Spatial comparison of molecular features associated with resistance to pembrolizumab in BCG unresponsive bladder cancer.

Intravenous immune checkpoint inhibition achieves a 40% 3-month response in BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ. Yet, only half of the early responders will continue to be disease-free by 12 months, and resistance mechanisms are poorly defined. We performed spatial profiling of BCG-unresponsive tumors from patients responsive or resistant to intravenous pembrolizumab treatment, analyzing samples both before initiating and 3 months post-intravenous pembrolizumab treatment. We analyzed 119 regions of interest, which included 59 pairs of epithelial and adjacent stromal segments across five patients: two responders and three non-responders. We demonstrate that BCG unresponsive tumors with an inflamed PanCK+ tumor area and an infiltrated stromal segment respond better to intravenous pembrolizumab. Furthermore, using segment-specific gene signatures generated from a cohort of BCG unresponsive NMIBC treated with intravesical BCG+pembrolizumab, we find that non-inflamed, immune-cold tumors that do not respond to intravenous pembrolizumab exhibit a favorable outcome to the combined application of BCG and pembrolizumab. For the first time, we have identified molecular features of tumors associated with response and resistance to intravenous pembrolizumab in BCG unresponsive NMIBCs. Further research with more patients and alternative checkpoint inhibitors is essential to validate our findings. We anticipate that using a transcriptomics signature like the one described here can help identify tumors with a higher possibility of responding to intravenous pembrolizumab.

Heteronormative biases and distinctive experiences with prostate cancer among men who have sex with men: a qualitative focus group study.

BACKGROUND: Men who have sex with men (MSM) face many challenges and biases in healthcare. Within urology there is a need to better understand how prostate cancer impacts MSM given the unique ways in which side effects that accompany treatment may affect this population. The goal of this study is to explore the experience of MSM with prostate cancer to advance the existing literature in this area and inform implementation and delivery of clinical practice and policy guidelines. METHODS: Four focus groups were conducted with a semi-structured interview guide. Using a phenomenological qualitative approach consistent with grounded theory [1] and naturalistic inquiry principles we sought to better understand the direct experiences of MSM with prostate cancer. Audio transcriptions were thematically analyzed to identify themes that impact MSM throughout their prostate cancer journey. An iterative, team-wide classification process was used to identify, organize, and group common codes into higher-order categories and themes. RESULTS: Patient's choice of provider and their interactions with the healthcare system were strongly impacted by their sexual identities. Participants commented on navigating the heteronormative healthcare environment and the impact of assumptions they encountered. MSM experienced the sexual side effects of prostate cancer treatment in unique ways. Issues with erectile dysfunction and ejaculatory dysfunction had significant impacts on patient's sexual experience, with some describing being forced to explore new modes of sexual expression. Anejaculation was a theme that was distressing for many participants. The emotional impact of a prostate cancer diagnosis was significant in the men interviewed. Common themes included loss of identity and fear for future relationships. CONCLUSIONS: MSM have unique concerns after prostate cancer treatment that differ from men who don't identify as MSM. It is critical that providers familiarize themselves with the concerns of this patient population regarding prostate cancer treatment. An important step toward reducing heteronormative bias in prostate cancer care is to better understand the goals, identity, and sexual practices of MSM and to provide informed anticipatory guidance.

A Spatial Comparison of Molecular Features Associated with Resistance to Pembrolizumab in BCG Unresponsive Bladder Cancer.

Background: Intravenous immune checkpoint inhibition achieves a 40% three-month response in BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS). Yet only half of early responders will continue to be disease free by 12 months, and resistance mechanisms are poorly defined. Objective: We assessed the molecular features associated with response to immunotherapy in BCG unresponsive non-muscle invasive bladder cancers treated with pembrolizumab. Design Setting and Participants: We performed digital spatial profiling (DSP) of BCG unresponsive NMIBC tumors before and after IV pembrolizumab therapy. Intervention: Pembrolizumab was administered intravenously in patients with NMIBC at the time of recurrence after BCG therapy. Biopsies were obtained before starting IV pembrolizumab and three months post-treatment. Outcomes and Statistical Analysis: Spatial gene expression profiling of the tumor niche pre- and post IV pembrolizumab. Results and Limitations: We evaluated 119 regions of interest (ROIs) from five patients, which included 60 epithelial (PanCK+) and 59 stromal segments (PanCK-). ROIs from responders had distinct expression signatures from non-responders for both the tumor and TME. Responders were more likely to have a dynamic change in expression after pembrolizumab than non-responders. A major limitation of this study was the number of patients evaluated. Conclusion: For the first time, we have identified distinct expression signatures associated with response and resistance to IV pembrolizumab in NMIBCs. Further research with more patients and alternative checkpoint inhibitors is essential to validate our findings. Patient Summary: We identify the molecular features of tumors associated with response to pembrolizumab for patients with BCG unresponsive NMIBCs.

