Extracellular 20S proteasome secreted via microvesicles can degrade poorly folded proteins and inhibit Galectin-3 agglutination activity.

Proteasomes are major non-lysosomal proteolytic complexes localized in the cytoplasm and in the nucleus of eukaryotic cells. Strikingly, high levels of extracellular proteasome have also been evidenced in the plasma (p-proteasome) of patients with specific diseases. Here, we examined the process by which proteasomes are secreted, as well as their structural and functional features once in the extracellular space. We demonstrate that assembled 20S core particles are secreted by cells within microvesicles budding from the plasma membrane. Part of the extracellular proteasome pool is also free of membranes in the supernatant of cultured cells, and likely originates from microvesicles leakage. We further demonstrate that this free proteasome released by cells (cc-proteasome for cell culture proteasome) possesses latent proteolytic activity and can degrade various extracellular proteins. Both standard (no immune-subunits) and intermediate (containing some immune-subunits) forms of 20S are observed. Moreover, we show that galectin-3, which displays a highly disordered N-terminal region, is efficiently cleaved by purified cc-proteasome, without SDS activation, likely after its binding to PSMA3 (α7) subunit through its intrinsically disordered region. As a consequence, galectin-3 is unable to induce red blood cells agglutination when preincubated with cc-proteasome. These results highlight potential novel physio- and pathologic functions for the extracellular proteasome.

Molecularly matched targeted therapy: a promising approach for refractory metastatic melanoma.

BACKGROUND: Only a fraction of patients with metastatic melanoma derive durable benefit from approved treatments. The clinical impact of personalized medicine strategies for melanoma, apart from BRAF, NRAS, or CKIT targeting, has rarely been reported. MATERIALS AND METHODS: By means of the Group of Cutaneous Oncology of the French Society of Dermatology, we retrospectively included all patients with advanced melanoma aged 18 years and older for whom molecular testing identified one or more actionable molecular alterations and who accordingly received molecularly matched therapy. We excluded patients with only BRAF, NRAS, or CKIT alterations and patients who received molecularly matched therapy for less than 15 days. RESULTS: We included 26 patients with a median follow-up of 8 months (1-54), a median age of 63 years (24-89), and a sex ratio of 2.7. These patients had been heavily pretreated, and 64% had elevated LDH levels. The disease control rate was 38%, with 4 cases of partial response (overall response rate: 15%) and 6 of stable disease for at least 6 months. The median duration of treatment was 3.1 months (0.9-13.5). Among patients with disease control, the median duration of control was 6.6 months (2.6-13.5) and 3 cases were ongoing at the end of the study. Patients with controlled disease had GNA11, MAP2K1, FYCO1-RAF1, HRAS, ATM, CCND1, MDM2/CDK4, and CDKN2A/NRAS alterations. CONCLUSIONS: High-throughput sequencing followed by matched targeted therapy is a promising approach for patients with advanced melanoma refractory to approved treatments.

Impact of systemic therapies in metastatic melanoma of unknown primary: A study from MELBASE, a French multicentric prospective cohort.

BACKGROUND: Clinical outcomes of advanced melanoma of unknown primary (MUP) in the era of novel therapies have been scarcely studied. OBJECTIVE: To investigate the efficacy and safety of systemic treatments in patients with advanced MUP compared to patients with stage-matched melanoma of known cutaneous primary (cMKP). METHODS: Based on the nationwide MelBase prospective database, this study included advanced melanoma patients treated from March 2013 to June 2021 with first-line immunotherapies, targeted therapies, or chemotherapy. Co-primary outcomes were progression-free survival and overall survival. Secondary outcome was treatment-related toxicities. Multivariate and propensity score analyses were performed. RESULTS: Of 1882 patients, 265 (14.1%) had advanced MUP. Patients with advanced MUP displayed more often unfavorable initial prognostic factors than those with cMKP. Progression-free and overall survival did not differ significantly between the groups (P = .73 and P = .93, respectively), as well as treatment-related toxicity rate and severity, regardless of treatment type. LIMITATIONS: No record of standard diagnostic criteria of MUP used in the participating centers. CONCLUSIONS: Although patients with MUP had less favorable baseline prognostic factors, they benefited from the novel therapies as much as those with cMKP. They should be managed according to similar strategies.

