Hypohidrosis as an immune-related adverse event of checkpoint inhibitor therapy

Background: Immune checkpoint blockade therapies including cytotoxic-T-lymphocyte antigen 4 (CTLA-4) and programmed cell death protein-1 (PD-1) inhibitors have become indispensable tools for treating melanoma and other cancers. An increasing number of diverse cutaneous adverse reactions to immunotherapy have been documented in the literature and have been reported to affect up to 40% of patients treated with targeted therapies. Method & results: Herein, we report a case of a patient with metastatic melanoma treated with checkpoint inhibitor therapy who developed vitiligo, gastritis and hepatitis, all identified as adverse immune events and attributable to his immunotherapy regimen. He subsequently developed acquired idiopathic generalized hypohidrosis with biopsy of lesional skin demonstrating a peri-eccrine lymphocytic infiltrate. Conclusion: These findings suggest this acquired generalized hypohidrosis represents a lymphocyte-mediated adverse immune event related to this patient's checkpoint inhibitor therapy.

Urethral involvement is associated with higher mortality and local recurrence in vulvar melanoma: a single institutional experience

Vulvar malignant melanoma (VMM), although uncommon, comprises 5-10% of all vulvar malignancies. Local control is notoriously poor in VMM with recurrence rates of 30-50% compared with approximately 3% in cutaneous melanomas. We studied clinicopathologic features of 37 women with VMM, after reviewing three decades of clinical follow-up data in our institutional databases. Most patients were Caucasian (n = 35) with an average age at diagnosis of 60.6 years (range 23-83). The most common subtype was mucosal lentiginous melanoma (n = 25). We compared Kaplan-Meier survival curves of 31 patients defined by clinical and microscopic attributes using exact log-rank tests. Younger patients at diagnosis (23-64 years), those with thin melanomas (≤1 mm), and those with Clark's level II or III tumors had better 5-year survival rates than older patients (65-83 years) and those with thick melanomas (>1 mm) and those with Clark's level IV or V (P ≤ 0.05), respectively, by exact log-rank test. Local recurrence of melanoma occurred in 15 patients. Nine patients (24%) had eventual urethral involvement by malignant melanoma, and this feature was associated with significantly shorter survival (P = 0.036). Patients with urethral involvement had shorter median time to death and worse 5-year survival rates. Given that spread to the urethra is common in VMM and urethral recurrence is also associated with mortality, pathology excision specimens should be carefully reviewed with attention to urethral involvement as a potentially important prognostic factor.

Genetic and pharmacologic modulation of cementogenesis via pyrophosphate regulators

Pyrophosphate (PP_i) serves as a potent and physiologically important regulator of mineralization, with systemic and local concentrations determined by several key regulators, including: tissue-nonspecific alkaline phosphatase (ALPL gene; TNAP protein), the progressive ankylosis protein (ANKH; ANK), and ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1; ENPP1). Results to date have indicated important roles for PP_i in cementum formation, and we addressed several gaps in knowledge by employing genetically edited mouse models where PP_i metabolism was disrupted and pharmacologically modulating PP_i in a PP_i-deficient mouse model. We demonstrate that acellular cementum growth is inversely proportional to PP_i levels, with reduced cementum in Alpl KO (increased PP_i levels) mice and excess cementum in Ank KO mice (decreased PP_i levels). Moreover, simultaneous ablation of Alpl and Ank results in reestablishment of functional cementum in dKO mice. Additional reduction of PP_i by dual deletion of Ank and Enpp1 does not further increase cementogenesis, and PDL space is maintained in part through bone modeling/remodeling by osteoclasts. Our results provide insights into cementum formation and expand our knowledge of how PP_i regulates cementum. We also demonstrate for the first time that pharmacologic manipulation of PP_i through an ENPP1-Fc fusion protein can regulate cementum growth, supporting therapeutic interventions targeting PP_i metabolism.

