable of evaluating the risk for recurrence of primary melanoma patients with negative sentinel lymph node biopsies (SLNBs). METHODS: We used a retrospective cohort of patients who underwent SLNB during 2000-2015 at a single institution. RESULTS: Our cohort comprised 1213 patients. Among these patients, 967 (79.7%) had a negative SLNB, and mean follow-up was 59.67 months. There were 133 recurrences (13.8%); 45 (33.8%) presented with nodal recurrence, and 35 (26.3%) recurred where a SLNB was performed. Breslow thickness, ulceration, and microsatellitosis were found to be predictive of risk for recurrence at 1, 2, 5, and 10 years. LIMITATION: Single center analysis. CONCLUSION: We created a predictive nomogram for melanoma patients with negative SLNBs. This nomogram is easy to use and identifies high-risk patients who should have more strict surveillance and be considered for adjuvant treatment.

Angiogenesis-related protein expression in bevacizumab-treated metastatic colorectal cancer: NOTCH1 detrimental to overall survival.

BACKGROUND: The development of targeted therapies has undoubtedly broadened therapeutic options for patients with colorectal cancer (CRC). The use of bevacizumab to reduce angiogenesis has been associated with improved clinical outcomes. However, an urgent need for prognostic/predictive biomarkers for anti-angiogenic therapies still exists. METHODS: Clinical data of 105 CRC patients treated with bevacizumab in conjunction with chemotherapy were analyzed. The expression of vascular endothelial growth factor (VEGF) receptors, NOTCH1 receptor and its ligand DLL4 were determined by immunohistochemistry. Tumor samples were arranged on a tissue microarray. The association between protein expression and clinicopathological characteristics and outcomes was determined. RESULTS: Bevacizumab was administered as a first-line of treatment in 70.5 % of our cases. The median progression-free survival (PFS) was 10.2 months. The median overall survival (OS) of the total cohort was 24.4 months. Bevacizumab, as the first-line of treatment, and the presence of liver metastasis were independently associated with objective response rate. Membrane VEGFR1 and VEGFR3 expressions were associated with the presence of lung metastasis; interestingly, VEGFR3 was associated with less liver metastasis. NOTCH1 expression was associated with lymph node metastasis. There was a trend toward association between improved PFS and lower NOTCH1 expression (p = 0.06). Improved OS was significantly associated with lower NOTCH1 expression (p = 0.01). In a multivariate analysis, ECOG (Eastern Cooperative Oncology Group) performance status, liver metastasis, histological grade, and NOTCH1 expression were independently associated with OS. CONCLUSION: Our findings illustrated the expression profile of angiogenesis-related proteins and their association with clinicopathological characteristics and outcomes. NOTCH1 expression is a detrimental prognostic factor in metastatic CRC patients treated with chemotherapy plus bevacizumab.

Popliteal sentinel lymph node involvement in melanoma patients.

BACKGROUND: Sentinel lymph nodes (SLN) in popliteal basins are rare, and there is controversy in literature regarding their origin, management, and outcomes. OBJECTIVES: To correlate clinical and pathological features of popliteal basin drainage and analyze the impact of popliteal lymph node drainage on survival. MATERIALS AND METHODS: Retrospective analysis of SLN biopsies performed at a single institution between 2000 and 2010. RESULTS: SLN biopsies were performed in 254 patients with melanoma in lower limbs, 247 of which were evaluated. In this group, there were 59 patients (24%) with a positive SLN. Twenty-seven cases (11%) presented with popliteal drainage, one of which lacked concurrent groin drainage. Among these 27 patients, three (11%) had popliteal metastasis, one of which had exclusive involvement of this basin. Popliteal drainage was associated with worse 5-year disease-free survival (DFS) (P = 0.028) but not 5-year overall survival (OS) (P = 0.219) in univariate analysis. In multivariate analysis, Breslow thickness, mitotic index, and positive SLN were prognostic factors for DFS. Only mitotic index correlated significantly with OS (P = 0.044). CONCLUSIONS: Popliteal drainage seems to be associated with worse prognostic features of the primary tumor.

KRAS gene mutation in a series of unselected colorectal carcinoma patients with prognostic morphological correlations: a pyrosequencing method improved by nested PCR.

