Thoracic and cutaneous sarcoid-like reaction associated with anti-PD-1 therapy: longitudinal monitoring of PD-1 and PD-L1 expression after stopping treatment

HSP90AA1 is an unfavorable prognostic factor for hepatocellular carcinoma and contributes to tumorigenesis and chemotherapy resistance

Hepatocellular carcinoma (HCC) is still one of the leading causes of tumor-related deaths. Accumulating evidence indicates that immunogenic cell death (ICD) could occur in tumor cells. However, ICD-related studies are limited in HCC. This study collected HCC RNA sequencing data from the Cancer Genome Atlas, International Cancer Genome Consortium, and Gene Expression Omnibus databases. R software was used to analyze the expression of ICD in HCC and to screen essential genes with prognostic value. qRT-PCR and WB determined the mRNA and protein expressions of hub gene. Cell viability assay, Clonal formation assay, and Live/dead staining assay were employed to determine the gene functions. After cross-analysis of differentially expressed genes (DEGs) and ICD-related genes (ICDRGs), 7 differentially expressed ICDRGs were identified in HCC. Of them, HSP90AA1, with the most excellent prognostic value in HCC, was selected, whose expression was also validated in public cohorts, cell lines, and clinical tissue samples. High HSP90AA1 expression indicated an inferior prognosis of HCC, and HSP90AA1 knockdown significantly suppressed cell viability and chemotherapy resistance of HCC. ICD-related gene HSP90AA1 was an unfavorable factor for HCC, and high HSP90AA1 expression contributed to tumor cell survival and chemotherapy resistance.

Leveraging a gene signature associated with disulfidptosis identified by machine learning to forecast clinical outcomes, immunological heterogeneities, and potential therapeutic targets within lower-grade glioma

Background

Disulfidptosis, a newly defined type of programmed cell death, has emerged as a significant regulatory process in the development and advancement of malignant tumors, such as lower-grade glioma (LGG). Nevertheless, the precise biological mechanisms behind disulfidptosis in LGG are yet to be revealed, considering the limited research conducted in this field.

Methods

We obtained LGG data from the TCGA and CGGA databases and performed comprehensive weighted co-expression network analysis, single-sample gene set enrichment analysis, and transcriptome differential expression analyses. We discovered nine genes associated with disulfidptosis by employing machine learning methods like Cox regression, LASSO regression, and SVM-RFE. These were later used to build a predictive model for patients with LGG. To confirm the expression level, functional role, and impact on disulfidptosis of ABI3, the pivotal gene of the model, validation experiments were carried out in vitro.

Results

The developed prognostic model successfully categorized LGG patients into two distinct risk groups: high and low. There was a noticeable difference in the time the groups survived, which was statistically significant. The model's predictive accuracy was substantiated through two independent external validation cohorts. Additional evaluations of the immune microenvironment and the potential for immunotherapy indicated that this risk classification could function as a practical roadmap for LGG treatment using immune-based therapies. Cellular experiments demonstrated that suppressing the crucial ABI3 gene in the predictive model significantly reduced the migratory and invasive abilities of both SHG44 and U251 cell lines while also triggering cytoskeletal retraction and increased cell pseudopodia.

Conclusion

The research suggests that the prognostic pattern relying on genes linked to disulfidptosis can provide valuable insights into the clinical outcomes, tumor characteristics, and immune alterations in patients with LGG. This could pave the way for early interventions and suggests that ABI3 might be a potential therapeutic target for disulfidptosis.

Roles of circulating tumor DNA in PD-1/PD-L1 immune checkpoint Inhibitors: Current evidence and future directions

Circulating tumor DNA (ctDNA) sequencing holds considerable promise for early diagnosis and detection of surveillance and minimal residual disease. Blood ctDNA monitors specific cancers by detecting the alterations found in cancer cells, such as apoptosis and necrosis. Due to the short half-life, ctDNA reflects the actual burden of other treatments on tumors. In addition, ctDNA might be preferable to monitor tumor development and treatment compared with invasive tissue biopsy. ctDNA-based liquid biopsy brings remarkable strength to targeted therapy and precision medicine. Notably, multiple ctDNA analysis platforms have been broadly applied in clinical immunotherapy. Through targeted sequencing, early variations in ctDNA could predict response to immune checkpoint inhibitor (ICI). Several studies have demonstrated a correlation between ctDNA kinetics and anti-PD1 antibodies. The need for further research and development remains, although this biomarker holds significant prospects for early cancer detection. This review focuses on describing the basis of ctDNA and its current utilities in oncology and immunotherapy, either for clinical management or early detection, highlighting its advantages and inherent limitations.