Histologic features of melanoma associated with germline mutations of CDKN2A, CDK4, and POT1 in melanoma-prone families from the United States, Italy, and Spain

BACKGROUND

CDKN2A, CDK4, and POT1 are well-established melanoma-susceptibility genes.

OBJECTIVE

We evaluated melanoma histopathology for individuals with germline mutations of CDKN2A, CDK4, and POT1.

METHODS

We assessed histopathology for melanomas diagnosed in melanoma-prone families (≥2 individuals with melanoma) from the United States, Italy, and Spain. Comparisons between mutation carriers and noncarriers (no mutation) were adjusted for age, sex, Breslow depth, and correlations among individuals within the same family.

RESULTS

Histologic slides were evaluated for 290 melanomas (139 from 132 noncarriers, 122 from 68 CDKN2A carriers, 10 from 6 CDK4 carriers, and 19 from 16 POT1 carriers). Superficial spreading was the predominant subtype for all groups. Spitzoid morphology (>25% of tumor) was observed in 10 of 15 invasive melanomas (67%) from POT1 carriers (P < .0001 vs noncarriers). This finding was independently confirmed by 3 expert melanoma dermatopathologists in 9 of 15 invasive melanomas (60%). In situ and invasive melanomas from CDKN2A and CDK4 carriers were histologically similar to melanomas from noncarriers.

LIMITATIONS

Limited sample sizes for rare melanoma-susceptibility syndromes (CDK4, POT1).

CONCLUSION

Spitzoid morphology was associated with POT1 mutations suggesting that telomere dysfunction (POT1 mutations) may contribute to spitzoid differentiation in melanocytic tumors.

Dental and craniofacial defects in the Crtap-/- mouse model of osteogenesis imperfecta type VII

BACKGROUND

Inactivating mutations in the gene for cartilage-associated protein (CRTAP) cause osteogenesis imperfecta type VII in humans, with a phenotype that can include craniofacial defects. Dental and craniofacial manifestations have not been a focus of case reports to date. We analyzed the craniofacial and dental phenotype of Crtap^-/- mice by skull measurements, micro-computed tomography (micro-CT), histology, and immunohistochemistry.

RESULTS

Crtap^-/- mice exhibited a brachycephalic skull shape with fusion of the nasofrontal suture and facial bones, resulting in mid-face retrusion and a class III dental malocclusion. Loss of CRTAP also resulted in decreased dentin volume and decreased cellular cementum volume, though acellular cementum thickness was increased. Periodontal dysfunction was revealed by decreased alveolar bone volume and mineral density, increased periodontal ligament (PDL) space, ectopic calcification within the PDL, bone-tooth ankylosis, altered immunostaining of extracellular matrix proteins in bone and PDL, increased pSMAD5, and more numerous osteoclasts on alveolar bone surfaces.

CONCLUSIONS

Crtap^-/- mice serve as a useful model of the dental and craniofacial abnormalities seen in individuals with osteogenesis imperfecta type VII.

Comparison of C3d immunohistochemical staining to enzyme-linked immunosorbent assay and immunofluorescence for diagnosis of bullous pemphigoid

BACKGROUND

Bullous pemphigoid (BP), the most common autoimmune blistering disease, may be diagnostically challenging. Direct immunofluorescence (DIF), indirect immunofluorescence (IIF), enzyme-linked immunosorbent assay (ELISA), and recently, C3d immunohistochemistry (IHC), are used as adjuncts to diagnosis.

OBJECTIVE

To compare C3d IHC to DIF, IIF, and ELISA testing in BP diagnosis.

METHODS

C3d IHC was performed on skin biopsy specimens from 51 patients (27 with BP and 24 with other blistering diseases) and compared to DIF and IIF, with anti-BP180 or anti-BP230 ELISA results used as the gold standard.

RESULTS

We found C3d IHC, DIF, and IIF had similar sensitivity (74.1%, 63.1%, and 70.4%), specificity (95.8%, 100%, and 100%), positive predictive value (95.2%, 100%, and 100%), and negative predictive value (76.7%, 70.6%, and 75%) for BP. Cases with positive C3d IHC, DIF, and IIF had significantly higher anti-BP180 and anti-BP230 by ELISA than cases with negative testing (P < .0001). False-negative IIF results were associated with lower BP230 compared with true-positive results (P = .03).