INTRODUCTION: Inhibition of EGFR is a strategy for treating metastatic colorectal cancer (CRC) patients. KRAS sequencing is mandatory for selecting wild-type tumor patients who might benefit from this treatment. DNA from formalin-fixed paraffin-embedded (FFPE) tissues is commonly used for routine clinical detection of mutations, and its amplification succeeds only when all preanalytical histological processes have been controlled. In cases that are not properly processed, the DNA results can be poor, with low peak pyrosequencing findings. We designed and tested a pair of forward and reverse primers for a nested PCR method, followed by pyrosequencing, in a single Latin American institution series of 422 unselected CRC patients, correlating KRAS mutations with pathological and clinical data. MATERIALS AND METHODS: Patient DNA samples from tumors were obtained by scraping or laser microdissection of cells from FFPE tissue and extracted using a commercial kit. DNA was first amplified by PCR using 2 primers that we designed; then, nested PCR was performed with the amplicon from the preamplification PCR using the KRAS PyroMark™ Q96 V2.0 kit (Qiagen). Pathological data were retrieved from pathology reports. RESULTS: KRAS mutation was observed in 33% of 421 cases. Codon 12 was mutated in 76% of cases versus codon 13 in 24%. Right-sided CRCs harbored more KRAS mutations than left-sided tumors, as did tumors that presented with perineural invasion. CONCLUSION: Our findings in this Latin American population are consistent with the literature regarding the frequency of KRAS mutations in CRC, their distribution between codons 12 and 13, and type of nucleotide substitution. By combining nested PCR and pyrosequencing, we achieved a high rate of conclusive results in testing KRAS mutations in CRC samples - a method that can be used as an ancillary test for failed assays by conventional PCR.

KRAS insertions in colorectal cancer: what do we know about unusual KRAS mutations?

INTRODUCTION: KRAS mutations are negative predictors of the response to anti-EGFR therapy in colorectal carcinomas (CRCs). Point mutations in codons 12, 13, and 61 are the most common KRAS mutations in CRC. There are few reports on insertions in KRAS, and little is known about its ability to activate the RAS pathway. The scarcity of data regarding insertion frequencies and nucleotide additions in KRAS impedes the management of patients with such mutations. We present data on KRAS insertions in CRC and discuss a case. MATERIALS AND METHODS: Pyrosequencing and Sanger sequencing were performed to identify KRAS and BRAF mutations in paraffin-embedded samples of CRC. Expression of mismatch repair proteins was examined by immunohistochemistry. RESULTS: We detected a GGT insertion between codons 12 and 13 (c.36_37insGGT;p.G12_G13insG) in a CRC patient. We found that insertions in KRAS is very rare in CRC and that the most frequent type of insertion is c.36_37insGGT. CONCLUSIONS: KRAS gene insertions represent a diagnostic and clinical challenge due to the difficult and unusual pyrosequencing findings and the lack of information regarding its clinical impact.

Pigmented lesion on the face: which is the chance of being melanoma using reflectance confocal microscopy features?

Facial melanoma presents itself as a brownish macula, being difficult to differentiate it from benign pigmented lesions of the face on clinical examination. Reflectance confocal microscopy (RCM) assists in diagnosing facial lesions in which dermoscopy has limitations, allowing to increase the diagnostic accuracy. The study aimed to analyze the RCM features of pigmented isolated lesions of the face for diagnosing melanoma. Also, we sought to establish the chance of a pigmented lesion on the face being a melanoma using RCM criteria. In this retrospective and prospective study, 105 clinical pigmented lesions on the face underwent RCM, and cytoarchitectural features in the epidermis, the dermo-epidermal junction (DEJ), and dermis were described. For statistical analysis, the exact chi-square test was applied to the RCM criteria. The odds ratio was estimated using univariate logistic regression. Finally, we used the multiple logistic regression method for creating a nomogram to predict the chance of a lesion being a melanoma. After univariate and multivariate logistic regression, atypical round nucleated cells within the epidermis, pagetoid spread, and follicular dendritic cells presented as statistically significant features. Then, a complex nomogram was created to give the chance of a pigmented lesion on the face being a melanoma. The presence of these three features resulted in a 98% probability for melanoma. This study allowed to estimate the diagnosis of melanoma on the face, using RCM, practicable and feasible in the daily routine, through the presence of some RCM nomogram criteria.

Intraoperative assessment of surgical margins using "en face" frozen sections in the management of cutaneous carcinomas.