Suspected immune checkpoint inhibitor-induced pulmonary sarcoid reaction in metastatic renal cell carcinoma

We present the case of a 50-year-old male patient with metastatic clear cell renal cell carcinoma (mRCC) who developed a diffuse pulmonary opacification and lymphadenopathy during nivolumab maintenance therapy. This was diagnosed as presumed sarcoid granulomatous inflammatory reaction secondary to immunotherapy, which resolved with holding off therapy and the nivolumab was resumed.

The Meaning of Lymphadenopathies During Adjuvant Durvalumab After Chemoradiotherapy for Lung Cancer: Thinking Beyond Disease Progression

Immune-checkpoint inhibitors (ICIs) have become the mainstay of treatment for many malignancies. With this new strategy, relevant immune-related adverse events (irAEs) have been reported, some of which can be mistaken for disease progression. To better illustrate the current challenges in diagnosing and managing a patient under adjuvant ICI treatment, we present the case of a 67-year-old female patient with stage IIIB unresectable, epidermal growth factor receptor (EGFR)-mutated, non-small-cell lung cancer who was initially treated with chemoradiotherapy, followed by immunotherapy with durvalumab. During the course of immunotherapy, the patient presented with madarosis and erythematous and endured skin lesions, in addition to lymphadenopathies and pulmonary infiltrates. She was started on first-line palliative treatment with an EGFR tyrosine kinase inhibitor. After reviewing the case, a multidisciplinary team meeting suggested diagnostic procedures, including a transbronchial needle aspiration from mediastinal lymph nodes. The histologic examination showed chronic systemic inflammation and non-caseating granulomas of the sarcoid type. In this case, palliative treatment was suspended and systemic therapy with prednisolone was initiated. The patient became asymptomatic and the previously observed radiologic abnormalities resolved. This case highlights the importance of early recognition and appropriate treatment of irAEs, mainly because these conditions remain poorly understood and are probably underdiagnosed. Considering differential diagnosis is paramount to guide clinical management, despite curative or palliative treatment intent.

Case Report: Hepatic Sarcoid-Like Reaction Associated With Checkpoint Inhibition in a NSCLC Patient and a Literature Review

Immune checkpoint inhibitor (ICI) treatment has dramatically revolutionized the landscape of therapeutic approaches in multiple cancers, particularly, non-small-cell lung cancer (NSCLC). With the increasing use of programmed death-1 (PD-1) inhibitors in the clinic, the emerging toxicity profile presents a novel learning curve for clinicians. Here we report the first case of an NSCLC patient displaying sarcoid/granulomatous-like reaction (SLR, also known as GLR) in the liver during an anti-PD-1 therapy which showed efficacious response of complete regression. Also, this is the first report describing the SLR induced by toripalimab, a novel PD-1 inhibitor. Given this kind of hepatic findings can be easily mistaken as metastasis, even resulting in premature use of second-line treatments. In particular, we briefly review the clinical features of all those cases reporting sarcoidosis and SLRs manifested on different organs during anti-PD-(L)1 therapy. We anticipate that these clinical cases would help to alert the attention of clinicians that SLRs, as a rare immune-related adverse event (irAE), is manageable and that histopathological analysis is necessary before interpreting it as disease progression.

