{"title":"Melanoma skin cancer statistics derived from 7442 Japanese patients: Japanese melanoma study.","authors":"Yasuhiro Fujisawa, Shusuke Yoshikawa, Tatsuya Takenouchi, Shoichiro Mori, Jun Asai, Hisashi Uhara, Yuki Ichigosaki, Taku Fujimura, Yoshiyuki Nakamura, Yasuhiro Nakamura, Fumitaka Ohno, Takeshi Fukumoto, Toshiyuki Ozawa, Kenjiro Namikawa, Satoru Sugihara, Toshihiko Hoashi, Takatoshi Shimauchi, Yu Sawada, Hiroaki Iwata, Taku Maeda, Takuya Miyagawa, Yoshitsugu Shibayama, Naohito Hatta, Akiko Kishi, Masashi Ishikawa, Hisao Kawahira, Norito Katoh, Ryuhei Okuyama","doi":"10.1007/s10147-025-02747-9","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Malignant melanoma (MM) is a rare but aggressive cutaneous cancer, accounting for only 2% of skin cancers in Japan but nearly half of skin cancer-related deaths. While the global incidence of MM is rising, its epidemiology varies significantly by ethnicity and geographic region. In Japan, melanoma incidence remains lower than in Western countries, with acral lentiginous melanoma (ALM) being the most prevalent subtype. However, comprehensive epidemiological and clinical data remain limited.</p><p><strong>Methods: </strong>We analyzed data from 7442 Japanese melanoma patients collected between 2005 and 2022 through the Japanese Melanoma Study (JMS). Demographic, clinical, and survival data were evaluated, including subtype distribution, TNM staging, and treatment outcomes.</p><p><strong>Results: </strong>ALM was the most common subtype (40.8%), followed by superficial spreading melanoma (20.2%). Lymph node metastasis was observed in 28.6% of cases, and distant metastasis in 10.9%. The BRAF mutation rate was 27.2%, with significantly lower frequencies in ALM (8.5%) and mucosal melanoma (4.8%). Among Stage IV patients, those treated with both immune checkpoint inhibitors (ICIs) and BRAF(+ MEK) inhibitors demonstrated significantly improved survival compared to chemotherapy alone (P < 0.05). Adjuvant BRAF(+ MEK) inhibitor therapy also resulted in superior relapse-free survival compared to those who did not receive adjuvant therapy (P < 0.005).</p><p><strong>Conclusion: </strong>This study provides the largest dataset of Japanese melanoma patients to date, highlighting distinct epidemiological and clinical characteristics. Given their lower BRAF mutation rates and the limited efficacy of current ICI treatments, these findings emphasize the urgent need for optimize immunotherapy strategies in Japanese melanoma patients.</p>","PeriodicalId":13869,"journal":{"name":"International Journal of Clinical Oncology","volume":" ","pages":""},"PeriodicalIF":2.4000,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Clinical Oncology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s10147-025-02747-9","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ONCOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Malignant melanoma (MM) is a rare but aggressive cutaneous cancer, accounting for only 2% of skin cancers in Japan but nearly half of skin cancer-related deaths. While the global incidence of MM is rising, its epidemiology varies significantly by ethnicity and geographic region. In Japan, melanoma incidence remains lower than in Western countries, with acral lentiginous melanoma (ALM) being the most prevalent subtype. However, comprehensive epidemiological and clinical data remain limited.
Methods: We analyzed data from 7442 Japanese melanoma patients collected between 2005 and 2022 through the Japanese Melanoma Study (JMS). Demographic, clinical, and survival data were evaluated, including subtype distribution, TNM staging, and treatment outcomes.
Results: ALM was the most common subtype (40.8%), followed by superficial spreading melanoma (20.2%). Lymph node metastasis was observed in 28.6% of cases, and distant metastasis in 10.9%. The BRAF mutation rate was 27.2%, with significantly lower frequencies in ALM (8.5%) and mucosal melanoma (4.8%). Among Stage IV patients, those treated with both immune checkpoint inhibitors (ICIs) and BRAF(+ MEK) inhibitors demonstrated significantly improved survival compared to chemotherapy alone (P < 0.05). Adjuvant BRAF(+ MEK) inhibitor therapy also resulted in superior relapse-free survival compared to those who did not receive adjuvant therapy (P < 0.005).
Conclusion: This study provides the largest dataset of Japanese melanoma patients to date, highlighting distinct epidemiological and clinical characteristics. Given their lower BRAF mutation rates and the limited efficacy of current ICI treatments, these findings emphasize the urgent need for optimize immunotherapy strategies in Japanese melanoma patients.
期刊介绍:
The International Journal of Clinical Oncology (IJCO) welcomes original research papers on all aspects of clinical oncology that report the results of novel and timely investigations. Reports on clinical trials are encouraged. Experimental studies will also be accepted if they have obvious relevance to clinical oncology. Membership in the Japan Society of Clinical Oncology is not a prerequisite for submission to the journal. Papers are received on the understanding that: their contents have not been published in whole or in part elsewhere; that they are subject to peer review by at least two referees and the Editors, and to editorial revision of the language and contents; and that the Editors are responsible for their acceptance, rejection, and order of publication.