BACKGROUND: Basal cell and squamous cell carcinomas (BCC and SCC) are the most common types of cancer worldwide. Intraoperative assessment of surgical margins by frozen section has been widely used to ensure disease-free margins. The intraoperative "en face" freezing technique evaluates all peripheral and deep margins. OBJECTIVE: To report the results of the "en face" freezing technique in relation to tumor recurrence and agreement with paraffin-embedded tissue examination. METHODS: Retrospective analysis of patients undergoing surgical excision of BCC and SCC at the A. C. Camargo Cancer Center, Brazil. RESULTS: This study included 542 skin carcinomas, which were excised from 397 patients. A total of 201 male patients (50.6%), and 196 female patients (49.4%) were assessed, whose mean age was 64 years. The tumors were mostly located on the head and neck region (87.8%). BCC corresponded to 79.7% of the cases. The mean follow-up was 38 months. Tumor relapse occurred in 0.86% of the primary tumors and 3.7% of recurrent tumors. The result of the intraoperative "en face" frozen section evaluation was in agreement with the final result of the anatomopathological examination (paraffin test) in 98% of the lesions. STUDY LIMITATIONS: Not having a minimum follow-up time of 5 years for all patients. CONCLUSION: The "en face" freezing technique shows low tumor relapse, being reliable and safe to guarantee negative surgical margins of the tumor.

Unique SLC12A2-ROS1 fusion is associated with marked response to crizotinib in lung adenocarcinoma.

Chromosomal rearrangements involving the c-ros oncogene 1 (ROS1) gene define a subset of non-small cell lung cancers highly sensitive to small-molecule tyrosine kinase inhibitors. However, little is known about the impact of different fusion partners on tyrosine kinase inhibitor efficacy. We herein describe a case of a 26-year-old never-smoker patient from southern Africa with metastatic lung adenocarcinoma driven by SLC12A2-ROS1 fusion, who had a pronounced and durable response to crizotinib. The present case underscores the importance of pursuing actionable alterations in patients with similar clinical and epidemiological characteristics. In addition, provides the second report of crizotinib activity against lung malignancies harboring the unique SLC12A2-ROS1 fusion and highlights the importance of a deeper understanding of molecular alterations in underrepresented subgroups of patients to tailor the decision-making in daily practice.

Tumor glycolytic profiling through 18F-FDG PET/CT predicts immune checkpoint inhibitor efficacy in advanced NSCLC.

Background: A significant proportion of patients with non-small-cell lung cancer (NSCLC) do not respond to immune checkpoint inhibitors (ICIs). Since metabolic reprogramming with increased glycolysis is a hallmark of cancer and is involved in immune evasion, we used 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) to evaluate the baseline glycolytic parameters of patients with advanced NSCLC submitted to ICIs, and assessed their predictive value. Methods: 18F-FDG PET/CT results in the 3 months before ICIs treatment were included. Maximum standardized uptake values, whole metabolic tumor volume (wMTV), and whole-body total lesion glycolysis (wTLG) were evaluated. Cutoff values for high or low glycolytic categories were determined using receiver-operating characteristic curves. Progression-free survival (PFS) and overall survival (OS) were evaluated. Patients with a complete response and a matching group with resistance to ICIs underwent immunohistochemistry analysis. An unsupervised k-means clustering model integrating programmed cell death ligand 1 (PD-L1) expression, glycolytic parameters, and ICIs therapy was performed. Results: In all, 98 patients were included. Lower baseline 18F-FDG PET/CT parameters were associated with responses to ICIs. Patients with low wMTV or wTLG had improved PFS and OS. High wTLG, strong tumor expression of glucose transporter-1, and lack of responses were significantly associated. Patients with low glycolytic parameters benefited from ICIs, regardless of chemotherapy. Conversely, those with high parameters benefited from the addition of chemotherapy. Patients with higher wTLG and lower PD-L1 were associated with progression and worse survival to ICIs monotherapy. Conclusions: Glycolytic metabolic profiles established through baseline 18F-FDG PET/CT are useful biomarkers for evaluating ICI therapy in advanced NSCLC.

Emerging biomarkers in metastatic urothelial carcinoma: tumour mutational burden, PD-L1 expression and APOBEC polypeptide-like signature in a patient with complete response to anti-programmed cell death protein-1 inhibitor.