Adverse cutaneous toxicities by PD-1/PD-L1 immune checkpoint inhibitors: Pathogenesis, Treatment, and Surveillance

Introduction-The therapeutic use of humanized monoclonal programmed cell death 1 (PD-1) (pembrolizumab, and nivolumab) and programmed cell death ligand-1 (PD-L1) (atezolizumab, avelumab, durvalumab) immune checkpoint inhibitors (ICPi) as potent anticancer therapies is rapidly increasing. The mechanism of signaling of anti-PD-1/PD-L1 involves triggering cytotoxic CD4+/CD8 + T cell activation and subsequent abolition of cancer cells which induces specific immunologic adverse events that are specific to these therapies. These drugs can cause numerous cutaneous reactions and are characterized as the most frequent immune-related adverse events (irAEs). Majority of cutaneous irAEs range from nonspecific eruptions to detectible skin manifestations, which may be self-limiting and present acceptable skin toxicity profiles, while some may produce life-threatening complications.Objective-.This review aims to illuminate the associated cutaneous irAEs related to drugs used in oncology along with the relevant mechanism(s) and management.Areas covered-Literature was searched using various databases including Pub-Med, Google Scholar, and Medline. The search mainly involved research articles, retrospective studies, case reports, and clinicopathological findings. With this review article, an overview of the cutaneous irAEs with anti-PD-1/PD-L1 therapy, as well as suggestions, have been provided, so that their recognition at early stages could help in better management and would prevent treatment discontinuation.Article highlightsCutaneous adverse effects are the most prevalent immune-related adverse events induced by anti-PD-1/PD-L1 immune-checkpoint antibodies.Cutaneous toxicities mainly manifest in the form of maculopapular rash and pruritus.More specific cutaneous complications can also occur, including vitiligo, worsened psoriasis, lichenoid dermatitis, mucosal involvement (e.g., oral lichenoid reaction), dermatomyositis, lupus erythematosus.Cutaneous manifestations can be life-threatening including Stevens-Johnson syndrome/toxic epidermal necrolysis (TEN).Dermatologic toxicities are usually mild, readily manageable, and rarely result in significant morbidity.Adequate management of the cutaneous adverse event and recognition in early stages could lead to the prevention of worsening of the lesions and limit treatment disruption.

Case Report: Sarcoid-Like Reactions and Tertiary Lymphoid Structures Following Dual Checkpoint Inhibition in a Patient with Early-Stage Lung Adenocarcinoma

Immune checkpoint inhibitor-induced sarcoid-like reactions and tertiary lymphoid structures (TLSs) are increasingly recognized but rarely reported in the same patient. We report a patient with lung adenocarcinoma who displayed sarcoid-like reactions in intrathoracic lymph nodes and tertiary lymphoid structures in surgical tumor after neoadjuvant therapy with nivolumab plus ipilimumab. Pathological examination revealed 50% residual tumor cells after treatment, and the CT evaluation of the primary tumor showed a stable disease. The patient experienced a recurrence eight months after surgery. To identify immune correlates of the limited response to immunotherapy, we conducted genomic and transcriptional assays, multiplex immunoassay, and multiplex immunohistochemistry on the pre- and post-immunotherapy tumor, lymph node, and plasma samples. TP53 R181C, KRAS G12C and SMAD4 R361H were identified as driver mutations of the tumor. In addition to abundant infiltrated lymphocytes, immunotherapy induced high levels of inhibitory components in post-treatment tissue samples, especially the FOXP3⁺ regulatory T cells in tumor and PD-L1 expression in the lymph node. Despite abundant TLSs in the post-treatment tumor, most TLSs were immature. Moreover, increasing levels of circulating checkpoint proteins BTLA, TIM-3, LAG-3, PD-1, PD-L1, and CTLA4 were observed during immunotherapy. Collectively, our observations revealed that high levels of immunosuppressive molecules in tumor, lymph nodes and/or in peripheral blood might indicate poor outcomes after immunotherapy, even in the setting of a patient with concurrent sarcoid-like reactions and tertiary lymphoid structures.