Risk of irAEs in patients with autoimmune diseases treated by immune checkpoint inhibitors for stage III or IV melanoma: results from a matched case-control study.

OBJECTIVE: To quantify the risk of immune-related adverse events (irAEs) in patients with pre-existing autoimmune disease (pAID) treated by immune checkpoint inhibitors (ICIs) for stage III or IV melanoma. METHODS: Case-control study performed on a French multicentric prospective cohort of patients with melanoma, matched for irAE risk factors and oncological staging. Risk of irAE was assessed by logistic regression. RESULTS: 110 patients with pAID were included and matched with 330 controls, from March 2013 to October 2020. Over a median follow-up period of 7.2 months for cases and 6.9 months for controls, the ORs of developing all-grade and grade ≥3 irAEs among cases compared with controls were 1.91 (95% CI (1.56 to 2.27)) and 1.44 (95% CI (1.08 to 1.82)), respectively. Patients with pAID had an increased risk of multiple irAEs (OR 1.46, 95% CI (1.15 to 2.67)) and a shorter time to irAE onset. In contrast, there were no difference in irAE-related mortality nor in the rate of treatment discontinuation, and a landmark analysis revealed a better survival at 24 months among cases (p=0.02). Thirty per cent of cases experienced a pAID flare during follow-up, and baseline immunosuppression did not prevent irAE occurrence. Last, we report associations between the pAID clinical subsets and organ-specific irAEs. CONCLUSION: In our study, patients with pAID were at greater risk of all-grade, severe and multiple irAEs, yet had a better 24-month survival than controls. Thus, patients with pAID should be eligible for ICI therapy but benefit from a close monitoring for irAE occurrence, especially during the first months of therapy.

Proteasome 19S RP and translation preinitiation complexes are secreted within exosomes upon serum starvation.

The aim of our study was to investigate the impact of macroautophagy on exosome secretion. Exosomes are small membrane vesicles released in the extracellular space upon fusion of multivesicular endosomes with the plasma membrane. They were initially discovered as a way to remodel the reticulocyte plasma membrane before entering the blood circulation (Current Opinion in Hematology 2010, 17:177-183) and are now essentially studied as mediators of intercellular communication. Using iTRAQ proteomics, we compared the protein composition of purified exosomes secreted by cells impaired or not for macroautophagy by Atg5 depletion, during serum starvation conditions or complete medium culture. We show that the absence of serum modifies exosomal content, especially inducing secretion of two cytoplasmic protein complexes, namely proteasomal 19S regulatory particle (RP) and components of noncanonical translation preinitiation complex (PIC). This process is enhanced when autophagy is impaired by Atg5 depletion. Moreover, we show that the proteasome 20S core particle (CP) is released in the extracellular space. However, in striking contrast to what seen for its 19S RP regulator, release is independent of the exosomal vesicles, Atg5 expression and cell culture conditions. Exosome secretion can thus be considered as a cell process that participates in and reflects cell homeostasis, and care must be taken when studying potential extracellular function of exosomes due to the possible copurification of proteasome 20S CP.

Quality-of-life assessment in French patients with metastatic melanoma in real life.