Immunotherapy has recently been incorporated into the treatment guidelines for metastatic urothelial carcinoma. Nevertheless, the role of prognostic and predictive biomarkers in this setting is not completely defined. To date, PD-L1 expression and a high tumour mutational burden (TMB) seem to predict better responses to immune checkpoint inhibitors, but patients without these biomarkers may still respond to immunotherapy. There are some caveats regarding these biomarkers, such as lack of standardisation of techniques, tumour heterogeneity and other factors influencing the tumour microenvironment. Genomic signatures are other promising emerging strategies. We hereby discuss the management of a 70-year-old man with a metastatic recurrence of urothelial carcinoma within 1 year after neoadjuvant chemotherapy and radical cystectomy. Tumour next-generation sequencing showed a high TMB and a CD274 (PD-L1) amplification. The patient was treated with pembrolizumab and achieved a complete response.

Identification of the TP53 p.R337H Variant in Tumor Genomic Profiling Should Prompt Consideration of Germline Testing for Li-Fraumeni Syndrome.

PURPOSE: Li-Fraumeni syndrome (LFS) is rare in the worldwide population, but it is highly prevalent in the Brazilian population because of a founder mutation, TP53 p.R337H, accounting for 0.3% of south and southeastern population. Clinical criteria for LFS may not identify all individuals at risk of carrying the Brazilian founder mutation because of its lower penetrance and variable expressivity. This variant is rarely described in databases of somatic mutations. Somatic findings in tumor molecular profiling may give insight to identify individuals who might be carriers of LFS and allow the adoption of risk reduction strategies for cancer. MATERIALS AND METHODS: We determined the frequency of the TP53 p.R337H variant in tumor genomic profiling from 755 consecutive Brazilian patients with pan-cancer. This is a retrospective cohort from January 2013 to March 2020 at a tertiary care center in Brazil. RESULTS: The TP53 p.R337H variant was found in 2% (15 of 755) of the samples. The mutation allele frequency ranged from 30% to 91.7%. A total of seven patients were referred for genetic counseling and germline testing after tumor genomic profiling results were disclosed. All the patients who proceeded with germline testing (6 of 6) confirmed the diagnosis of LFS. Family history was available in 12 cases. Nine patients (9 of 12) did not meet LFS clinical criteria. CONCLUSION: The identification of the TP53 p.R337H variant in tumor genomic profiling should be a predictive finding of LFS in the Brazilian population and should prompt testing for germline status confirmation.

How does the mitotic index impact patients with T1 melanoma? Comparison between the 7th and 8th edition of the American Joint Committee on Cancer melanoma staging system.

BACKGROUND: The mitotic index is no longer used to classify T1 melanoma patients into T1a and T1b, so it should not be used to indicate sentinel node biopsy in these patients. OBJECTIVES: To evaluate patients with T1 melanoma who underwent sentinel lymph node biopsy and to compare those who were classified as T1a with those classified T1b, according to the 7th and 8th Edition of the melanoma staging system, regarding a positive biopsy result. The authors also aimed to assess whether there is any difference in the results in both staging systems. MATERIAL AND METHODS: This was a retrospective analysis of 1213 patients who underwent sentinel lymph node biopsy for melanoma, from 2000 to 2015, in a single institution. RESULTS: Of 399 patients with thin melanomas, 27 (6.7%) presented positive sentinel lymph nodes; there was no difference in positivity for sentinel node biopsy when comparing T1a vs. T1b in both staging systems. Furthermore, the clinical results were also similar between the two groups. However, in the complete cohort analysis, the mitotic index was associated with positivity for sentinel lymph node biopsy (p < 0.0001), positivity for non-sentinel lymph node (p < 0.0001), recurrence-free survival (p < 0.0001), and specific melanoma survival (p = 0.023). STUDY LIMITATION: Unicentric study. CONCLUSION: The mitotic index was shown to be a very important prognostic factor in the present study, but it was not observed in patients classified as T1. The mitotic index should no longer be used as the only reason to refer sentinel lymph node biopsy in patients with thin melanoma.

The prognostic influence of tumour budding in Western patients with stage II colorectal cancer.