Development of thoracic sarcoid reactions associated with complete response to anti-PD-1 therapy in a patient with advanced cutaneous squamous cell carcinoma

In patients with advanced cutaneous squamous cell carcinoma (cSCC), positive efficacy data were reported for anti-PD-1 antibodies. However, anti-PD-1 treatment is associated with a wide range of immune-related adverse events (irAEs). Here, we report on a 78-year-old woman with a huge cSCC on the right cheek spanning from the temporal to the cervical region with evidence for infiltration of the parotid gland, right masseter muscle and right auditory canal. Ultrasound revealed cervical, submandibular and supraclavicular lymph node metastases on patient's right side. On the basis of a medical hardship application, treatment with pembrolizumab was initiated. After two applications, a dramatic regression of the tumour was observed. At this point, the patient was switched to cemiplimab, which, in the meantime, had become available in Germany. After 3 months on cemiplimab, the tumour-related ulcer on the right cheek showed almost complete regression and all previously affected lymph nodes displayed no evidence for malignancy. Thoracic computed tomography (CT) scans revealed enlarged mediastinal and bilateral hilar lymph nodes assessed as primarily reactive. Three months later, however, mediastinal and bilateral hilar lymph nodes further increased in size, accompanied by radiological alterations of the lung parenchyma. Lymph node biopsies revealed sarcoid reactions (SRs) including fibrotic non-caseating epitheloid cell granulomas surrounded by lymphocytes. Since the patient did not display any clinical symptoms, cemiplimab treatment was continued following a 4-week break. Three months later, CT showed significant regression of the described enlarged lymph nodes and parenchymal lung changes. Twenty months after anti-PD-1 treatment, the patient was still in complete remission. In conclusion, we describe, for the first time, the case of a patient with advanced cSCC who developed disseminated thoracic SRs which were associated with dramatic regression of tumour masses. Thus, as with other irAEs, development of SRs might be indicative of an anti-tumour response to anti-PD-1 therapy.

Nodal immune flare mimics nodal disease progression following neoadjuvant immune checkpoint inhibitors in non-small cell lung cancer

Radiographic imaging is the standard approach for evaluating the disease involvement of lymph nodes in patients with operable NSCLC although the impact of neoadjuvant immune checkpoint inhibitors (ICIs) on lymph nodes has not yet been characterized. Herein, we present an ad hoc analysis of the NEOSTAR trial (NCT03158129) where we observed a phenomenon we refer to as “nodal immune flare” (NIF) in which patients treated with neoadjuvant ICIs demonstrate radiologically abnormal nodes post-therapy that upon pathological evaluation are devoid of cancer and demonstrate de novo non-caseating granulomas. Abnormal lymph nodes are analyzed by computed tomography and ¹⁸F-fluorodeoxyglucose positron emission tomography/computer tomography to evaluate the size and the maximum standard uptake value post- and pre-therapy in NEOSTAR and an independent neoadjuvant chemotherapy cohort. NIF occurs in 16% (7/44) of patients treated with ICIs but in 0% (0/28) of patients after neoadjuvant chemotherapy. NIF is associated with an inflamed nodal immune microenvironment and with fecal abundance of genera belonging to the family Coriobacteriaceae of phylum Actinobacteria, but not with tumor responses or treatment-related toxicity. Our findings suggest that this apparent radiological cancer progression in lymph nodes may occur due to an inflammatory response after neoadjuvant immunotherapy, and such cases should be evaluated by pathological examination to distinguish NIF from true nodal progression and to ensure appropriate clinical treatment planning.

Granulomatous/sarcoid-like lesions have been reported in patients treated with immune checkpoint inhibitors (ICIs). Here the authors report the occurrence of “nodal immune flare”, an apparent radiological cancer progression in the nodes characterized by the absence of cancer and the presence of non-caseating granulomas, in patients with non-small cell lung cancer following neoadjuvant ICI treatment.

Chronic activation of 4-1BB signaling induces granuloma development in tumor-draining lymph nodes that is detrimental to subsequent CD8+ T cell responses

The antitumor capabilities of agonistic anti-4-1BB mAbs have made them an attractive target for tumor immunotherapy. However, the adverse side effects associated with agonist antibodies have hindered their clinical development. Here, we aimed to study the immune-related adverse events of repeated doses and long-term use of agonistic anti-4-1BB mAbs. We show that chronic activation of 4-1BB signals induced the accumulation of IFN-γ-producing PD-1+CD8+ T cells in the secondary lymphoid organs of tumor-bearing mice by increasing the number of dividing CD8+ T cells, which was beneficial for suppressing tumor growth in the early phase of anti-4-1BB induction. However, repeated exposure to anti-4-1BB mAbs led to granuloma development in tumor-draining lymph nodes (TDLNs) of mice due to recruitment and accumulation of macrophages via the CD8+ T cell-IFN-γ axis. This was accompanied by excessive lymph node swelling, which impaired the sequential activation of CD8+ T cells. Our data provide insights into the immune-related adverse events of long-term agonist 4-1BB antibody dosing, which should be considered during the clinical development of immunomodulating therapy.