BACKGROUND: Significant progress was recently observed in the treatment of metastatic melanoma (MM). With >50% of patients now reaching a second line of treatment and a significant improvement in the survival rate, an assessment of quality of life (QoL) during the whole course of the disease becomes necessary. The objective of this study was to describe the QoL of patients with MM in France, from their diagnosis of advanced disease to their death, in real life. METHODS: QoL data were collected through MelBase, a prospective, French, multicentric cohort dedicated to the follow-up of adults with MM. QoL was assessed using the EuroQoL-5D questionnaire and the Functional Assessment of Cancer Treatment (FACT)-Melanoma questionnaire at the time of study inclusion, every 3 months, and at the time of each treatment change until death. To assess longitudinal changes from baseline to death, mixed-effect models for repeated-measures analyses were used to control for baseline covariates. RESULTS: QoL was assessed in 1435 patients who were included in the study between 2013 and 2018. The median follow-up was 9.4 months, and 47% of patients died during follow-up. During first-line treatment, the model-based, mean utility score was 0.830 (95% CI, 0.818-0.843), the mean FACT-General score was 77.22 (95% CI, 76.23-78.22), and the mean FACT-Melanoma score was 129.46 (95% CI, 128.02-130.90). At the time of a change in treatment line, there was a decrease of -0.027 (95% CI, -0.03, -0.02) in the utility score, -1.82 (95% CI, -1.88, -1.76) in the FACT-General score, and -2.98 (95% CI, -3.05, -2.91) in the FACT-Melanoma score compared with first-line treatment. CONCLUSIONS: In the MelBase cohort, the QoL among patients with MM seems to be fairly stable over the whole disease course, although a small but significant decrease at time therapy is changed is observed.

Documented cutaneous loxoscelism in the south of France: an unrecognized condition causing delay in diagnosis.

BACKGROUND: Loxoscelism is an envenomation due to a bite by spiders of the genus Loxosceles, very well known on the American continent but unrecognized in Europe. CASE REPORT: We report the case of a 36-year-old woman, without any medical history or treatment, who went to a University Hospital in the South of France, for a painful skin lesion on the internal part of her left thigh, which appeared in the morning and developed rapidly during the day. She was directed to the infectious disease department with a diagnosis of skin infection. In spite of the antibiotics, the lesion increased, with a hemorrhagic central blister, an irregular ecchymotic center, a pale perimeter, and an extensive inflammatory and indurate oedema affecting the whole thigh. There was also a low-grade fever, chills, intense pain and a generalized scarlatiniform exanthema. The lesion was finally diagnosed as cutaneous loxoscelism, then confirmed by collection and identification of a Loxosceles rufescens spider killed by the patient the morning of the occurrence of the lesion. Following an initial symptomatic treatment, the development of a necrotic ulcer justified a delayed surgical reconstruction, after stabilization of the lesion. CONCLUSIONS: Loxosceles bites are usually painless and rarely noticed by patients, often leading to a presumptive diagnosis. Therefore, in the case of a dermonecrotic lesion developing unfavourably with antibiotics, cutaneous loxoscelism should be one of the diagnoses to be considered.

Sentinel node status and immunosuppression: recurrence factors in localized Merkel cell carcinoma.

The prognostic value of the sentinel lymph node in Merkel cell carcinoma (MCC) has been examined previously in heterogeneous retrospective studies. The current retrospective study included a homogeneous population of patients with a localized MCC, all staged with sentinel lymph node biopsy. Factors associated with 3-year progression-free survival were analysed using logistic regression. The sentinel lymph node was positive in 32% of patients. The recurrence rate was 26.9%. In first analyses (n = 108), gender (p = 0.0115) and the presence of immunosuppression (p = 0.0494) were the only significant independent factors. In further analyses (n = 80), excluding patients treated with regional radiotherapy, sentinel lymph node status was the only significant prognostic factor (p = 0.0281). Immunosuppression and positive sentinel lymph node are associated with a worse prognosis in patients with MCC. Nodal irradiation impacts on the prognostic value of the sentinel lymph node status.

Macular lymphocytic arteritis: three cases questioning its classification as primary lymphocytic vasculitis.

