Pathological response and tumour bed histopathological features correlate with survival following neoadjuvant immunotherapy in stage III melanoma.

BACKGROUND: Guidelines for pathological evaluation of neoadjuvant specimens and pathological response categories have been developed by the International Neoadjuvant Melanoma Consortium (INMC). As part of the Optimal Neo-adjuvant Combination Scheme of Ipilimumab and Nivolumab (OpACIN-neo) clinical trial of neoadjuvant combination anti-programmed cell death protein 1/anti-cytotoxic T-lymphocyte-associated protein 4 immunotherapy for stage III melanoma, we sought to determine interobserver reproducibility of INMC histopathological assessment principles, identify specific tumour bed histopathological features of immunotherapeutic response that correlated with recurrence and relapse-free survival (RFS) and evaluate proposed INMC pathological response categories for predicting recurrence and RFS. PATIENTS AND METHODS: Clinicopathological characteristics of lymph node dissection specimens of 83 patients enrolled in the OpACIN-neo clinical trial were evaluated. Two methods of assessing histological features of immunotherapeutic response were evaluated: the previously described immune-related pathologic response (irPR) score and our novel immunotherapeutic response score (ITRS). For a subset of cases (n = 29), cellular composition of the tumour bed was analysed by flow cytometry. RESULTS: There was strong interobserver reproducibility in assessment of pathological response (κ = 0.879) and percentage residual viable melanoma (intraclass correlation coefficient = 0.965). The immunotherapeutic response subtype with high fibrosis had the strongest association with lack of recurrence (P = 0.008) and prolonged RFS (P = 0.019). Amongst patients with criteria for pathological non-response (pNR, >50% viable tumour), all who recurred had ≥70% viable melanoma. Higher ITRS and irPR scores correlated with lack of recurrence in the entire cohort (P = 0.002 and P ≤ 0.0001). The number of B lymphocytes was significantly increased in patients with a high fibrosis subtype of treatment response (P = 0.046). CONCLUSIONS: There is strong reproducibility for assessment of pathological response using INMC criteria. Immunotherapeutic response of fibrosis subtype correlated with improved RFS, and may represent a biomarker. Potential B-cell contribution to fibrosis development warrants further study. Reclassification of pNR to a threshold of ≥70% viable melanoma and incorporating additional criteria of <10% fibrosis subtype of response may identify those at highest risk of recurrence, but requires validation.

Histopathological features of complete pathological response predict recurrence-free survival following neoadjuvant targeted therapy for metastatic melanoma.

BACKGROUND: Recent clinical trials demonstrated the safety and efficacy of neoadjuvant dabrafenib and trametinib (DT) among patients with surgically resectable clinical stage III BRAFV600E/K mutant melanoma. Although patients achieving a complete pathological response (pCR) exhibited superior recurrence-free survival (RFS) versus those who did not, 30% of pCR patients relapsed. We sought to identify whether histopathological features of the pathological response further delineated risk of relapse. METHODS: Surgical resection specimens from DT-treated patients in two phase 2 clinical trials were reviewed. Histopathological features, including relative amounts of viable tumour, necrosis, melanosis, and fibrosis (hyalinized or immature/proliferative) were assessed for associations with patient outcomes. RESULTS: Fifty-nine patients underwent surgical resection following neoadjuvant DT. Patients achieving pCR (49%) had longer RFS compared with patients who did not (P = 0.005). Patients whose treated tumour showed any hyalinized fibrosis had longer RFS versus those without (P = 0.014), whereas necrosis (P = 0.012) and/or immature/proliferative fibrosis (P = 0.026) correlated with shorter RFS. Multivariable analyses showed absence of pCR or presence of immature fibrosis independently predicted shorter RFS. Among pCR patients, mature/hyalinized-type fibrosis correlated with improved RFS (P = 0.035). CONCLUSIONS: The extent and composition of the pathological response following neoadjuvant DT in BRAFV600E/K mutant melanoma correlates with RFS, including pCR patients. These findings support the need for detailed histological analysis of specimens collected after neoadjuvant therapy.

