Differentiating atypical Spitz tumors (ASTs) from true Spitz melanomas (SMs) and conventional melanomas with spitzoid features (MSFs) remains a formidable diagnostic challenge. Because current molecular epidemiological data are overwhelmingly derived from Caucasian cohorts, the genomic landscape of Asian populations remains largely unexplored. To elucidate the molecular progression landscape and refine the diagnostic criteria, we performed a comprehensive multimodal analysis-integrating histomorphology, immunohistochemistry, multiprobe fluorescence in situ hybridization (FISH), and targeted RNA/DNA-based next-generation sequencing (NGS)-on a cohort of 140 spitzoid neoplasms. This cohort, comprising 126 ASTs, 8 SMs, and 6 MSFs, represents the largest Asian cohort to date. Malignant phenotype strongly correlated with lesional asymmetry, deep atypical mitoses, a sheet-like growth pattern, diffuse preferentially expressed antigen of melanoma positivity, and significant loss of p16 expression (64.3% in SM/MSF vs 9.5% in ASTs; P < .0001). Building upon the established melanoma FISH criteria, we optimized a prognostic threshold of ≥2 FISH abnormalities specifically tailored for spitzoid neoplasms. We demonstrated that isolated single chromosomal aberrations (particularly MYB loss) are relatively stable events that are frequent in indolent ASTs, whereas our refined ≥2 threshold yielded 100% sensitivity and 92.5% specificity for predicting regional lymph node metastasis/local recurrence. Molecularly, NGS identified mutually exclusive initiating driver alterations (comprising kinase fusions and HRAS mutations) in 89.9% of true Spitz neoplasms, a remarkably high prevalence suggesting a distinct genetic background in Asian populations. We also characterized 5 entirely novel kinase fusions (ZNF24::ROS1, PCBP1::ROS1, NUMA1::RET, CBWD1::ALK, and TPR::NTRK1). Furthermore, NGS definitively segregated true Spitz neoplasms from morphological mimics (MSF), which lacked fusions and were driven by canonical genomic alterations of the conventional melanoma pathway. Integrating these genomic landscapes validated a stepwise progression model. Although isolated kinase fusions drove indolent ASTs, malignant SM invariably harbored concurrent pathogenic secondary alterations, demonstrating a profound reliance on CDKN2A/B, TP53, and CDK4 aberrations. Ultimately, we propose an integrated diagnostic algorithm combining morphological evaluation, the refined FISH threshold, and comprehensive NGS profiling, providing a precise, evidence-based framework for pathway classification and clinical management of spitzoid neoplasms.

