Epidemiology and survival analysis of Merkel cell carcinoma in South Korea: a nationwide, multicenter retrospective study.

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer, of which most research has been conducted in Caucasians. Therefore, the clinicopathological features and prognosis of Merkel cell carcinoma in Asians are still scarce. The aim of this study is to investigate the epidemiology and survival of MCC in South Korea and provide representative information regarding MCC in Asia. This was a retrospective, nationwide, multicenter study conducted in 12 centers across South Korea. Patients with pathologically proven MCC were included in the study. The clinicopathological features and clinical outcomes of the patients were investigated. Overall survival (OS) was analyzed using the Kaplan-Meier method, and independent prognostic factors were identified using Cox regression analysis. A total of 161 patients with MCC were evaluated. The mean age was 71 years with a female predominance. OS was significantly different among the stages. Among clinicopathological features, multivariate Cox regression analysis demonstrated that only the stage at diagnosis was associated with poorer overall survival. The results of our study suggest that the incidence of MCC was higher in females than in males and that there was a higher rate of local disease at the time of diagnosis. Among the variable clinicopathological features, disease stage at diagnosis was the only significant prognostic factor for MCC in South Korea. The findings of this nationwide, multicenter study suggest that MCC has distinct features in South Korea compared with other countries.

Choi JW ，Kim YH ，Mun JH ，Jo SJ ，Roh MR ，Chung KY ，Yun SJ ，Lee JB ，Yun SK ，Kim MS ，Kim HJ ，Kim KH ，Kim IH ，Park JH ，Li K ，Kim YC ，Korean Society of Skin Cancer (KSSC) ... -  《-》

Clinicopathological characteristics and prognosis of Merkel cell carcinoma: a single-center retrospective study in Korea.

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin with high mortality. However, its clinical characteristics in Asian patients remain uncertain owing to its low incidence. To analyze the clinicopathological features of MCC and identify factors associated with its prognosis. The medical records of 62 patients with MCC were retrospectively reviewed. Data on clinical features, survival outcomes, prognostic factors, histopathology and immunohistochemical profile of the patients were collected and analyzed. Merkel cell polyomavirus status was evaluated using immunohistochemistry. The incidence of MCC significantly increased over time. The mean duration of follow-up was 51.2 months, with an overall 5-year survival of 80.6%. More female patients with MCC were identified than male patients (1.3:1). Approximately half of the patients had stage I disease at the time of initial presentation. The primary tumor was frequently located in the lower extremities (40.3%), followed by the head and neck (32.3%), upper extremities (22.6%), and the trunk (4.8%). Male sex was associated with poorer overall survival (p = 0.003). Post-resection adjuvant radiotherapy significantly improved the overall survival (p = 0.023). Sentinel lymph node biopsy during surgery ameliorated the progression-free survival (p = 0.036) in patients with stage I or II cancer. Lymphovascular and perineural invasion were associated with a poor prognosis. Old age, immunohistochemical profiles, and Merkel cell polyomavirus-positivity were not associated with prognosis. Post-surgical adjuvant radiotherapy and sentinel lymph node biopsy significantly improve the course of MCC.

Moon IJ ，Na H ，Cho HS ，Won CH ，Chang SE ，Lee MW ，Lee WJ ... -  《-》

Different prognosis in cutaneous early-onset and late-onset Merkel cell carcinoma: a population-based retrospective study.

Merkel cell carcinoma (MCC) is a rare and highly aggressive form of skin cancer. However, there is limited research on the clinicopathological features of early-onset MCC (EOMCC) and the differences between EOMCC and late-onset MCC (LOMCC). Our objective was to evaluate the clinicopathological features and cancer-specific survival (CSS) of EOMCC. Our cohort study analyzed data from the Surveillance, Epidemiology, and End Results (SEER) database from January 1, 2018, to December 31, 2020. Data from 1941 patients who were diagnosed with primary cutaneous MCC were included. We then divided the patients with MCC into two groups: those with EOMCC (526 patients) and those with LOMCC (1415 patients). CSS is used as the primary outcome. The EOMCC group exhibited trends toward advanced tumor progression, an expanded surgical scope, increased lymph node retrieval, intensified radiotherapy, greater utilization of systemic therapy, and a better prognosis. Multivariate analysis revealed that LOMCC (HR 3.305 [2.002-5.456], P < 0.001), advanced T stage (HR 1.430 [1.139-1.797], P = 0.002), advanced N stage (HR 1.522 [1.221-1.897], P < 0.001), M1 stage (HR 2.587 [1.480-4.521], P < 0.001), and radiation (HR 0.586 [0.410-0.837], P = 0.003) were significantly associated with CSS. Among these factors, EOMCC/LOMCC was most strongly associated with CSS, indicating that LOMCC is an independent risk factor for CSS. Interestingly, we found that regional EOMCC and localized or in situ LOMCC had almost completely overlapping survival curves (Plog-rank = 0.620). Additionally, we observed that the TNM staging + age model was a more accurate predictor of CSS among MCC patients than using TNM staging alone. We found that EOMCC has distinct clinicopathological features compared to LOMCC. EOMCC is associated with better CSS. The combination of TNM staging and age was more accurate for predicting patient outcomes than TNM staging alone.

Li Z ，Hu B ，Kang L ，Zeng S ，Xiao Y ，Yu N ，Huang J ，Long X ... -  《-》

Merkel cell carcinoma: identification of prognostic factors unique to tumors located in the head and neck based on analysis of SEER data.

Merkel cell carcinoma (MCC) is an aggressive cutaneous neoplasm that occurs most frequently in the head and neck region. Because of its rarity, prognostic factors are poorly characterized. Head and neck MCC (HN-MCC) may require separate consideration from MCC that occurs in other anatomic regions. Our objective was to determine the relevance of clinicopathologic parameters as prognostic factors in a large series of patients with HN-MCC and to compare these to a series of patients with non-head and neck MCC (NHN-MCC). Retrospective analysis of large population database. Patients with MCC were identified using the Surveillance, Epidemiology, and End Results database and categorized according to tumor location either 1) within or 2) outside of the head and neck region. Clinicopathologic data were compared between groups. Retrospective univariable and multivariable analyses of factors associated with disease-specific survival (DSS) were performed. We identified 2,104 patients with HN-MCC and 2,272 with NHN-MCC. DSS was similar between groups. Independent prognostic factors in HN-MCC are male sex (P < .001), lip primary site (P = .005), tumor extension beyond the dermis (P = .03), histologically confirmed nodal disease (P < .001), absence of histologic lymph node evaluation (P = .01), and distant metastasis (P = .001). Male sex and tumor extension limited to the subcutis are prognostic factors that are unique to HN-MCC. Because independent markers of aggressive disease appear to be unique in HN-MCC, it is important that future studies provide separate consideration for HN-MCC to allow for the most accurate identification of prognostic indicators and assessment of treatment outcomes accordingly.

Smith VA ，Camp ER ，Lentsch EJ 《-》

Tumor location is an independent prognostic factor in head and neck Merkel cell carcinoma.

Smith VA ，MaDan OP ，Lentsch EJ 《-》