Molecular profiling of Asian patients with advanced melanoma receiving check-point inhibitor treatment.

OBJECTIVE: Melanoma is major medical challenge and being able to monitor treatment response is critical. This study aimed to use molecular profiling of Asian patients with advanced melanoma who were receiving treatment with check-point inhibitors (CPIs) to identify novel biomarkers of tumor response. METHODS: Next-generation sequencing (NGS) was performed using tumor specimens collected from 178 Asian patients with metastatic melanoma receiving CPIs. The NGS data and clinical-pathological factors were analyzed for potential genetic biomarkers of tumor response to CPI treatment. RESULTS: The most common melanoma subtype was acral melanoma (40%), followed by cutaneous melanoma (32%), mucosal melanoma (26%), and others (2%). For calculation of treatment efficacy, 164 of the patients could be evaluated. The overall response rate was 45.7%, of which 41 cases exhibited complete responses (25.0%) and 34 showed partial responses (20.7%). There were no significant differences in tumor responses based on melanoma subtype (P = 0.295). Genetically, NRAS mutations, TP53 mutations, and NF2 deletions were significantly associated with resistance to CPIs (P < 0.05). In contrast, MYC and RPS6KB1 amplifications were associated with responsiveness to CPIs (P < 0.05). Median progression-free survival (PFS) for patients treated with CPIs was 5.9 months (95% CI, 3.8-8.05 months). Univariate analysis identified TP53 and BRAF mutations, NF2 deletions, and BIRC2 amplifications as poor prognostic factors for PFS (P < 0.05). CONCLUSIONS: This study determined the integrated genomic profiles of Asian patients with metastatic melanoma receiving CPIs and identified candidate biomarkers that reflected treatment outcomes.

Prediction and clinical implications of portal vein/superior mesenteric vein invasion in patients with resected pancreatic head cancer: the significance of preoperative CT parameters.

AIM: To determine the preoperative computed tomography (CT) parameters that predict portal vein/superior mesenteric vein (PV-SMV) invasion in patients with pancreatic head cancer, and to assess whether PV-SMV invasion affects patient survival. MATERIALS AND METHODS: Sixty patients with PV-SMV invasion, and 60 randomly selected patients without it, who had undergone preoperative CT and subsequent surgery for pancreatic head cancer were enrolled. The following CT parameters were evaluated using multivariate logistic regression and receiver operating characteristic analyses to predict vessel invasion (tumour size and margin, length of involved vessel, distance from the tumour to the vessel, vessel irregularity, the teardrop sign, and tumour-vein interface [TVI]). The Cox proportional hazard model was used to evaluate the effects of PV-SMV invasion on survival. RESULTS: In multivariate analysis, tumour size (odds ratio [OR]=1.99) and TVI (OR=3.79 [≤90°], 20.66 [>90°, ≤180°], and 47.24 [>180°]) were independent CT predictors of PV-SMV invasion (p<0.05); they achieved a sensitivity of 87%, a specificity of 75%, and an accuracy of 81%; however, PV-SMV invasion did not affect patient survival after surgery (p=0.374). CONCLUSION: In patients with pancreatic head cancer, preoperative CT parameters can predict PV-SMV invasion with high accuracy. PV-SMV invasion did not affect treatment outcome after surgery.

Emergence of CTNNB1 mutation at acquired resistance to KIT inhibitor in metastatic melanoma.