9562 Background: Neoadjuvant immune checkpoint inhibitors (ICIs) have demonstrated efficacy in resectable cutaneous melanoma and are recommended by current guidelines. Nevertheless, the clinical benefit of combining ICIs with chemotherapy as neoadjuvant setting in Chinese patients remains to be established. This study is being conducted to explore the efficacy and safety of neoadjuvant toripalimab combined with temozolomide in resectable stage III melanoma. Methods: This is a prospective, single-center, single-arm clinical trial (ClinicalTrials.gov identifier: NCT05827770). Patients with resectable stage IIIB-IIID acral or cutaneous melanoma and an ECOG performance status of 0-1 were enrolled and received two cycles of neoadjuvant temozolomide 200 mg/m² plus toripalimab 240 mg every 3 weeks, followed by radical surgery. The primary endpoint was the pathologic response rate (pRR). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), recurrence-free survival (RFS), overall survival (OS) and safety. Results: As of December 2025, 20 eligible patients with resectable stage IIIB-IIID melanoma were enrolled, with 14 (70%) acral, 5 (25%) cutaneous and 1 (5%) of unknown primary. Of 20 patients underwent surgery, nine achieved pRR (45%), including 3 with near pathologic complete response (near pCR) and 6 with partial pathologic response (pPR). Radiological assessment showed partial response in 5 patients, stable disease in 12 patients, and progressive disease in 3 patients, yielding an objective response rate of 25% (5/20) and a disease control rate of 85% (17/20) according to RECIST criteria. With a median follow-up of 12 months, 8 recurrence-free survival events had been observed; the median RFS and OS had not yet been reached. Notably, one patient who attained near pCR remained relapse free for 27 months. No new safety signals were observed with the combination therapy. We further performed single-cell-resolution spatial transcriptomics and single-cell RNA sequencing in the current cohort. Integrative multi-omics analyses identified a T cell-excluded tumor microenvironment preferentially associated with non-response. Leveraging these features, we robustly distinguished immunotherapy responders from non-responders. Conclusions: This study demonstrates the preliminary efficacy and tolerability of toripalimab combined with temozolomide in the neoadjuvant treatment of patients with resectable stage IIIB-IIID acral and cutaneous melanoma. Given the fact that ICIs alone has limited response rate in acral melanoma, further studies are warranted. Clinical trial information: NCT05827770 . Treatment outcomes. Pathologic Response Eligible patients (%)N=20 Radiological Response Eligible patients (%)N=20 Near pCR 3 (15) PR 5 (25) pPR 6 (30) SD 12 (60) pNR 11 (55) PD 3 (15) pRR (pCR+Near pCR+pPR) 9 (45) ORR (CR+PR) 5 (25) DCR (CR+PR+SD) 17 (85)

AIMS:To develop and validate a deep learning framework for discriminating BRAF mutation status in cutaneous melanoma from routine H&E whole-slide images (WSIs) as a proof-of-concept complementary approach alongside molecular testing. METHODS:We built a two-stage pipeline comprising U-Net-based tumour segmentation followed by an Inception v3 classifier. In total, 272 institutional melanoma cases with confirmed BRAF status were used for model development (training and internal validation). Generalisability was assessed in an external test set of 76 cutaneous melanoma cases from the Cancer Genome Atlas (TCGA). Dermatopathologist-defined tumour-rich regions of interest were used to train and evaluate segmentation. WSIs were processed at 20×magnification using 512×512 tiles; slide-level mutation probabilities were obtained by averaging the predicted probabilities across all tumour-enriched tiles. RESULTS:Inception v3 achieved area under the receiver operating characteristic curve values of 0.973 (training), 0.954 (validation) and 0.915 (TCGA testing) and outperformed a ResNet50 baseline, showing stable external generalisation. Performance remained robust in advanced pathological T-category primary tumours (pT3-T4). Tumour probability heatmaps supported spatial interpretability by localising regions contributing most strongly to predicted mutation status. CONCLUSIONS:Deep learning applied to routine H&E WSIs can infer BRAF mutation status in cutaneous melanoma with consistent performance across institutional and external cohorts. Given the observed external sensitivity and negative predictive value, the model is not suitable for rule-out use or for deferring/omitting molecular testing. Any workflow integration is future work and would require prospective validation and calibration of probability outputs in real-world clinical series.

Diffusion-weighted imaging with higher b-value improves detection rate for prostate cancer lesions. However, obtaining high b-value DWI requires more advanced hardware and software configuration. Here we use a novel deep learning network, NAFNet, to generate a deep learning reconstructed (DLR1500) images from 800 b-value to mimic 1500 b-value images, and to evaluate its performance and lesion detection improvements based on whole-slide images (WSI). We enrolled 303 prostate cancer patients with both 800 and 1500 b-values from Fudan University Shanghai Cancer Centre between 2017 and 2020. We assigned these patients to the training and validation set in a 2:1 ratio. The testing set included 36 prostate cancer patients from an independent institute who had only preoperative DWI at 800 b-value. Two senior radiology doctors and two junior radiology doctors read and delineated cancer lesions on DLR1500, original 800 and 1500 b-values DWI images. WSI were used as the ground truth to assess the lesion detection improvement of DLR1500 images in the testing set. After training and generating, within junior radiology doctors, the diagnostic AUC based on DLR1500 images is not inferior to that based on 1500 b-value images (0.832 (0.788–0.876) vs. 0.821 (0.747–0.899), P = 0.824). The same phenomenon is also observed in senior radiology doctors. Furthermore, in the testing set, DLR1500 images could significantly enhance junior radiology doctors’ diagnostic performance than 800 b-value images (0.848 (0.758–0.938) vs. 0.752 (0.661–0.843), P = 0.043). DLR1500 DWIs were comparable in quality to original 1500 b-value images within both junior and senior radiology doctors. NAFNet based DWI enhancement can significantly improve the image quality of 800 b-value DWI, and therefore promote the accuracy of prostate cancer lesion detection for junior radiology doctors.

