Purpose Programmed death ligand-1 (PD-L1) tumor expression represents a mechanism of immune escape for melanoma cells. Drugs blocking PD-L1 or its receptor have shown unprecedented activity in melanoma, and our purpose was to characterize tumor PD-L1 expression and associated T-cell infiltration in metastatic melanomas. Experimental Design We used a tissue microarray (TMA) consisting of two cores from 95 metastatic melanomas characterized for clinical stage, outcome and anatomic site of disease. We assessed PD-L1 expression and tumor infiltrating lymphocytes (TIL) content (total T cells and CD4/CD8 subsets) by quantitative immunofluorescence. Results High PD-L1 expression was associated with improved survival (P=0.02) and higher T cell content (P=0.0005). Higher T cell content (total and CD8 cells) were independently associated with improved overall survival; PD-L1 expression was not independently prognostic. High TIL content in extra-cerebral metastases was associated with increased time to developing brain metastases (P=0.03). Cerebral and dermal metastases had slightly lower PD-L1 expression than other sites, not statistically significant. Cerebral metastases had less T cells (P=0.01). Conclusions T cell infiltrated melanomas, particularly those with high CD8 T cell content, are more likely to be associated with PD-L1 expression in tumor cells, an improved prognosis, and increased time to development of brain metastases. Studies of T cell content and subsets should be incorporated into trials of PD-1/PD-L1 inhibitors to determine their predictive value. Furthermore, additional studies of anatomic sites with less PD-L1 expression and T cell infiltrate are needed to determine if discordant responses to PD-1/PD-L1 inhibitors are seen at those sites.

Background: Expression of programmed death ligand (PD-L1/B7-H1/CD274) represents a mechanism of immune escape for renal cell carcinoma (RCC) cells. Drugs blocking PD-L1 or its receptor are in clinical development and early data suggests that tumor PD-L1 expression may predict response.Patients and Methods: A tissue microarray (TMA) consisting of four biopsy cores from 34 matched pairs of nephrectomy and metastatic sites of clear cell RCC was used to assess PD-L1 expression by quantitative immunofluorescence. Assessment of intra- and inter-tumor heterogeneity and primary and metastatic tumor expression was performed using a method of Automated Quantitative Analysis (AQUA).Results: The median AQUA scores were higher in metastatic than primary specimens (P < 0.0001). The correlation between PD-L1 expression in matched primary and metastatic specimens was weak (R= 0.24). Within a given tumor, variable PD-L1 staining heterogeneity was seen, however the degree of heterogeneity was similar in primary and metastatic sites (P = 0.482).Conclusions: The weak correlation between PD-L1 expression in primary and metastatic sites for a given patient suggests that expression in nephrectomy specimens cannot be used to select metastatic RCC patients for PD-L1 and PD-1 inhibitors. The intra-tumor heterogeneity seen in both primary and metastatic specimens indicates that a single core biopsy might not be sufficient to determine PD-L1 expression.

Purpose Approximately 40% of metastatic melanoma patients develop brain metastases. Our purpose was to identify genes aberrantly expressed in melanoma that might be associated with propensity for brain homing. Experimental Design We studied gene expression profiles in a cell line model of brain metastasis (cerebrotropic A375Br cells versus parental A375P cells) and compared them to profiles of patients who developed early brain metastases and who did not. A tissue microarray containing 169 metastatic melanoma cases with variable time to brain metastasis was constructed to further study marker expression by quantitative immunofluorescence. An in vitro model of the blood brain barrier (BBB) was generated to evaluate potential mediators of brain metastases. Results PLEKHA5 was differentially expressed in both the A375 cell line model and patient samples subjected to gene expression profiling. At the protein level, by quantitative immunofluorescence, PLEKHA5 was associated with decreased brain metastasis free survival. PLEKHA5 over-expression was not associated with other metastatic sites. Knock-down of PLEKHA5 decreases viability of A375Br cells, inhibits BBB transmigration and invasion in vitro. Similar results were found with YUMUL cells, cultured from a patient with overwhelming brain metastases. PLEKHA5 knock-down did not affect the viability of A375P cells. Conclusions PLEKHA5 expression in melanoma tumors was associated with early development of brain metastases. Inhibition of PLEKHA5 might decrease passage across the BBB and decrease proliferation and survival of melanoma cells both in the brain and in extra-cerebral sites.

Background The fibula free flap (FFF) remains the criterion standard for complex mandibular reconstruction. Surgeons have incorporated virtual surgical planning (VSP) into the reconstructive algorithm with the assertion that VSP increases operative efficiency and may improve clinical outcomes. To date, no large-scale studies have analyzed these claims. This study examines the literature and tests the hypothesis that VSP improves operative efficiency, clinical outcomes, and accuracy when compared with traditional techniques. Methods A systematic review was performed to identify articles utilizing VSP and traditional techniques for FFF-based mandibular reconstruction. Two reviewers independently assessed all articles for methodological quality using a validated instrument (weighted Cohen κ for interrater reliability = 0.70). Outcomes included operative time, length of stay, complications, and accuracy. Meta-analytic comparisons were performed using data from comparative studies using a random-effects model and differences of means analysis for outcomes measured on identical scales. Results One hundred thirty-one articles were identified, and 25 met the inclusion criteria: 12 were VSP only, whereas 13 were comparative. There were 241 VSP patients and 214 traditional patients available for meta-analysis. Patients undergoing reconstruction with VSP had a significant reduction in operative time by 44.64 minutes (95% confidence interval [CI], −74.69 to −14.58 minutes; P < 0.01) and demonstrated a mean trend toward shorter hospital admission (mean difference, −1.24 days; 95% CI, −4.00 to 1.52 days; P = 0.38). There was no statistical difference between cohorts for major (odds ratio, 1.03; 95% CI, 0.46–2.31; P = 0.95) or minor complications (odds ratio, 0.97; 95% CI, 0.54–1.71; P = 0.90). Insufficient data were available for cost analysis and accuracy. Conclusions Virtual surgical planning–guided mandibular reconstruction with FFF is associated with significantly decreased operative time and a mean trend toward shorter hospital admission. While multiple studies reported a high degree of accuracy, no standard measurement was available for meta-analysis.

Aims Immunohistochemical stains have greatly improved the diagnostic accuracy of renal cell carcinoma (RCC) for primary and distant tumours. We evaluate a marker that has recently been incorporated in clinical practice, PAX-8, in primary and metastatic RCCs. Methods Two distinct tissue microarrays were used, one consisting of over 334 renal tumours, 294 with adjacent normal kidney and the other with 40 matched nephrectomy and metastatic sites of RCC. PAX-8 expression was assessed by a method of quantitative immunofluorescence. Results PAX-8 was positive in 96% (146/152) of normal renal tissue and 83% (227/272) of renal tumours. PAX-8 staining was positive in clear cell, papillary and chromophobe tumours in 80% (165/207), 95% (39/41) and 100% (6/6) of samples, respectively. Overall, intensity of PAX-8 expression was significantly higher in RCC metastatic sites than in the primary site (p=0.0047), however, in matched sites there was no statistically significant difference in the proportion of positive versus negative specimens (p=0.274). Conclusions As the role of molecular markers expands in the diagnostic algorithm, this study confirms that PAX-8 expression is a useful diagnostic marker for RCC. PAX-8 expression was found in the primary tumour and distant sites. Compared with normal tissue and other histological types, clear cell RCC has lower PAX-8 expression and is less frequently positive, therefore, the lack of expression does not exclude a tumour of renal origin.