Non-Muscle Invasive Papillary Urothelial Carcinoma Metastatic to the Mandible.

Urothelial carcinoma, the most common histologic subtype of bladder cancer in the United States, most frequently presents as non-muscle invasive disease. Initially, therapy involves transurethral endoscopic resection and subsequent intravesical therapies with extended surveillance for high-risk disease. Even with the best treatments, recurrence and progression can occur. However, metastasis of non-muscle invasive bladder cancer to distant sites without evidence of progression or regional metastasis is rare. In this article, we present the case of a patient with high-grade papillary urothelial carcinoma who developed an unusual metastasis to the mandible, confirmed by GATA-3 immunostaining, over 4 years after initial transurethral resection. Prior to the development of metastatic disease, this patient had no evidence of local recurrence during maintenance Bacillus Calmette-Guerin intravesical therapy and concurrent surveillance. Positron emission tomography-computed tomography taken after presentation with mandibular metastasis did not show any evidence of regional metastasis. This case highlights an unusual location for distant metastasis of urothelial carcinoma occurring in a patient without evidence of muscle invasive disease or regional metastasis. We additionally highlight the utility of GATA-3 immunostaining in identifying urothelial carcinoma histologically.

Targeting epigenetics for treatment of BRAF mutated metastatic melanoma with decitabine in combination with vemurafenib: A phase lb study.

INTRODUCTION: Epigenetic modifications play an important role in progression and development of resistance in V600EBRAF positive metastatic melanoma. Therefore, we hypothesized that the action of vemurafenib (BRAF inhibitor) can be made more effective by combining with low dose decitabine (a DNA methyltransferase inhibitor). The primary objective of this phase lb study was to determine the dose limiting toxicity and maximum tolerated dose of combination of subcutaneous decitabine with oral vemurafenib in patients with V600EBRAF positive metastatic melanoma with or without any prior treatment. EXPERIMENTAL DESIGN: The study employed 3+3 dose escalation combining subcutaneous decitabine at different doses and schedules (4 cohorts) with the standard oral dose of vemurafenib 960 mg twice daily. Preclinical assessment and further analysis were also performed in A375 melanoma cell line. RESULTS: Fourteen patients received study treatment. No dose limiting toxicity was encountered and maximum tolerated dose was not reached. Important toxicities included fatigue, increased creatinine, neutropenia, leucopenia, hypophosphatemia, rash and hyperuricemia. Three patients achieved complete response, three had partial response and five had stable disease. Preclinical assessment demonstrated action of the combination which delayed the development of acquired resistance and improved duration of treatment sensitivity. CONCLUSIONS: The combination of oral vemurafenib with subcutaneous decitabine is safe and showed activity in V600EBRAF positive metastatic melanoma. Since most responses were seen in cohort 1, which utilized low-dose, long-term decitabine, future studies of this combination treatment should utilize longer duration of decitabine, at the lowest dose of 0.1 mg/kg.

PD-L1 and immune escape: insights from melanoma and other lineage-unrelated malignancies.

One of the major breakthroughs in oncology in the past decade has been the research and development of immune checkpoint inhibitors. Since the discovery of the PD-1/PD-L1 axis as a key mediator in peripheral self-tolerance and the subsequent discovery of its role promoting immune escape in cancers, the PD-1/PD-L1 pathway has produced considerable excitement from both a scientific and therapeutic standpoint. The past decade has seen an explosion in the number of clinical trials utilizing anti-PD-1/PD-L1 therapy. Notably, pathologists have played a critical role in the development of these trials, and in guiding the use of anti-PD-1/PD-L1 therapies in FDA-approved clinical settings. Analysis of tissue biopsies has been increasingly used to predict patients with which cancers are most likely to benefit from these new therapies. However, many open questions remain in a rapidly changing therapeutic and scientific landscape. In this review, we describe the basic functioning of the PD-1/PD-L1 axis in normal biology, how it is coopted by cancers to promote immune escape, and then review the literature regarding the prognostic value of tumoral PD-L1 expression on its own before discussing recent therapeutic advances, and the emerging role for pathologists in predicting response to anti-PD-1/PD-L1 therapies. Special attention is given to melanoma and non-small cell lung cancer, malignancies that have seen the broadest applications of anti-PD-L1/PD-1 therapies.

Tumoral PD-L1 expression in desmoplastic melanoma is associated with depth of invasion, tumor-infiltrating CD8 cytotoxic lymphocytes and the mixed cytomorphological variant.