LIMITATIONS

This was a single-center, retrospective study.

CONCLUSION

Our study compared C3d IHC to DIF and IIF in BP diagnosis, demonstrating C3d IHC on fixed tissue provides similar diagnostic utility to immunofluorescence and ELISA.

Dentoalveolar Defects in the Hyp Mouse Model of X-linked Hypophosphatemia

Mutations in PHEX cause X-linked hypophosphatemia (XLH), a form of hypophosphatemic rickets. Hyp (Phex mutant) mice recapitulate the XLH phenotype. Dental disorders are prevalent in individuals with XLH; however, underlying dentoalveolar defects remain incompletely understood. We analyzed Hyp mouse dentoalveolar defects at 42 and 90 d postnatal to comparatively define effects of XLH on dental formation and function. Phex mRNA was expressed by odontoblasts (dentin), osteocytes (bone), and cementocytes (cellular cementum) in wild-type (WT) mice. Enamel density was unaffected, though enamel volume was significantly reduced in Hyp mice. Dentin defects in Hyp molars were indicated histologically by wide predentin, thin dentin, and extensive interglobular dentin, confirming micro-computed tomography (micro-CT) findings of reduced dentin volume and density. Acellular cementum was thin and showed periodontal ligament detachment. Mechanical testing indicated dramatically altered periodontal mechanical properties in Hyp versus WT mice. Hyp mandibles demonstrated expanded alveolar bone with accumulation of osteoid, and micro-CT confirmed decreased bone volume fraction and alveolar bone density. Cellular cementum area was significantly increased in Hyp versus WT molars owing to accumulation of hypomineralized cementoid. Histology, scanning electron microscopy, and nanoindentation revealed hypomineralized "halos" surrounding Hyp cementocyte and osteocyte lacunae. Three-dimensional micro-CT analyses confirmed larger cementocyte/osteocyte lacunae and significantly reduced perilacunar mineral density. While long bone and alveolar bone osteocytes in Hyp mice overexpressed fibroblast growth factor 23 (Fgf23), its expression in molars was much lower, with cementocyte Fgf23 expression particularly low. Expression and distribution of other selected markers were disturbed in Hyp versus WT long bone, alveolar bone, and cementum, including osteocyte/cementocyte marker dentin matrix protein 1 (Dmp1). This study reports for the first time a quantitative analysis of the Hyp mouse dentoalveolar phenotype, including all mineralized tissues. Novel insights into cellular cementum provide evidence for a role for cementocytes in perilacunar mineralization and cementum biology.

Timing of Onset of Adverse Cutaneous Reactions Associated With Programmed Cell Death Protein 1 Inhibitor Therapy

Importance

An increasing number of cutaneous adverse reactions resulting from use of programmed cell death protein 1 (PD-1) inhibitors have been described, but with relatively little focus to date on the timing of these reactions.

Objective

To determine the timing of cutaneous drug reactions after initiation of PD-1 inhibitor therapy.

Design, Setting, and Participants

This retrospective observational study included patients referred to an academic dermatology clinic by an oncologist from January 1, 2014, through February 28, 2018, with at least 1 skin biopsy specimen of a skin reaction associated with PD-1 inhibitor use. Participants were included if they had a biopsy-proven cutaneous reaction in response to a PD-1 inhibitor used alone or in combination with ipilimumab.

Exposures

All patients included in this study received pembrolizumab, nivolumab, or nivolumab with ipilimumab as immunotherapy for cancer.

Main Outcomes and Measures

The main outcome measure was time to onset of biopsy-proven cutaneous reactions that occurred during or after use of pembrolizumab or nivolumab.