This study investigated the clinicopathological, immunohistochemical, and molecular features of primary leptomeningeal melanocytic neoplasms (LMNs). Twelve LMN cases were retrospectively reviewed. We performed Fluorescence in-situ hybridization (including a 4-probe FISH assay with CDKN2A and MYC assay) and NextGeneration sequencing analyses on available cases. Histologically, 2 tumours were classified as melanocytomas (MC), 2 as intermediate-grade melanocytomas (IMC), and 8 as leptomeningeal melanomas (LMM). Two rare cases of LMM were associated with large plaque-like blue nevus. One MC case was associated with Ota. Ten cases (83.3%) showed melanocytic cells with benign features diffusely proliferating within the meninges. The Ki-67 in three categories differed (MC 0-1%, IMC 0-3%, LMM 3-10%). 57.1% of LMM cases (4/7) were positive for FISH. Nine of 10 tumours harboured activating hotspot mutations in GNAQ, GNA11, or PLCB4. Additional mutations of EIF1AX, SF3B1, or BAP1 were found in 40%, 30%, and 10% of tumours, respectively. During the follow-up (median = 43 months), 5 LMM patients experienced recurrence and/or metastasis, 3 of them died of the disease and the other 2 are alive with the tumour. Our study is by far the first cohort of LMN cases tested by FISH. In addition to morphological indicators including necrosis and mitotic figures, using a combination of Ki-67 and FISH helps to differentiate between IMC and LMM, especially in LMM cases with less pleomorphic features. SF3B1 mutation is first described in 2 cases of plaque-type blue nevus associated with LMM. Patients with SF3B1 mutation might be related to poor prognosis in LMN.

Purpose: Metastatic ocular and orbital melanomas are extremely rare. The clinical characteristics and standard treatments for these patients are not fully established.Materials and Methods: We retrospectively analyzed patients with metastatic ocular and orbital melanoma from Fudan University Shanghai Cancer Center and Eye & ENT Hospital of Fudan University between January 2012 and May 2022.Results: Overall, 51 patients with metastatic ocular and orbital melanoma were included. The most common primary sites were uvea (73%), followed by conjunctiva (22%), lacrimal sac (4%), and orbit (2%). Patients with uveal melanoma (UM) had a significantly younger age (48 vs. 68 years, p < 0.001), higher incidence of liver metastases (89% vs. 9%, p<0.001), a lower incidence of lymph nodes metastases (16% vs. 46%, p = 0.043) and a lower incidence of BRAF mutation (0% vs. 55%, p<0.001) compared with patients with conjunctival melanoma (CM). The overall response rate of the first-line treatment was 18%. Three of the four patients with BRAF-mutated CM responded to dabrafenib and trametinib treatment. The median progression-free survival (PFS) and overall survival (OS) of first-line treatment were 5.1 and 11.9 months, respectively. Among patients with liver metastases, liver-directed treatment was correlated with better patient PFS (p < 0.001) and OS (p < 0.001) after adjusting for number of metastatic sites and primary sites.Conclusion: CM and UM have different characteristics. Patient with CM had a high incidence of BRAF mutation, and the treatment of BRAF and MEK inhibitors conferred clinical benefit. Liver directed therapies had a potential benefit in disease control in patients with liver metastases.