BACKGROUND: Tumour budding (TB) refers to loss of tumour cohesiveness and is defined as isolated cells or a cell cluster of up to four tumour cells at the microscopic analysis. The International Tumour Budding Consensus Conference (ITBCC) in 2016 proposed a scoring system to standardise the pathology evaluation of TB in colorectal cancer (CRC) as high (H), intermediate (I) and low (L) TB. OBJECTIVE: To evaluate the recurrence-free survival (RFS) of stage II CRC patients as per the ITBCC 2016 classification and associations between TB and clinical pathological features. METHODS: Cases of stage II CRC undergoing surgery with available tumour tissue underwent central pathology review for TB. Prognostic factors, retrospectively retrieved from electronic medical charts, were evaluated in univariate and multivariate Cox regression analyses for RFS (primary end point). RESULTS: Among 137 patients included, L-TB was observed in 107 (78.1%), I-TB in 21 (15.3%) and H-TB in 9 (6.6%). In a median follow-up of 69 months, the median RFS was 134 months, with 14 patients (10.2%) presenting with tumour recurrence: 10 (9.3%) with L-TB, 2 (9.5%) with I-TB and 2 (22.2%) with H-TB. Perineural invasion was more commonly seen in the H-TB group. In multivariate analysis, TB (H and I versus L; HR = 2.6; p = 0.059) and not receiving adjuvant chemotherapy (HR 3.7; p = 0.020) were independently associated with RFS. Adjuvant chemotherapy was associated longer RFS (HR = 3.7; p = 0.022). CONCLUSION: In this series of Western patients, TB grade was associated with perineural invasion and increased risk of disease relapse.

Immune profiling of uveal melanoma identifies a potential signature associated with response to immunotherapy.

BACKGROUND: To date, no systemic therapy, including immunotherapy, exists to improve clinical outcomes in metastatic uveal melanoma (UM) patients. To understand the role of immune infiltrates in the genesis, metastasis, and response to treatment for UM, we systematically characterized immune profiles of UM primary and metastatic tumors, as well as samples from UM patients treated with immunotherapies. METHODS: Relevant immune markers (CD3, CD8, FoxP3, CD68, PD-1, and PD-L1) were analyzed by immunohistochemistry on 27 primary and 31 metastatic tumors from 47 patients with UM. Immune gene expression profiling was conducted by NanoString analysis on pre-treatment and post-treatment tumors from patients (n=6) receiving immune checkpoint blockade or 4-1BB and OX40 dual costimulation. The immune signature of UM tumors responding to immunotherapy was further characterized by Ingenuity Pathways Analysis and validated in The Cancer Genome Atlas data set. RESULTS: Both primary and metastatic UM tumors showed detectable infiltrating lymphocytes. Compared with primary tumors, treatment-naïve metastatic UM showed significantly higher levels of CD3+, CD8+, FoxP3+ T cells, and CD68+ macrophages. Notably, levels of PD-1+ infiltrates and PD-L1+ tumor cells were low to absent in primary and metastatic UM tumors. No metastatic organ-specific differences were seen in immune infiltrates. Our NanoString analysis revealed significant differences in a set of immune markers between responders and non-responders. A group of genes relevant to the interferon-γ signature was differentially up-expressed in the pre-treatment tumors of responders. Among these genes, suppressor of cytokine signaling 1 was identified as a marker potentially contributing to the response to immunotherapy. A panel of genes that encoded pro-inflammatory cytokines and molecules were expressed significantly higher in pre-treatment tumors of non-responders compared with responders. CONCLUSION: Our study provides critical insight into immune profiles of UM primary and metastatic tumors, which suggests a baseline tumor immune signature predictive of response and resistance to immunotherapy in UM.

Clinical and Molecular Assessment of Patients with Lynch Syndrome and Sarcomas Underpinning the Association with MSH2 Germline Pathogenic Variants.