PURPOSE: The KIT inhibitor, imatinib, has shown promising efficacy in patients with KIT-mutated melanoma; however, acquisition of resistance to imatinib occurs rapidly in the majority of patients. The mechanisms of acquired resistance to imatinib in melanoma remain unclear. METHODS: We analyzed biopsy samples from paired baseline and post-treatment tumor lesions in one patient with KIT-mutated melanoma who had had an initial objective tumor regression in response to imatinib treatment followed by disease progression 8 months later. RESULTS: Targeted deep sequencing from post-treatment biopsy samples detected an additional mutation in CTNNB1 (S33C) with original KIT L576P mutation. We examined the functional role of the additional CTNNB1 S33C mutation in resistance to imatinib indirectly using the Ba/F3 cell model. Ba/F3 cell lines transfected with both the L576P KIT mutation and the CTNNB1 S33C mutation demonstrated no growth inhibition despite imatinib treatment, whereas growth inhibition was observed in the Ba/F3 cell line transfected with the L576 KIT mutation alone. CONCLUSIONS: We report the first identification of the emergence of a CTNNB1 mutation that can confer acquired resistance to imatinib. Further investigation into the causes of acquired resistance to imatinib will be essential to improve the prognosis for patients with KIT-mutated melanoma.

Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas).

OBJECTIVES: Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality. DESIGN: Retrospective multinational study including SCN diagnosed between 1990 and 2014. RESULTS: 2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2-200)), 9% had resection beyond 1 year of follow-up (3 years (1-20), size at diagnosis: 25 mm (4-140)) and 39% had no surgery (3.6 years (1-23), 25.5 mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1). CONCLUSIONS: After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN. TRIAL REGISTRATION NUMBER: IRB 00006477.

Comparison of diagnostic methods for onychomycosis, and proposal of a diagnostic algorithm.

BACKGROUND: Traditionally, the gold standard for diagnosis of onychomycosis has been the combination of direct microscopy with potassium hydroxide (KOH) staining and fungal culture. However, several studies have suggested that periodic-acid-Schiff (PAS) staining of nail-plate clippings may be a very sensitive method for the diagnosis of onychomycosis. AIM: To compare the sensitivities of direct microscopy with KOH, fungal culture and PAS staining of nail-plate clippings, and to define an efficient, high-yield and cost-effective diagnostic strategy for the diagnosis of onychomycosis in the clinical setting. METHODS: We evaluated a total of 493 patients with clinically suspected onychomycosis. Group A comprised 400 patient samples, evaluated using fungal culture and PAS stain, while group B comprised 93 patient samples evaluated using KOH, fungal culture and PAS. Diagnosis of onychomycosis was defined as clinical morphology plus at least one positive test result. RESULTS: In group A, sensitivities of fungal culture and PAS were 49.5% and 93.1% (P < 0.005), respectively. In group B, the most sensitive single test was PAS (88.2%) followed by KOH (55.9%) and fungal culture (29.4%). The combination of fungal culture and PAS (94.1%) was significantly (P < 0.001) more sensitive than that of KOH and culture (72.1%). CONCLUSION: PAS staining of nail clippings is much more sensitive than KOH and fungal culture for the diagnosis of onychomycosis. Based on our results, we propose a diagnostic algorithm for onychomycosis that takes into consideration the sensitivity, cost-effectiveness and necessary time for each test.

Nuclear and cytoplasmic localization of ß-catenin in the nail-matrix cells and in an onychomatricoma.

ß-catenin plays an important role in hair morphogenesis. Previously, the nuclear and cytoplasmic localizations of ß-catenin were identified in hair-matrix cells. To evaluate ß-catenin expression in the nail matrix, we obtained human nail units. Immunohistochemistry for ß-catenin was used to evaluate sections of normal nail units and of sections from a single case of onychomatricoma. In the nail unit, ß-catenin was expressed in the nucleus and cytoplasm of the suprabasal nail-matrix cells. Of the other epithelial-cell types, only the cell membrane was ß-catenin-positive. In the nail tissue from the onychomatricoma case, ß-catenin was expressed in the nucleus and cytoplasm of the upper epithelial layers. Our result suggests that ß-catenin plays an important role in nail formation. In addition, ß-catenin expression in onychomatricoma supports the presence of nail-matrix cells in this condition. To our knowledge, this is the first report of ß-catenin expression in the nucleus and cytoplasm of the nail matrix.

Surgical strategies for non-functioning pancreatic neuroendocrine tumours.