We aimed to apply a potent deep learning network, NAFNet, to predict adverse pathology events and biochemical recurrence-free survival (bRFS) based on pre-treatment MRI imaging. 514 prostate cancer patients from six tertiary hospitals throughout China from 2017 and 2021 were included. A total of 367 patients from Fudan University Shanghai Cancer Center with whole-mount histopathology of radical prostatectomy specimens were assigned to the internal set, and cancer lesions were delineated with whole-mount pathology as the reference. The external test set included 147 patients with BCR data from five other institutes. The prediction model (NAFNet-classifier) and integrated nomogram (DL-nomogram) were constructed based on NAFNet. We then compared DL-nomogram with radiology score (PI-RADS), and clinical score (Cancer of the Prostate Risk Assessment score (CAPRA)). After training and validation in the internal set, ROC curves in the external test set showed that NAFNet-classifier alone outperformed ResNet50 in predicting adverse pathology. The DL-nomogram, including the NAFNet-classifier, clinical T stage and biopsy results, showed the highest AUC (0.915, 95% CI: 0.871–0.959) and accuracy (0.850) compared with the PI-RADS and CAPRA scores. Additionally, the DL-nomogram outperformed the CAPRA score with a higher C-index (0.732, P < 0.001) in predicting bRFS. Based on this newly-developed deep learning network, NAFNet, our DL-nomogram could accurately predict adverse pathology and poor prognosis, providing a potential AI tools in medical imaging risk stratification.

Background: Sentinel lymph node biopsy (SLNB) helps to determine accurate pathological stages and facilitates strategies for regional disease control in melanoma. However, whether the number of biopsied sentinel lymph nodes (SLNs) influences the patients' survival is rarely investigated.Methods: Acral or cutaneous melanoma patients with no history of nodal disease who received SLNB in Fudan University Shanghai Cancer Center (FUSCC) from January 1, 2017, to December 31, 2021 were retrospectively enrolled. Clinicopathological variables including Breslow index, ulceration, number of positive SLNs, SLN/non-SLN status were analyzed. The pathologic nodal (pN) stage and pathological stage were defined.Results: A total of 381 eligible patients were enrolled in this study, of whom 132 (34.7%) patients were diagnosed with SLN-positive. The median number of biopsied SLNs was 2 (range: 1 to 20). Different numbers of biopsied SLNs did not influence the release-free survival (RFS) of the general patients. However, patients with >2 SLNs had a longer RFS than those with 1-2 SLNs in T4, N1a group and those who rejected complete lymph node dissection (CLND).Conclusions: In patients with T4 melanomas, N1a melanomas and those that did not undergo a CLND, the prognosis of those with three or more SLNs retrieved seemed to be improved.

Mucosal melanoma is a rare and highly malignant type of melanoma. Among the sites that mucosal melanoma arises, anorectal and gynecological melanoma has more aggressive behavior and worse prognosis. There was no effective therapy for mucosal melanoma at present. Only a small number of mucosal melanoma patients which harbor mutations in BRAF or KIT benefit from targeted therapy. So it’s an urgent need to identify more actionable mutations in mucosal melanoma. To identify more potential therapeutic targets in mucosal melanoma, 48 samples were collected from 44 patients with anorectal or gynecological melanoma and subjected to whole-exome sequencing. The tumor mutation burden was low with a median of 1.75 mutations per Mb. In chromosomal level, 1q, 6p and 8q of mucosal melanoma were significantly amplified while 9p, 10p, 10q, 16p and 16q were significantly deleted. Muc16 was the most frequently mutated oncogene in our samples(25%). The mutation frequency of KIT(20%) was comparable to the "triple-wild" genes-NRAS(20%), NF1(20%), and BRAF(11%). KMT2D mutation was found in 18.18% patients, which is previously unidentified. MAPK signaling pathway and lysine degradation were the most frequently mutated pathways. Moreover, patients with TP53 mutations tend to have worse clinical outcome (median survival time 19 vs. 50 months, log-rank P = 0.006). 2000 ore mutated genes involved in MAPK signaling pathway were identified, which expand the patients potentially benefit from ample MAPK inhibitors. KMT2D could be a potential therapeutic target. Moreover, TP53 could be a potential prognosis marker for mucosal melanoma.