Results

A total of 17 patients (12 men, 5 women; mean [SD] age, 68.6 [11.1] years) were identified who presented with cutaneous adverse reactions associated with PD-1 inhibitor therapy; these reactions included lichenoid dermatitis, bullous pemphigoid, erythema multiforme, eczema, lupus, and sarcoidosis. Twelve patients presented with reactions at least 3 months after beginning pembrolizumab or nivolumab therapy. The skin reactions presented a median (range) of 4.2 months (0.5-38.0 months) after drug initiation. In 5 cases, the cutaneous adverse reactions attributed to the PD-1 inhibitor therapy developed after the drug therapy was terminated.

Conclusions and Relevance

Diverse cutaneous adverse reactions secondary to PD-1 inhibitor use may present with delayed onsets and even after discontinuation of therapy. Dermatologists should be aware of the potential for delayed presentations of cutaneous adverse reactions.

NRAS Q61R and BRAF G466A mutations in atypical melanocytic lesions newly arising in advanced melanoma patients treated with vemurafenib

BACKGROUND

BRAF inhibition has improved overall survival in patients with BRAF mutant melanoma, but this is associated with a range of known and predictable cutaneous side effects, including squamous cell carcinomas associated with RAS mutations.

METHODS

We identified three severely dysplastic nevi, one atypical intraepidermal melanocytic proliferation, and four melanoma in situ lesions, newly arising in four patients undergoing treatment with vemurafenib. To characterize mutations in these atypical melanocytic lesions, we used a custom iPlex panel detecting 74 mutations in 13 genes known to play a role in melanoma pathogenesis.

RESULTS

We identified an NRAS mutation at codon 61 (Q61R) and a rare BRAF exon 11 mutation (G466A) in atypical melanocytic lesions that arose in patients treated with vemurafenib.

CONCLUSION

There appears to be development or accelerated growth of atypical melanocytic lesions in the setting of BRAF inhibition. Our results underscore the need for careful surveillance for melanocytic lesions in patients on BRAF inhibitor therapy and shed light on potential mechanisms for melanoma pathogenesis in the context of BRAF pathway blockade. Further studies are warranted to show a causal relationship.

Expression of p15 in a spectrum of spitzoid melanocytic neoplasms

BACKGROUND

Accurate classification of spitzoid melanocytic lesions is difficult due to overlapping clinical and histopathologic features between Spitz nevi, atypical Spitz tumors (ASTs), and spitzoid melanomas. Expression of p16 (CDKN2A) has been used as a marker of spitzoid lesions. However, its expression may be variable. p15 is a tumor suppressor encoded by CDKN2B, loss of which has been recently shown to promote transition from nevus to melanoma. We sought to determine whether p15 is a useful immunohistochemical marker to distinguish Spitz nevi from spitzoid melanomas and to compare p15 and p16 staining in this population.

METHODS

Immunohistochemistry for p15 and p16 was performed on Spitz nevi (n = 19), ASTs (n = 41), and spitzoid melanomas (n = 17). Immunoexpression was categorized by a four-tiered system: 0 (negative), 1+ (weak), 2+ (moderate), 3+ (strong).

RESULTS

3+/strong p15 staining was observed in 68.4% of Spitz nevi, 34.2% of ASTs, and 17.7% of spitzoid melanomas. By contrast, we observed 3+ p16 staining in roughly equivalent percentages of Spitz nevi (57.9%), ASTs (56.1%), and spitzoid melanomas (58.8%).

CONCLUSION

These data illustrate that p15 may be more useful than p16 as a biomarker to help distinguish benign from malignant spitzoid lesions.

Risk of Subsequent Cutaneous Melanoma in Moderately Dysplastic Nevi Excisionally Biopsied but With Positive Histologic Margins

Importance

Little evidence exists to guide the management of moderately dysplastic nevi excisionally biopsied without residual clinical pigmentation but with positive histologic margins (hereafter referred to as moderately dysplastic nevi with positive histologic margins).

Objective

To determine outcomes and risk for the development of subsequent cutaneous melanoma (CM) from moderately dysplastic nevi with positive histologic margins observed for 3 years or more.