BACKGROUND: Macular arteritis, macular lymphocytic arteritis (MLA) or lymphocytic thrombophilic arteritis all correspond to an identical new clinicopathological entity. Its individualization as a primary cutaneous lymphocytic arteritis is still controversial for certain authors as it could represent a latent form of cutaneous polyarteritis nodosa. MATERIALS AND METHODS: We report here 3 additional cases of MLA, present a review of the literature and discuss the disease's nosology. RESULTS: MLA is characterized clinically by a benign skin eruption consisting in bilateral asymptomatic erythematous/hyperpigmented macules mainly located on the lower legs and histologically by a medium-sized cutaneous lymphocytic prominent arteritis present in early cutaneous lesions. CONCLUSION: These findings support that MLA may be considered as a chronic and indolent primary lymphocytic cutaneous arteritis. Nevertheless, in some cases the objective obliteration of cutaneous vessels underlines the need for continuous monitoring in MLA patients.

Clinical use of p-proteasome in discriminating metastatic melanoma patients: comparative study with LDH, MIA and S100B protein.

Plasmatic proteasome (p-proteasome) has recently been described as a new marker for metastatic melanoma. The objective of this study was to compare the diagnostic and prognostic values of p-proteasome with three other melanoma serological markers: S100B protein, melanoma inhibitory activity protein (MIA) and lactate dehydrogenase (LDH) in the plasma of 121 stage I-IV melanoma patients. Laboratory analyses were performed by standardized ELISA (p-proteasome, MIA), immunoluminometric assay (S100B) and colorimetry (LDH). We found that all markers were relevant for discriminating metastatic from nonmetastatic patients but p-proteasome displayed the highest diagnostic accuracy. P-proteasome and S100B were the most sensitive (58.1%) and p-proteasome and MIA the most specific (98.7 and 100%) in detecting metastatic disease. P-proteasome and S100B had the highest area under receiver operating characteristics curve, 0.811 (95% CI: 0.725-0.897) and 0.822 (95% CI: 0.738-0.906), respectively. These two markers were the best in detecting patients with lymph node metastases. S100B, MIA and LDH diagnostic accuracy was increased when these markers were combined with p-proteasome. As shown with univariate analysis, shorter progression-free and overall survival rates were significantly associated with elevated plasma levels of each markers. The multivariate Cox regression analysis identified p-proteasome as the only independent predictor of a poorer progression-free survival (p = 0.030). In conclusion, this comparative study established that p-proteasome quantification in combination with other melanoma biomarkers is an attractive approach for the biological follow-up of melanoma patients.

Anti-PD-1 for the treatment of advanced cutaneous squamous cell carcinoma in elderly patients: a French multicenter retrospective survey.

BACKGROUND: Anti-PD1 agents are currently recommended as first-line treatment in advanced cutaneous squamous cell carcinoma (acSCC) by updated European guidelines. Although acSCC frequently affects elderly patients with multiple comorbidities, this subset of patients is often excluded of registration clinical trials. PURPOSE: To assess anti-PD-1 efficacy and safety in elderly acSCC patients in real-life conditions and describe this specific population with oncogeriatric evaluation tools. METHODS: A multicenter retrospective study including acSCC patients at least 70 years old treated with PD-1 inhibitors was conducted in French referral centers. The primary endpoint was the overall response rate (ORR). Secondary endpoints included safety data, time to response (TTR), duration of response (DOR), overall survival (OS), and progression-free survival (PFS). RESULTS: 63 patients were included. ORR was 57.1% (95% CI 44.0-69.5), median TTR and DOR were 3 and 5.5 months respectively. Median OS was not reached (95% CI 12.5 months-not reached) at data cut-off after a median follow-up of 8 months while median PFS was 8 months. (95% CI 5 months-not reached). Grade 3-5 adverse effects occurred in 47.6% of patients. 41.3% of patients experienced degradation of ECOG performance status during anti-PD-1 treatment. Nutritional state worsened in 27% of patients and 57.1% lost weight during treatment. CONCLUSION: In this particular subset of acSCC patients PD-1 inhibitors obtain results similar to those obtained in younger populations included in pivotal clinical trials, with acceptable safety. A specific oncogeriatric evaluation at treatment initiation and during follow-up appears important in this setting most notably to help manage toxicity.

MC1R expression in HaCaT keratinocytes inhibits UVA-induced ROS production via NADPH oxidase- and cAMP-dependent mechanisms.