BACKGROUND: The purpose of this study was to identify management strategies for non-functioning pancreatic neuroendocrine tumours (NF-PNETs) by analysis of surgical outcomes at a single institution. METHODS: Archived records of patients with NF-PNETs who underwent surgery between 1994 and 2010 were reviewed. RESULTS: Among 125 patients, the median tumour size was 2·5 (range 0·15-20·5) cm. Of the 51 NF-PNETs with a diameter of no more than 2 cm, 12 (24 per cent) were diagnosed as carcinoma. Overall 20 patients (16·0 per cent) had metastases to the lymph nodes. The minimum size of the tumour with lymph node metastasis was 1·2 cm. Having a NF-PNET of 2 cm or larger significantly increased the probability of a poorly differentiated carcinoma (P = 0·006), and having a NF-PNET of at least 2·5 cm significantly increased the probability of lymph node metastasis (P = 0·048). The 5-year cumulative survival rate after curative resection was 89·7 per cent. During a median follow-up of 31·5 months, there were 27 recurrences (23·1 per cent) and 13 disease-specific deaths (11·1 per cent) among the 117 patients who had an R0 resection. All patients who underwent repeat operations were alive without additional recurrence after a mean(s.d.) follow-up of 27·1(18·0) months. CONCLUSION: Curative surgery should be performed for control of primary NF-PNETs. Lymph node dissection for NF-PNETs of 2·5 cm or larger and at least node sampling for tumours with a diameter of 1 cm or more are recommended. Debulking surgery should be considered for advanced tumours.

Detection of Merkel cell polyomavirus in Merkel cell carcinomas and small cell carcinomas by PCR and immunohistochemistry.

Recently, the clonal integration of a new human polyomavirus (Merkel cell polyomavirus or MCPyV) has been reported in Merkel cell carcinoma (MCC). In order to investigate the presence of MCPyV in small cell carcinomas (SCCs) and small round cell tumors (SRCTs), we collected formalin-fixed paraffin-embedded tissue specimens including 14 MCCs, 24 SCCs, 7 Ewing sarcoma/primitive neuroectodermal tumors (ES/PNETs) and 5 neuroblastomas. We also collected specimens of other cancers including 12 malignant melanomas, 10 breast, 10 ovarian and 20 gastric cancers. We used 3 primer sets for which the sequences were previously published (LT1, LT3, and VP1) and 3 newly designed primer sets (LT1-1, LT1-1a, and LT3a). Quantitative real-time PCR was also performed with the LTq primer set. Nested PCR using the LT3a primer set detected more cases of MCPyV infection in MCC. In total, 12 of 14 (85.7%) MCC cases were positive for MCPyV by PCR, which was consistent with published data. Some SCC specimens were also positive for MCPyV (37.5%) by PCR. PCR products from MCC and SCC cases showed premature truncation and frameshift mutation. Furthermore, one case of ES/PNET and one gastric carcinoma showed MCPyV DNA. However, MCPyV DNA and transcript were only detected in MCCs with quantitative real-time PCR analysis. In addition, 11 of 13 (84.6%) MCC cases and 6 of 23 (26.1%) SCC cases showed immunoreactivity with monoclonal antibodies against MCPyV large T-antigen. Considering both PCR and IHC results, MCPyV was detected in all MCCs tested. The presence of MCPyV in all MCC cases tested and in some SCC cases suggests that MCPyV may be involved in the malignant transformation.

Farnesoid X receptor, overexpressed in pancreatic cancer with lymph node metastasis promotes cell migration and invasion.