Background: Metastasis in a nonsentinel lymph node (non-SLN) is an unfavorable independent prognostic factor in cutaneous melanoma (CM). Recent data did suggest potential value of completion lymph node dissection (CLND) in CM patients with non-SLN metastasis. Prediction of non-SLN metastasis assists clinicians in deciding on adjuvant therapy without CLND. We analyzed risk factors and developed a prediction model for non-SLN status in acral melanoma (AM). Methods: This retrospective study enrolled 656 cases of melanoma who underwent sentinel lymph node biopsy at Fudan University Shanghai Cancer Center from 2009 to 2017. We identified 81 SLN + AM patients who underwent CLND. Clinicopathologic data, including SLN tumor burden and non-SLN status were examined with Cox and Logistics regression models. Results: Ulceration, Clark level, number of deposits in the SLN (NumDep) and maximum size of deposits (MaxSize) are independent risk factors associated with non-SLN metastases. We developed a scoring system that combines ulceration, the cutoff values of Clark level V, MaxSize of 2 mm, and NumDep of 5 to predict non- SLN metastasis with an efficiency of 85.2% and 100% positive predictive value in the high-rank group (scores of 17-24). Conclusions: A scoring system that included ulceration, Clark level, MaxSize, and NumDep is reliable and effective for predicting non-SLN metastasis in SLNpositive AM.

The purpose of our study is to investigate the prognostic value of phosphatase and tensin homolog on chromosome 10 (PTEN) expression in patients with de novo metastatic castration naïve prostate cancer (mCNPC). A total of 205 patients with mCNPC at Fudan University Shanghai Cancer Center (Shanghai, China) were retrospectively examined. Immunohistochemical staining of PTEN was performed on prostate biopsy samples of these patients. Associations among clinicopathological features, patient survival and PTEN protein expression were analyzed. PTEN loss occurred in 58 of 205 (28.3%) patients. Loss of PTEN was significantly correlated with high metastatic volume (P = 0.017). No association between PTEN expression and Gleason score was observed. Patients with PTEN loss had significantly shorter progression-free survival (PFS, P < 0.001) and overall survival (OS, P < 0.001) compared with patients with intact PTEN expression. Multivariate analysis showed that elevated alkaline phosphatase, high metastatic volume and PTEN loss were independent poor prognostic factors for PFS. The Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2 and PTEN loss were independent poor prognostic factors for OS. The adjusted hazard ratio of PTEN loss for PFS and OS was 1.67 (95% confidence interval [CI]: 1.14–2.43, P = 0.008) and 1.95 (95% CI: 1.23–3.10, P = 0.005), respectively. PTEN loss was also significantly associated with shorter PFS (P = 0.025) and OS (P < 0.001) in patients with low-volume metastatic disease. Our data showed that PTEN loss is an independent predictor for shorter PFS and OS in patients with de novo mCNPC.