Ultraviolet A (UVA) radiations are responsible for deleterious effects, mainly due to reactive oxygen species (ROS) production. Alpha-melanocyte stimulating hormone (α-MSH) binds to melanocortin-1 receptor (MC1R) in melanocytes to stimulate pigmentation and modulate cutaneous inflammatory responses. MC1R may be induced in keratinocytes after UV exposure. To investigate the effect of MC1R signaling on UVA-induced ROS (UVA-ROS) production, we generated HaCaT cells that stably express human MC1R (HaCaT-MC1R) or the Arg151Cys (R(151)C) non-functional variant (HaCaT-R(151)C). We then assessed ROS production immediately after UVA exposure and found that: (1) UVA-ROS production was strongly reduced in HaCaT-MC1R but not in HaCaT-R(151)C cells compared to parental HaCaT cells; (2) this inhibitory effect was further amplified by incubation of HaCaT-MC1R cells with α-MSH before UVA exposure; (3) protein kinase A (PKA)-dependent NoxA1 phosphorylation was increased in HaCaT-MC1R compared to HaCaT and HaCaT-R(151)C cells. Inhibition of PKA in HaCaT-MC1R cells resulted in a marked increase of ROS production after UVA irradiation; (4) the ability of HaCaT-MC1R cells to produce UVA-ROS was restored by inhibiting epidermal growth factor receptor (EGFR) or extracellular signal-regulated kinases (ERK) activity before UVA exposure. Our findings suggest that constitutive activity of MC1R in keratinocytes may reduce UVA-induced oxidative stress via EGFR and cAMP-dependent mechanisms.

Non-V600E/K BRAF Mutations in Metastatic Melanoma: Molecular Description, Frequency, and Effectiveness of Targeted Therapy in a Large National Cohort.

PURPOSE: Mitogen-activating protein kinase inhibitors (MAPKis) are largely used in V600E/K BRAF-mutated metastatic melanomas, but data regarding effectiveness of targeted therapy in patients with rare BRAF mutations and molecular description of these infrequent mutations are scarce. PATIENTS AND METHODS: A multicenter study was conducted on patients with metastatic melanoma harboring a well-identified mutation of BRAF and enrolled from March 2013 to June 2021 in the French nationwide prospective cohort MelBase. The molecular BRAF mutation pattern, response to MAPKis when applicable, and survival data were analyzed. RESULTS: Of 856 selected patients, 51 (6%) harbored a non-V600E/K BRAF mutation involving codons V600 (24 of 51, 47%; V600G 27.4%, V600R 15.6%), K601 (6 of 51, 11.7%), and L597 (4 of 51, 7.8%). An objective response to MAPKis either BRAF inhibitor (BRAFi) alone or combined with MEK inhibitor was achieved in 56% (353 of 631) of V600E/K, 58% (11 of 19) of non-E/K V600, and 22% (2 of 9) of non-V600 BRAF-mutated patients, with a median progression-free survival of 7.7, 7.8, and 2.8 months, respectively. Overall, objective response rate was higher with BRAFi + MEK inhibitor combination than with BRAFi in monotherapy for each subset. CONCLUSION: Rare BRAF mutations are not anecdotal in the metastatic melanoma population. Although data interpretation must remain careful owing to the limited size of some subsets of patients, non-E/K V600 BRAF mutations seem to confer a high sensitivity to targeted therapy, whereas MAPKis seem less effective in patients with non-V600 BRAF mutations. However, this strategy may be used as an alternative option in the case of immunotherapy failure in the latter population.

Cost-Effectiveness Analysis of Sequential Treatment Strategies for Advanced Melanoma in Real Life in France.