Recently, patients with metastatic desmoplastic melanoma (DM) have been shown to respond more favorably to anti-PD1/PD-L1 therapy than other melanoma subtypes. Given this, we evaluated PD-L1/2 expression in primary DM samples and correlated these with subtype, CD8+ lymphocyte status, histopathological prognosticators, and select genetic alterations. Eighty-six (36 mixed DM, 50 pure DM) archival annotated samples met inclusion criteria and were immunohistochemically semiquantitatively evaluated. Per established criteria, for PD-L1/L2, cases with ⩾5% tumoral expression, and for CD8, cases with a predominantly peri/intratumoral CD8+ infiltrate were scored positive. Univariate analysis (chi-square and Wilcoxon) identified potential confounders and a nested case-control study was accomplished using multiple logistic regression. For PD-L1, 49% of cases were positive and 71% of cases with thickness >4 mm were positive; PD-L1 expression differed by median depth (3.29 mm, interquartile range=3.58 mm for PD-L1 positives vs 1.75 mm, interquartile range=2.04 mm for PD-L1 negatives, P=0.0002) and was linearly associated with increasing depth of invasion (P=0.0003). PD-L1-positive cases were more likely to display CD8+ lymphocytes (60 vs 28% P=0.0047).The presence of CD8+ lymphocytes correlated significantly with depth of invasion >1 mm (P=0.022). On multivariate analysis, PD-L1 was 6.14 × more likely to be expressed in mixed DM than pure DM (P=0.0131), CD8+ staining was 6.22 × more likely in PD-L1 positive cases than in PD-L1 negative (P=0.0118), and tumor depth was associated with greater odds of PD-L1 expression (OR=1.61, P=0.0181). PD-L2 expression was observed in 48% of cases but did not correlate with any variables. Correlation of tumoral PD-L1 with increased depth and CD8+ lymphocytes implicates the tumoral immune microenvironment with advancing disease in DM. Enhanced tumoral PD-L1 expression in the mixed cytomorphological variant provides an insight into the differential pathogenesis of the subtypes and suggests that these patients are likely better candidates for anti-PD/PD-L1 therapy.

Frequency of telomerase reverse transcripter promoter mutations in desmoplastic melanoma subtypes: analyses of 76 cases.

Estimates of the frequency of telomerase reverse transcripter (TERT) mutations in desmoplastic melanoma (DM) are limited. DM is categorized into subtypes, pure and mixed, differing in prognosis, suggesting genetic heterogeneity. Given this, our aims were to determine the incidence of TERT promoter mutations in DM subtypes and to evaluate its relationship with established histopathologic prognosticators, BRAF and RETp status, and neurofibromin protein expression. Of the archival annotated samples retrieved, 76 cases of DM (48 pure and 28 mixed) fulfilled the criteria for inclusion. PCR amplification of the TERT promoter region was performed on DNA extracted from formalin-fixed paraffin-embedded tissue using primers5'-GCCGATTCGACCTCTCTCC-3' (forward) and 5'-CAGCGCTGCCTGAAACTC-3' (reverse). For each case, appropriate C>T mutations were identified on the electropherograms. Univariate analysis using χ-test was carried out to identify potential confounders; a nested case-control study of demographic, clinical, histopathological, and genetic determinants was carried out using multiple logistic regression. Significant differences in TERT promoter mutation frequencies were noted in the subtypes (mixed vs. pure; 15/28, 54% vs. 11/48, 23%, respectively, P=0.0066). After adjusting for potential confounding, multivariate analyses indicated a three-fold increase in the odds of the TERT mutation for those with the mixed subtype compared with the pure subtype (P=0.04, adjusted odds ratio =3.32). No other significant associations were noted (sex/junctional component/Breslow depth/ulceration/mitoses/host response/RETp, BRAF status, and neurofibromin protein expression). Our findings, the largest to date investigating TERT promoter mutations in DM, support the hypothesis that the subtypes have distinct genetic drivers and underscore the relevance of telomere integrity in the etiopathogenesis of the mixed variant.

Neurofibromin protein loss in desmoplastic melanoma subtypes: implicating NF1 allelic loss as a distinct genetic driver?

Loss of the NF1 allele, coding for the protein neurofibromin, and polymorphism in the proto-oncogene RET (RETp) are purportedly common in desmoplastic melanoma (DM). DM is categorized into pure (PDM) and mixed (MDM) subtypes, which differ in prognosis. Most NF1 mutations result in a truncated/absent protein, making immunohistochemical screening for neurofibromin an ideal surrogate for NF1 allelic loss. Using antineurofibromin, our aims were to ascertain the incidence of neurofibromin loss in DM subtypes and to evaluate the relationship with RET, perineural invasion (PNI) and established histopathologic prognosticators. A total of 78 archival samples of DM met criteria for inclusion (54 cases of non-DM serving as controls). Immunohistochemistry was performed for neurofibromin, whereas direct DNA sequencing was used for RETp and BRAF mutation status. Statistical analyses included χ(2) test as well as Fisher exact test. Neurofibromin loss was more common in DM than non-DM (69% versus 54%; P=.02). In DM, significant differences in neurofibromin loss were noted in the following: non-head and neck versus head and neck biopsy site (88% versus 55%) and PDM versus MDM variants (80% versus 56%). No significant associations were noted with sex, presence of a junctional component, Breslow depth, ulceration, mitoses, host response, RETp, BRAF status, or PNI. RETp was marginally associated with PNI-positive DM versus PNI-negative DM (36 versus 18%; P=.08). Our findings, the largest to date investigating neurofibromin in DM, validate the incidence of NF1 mutations/allelic loss in DM and suggest that the DM subtypes have distinct genetic drivers.