Individualized treatment of prostate cancer depends on an accurate stratification of patients who are sensitive to various treatments. Interleukin-23 (IL-23) was reported to play a significant role in prostate cancer. Here, we aimed to explore the clinical value of IL-23-secreting (IL-23+) cells in prostate cancer patients. We evaluated interleukin-23A (IL-23A) expression in The Cancer Genome Atlas database and retrospectively enrolled 179 treatment-naïve metastatic prostate cancer patients diagnosed in our institute between June 2012 and December 2014. IL-23+ cells were stained and evaluated via immunohistochemistry. Further, survival and multivariate Cox regression analyses were conducted to explore the prognostic value of IL-23+ cells. We found that IL-23A expression correlated with disease progression, while IL-23+ cells were clearly stained within prostate cancer tissue. Patients with higher Gleason scores and multiple metastatic lesions tended to have more IL-23+ cell infiltration. Further analyses showed that patients with higher levels of IL-23+ cells had significantly worse overall survival (hazard ratio [HR] = 2.996, 95% confidence interval [95% CI]: 1.812–4.955; P = 0.001) and a higher risk of developing castration resistance (HR = 2.725, 95% CI: 1.865–3.981; P = 0.001). Moreover, subgroup analyses showed that when patients progressed to a castration-resistant status, the prognostic value of IL-23+ cells was observed only in patients treated with abiraterone instead of docetaxel. Therefore, we showed that high IL-23+ cell infiltration is an independent prognosticator in patients with metastatic prostate cancer. IL-23+ cell infiltration may correlate with abiraterone effectiveness in castration-resistant prostate cancer patients.

OBJECTIVE:To investigate the clinical significance of the expression of the stemness marker CD133 in circulating tumor cells of newly diagnosed metastatic castration-sensitive prostate cancer patients.METHODS:For this study, 104 metastatic castration-sensitive prostate cancer patients treated at the Fudan University Shanghai Cancer Center from September 2015 to February 2017 were considered. After enrollment, the patients received androgen deprivation therapy (bicalutamide + goserelin). Circulating tumor cells were isolated and identified using the CanPatrol system, which can identify not only traditional epithelial markers but also mesenchymal markers in cells that have undergone epithelial mesenchymal transition. CD133 was used to characterize the circulating tumor cells. The primary endpoint of this research was to evaluate progression to castration resistance.RESULTS:Among the 104 patients enrolled, 89 patients were circulating tumor cell positive at baseline, and the median circulating tumor cell count was four. The median follow-up was 24 months, and at the end of follow-up, the proportion of patients who progressed to castration-resistant prostate cancer in the CTC+CD133+ group was 93.3%, which was significantly higher than that of the circulating tumor cell negative group (73.3%) and the CTC+CD133- group (75.0%), with P = 0.043. After follow-up, progression-free survival for CTC+CD133+, CTC+CD133-, and circulating tumor cell patients was 10.0, 13.0, and 14.0 months, respectively, with P = 0.022. Univariate and multivariate analyses also confirmed that the characterization of circulating tumor cells using CD133 can independently predict progression-free survival in metastatic castration-sensitive prostate cancer patients after receiving androgen deprivation therapy (P = 0.042; hazard ratio 1.396).CONCLUSION:Baseline CTC+CD133+ was a poor independent prognostic factor for metastatic castration-sensitive prostate cancer patients to progress to castration-resistant prostate cancer after receiving androgen deprivation therapy.

Background: Previous studies suggested that men with metastatic prostate cancer might benefit from local treatment of the primary tumor. Objective: To determine whether radical local therapy (RLT) improves survival for men with oligometastatic prostate cancer (OMPCa). Design, setting, and participants: This open-label randomized controlled trial included patients with newly diagnosed OMPCa defined as five or fewer bone or extrapelvic lymph node metastases and no visceral metastases. Intervention: Patients were randomly allocated to androgen deprivation therapy (ADT) or ADT and RLT. Men allocated RLT received either cytoreductive radical prostatectomy (RP) or prostate radiation therapy (RT) with a radical dose schedule. Outcome measurements and statistical analysis: The primary outcome was radiographic progression-free survival (rPFS). Secondary outcomes were overall survival (OS) and prostate-specific antigen (PSA) progression-free survival. Results and limitations: Between September 2015 and March 2019, 200 patients were randomized, with 100 men allocated to each group. The median age was 68 yr and the median PSA at diagnosis was 99 ng/ml. In the study group, 96 patients underwent RLT (85 RP and 11 RT). In the control group, 17 patients eventually received RLT (15