Nine drugs have been marketed for 10 years for the treatment of advanced melanoma (AM). With half of patients reaching a second line, the optimal sequence of treatments remains unclear. To inform policy-makers about their efficiency, we performed a cost-effectiveness analysis of sequential strategies in clinical practice in France, for BRAF-mutated and wild-type patients. A multistate model was developed to describe treatment sequences, associated costs, and health outcomes over 10 years. Sequences, clinical outcomes, utility scores, and economic data were extracted from the prospective Melbase cohort, collecting individual data in 1518 patients since 2013, from their AM diagnosis until their death. To adjust the differences in patients' characteristics among sequences, weighting by inverse probability was used. In the BRAF-mutated population, the MONO-targeted therapies (TT)-anti-PD1 sequence was the less expensive, whereas the anti-PD1-BI-TT sequence had an incremental cost-effectiveness ratio (ICER) of 180,441 EUR/QALY. Regarding the BRAF wild-type population, the three sequences constituted the cost-effective frontier, with ICERs ranging from 116 to 806,000 EUR/QALY. For BRAF-mutated patients, the sequence anti-PD1-BI-TT appeared to be the most efficient one in BRAF-mutated AM patients until 2018. Regarding the BRAF wild-type population until 2018, the sequence starting with IPI+NIVO appeared inefficient compared to anti-PD1, considering the extra cost for the QALY gained.

Melanotransferrin is efficiently sorted on the surface of exosomes secreted by melanoma cells.

Cutaneous melanoma is the most lethal type of skin cancer. Early detection is crucial to improve the outcome of melanoma patients. The identification of noninvasive prognostic biomarkers for the follow-up of melanoma patients is still in demand for clinical use. We show here that exosomal melanotransferrin fulfills the biomarker characteristics required to meet this demand. Melanotransferrin is typically overexpressed in melanoma cells compared to other cell types - including cancer cells - and is efficiently sorted and secreted with nanovesicles, or so-called exosomes, due to its membrane-anchoring by a glycosylphosphatidylinositol. Melanotransferrin is exposed on the surface of exosomes and is accessible for antibody recognition. An ELISA was set up to quantify melanotransferrin after immobilization of nanovesicles through the exosomal constituent tetraspanins CD63. Melanotransferrin was detected using a low number of exosomes purified from melanoma cell line cultures, and melanotransferrin detection was abolished by phosphatidylinositol-specific phospholipase C treatment. This exosomal melanotransferrin ELISA was able to discriminate an equal number of assayed exosomes purified from two different melanoma cell lines (A-375 vs. SK-MEL-28). Moreover, plasma samples from patients with melanoma and noncancer disease were assayed using this ELISA and elevated levels of exosomal melanotransferrin were seen in the plasma of patients with melanoma. We propose that exosomal melanotransferrin should be assessed as a potential melanoma biomarker.

Tolerance and Effectiveness of Targeted Therapies in Aged Patients with Metastatic Melanoma.

PURPOSE: Melanoma's incidence is increasing, and elderly people could be significantly impacted since the majority occurs in people over 65 years of age. Combined BRAF and MEK targeted therapies (TT) are current standard regimen for BRAF mutated metastatic melanoma (MM). Except for subgroups of pivotal trials, little data are available for TT in this population. MATERIALS AND METHODS: Outcomes were explored in real life patients from MelBase, a French multicentric biobank dedicated to the prospective follow-up of unresectable stage III or IV melanoma. Patients treated by BRAF TT and/or MEK TT combined or not, were included from 2013 to 2017 in 2 groups: group 1 ≤ 65-year-old (yo), group 2 > 65 yo, analyzed for tolerance and efficacy. RESULTS: 353 patients were included: 231 in group 1, 122 in group 2. Median follow-up was 12 months (M). Median time of treatment was 6.9 M. A total of 80% had at least one Adverse Effect (AE). Most frequent AE (all grades) were mainly skin and subcutaneous, general, and gastrointestinal disorders. A total of 31% of AE were grade 3-4: 28% in group 1 and 39% in group 2 (p = 0.05). No differences were observed in all AE grades proportion, dose modifications, interruptions, and discontinuations. For each group, median overall survival was 20.3 M (CI 95%: 15.5-27.9) and 16.3 M (CI: 14.5-26.9), respectively (p = 0.8). Median progression free survival was 7.8 M (6.4-9.9) and 7.7 M (CI: 5.8-11.3) (p = 0.4). Objective response rate was 59% and 50% (p = 0.6). CONCLUSION: This study on a large multicentric cohort is the first to assess that TT is well tolerated in elderly BRAF-mutated patients such as in patients younger than 65. Efficacy was similar between groups with outcomes reaching those from pivotal studies. There is thus no argument against using TT in elderly people, although an onco-geriatric opinion is welcome for the most vulnerable.