Design, Setting, and Participants

A multicenter (9 US academic dermatology sites) retrospective cohort study was conducted of patients 18 years or older with moderately dysplastic nevi with positive histologic margins and 3 years or more of follow-up data collected consecutively from January 1, 1990, to August 31, 2014. Records were reviewed for patient demographics, biopsy type, pathologic findings, and development of subsequent CM at the biopsy site or elsewhere on the body. The χ2 test, the Fisher exact test, and analysis of variance were used to assess univariate association for risk of subsequent CMs, in addition to multivariable logistic regression models. To confirm histologic grading, each site submitted 5 random representative slide cases for central dermatopathologic review. Statistical analysis was performed from October 1, 2017, to June 22, 2018.

Main Outcomes and Measures

Development of CM at a biopsy site or elsewhere on the body where there were moderately dysplastic nevi with positive histologic margins.

Results

A total of 467 moderately dysplastic nevi with positive histologic margins from 438 patients (193 women and 245 men; mean [SD] age, 46.7 [16.1] years) were evaluated. No cases developed into CM at biopsy sites, with a mean (SD) follow-up time of 6.9 (3.4) years. However, 100 patients (22.8%) developed a CM at a separate site. Results of multivariate analyses revealed that history of CM was significantly associated with the risk of development of subsequent CM at a separate site (odds ratio, 11.74; 95% CI, 5.71-24.15; P < .001), as were prior biopsied dysplastic nevi (odds ratio, 2.55; 95% CI, 1.23-5.28; P = .01). The results of a central dermatopathologic review revealed agreement in 35 of 40 cases (87.5%). Three of 40 cases (7.5%) were upgraded in degree of atypia; of these, 1 was interpreted as melanoma in situ. That patient remains without recurrence or evidence of CM after 5 years of follow-up.

Conclusions and Relevance

This study suggests that close observation with routine skin surveillance is a reasonable management approach for moderately dysplastic nevi with positive histologic margins. However, having 2 or more biopsied dysplastic nevi (with 1 that is a moderately dysplastic nevus) appears to be associated with increased risk for subsequent CM at a separate site.

The transcription factor AmeloD stimulates epithelial cell motility essential for tooth morphology

The development of ectodermal organs, such as teeth, requires epithelial-mesenchymal interactions. Basic helix-loop-helix (bHLH) transcription factors regulate various aspects of tissue development, and we have previously identified a bHLH transcription factor, AmeloD, from a tooth germ cDNA library. Here, we provide both in vitro and in vivo evidence that AmeloD is important in tooth development. We created AmeloD-knockout (KO) mice to identify the in vivo functions of AmeloD that are critical for tooth morphogenesis. We found that AmeloD-KO mice developed enamel hypoplasia and small teeth because of increased expression of E-cadherin in inner enamel epithelial (IEE) cells, and it may cause inhibition of the cell migration. We used the CLDE dental epithelial cell line to conduct further mechanistic analyses to determine whether AmeloD overexpression in CLDE cells suppresses E-cadherin expression and promotes cell migration. Knockout of epiprofin (Epfn), another transcription factor required for tooth morphogenesis and development, and analysis of AmeloD expression and deletion revealed that AmeloD also contributed to multiple tooth formation in Epfn-KO mice by promoting the invasion of dental epithelial cells into the mesenchymal region. Thus, AmeloD appears to play an important role in tooth morphogenesis by modulating E-cadherin and dental epithelial-mesenchymal interactions. These findings provide detailed insights into the mechanism of ectodermal organ development.