Preferentially expressed antigen in melanoma (PRAME) has shown promising utility in distinguishing benign melanocytic lesions from melanomas, but knowledge of its expression pattern in acral lentiginous melanoma (ALM) and acral nevi (ANs) is limited. Immunohistochemical expression of PRAME was examined in 75 ALMs and 34 ANs. The clinical and histopathologic characteristics of patients with ALM were collected. PRAME was immunoreactive in 89.3% (67/75) of ALMs, but entirely negative in 94.1% (32/34) of ANs. When staining at least 50% of lesional melanocytes was determined as positivity, the sensitivity and specificity of PRAME for distinguishing ALM from ANs were 69.3% and 100%, respectively. Seventy-one cases of ALMs had tumor cells in the epidermis; 71.8% (51/71) of them showed positive for PRAME. By contrast, 61 ALMs had tumor cells in the dermis; 65.6% (40/61) exhibited positive expression. Twenty-nine of 39 (74.4%) epithelioid cell ALMs were observed to be positive for PRAME. By comparison, 63.8% (23/36) of ALMs with spindle tumor cells were positive for PRAME. However, PRAME positive expression was not associated with any clinical and histopathologic characteristics of patients with ALM, including Breslow thickness, ulcer, cytomorphology, lymph node metastasis, or tumor-infiltrated lymphocytes (TILs). Nevertheless, we observed that 82.6% (19/23) of ALMs with lymph node involvement at diagnosis expressed PRAME, compared with 57.6% (20/35) of those without. In summary, PRAME immunohistochemistry can serve as a helpful adjunct in the differential diagnosis of ALMs and ANs with good sensitivity and high specificity. Additionally, PRAME tends to have a higher positive rate in epidermal melanocytes than in the dermis and is inclined to express in epithelioid cells than in spindle cells of ALMs.

Background Discrepancies in genetic alterations found in melanoma are conspicuous between different ethnic groups. With the approval of BRAF- and MEK-targeted inhibitors in China, it is necessary to further elucidate the landscape of gene mutation in Chinese melanoma patients. Methods The frequency and distribution of BRAF, C-KIT, and NRAS mutations in 691 melanoma patients was determined, and the statistical significance of correlations between different gene mutations and clinicopathological features was analyzed. Results Among a total of 691 patients, BRAF mutation was found in 166 patients (24.0%), and V600E was the prominent genetic alteration (145/166, 87.3%). Statistical analyses showed that younger patients (<60) had a higher BRAF mutation rate than older patients (≥60, P=0.000), and the frequency of BRAF mutation was more likely to be lower in patients with the following: melanoma located in an extremity (P=0.000), acral-lentiginous melanoma subtype (P=0.000), thinner melanoma thickness (P=0.047), and no ulceration (P=0.030). The frequency of NRAS mutation was 12.6% (38/302), and primarily involved codon 61 in exon 3 and codon 12 in exon 2. Mutation of C-KIT was detected in 65 patients (9.4%), and the most common site of mutations was L576 in exon 11 (29/65, 44.6%). Patients with NRAS or C-KIT mutation had higher Clark level (P=0.035 and 0.047, respectively) and were more likely to have melanoma located in an extremity (P=0.003 and 0.009, respectively) than those without such mutation. The concordance of gene mutations between paired primary and metastatic lesions was 89.6% (60/67), and visceral metastases showed the highest distribution of gene mutations versus primary melanomas (100.0%) compared with lymph nodes (90.9%) and cutaneous metastases (83.3%). Conclusions In this large cohort of Chinese melanoma patients, the frequencies of BRAF and NRAS mutations were lower than those observed in Caucasian cohorts, but the clinicopathological features of BRAF, C-KIT, and NRAS mutation were consistent. Paired primary and metastatic lesions showed high concordance of gene mutations.