Lynch syndrome (LS) is a hereditary cancer-predisposing syndrome associated most frequently with epithelial tumors, particularly colorectal (CRC) and endometrial carcinomas (EC). The aim of this study was to investigate the relationship between sarcomas and LS by performing clinical and molecular characterization of patients presenting co-occurrence of sarcomas and tumors from the LS spectrum. We identified 27 patients diagnosed with CRC, EC, and other LS-associated tumors who had sarcomas in the same individuals or families. Germline genetic testing, mismatch repair (MMR) protein immunohistochemistry, microsatellite instability (MSI), and other molecular analyses were performed. Five LS patients presenting personal or family history of sarcomas were identified (3 MSH2 carriers and 2 MLH1), with 2 having Muir-Torre phenotypes. For two MSH2 carriers we confirmed the etiology of the sarcomas (one liposarcoma and two osteosarcomas) as LS-related, since the tumors were MSH2/MSH6-deficient, MSI-high, or presented a truncated MSH2 transcript. Additionally, we reviewed 43 previous reports of sarcomas in patients with LS, which revealed a high frequency (58%) of MSH2 alterations. In summary, sarcomas represent a rare clinical manifestation in patients with LS, especially in MSH2 carriers, and the analysis of tumor biological characteristics can be useful for definition of tumor etiology and novel therapeutic options.

Biological Validation of RNA Sequencing Data from Formalin-Fixed Paraffin-Embedded Primary Melanomas.

PURPOSE: Initiatives such as The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) have generated high-quality, multi-platform molecular data from thousands of frozen tumor samples. While these initiatives have provided invaluable insight into cancer biology, a tremendous potential resource remains largely untapped in formalin-fixed, paraffin-embedded (FFPE) samples that are more readily available, but which can present technical challenges due to crosslinking of fragile molecules such as RNA. MATERIALS AND METHODS: We extracted RNA from FFPE primary melanomas and assessed two gene expression platforms -- genome-wide RNA sequencing (RNA-seq) and targeted NanoString -- for their ability to generate coherent biological signals. To do so, we generated an improved approach to quantifying gene expression pathways, in which we refine pathway scores through correlation-guided gene subsetting. We also make comparisons to the TCGA and other publicly available melanoma datasets. RESULTS: Comparison of the gene expression patterns to each other, to established biological modules, and to clinical and immunohistochemical data confirmed the fidelity of biological signals from both platforms using FFPE samples to known biology. Moreover, correlations with patient outcome data were consistent with previous frozen-tissue-based studies. CONCLUSION: FFPE samples from previously difficult-to-access cancer types - such as small primary melanomas - represents a valuable and previously unexploited source of analyte for RNA-seq and NanoString platforms. This work provides an important step towards the use of such platforms to unlock novel molecular underpinnings and inform future biologically-driven clinical decisions.

Gastric Pouch Mixed Adenoneuroendocrine Carcinoma With a Mixed Adenocarcinoma Component After Roux-en-Y Gastric Bypass.

The Roux-en-Y gastric bypass is one of the most common procedures currently performed for surgical treatment of patients with severe obesity. Gastric cancer after bariatric surgery is not common, with most of them arising in the excluded stomach. Gastric mixed adenoneuroendocrine carcinomas are a rare type of stomach malignancy, composed of both adenocarcinoma and neuroendocrine tumor-cell components, with the latter comprising at least 30% of the whole neoplasm. In this article, we report a unique case of a mixed adenoneuroendocrine carcinoma with a mixed adenocarcinoma (tubular and poorly cohesive) component arising in the gastric pouch of a patient who underwent previous Roux-en-Y gastric bypass for glycemic control. Since stomach cancer is not usual in patients who have formerly undergone bariatric surgery and symptoms tend to be nonspecific, such diagnosis is often rendered at an advanced stage. Full assessment of these patients when presenting such vague symptoms is critical for an early cancer diagnosis.

Integrated molecular analysis of tumor biopsies on sequential CTLA-4 and PD-1 blockade reveals markers of response and resistance.

Immune checkpoint blockade produces clinical benefit in many patients. However, better biomarkers of response are still needed, and mechanisms of resistance remain incompletely understood. To address this, we recently studied a cohort of melanoma patients treated with sequential checkpoint blockade against cytotoxic T lymphocyte antigen-4 (CTLA-4) followed by programmed death receptor-1 (PD-1) and identified immune markers of response and resistance. Building on these studies, we performed deep molecular profiling including T cell receptor sequencing and whole-exome sequencing within the same cohort and demonstrated that a more clonal T cell repertoire was predictive of response to PD-1 but not CTLA-4 blockade. Analysis of CNAs identified a higher burden of copy number loss in nonresponders to CTLA-4 and PD-1 blockade and found that it was associated with decreased expression of genes in immune-related pathways. The effect of mutational load and burden of copy number loss on response was nonredundant, suggesting the potential utility of a combinatorial biomarker to optimize patient care with checkpoint blockade therapy.