BACKGROUND: Lymph node metastasis is one of the most important adverse prognostic factors for pancreatic cancer. The aim of this study was to identify novel lymphatic metastasis-associated markers and therapeutic targets for pancreatic cancer. METHODS: DNA microarray study was carried out to identify genes differentially expressed between 17 pancreatic cancer tissues with lymph node metastasis and 17 pancreatic cancer tissues without lymph node metastasis. The microarray results were validated by real-time PCR. Immunohistochemistry and western blotting were used to examine the expression of farnesoid X receptor (FXR). The function of FXR was studied by small interfering RNA and treatment with FXR antagonist guggulsterone and FXR agonist GW4064. RESULTS: Farnesoid X receptor overexpression in pancreatic cancer tissues with lymph node metastasis is associated with poor patient survival. Small interfering RNA-mediated downregulation of FXR and guggulsterone-mediated FXR inhibition resulted in a marked reduction in cell migration and invasion. In addition, downregulation of FXR reduced NF-κB activation and conditioned medium from FXR siRNA-transfected cells showed reduced VEGF levels. Moreover, GW4064-mediated FXR activation increased cell migration and invasion. CONCLUSIONS: These findings indicated that FXR overexpression plays an important role in lymphatic metastasis of pancreatic cancer and that downregulation of FXR is an effective approach for inhibition of pancreatic tumour progression.

Extranodal NK/T-cell lymphoma with cutaneous involvement: 'nasal' vs. 'nasal-type' subgroups--a retrospective study of 18 patients.

BACKGROUND: Extranodal natural killer T (NK/T) cell lymphoma is subcategorized into 'nasal' and 'nasal-type' NK/T-cell lymphomas according to the primary sites of anatomical involvement. OBJECTIVES: The aim of this study was to characterize the cutaneous manifestations of the skin involving extranodal NK/T-cell lymphoma and to define the distinctive features of 'nasal' and 'nasal-type'. In addition, the prognostic factors that affect overall survival were investigated. METHODS: A retrospective case study of 18 patients with extranodal NK/T-cell lymphoma with cutaneous involvement was performed. RESULTS: The NK/T-cell lymphomas usually occurred in middle-aged, male patients. Most of the patients presented with either cellulitis or ulcer. A facial predilection for the location of the lesion was noted. The characteristic features of the 'nasal-type' compared with the 'nasal' were a localized involvement of the skin, less aggressive clinical course and better survival outcome. CONCLUSIONS: Extranodal NK/T-cell lymphomas are extremely aggressive regardless of their subgroup. However, the 'nasal-type' NK/T-cell lymphoma was clinically less aggressive, more localized and had a better outcome compared with the other type. Cellulitis and ulcer were the major cutaneous manifestations.

Characteristics of cutaneous cytomegalovirus infection in non-acquired immune deficiency syndrome, immunocompromised patients.

BACKGROUND: Although cytomegalovirus (CMV) disease is a severe complication among immunocompromised patients, its cutaneous features have not been frequently reported. As herpes simple virus (HSV) infection commonly develops in CMV skin lesions, a study is needed on the pathogenetic role of CMV in cutaneous lesion formation. OBJECTIVES: The purpose of this study is to characterize the clinical and histopathological features of cutaneous CMV infection and to determine whether CMV plays a true pathogenetic role in cutaneous lesions, or if it is just an innocent bystander during HSV infection among non-AIDS (acquired immune deficiency syndrome), immunocompromised patients. PATIENTS AND METHODS: A total of nine human immunodeficiency virus-negative patients diagnosed with cutaneous CMV infection from July 1999 to February 2005 at Samsung Medical Center were analysed in terms of their clinical and histopathological characteristics. In addition, we examined for the co-presence of HSV by performing immunohistochemical analysis and polymerase chain reaction. RESULTS: All the patients were immunocompromised; five had haematological diseases and four were organ transplant recipients. The clinical and histopathological features were similar to those of previous studies of patients with AIDS. Multiple anogenital ulcerations were the most frequent cutaneous presentation (66.7%). Most cytopathic changes were found in the dermis, particularly within the vascular endothelial cells (77.8%) and macrophages (66.7%). However, the association of CMV with concurrent HSV infection was even lower than that seen in patients with AIDS. Only one patient revealed a co-existing cutaneous HSV infection. CONCLUSIONS: In non-AIDS individuals, the cutaneous lesions from CMV infection showed similar clinical and histopathological features to those of patients with AIDS. However, skin lesions may not be highly associated with HSV, and CMV does seem to contribute to lesion development as a cutaneous manifestation among the CMV infected, non-AIDS, immunocompromised patients.