Background. Mucosal melanoma is rare and has distinct clinical and genetic features. Even with advances in targeted and immune therapies, the survival of patients with advanced or recurrent mucosal melanomas remains poor. The standard treatment remains controversial and we conducted this real-world study aimed to explore continuous intravenous recombinant human endostatin (Rh-endostatin) infusion plus chemotherapy in this population in the first-line setting. Methods. Overall, 43 patients with advanced or recurrent mucosal melanoma treated at Fudan University Shanghai Cancer Center between April 2017 and August 2020 were retrospectively included. Patients received dacarbazine plus cisplatin or temozolomide plus cisplatin per the investigators’ preference. Rh-endostatin (105 mg/m2) was administered with continuous infusion for 168 h (Civ 168 h). Results. Of the 43 patients, 72.1% had metastatic disease, and the most common primary site was the gastrointestinal tract (51.2%). The most commonly observed mutations were NRAS (23.1%), BRAF (7.7%) and CKIT mutations (5.1%). An objective response was observed in 12 (30.0%) of the 40 evaluable patients, and disease control was achieved in 31 (77.5%) patients. With a median follow-up of 17.6 months, the median progression-free survival (PFS) and overall survival (OS) were 4.9 and 15.3 months, respectively. Additionally, high lymphocyte-to-monocyte ratio (LMR) (p = 0.023, HR 0.29, 95% CI: 0.10–0.84) and BRAF/KIT/RAS mutation (p = 0.028, HR 0.24, 95% CI: 0.07–0.86) were independently correlated with prolonged OS. Toxicity was manageable overall. Conclusion. Continuous Rh-endostatin infusion plus chemotherapy was effective and safe for the treatment of advanced or recurrent mucosal melanoma. High LMR was correlated with favorable PFS and OS in this patient population.

e21517 Background: Mucosal melanoma is rare and has distinct clinical and genetic features. Even with advances in targeted and immune therapy, the survival of patients with advanced or recurrent mucosal melanomas remains poor. The standard treatment remains controversial and we conducted this real-world study aimed to test continuous intravenous Endostar infusion plus chemotherapy in patients with advanced or recurrent mucosal melanoma in the first-line setting. Methods: In total, all 43 patients with advanced or recurrent mucosal melanoma treated at Fudan University Shanghai Cancer Center between April 2017 and August 2020 were retrospectively included. Patients received dacarbazine plus cisplatin or temozolomide plus cisplatin regimens per the investigators’ preference. Endostar (105 mg/m2) was administered with continuous infusion for 168 hours (Civ 168h). Results: Of the 43 patients, 72.1% had metastatic disease, and 27.9% had locally advanced disease. The most common primary site was the gastrointestinal tract (51.2%), followed by the sinonasal tract (32.6%) and genitourinary tract (14.0%). The most commonly observed mutation was NRAS (23.1%), followed by BRAF (7.7%) and CKIT (5.1%). An objective response was observed in 12 (30.0%) of the 40 evaluable patients, and disease control was achieved in 31 (77.5%) patients. With a median follow-up of 17.6 months, the median progression-free survival (PFS) and overall survival (OS) were 4.9 and 15.3 months, respectively. Multivariate analysis indicated a high lymphocyte-to-monocyte ratio (LMR) was significantly correlated with favorable PFS (p = 0.012, hazard ratio [HR] 0.28, 95% CI: 0.10-0.76). Additionally, a high LMR (p = 0.023, HR 0.29, 95% CI: 0.10-0.84) and BRAF/KIT/RAS mutation (p = 0.028, HR 0.24, 95% CI: 0.07-0.86) were independently correlated with prolonged OS. Toxicity was manageable overall. Conclusions: Continuous Endostar infusion in combination with chemotherapy was effective and safe for the treatment of advanced or recurrent mucosal melanoma. Additionally, a high LMR was correlated with favorable PFS and OS in this patient population.