Desmoplastic melanoma, neurotropism, and neurotrophin receptors--what we know and what we do not.

Desmoplastic melanoma (DM) is a relatively rare cytomorphologic variant of melanoma with a marked propensity for perineural invasion (PNI). Historically, DMs that display PNI have been grouped under the umbrella term of neurotropic melanoma (NM). However, definitions for NM and desmoplastic NM are not consistent in the literature, presenting a barrier to a comprehensive understanding of these lesions. In this review, we parse the literature on DM, NM, and desmoplastic NM, to clarify definitions and ascertain the incidence of PNI, with a view toward understanding its prognostic relevance. Neurotrophins, which represent a family of signaling peptides important to the development and maintenance of the peripheral nervous system, have been implicated in the pathogenesis of PNI in select lineage-unrelated malignancies. Given this, we also detail evidence linking neurotrophins and their receptors (TrkA, RET, p75NGFR, and NCAM) to the pathogenesis of PNI in melanoma.

Perineural invasion in cutaneous squamous cell carcinoma: role of immunohistochemistry, anatomical site, and the high-affinity nerve growth factor receptor TrkA.

Perineural invasion (PNI) has been recently added to the American Joint Committee on Cancer cutaneous squamous cell carcinoma (cSCC) staging criteria as a high-risk tumor characteristic and is purportedly more common in cSCCs of the head and neck (H&N). Expression of the high-affinity nerve growth factor receptor TrkA has been shown to be associated with PNI in noncutaneous neoplasms. Given this, we sought to ascertain the incidence of PNI in cSCCs using double immunostaining (DIS) and to investigate PNI's relationship with TrkA and established histopathologic prognosticators. Fifty-seven cSCCs from the H&N and 53 from non-H&N areas were immunohistochemically analyzed for PNI (DIS with S-100 and p63) and TrkA expression. Comparing H&N versus non-H&N areas, using hematoxylin and eosin, PNI was detected in 11% versus 6% cases, respectively, and, using DIS, in 23% versus 15%, respectively, with significant disagreement between both methods (κ = 0.47; P = .002). There was a 2.33-fold increase in PNI detection with DIS compared to hematoxylin and eosin (95% confidence interval, 1.12-4.87; P = .02). TrkA expression was 1.96 times more frequently observed in cSCCs from the H&N compared to those from non-H&N areas (P = .01). Regardless of site, TrkA expression was associated with decreased degree of differentiation (odds ratio, 6.46; P = .0006) and high-risk morphologic variants (odds ratio, 6.53; P = .002) but not significantly associated with PNI (P = .33). Increased PNI detection with DIS underscores the adjunctive utility of immunohistochemistry in microstaging. Significantly more common TrkA expression in cSCCs of the H&N argues in favor of heterogeneity among SCCs from different anatomical sites.

Neurotrophin receptors and perineural invasion in desmoplastic melanoma.

BACKGROUND: Perineural invasion (PNI) in desmoplastic melanoma is associated with increased local recurrence and reduced disease-free survival. The biological mechanisms underlying PNI remain unclear although several lines of evidence implicate neurotrophins and their receptors. OBJECTIVES: We investigated the expression of p75NGFR and TrkA, and the presence of functional RET polymorphism (RETp) as they relate to PNI in desmoplastic melanoma. METHODS: In all, 43 cases of desmoplastic melanoma were immunohistochemically evaluated for TrkA and p75NGFR expression and RETp was detected by direct DNA sequencing. RESULTS: PNI was present in 67% of cases. On univariate analysis, p75NGFR was associated with PNI (expression detected in 79% of PNI-positive cases compared with 36% of PNI-negative cases, P = .005), increased Breslow depth (P = .007), and greater Clark level (P = .01). RETp was noted in 28% of cases but was not significantly associated with PNI (P = .27) or other histopathologic variables. TrkA expression was absent in all cases. PNI was associated with increased Breslow depth and Clark level (P = .01 and P = .009, respectively). Controlling for the association between p75NGFR and depth, p75NGFR remained associated with an increased propensity for PNI (odds ratio 4.68, P = .04). LIMITATIONS: The sample size was limited. CONCLUSION: In desmoplastic melanoma, p75NGFR expression is significantly associated with PNI and a more locally aggressive phenotype.