Immune-Related Erythema Nodosum Mimicking in Transit Melanoma Metastasis on [18F]-FDG PET/CT

Early detection of immune-related adverse events (irAEs) with immune checkpoint inhibitors (ICIs) is crucial, particularly when these are likely to mimic tumor progression, as well as sarcoid-like reactions. Here, we report the case of a 68-year woman, with a history of four primary cutaneous melanomas (thickest lesion with BRAF mutation removed from the left axilla 2 years before), who was diagnosed with BRAF V600E-mutant metastatic melanoma and treated by ICI targeting the PD-1 receptor. Follow-up whole-body positron emission tomography/computed tomography (PET/CT) using 18F-fluorodeoxyglucose ([18F]-FDG) was performed at 15 months, and FDG-avid subcutaneous nodules on her legs were detected. A biopsy from a lesion on her right leg was obtained, and histology strongly suggested erythema nodosum. Given the isolated nature of these lesions, the normal serum Angiotensin-Converting Enzyme and the context of ICI, an immune-related sarcoid-like reaction was retained as the most likely diagnosis. Recent literature in immune-oncology suggests that erythema nodosum could be directly related to ICI(s). Although erythema nodosum is a rare occurrence with imaging features overlapping with malignancy, it should be considered in the differential diagnosis of suspicious in-transit metastasis, especially when the patient is treated with ICIs and when lesions follow a bilateral distribution. In conclusion, nuclear medicine physicians should keep in mind this irAE when interpreting PET/CT scans in clinical practice in order to avoid false-positive findings.

Mediastinal FDG-positive lymph nodes simulating melanoma progression: drug-induced sarcoidosis like/lymphadenopathy related to ipilimumab

Drug-induced sarcoidosis-like reactions (DISRs) are systemic granulomatous diseases that develop in the context of a new drug onset. Ipilimumab is an immune checkpoint inhibitor (ICI) approved for the treatment of advanced melanoma which has been associated with DISR. Differential diagnosis between tumour progression and DISR by positron emission tomography/computed tomography (PET/CT) in patients treated with an ICI can be a challenge. A 31-year-old woman was diagnosed with a stage IIIB melanoma in her back. Ipilimumab 10 mg/kg was initiated. After 1 month of finishing the treatment a routine, PET/CT showed multiple enlarged mediastinal and hilar lymph nodes FDG-positive. A transbronchial biopsy showed sarcoid-like granulomatous infiltration which favoured the diagnosis of DISR related to ipilimumab. The patient remained asymptomatic and lymphadenopathy regressed progressively after 11 months. Our work highlights the importance of differentiating DISR from tumour progression, before unnecessary changes in therapeutic strategies. PET/CT is a useful diagnostic tool for its follow-up.

Case Report and Review of 7 Similar Cases in the Literature: Cutaneous Sarcoidosis as Side Effect of Pembrolizumab Plus Chemotherapy in Stage IV Squamous Cell Carcinoma of Lung

Advanced squamous cell lung cancer used to have universally dismal long-term outcomes before the use of immune checkpoint inhibitors (ICIs). Due to the expanding role of ICIs, there has been an increasing number of long-term survivors in this relatively large group of patients. ICIs such as anti-cytotoxic T-lymphocyte-associated protein 4 and anti-programmed cell death protein 1/programmed death-ligand 1 monoclonal antibodies increase the T-cell activation and limit the tumor capacity to escape the adaptive immune response. However, efficacy comes along with unique immune-related adverse events. We present an unusual case of cutaneous sarcoidosis in a 63-year-old white female who was diagnosed with stage IV squamous cell lung cancer developed skin manifestations 3 months after started chemo/pembrolizumab. Sarcoidosis was confirmed by skin punch biopsy and resolved after a short course of systemic glucocorticoid while maintained on pembrolizumab with lower frequency. These sarcoid-like lesions associated with the blockage of programmed death receptor-1 have been increasingly described in many different malignancies especially in melanoma. There is a need for further investigation to the characterization of the population prone to this immune-related adverse events.