Thermal territories of the abdomen after caesarean section birth: infrared thermography and analysis.

OBJECTIVE: To develop and refine qualitative mapping and quantitative analysis techniques to define 'thermal territories' of the post-partum abdomen, the caesarean section site and the infected surgical wound. In addition, to explore women's perspectives on thermal imaging and acceptability as a method for infection screening. METHOD: Prospective feasibility study undertaken at a large University teaching hospital, Sheffield UK. Infrared thermal imaging of the abdomen was undertaken at the bedside on the first two days after elective caesarean section. Target recruitment: six women in each of three body mass index (BMI) categories (normal, 18.5-24.9 kg/m²; overweight 25-29.9 kg/m²; obese ≥30 kg/m²). Additionally, women presenting to the ward with wound infection were eligible for inclusion in the study. Perspectives on the use of thermal imaging and its practicality were also explored via semi-structured interviews and analysed using thematic content analysis. RESULTS: We recruited 20 women who had all undergone caesarean section. From the booking BMI, eight women were obese (including two women with infected wounds), seven women were overweight and five women had a normal BMI. Temperature (ºC) profiling and pixel clustering segmentation (hierarchical clustering-based segmentation, HCS) revealed characteristic features of thermal territories between scar and adjacent regions. Differences in scar thermal intensity profiles exist between healthy scars and infected wounds; features that have potential for wound surveillance. The maximum temperature differences (∆T) between healthy skin and the wound site exceed 2º C in women with established wound infection. At day two, two women had a scar thermogram with features observed in the 'infected' wound thermogram. CONCLUSION: Thermal imaging at early and later times after caesarean birth is feasible and acceptable. Women reported potential benefits of the technique for future wound infection screening. Thermal intensity profiling and HCS for pixel cluster dissimilarity between scar and adjacent healthy skin has potential as a method for the development of techniques targeted to early infection surveillance in women after caesarean section.

Oncogenic suppression of PHLPP1 in human melanoma.

Akt is constitutively activated in up to 70% of human melanomas and has an important role in the pathogenesis of the disease. However, little is known about protein phosphatases that dephosphorylate and thereby inactivate it in melanoma cells. Here we report that suppression of pleckstrin homology domain and leucine-rich repeat Ser/Thr protein phosphatase 1 (PHLPP1) by DNA methylation promotes Akt activation and has an oncogenic role in melanoma. While it is commonly downregulated, overexpression of PHLPP1 reduces Akt activation and inhibits melanoma cell proliferation in vitro, and retards melanoma growth in a xenograft model. In contrast, knockdown of PHLPP1 increases Akt activation, enhances melanoma cell and melanocyte proliferation, and results in anchorage-independent growth of melanocytes. Suppression of PHLPP1 involves blockade of binding of the transcription factor Sp1 to the PHLPP1 promoter. Collectively, these results suggest that suppression of PHLPP1 by DNA methylation contributes to melanoma development and progression.

BRAF(V600E) protein expression and outcome from BRAF inhibitor treatment in BRAF(V600E) metastatic melanoma.