Chemoprevention agents for melanoma: A path forward into phase 3 clinical trials

Recent progress in the treatment of advanced melanoma has led to unprecedented improvements in overall survival and, as these new melanoma treatments have been developed and deployed in the clinic, much has been learned about the natural history of the disease. Now is the time to apply that knowledge toward the design and clinical evaluation of new chemoprevention agents. Melanoma chemoprevention has the potential to reduce dramatically both the morbidity and the high costs associated with treating patients who have metastatic disease. In this work, scientific and clinical melanoma experts from the national Melanoma Prevention Working Group, composed of National Cancer Trials Network investigators, discuss research aimed at discovering and developing (or repurposing) drugs and natural products for the prevention of melanoma and propose an updated pipeline for translating the most promising agents into the clinic. The mechanism of action, preclinical data, epidemiological evidence, and results from available clinical trials are discussed for each class of compounds. Selected keratinocyte carcinoma chemoprevention studies also are considered, and a rationale for their inclusion is presented. These data are summarized in a table that lists the type and level of evidence available for each class of agents. Also included in the discussion is an assessment of additional research necessary and the likelihood that a given compound may be a suitable candidate for a phase 3 clinical trial within the next 5 years.

Piloting the Use of Smartphones, Reminders, and Accountability Partners to Promote Skin Self-Examinations in Patients with Total Body Photography: A Randomized Controlled Trial

OBJECTIVE

The aim of this study was to evaluate the use of a mobile application (app) in patients already using total body photography (TBP) to increase skin self-examination (SSE) rates and pilot the effectiveness of examination reminders and accountability partners.

DESIGN

Randomized controlled trial with computer generated randomization table to allocate interventions.

SETTING

University of Pennsylvania pigmented lesion clinic.

PARTICIPANTS

69 patients aged 18 years or older with an iPhone/iPad, who were already in possession of TBP photographs.

INTERVENTION

A mobile app loaded with digital TBP photos for all participants, and either (1) the mobile app only, (2) skin examination reminders, (3) an accountability partner, or (4) reminders and an accountability partner.

MAIN OUTCOME MEASURE

Change in SSE rates as assessed by enrollment and end-of-study surveys 6 months later.

RESULTS

Eighty one patients completed informed consent, however 12 patients did not complete trial enrollment procedures due to device incompatibility, leaving 69 patients who were randomized and analyzed [mean age 54.3 years, standard deviation 13.9). SSE rates increased significantly from 58% at baseline to 83% at 6 months (odds ratio 2.64, 95% confidence interval 1.20-4.09), with no difference among the intervention groups. The group with examination reminders alone had the highest (94%) overall satisfaction, and the group with accountability partners alone accounted for the lowest (71%).

CONCLUSION

A mobile app alone, or with reminders and/or accountability partners, was found to be an effective tool that can help to increase SSE rates. Skin examination reminders may help provide a better overall experience for a subset of patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02520622.

The prognostic significance of tumor-infiltrating lymphocytes for primary melanoma varies by sex

BACKGROUND

The immune response to melanoma is manifested locally by tumor-infiltrating lymphocytes (TILs). Men and women are known to have varying patterns of immunity, yet sex-specific prognostic implications of TILs have not been explored.

METHODS

Patients who had clinically localized primary melanoma with a Breslow thickness of 0.76 mm or more and underwent sentinel lymph node (SLN) biopsy at our institution were identified. The association between TILs (absent, nonbrisk, and brisk) and SLN positivity was evaluated by using logistic regression. Overall survival (OS) was evaluated by TIL status and sex.

RESULTS

Among 1367 patients identified, 794 were men. TILs were brisk in 143 lesions, nonbrisk in 903, and absent in 321, which did not vary by sex (P = .71). SLN positivity was associated with TILs among men (brisk, 3.8%; nonbrisk, 16.9%; and absent, 26.6% [P < .001]). In contrast, there was no association between SLN positivity and TILs among women (P = .49). Interaction between brisk TILs and sex on SLN positivity was significant (P = .029). Among men, presence of brisk TILs was associated with prolonged OS (P = .038) but not after adjustment for SLN status (P = .42). There was no association between TIL status and OS among women.

LIMITATIONS

Findings from this single-institution study have yet to be validated by other research groups.

CONCLUSIONS

The implications of TILs in predicting SLN positivity appear to be more relevant for men than for women.