Cardiothoracic Complications of Immune Checkpoint Inhibitor Therapy: An Imaging Review

Immune checkpoint inhibitor therapy has revolutionized the treatment of many different types of cancer. However, despite dramatic improvements in tumor oncologic response and patient outcomes, immune checkpoint blockade has been associated with multiple distinctive side-effects termed immune-related adverse events. These often have important clinical implications because these can vary in severity, sometimes even resulting in death. Therefore, it is important for both radiologists and clinicians to recognize and be aware of these reactions to help appropriately guide patient management. This article specifically highlights imaging manifestations of the most common cardiothoracic toxicities of these agents, including pneumonitis, sarcoid-like granulomatosis and lymphadenopathy, and myocarditis.

Cutaneous adverse reactions to anti-PD-1 treatment-A systematic review

The use of the humanized monoclonal anti-programmed cell death 1 antibodies pembrolizumab and nivolumab as potent anticancer therapies is rapidly increasing. However, since their approval, numerous cases of cutaneous reactions have been reported. Cutaneous adverse reactions to these agents have yet to be fully characterized and range from nonspecific eruptions to recognizable skin manifestations, which may be localized and vary from mild to life threatening. This systematic review article provides an overview of the various adverse cutaneous reactions to pembrolizumab and nivolumab therapy and offers suggestions for their management.

The Promise of JAK Inhibitors for Treatment of Sarcoidosis and Other Inflammatory Disorders with Macrophage Activation: A Review of the Literature

Certain inflammatory disorders are characterized by macrophage activation and accumulation in tissue; sometimes leading to the formation of granulomas, as in sarcoidosis. These disorders are often difficult to treat and more effective, molecularly targeted therapies are needed. Recent work has shown that overproduction of inflammatory cytokines, such as interferon gamma (IFN-γ) leading to constitutive activation of the JAK-STAT pathway may be a conserved feature of these disorders. Use of JAK inhibitors, which can block these signals, has resulted in dramatic improvement in several patients with sarcoidosis. JAK inhibitors also appear to have activity in other inflammatory disorders with macrophage activation including hemophagocytic lymphohistiocystosis, Crohn's disease, granuloma annulare, and necrobiosis lipoidica. Here, we review the role of JAK dependent cytokines in macrophage activation and granuloma formation and the clinical evidence supporting the use of JAK inhibition in these disorders. Ongoing efforts to evaluate role of JAK inhibitors in these disorders is also discussed.

Sarcoidosis and the mTOR, Rac1, and Autophagy Triad

Sarcoidosis is an enigmatic multisystem disease characterized by the development and accumulation of granulomas: a compact collection of macrophages that have differentiated into epithelioid cells and which are associated with T helper (Th)1 and Th17 cells. Although no single causative factor has been shown to underlie sarcoidosis in humans, its etiology has been related to microbial, environmental, and genetic factors. We examine how these factors play a role in sarcoidosis pathogenesis. Specifically, we propose that dysfunction of mTOR, Rac1, and autophagy-related pathways not only hampers pathogen or nonorganic particle clearance but also participates in T cell and macrophage dysfunction, driving granuloma formation. This concept opens new avenues for potentially treating sarcoidosis and may serve as a blueprint for other granulomatous disorders.

Immune response biomarkers as indicators of sarcoidosis presence, prognosis, and possible treatment: An Immunopathogenic perspective

Sarcoidosis has been a disease of puzzling occurrence and clinical course. Multiple immunological markers have been noted to be altered within sarcoidosis, however there is variable consistency among these reports. Previous studies have shown sarcoidosis to be a primary T cell-mediated disease, yet new data concerning B cell and mycobacterial involvement have been brought to light. The possibility of a uniform biomarker to characterize sarcoidosis presence, severity and prognosis greatly increases the movement towards directed and specialized treatment for this rare disease.