Cemiplimab for Locally Advanced and Metastatic Cutaneous Squamous-Cell Carcinomas: Real-Life Experience from the French CAREPI Study Group.

Although cemiplimab has been approved for locally advanced (la) and metastatic (m) cutaneous squamous-cell carcinomas (CSCCs), its real-life value has not yet been demonstrated. An early-access program enrolled patients with la/mCSCCs to receive cemiplimab. Endpoints were best overall response rate (BOR), progression-free survival (PFS), overall survival (OS), duration of response (DOR) and safety. The 245 patients (mean age 77 years, 73% male, 49% prior systemic treatment, 24% immunocompromised, 27% Eastern Cooperative Oncology Group performance status (PS) ≥ 2) had laCSCCs (35%) or mCSCCs (65%). For the 240 recipients of ≥1 infusion(s), the BOR was 50.4% (complete, 21%; partial, 29%). With median follow-up at 12.6 months, median PFS was 7.9 months, and median OS and DOR were not reached. One-year OS was 73% versus 36%, respectively, for patients with PS < 2 versus ≥ 2. Multivariate analysis retained PS ≥ 2 as being associated during the first 6 months with PFS and OS. Head-and-neck location was associated with longer PFS. Immune status had no impact. Severe treatment-related adverse events occurred in 9% of the patients, including one death from toxic epidermal necrolysis. Cemiplimab real-life safety and efficacy support its use for la/mCSCCs. Patients with PS ≥ 2 benefited less from cemiplimab, but it might represent an option for immunocompromised patients.

Diagnostic value and prognostic significance of plasmatic proteasome level in patients with melanoma.

Plasmatic proteasome (p-proteasome) also called circulating proteasome has recently been described as a tumor marker. We investigated the diagnostic and prognostic accuracies of p-proteasome levels in a melanoma population classified according to the American Joint Committee on Cancer staging system. Using an ELISA test, we measured p-proteasome levels in 90 patients and 40 controls between March 2003 and March 2008. The subunit composition of p-proteasomes was determined in metastatic melanoma by proteomic analysis. The mean p-proteasome levels were correlated with stages (P < 0.0001; r(S) = 0.664). They were significantly higher in patients with stage IV and stage III with lymph node metastasis (9187 ± 1294 and 5091 ± 454 ng/ml, respectively) compared to controls (2535 ± 187 ng/ml; P < 0.001), to stage I/II (2864 ± 166 ng/ml; P < 0.001) and to stage III after curative lymphadenectomy (2859 ± 271 ng/ml; P < 0.001). The diagnostic accuracy of p-proteasome was evaluated by receiver operating characteristic analysis. With a cut-off of 4300 ng/ml, diagnostic specificity and sensitivity of p-proteasome for regional or visceral metastases were respectively 96.3% and 72.2%. In univariate analysis, high p-proteasome levels (>4300 ng/ml) were significantly correlated with an increased risk of progression [hazard ratio (HR) = 7.34; 95% CI 3.54-15.21, P < 0.0001] and a risk of death (HR = 5.92; 95% CI 2.84-12.33, P < 0.0001). In multivariate analysis, high p-proteasome levels were correlated with a poorer clinical outcome in the subgroup analysis limited to patients with disease stages I, II and III. Proteomic analysis confirmed the presence of all proteasome and immunoproteasome subunits. Taken together, these results indicate that p-proteasomes are a new marker for metastatic dissemination in patients with melanoma.