BACKGROUND: To examine the association between level and patterns of baseline intra-tumoural BRAF(V600E) protein expression and clinical outcome of BRAF(V600E) melanoma patients treated with selective BRAF inhibitors. METHODS: Fifty-eight BRAF(V600E) metastatic melanoma patients treated with dabrafenib or vemurafenib on clinical trials had pre-treatment tumour BRAF(V600E) protein expression immunohistochemically (IHC) assessed using the BRAF V600E mutant-specific antibody VE1. Sections were examined for staining intensity (score 1-3) and percentage of immunoreactive tumour cells, and from this an immunoreactive score (IRS) was derived (intensity × per cent positive/10). The presence of intra-tumoural heterogeneity for BRAF(V600E) protein expression was also assessed. BRAF(V600E) expression was correlated with RECIST response, time to best response (TTBR), progression-free survival (PFS) and overall survival (OS). RESULTS: Expression was generally high (median IRS 28 (range 5-30)) and homogeneous (78%). Expression of mutated protein BRAF(V600E) as measured by intensity, per cent immunoreactive cells, or IRS did not correlate with RECIST response, TTBR, PFS or OS, including on multivariate analysis. Heterogeneity of staining was seen in 22% of cases and did not correlate with outcome. CONCLUSION: In the current study population, IHC-measured pre-treatment BRAF(V600E) protein expression does not predict response or outcome to BRAF inhibitor therapy in BRAF(V600E) metastatic melanoma patients.

The potential for non-heart beating organ donation within a paediatric intensive care unit.

OBJECTIVE: In the UK, the number of patients waiting for an organ transplant has increased by 30% since 2001. Non-heart beating organ donation (NHBD) programmes are advocated as a means of increasing the number of potential donors. Such programmes remain in their infancy within paediatrics. We examined all deaths in our paediatric intensive care unit (PICU) between January 2005 and December 2008 to establish the number of potential NHB donors. We further obtained data from UK NHS Blood and Transplant detailing all paediatric patients that became heart beating and NHB donors in the UK over the same period. DESIGN: (A) Data obtained from UK NHS Blood and Transplant detailing the number of organ donors within the unit and within the UK. (B) Retrospective review of our paediatric intensive care mortality database and patient notes to identify patients aged 1-16 years who died in the PICU over the same period. Assessment of patient suitability for NHBD was made according to predetermined exclusion criteria. RESULTS: During the study period, 126 children died in the PICU. Three children were referred for heart beating organ donation (two proceeded to be donors). Nine children were referred for NHBD (three proceeded to be donors). Of the remaining 114 patients, 39 (34%) were aged >1 year and died following active withdrawal of treatment. Of these 39, 27 (69%) had relative contraindications, leaving 12 patients that might have been considered as potential NHB donors. If a 50% conversion rate is used, six children may have been realised as actual NHB donors. CONCLUSION: If this situation were replicated in the PICUs throughout the UK, it would represent a significant increase in the number of organs available for transplantation.

Primary cutaneous Ewing sarcoma/primitive neuroectodermal tumour: a clinicopathological analysis of seven cases highlighting diagnostic pitfalls and the role of FISH testing in diagnosis.

AIMS: To perform a clinicopathological analysis of a series of primary cutaneous Ewing sarcomas/primitive neuroectodermal tumours (ES/PNET) to highlight the pathological features, discuss the differential diagnosis, emphasise the role of molecular testing (particularly fluorescence in situ hybridisation, FISH) in diagnosis and outline the patients' clinical course. METHODS: Seven cases of primary cutaneous ES/PNET were identified from the authors' consultation files. RESULTS: The patients were aged 16-61 years (median 25). Five were female and two were male. Five cases involved the limbs and two the trunk. Five were initially misdiagnosed (three as carcinoma and two as melanoma). All cases were characterised histologically by sheet-like growth of small round cells with little cytoplasm and showed strong membranous staining for CD99 and positive but variable staining for FLI-1. Six patients showed an EWS rearrangement (five on FISH analysis and one on RT-PCR). All tumours were completely excised. Three patients received adjuvant chemotherapy, one of whom also received radiotherapy. Follow-up was available in all cases (range 11-57 months; median 41). No recurrences or metastases occurred. CONCLUSIONS: Although rare, primary cutaneous ES/PNET should be considered in the differential diagnosis of cutaneous "small blue cell tumours". Immunostaining for FLI-1 and molecular testing for evidence of an EWS rearrangement are useful ancillary investigations to confirm the diagnosis. The prognosis of primary cutaneous ES/PNET appears to be more favourable than extracutaneous ES/PNET.