Frequency and distribution of various rheumatic disorders associated with checkpoint inhibitor therapy

Immune checkpoint inhibitors have advanced the treatment paradigm of various cancers, achieving remarkable survival benefits. However, a myriad of immune-related adverse events (irAE) has been recognized in almost every organ system, presumably because of persistent immune system activation. Rheumatic symptoms such as arthralgia or myalgia are very common. More specific irAE are increasingly being reported. The most frequent ones are inflammatory arthritis, polymyalgia-like syndromes, myositis and sicca manifestations. These rheumatic irAE can develop in ∼5-10% of patients treated with immune checkpoint inhibitors, although true incidence rates cannot be estimated given the lack of prospective cohort studies, and likely underreporting of rheumatic irAE in oncology trials. In this review, we will provide a summary of the epidemiologic data reported for these rheumatic irAE, until more robust prospective longitudinal studies become available to further define the true incidence rate of rheumatic irAE in patients receiving these novel cancer therapies.

Granulation Tissue-induced Pseudo-relapse During Nivolumab Treatment in Advanced Non-small Cell Lung Cancer

Atypical tumor responses such as pseudo-progression or hyper-progression sometimes occur during immune check point inhibitor therapy. Distinct from both responses, we experienced a case of non-small cell lung cancer (NSCLC) with a pseudo-relapse, in which development of granulation mimicked cancer relapse during nivolumab therapy. A male with advanced NSCLC started nivolumab as a second-line therapy. After 15 cycles of nivolumab with a complete response, tumor markers started increasing and positron-emission computed tomography indicated a hot spot in the sigmoid colon. Laparoscopic segmental sigmoid colon resection revealed granulation tissue without any relapse of malignant cells. The results showed that even if radiographical tumor progression is found during immune therapy, histological confirmation should be considered.

Exclusive Cutaneous and Subcutaneous Sarcoidal Granulomatous Inflammation due to Immune Checkpoint Inhibitors: Report of Two Cases with Unusual Manifestations and Review of the Literature

Recent emergence of immune checkpoint inhibitors (ICIs) has revolutionized the treatment of cancers and produced prolonged response by boosting the immune system against tumor cells. The primary target antigens are cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), a downregulator of T-cell activation, and programmed cell death-1 receptor (PD-1), a regulator of T-cell proliferation. This enhanced immune response can induce autoimmune adverse effects in many organs. Although skin toxicities are the most common, sarcoidal inflammation with exclusive cutaneous involvement is a rare occurrence with only 6 cases reported to date. We report 2 cases with unusual features. One patient is a female who was treated for metastatic renal cell carcinoma with combination of ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1). She developed deep nodules showing sarcoidal dermatitis and panniculitis on histopathologic exam. The second patient is a male with melanoma of eyelid conjunctiva who was treated prophylactically with ipilimumab. He presented with papules/plaques confined to black tattoos, where the biopsy revealed sarcoidal dermatitis. By a comprehensive literature review, we intend to raise awareness about this potential skin side effect in the growing number of patients receiving targeted immunotherapies. It is crucial to have a high index of suspicion and perform timely biopsies to implement appropriate management strategies.

Immune checkpoint inhibitors and the development of granulomatous reactions

Immune checkpoint inhibitors (ICPIs) have emerged as a frontline treatment for a growing list of malignancies. Disruption of the negative regulatory immune checkpoints by ICPIs has been associated with many immune-related adverse events. Granulomatous reactions, such as sarcoidosis-like reactions, granulomatous panniculitis, granuloma annulare, and granulomatous dermatitis, are uncommon but increasingly recognized immune-related adverse events seen in patients treated with ICPIs. The frequency and significance of these eruptions, including whether they portend responsiveness to treatment, remain unclear. Additionally, understanding the role of immune checkpoint blockade in these reactions may provide mechanistic insight into the relevant signaling pathways involved in sarcoidosis and other granulomatous disorders.