Opinion statement
Melanoma has several clinically and pathologically distinguishable subtypes, which also differ genetically. Mutation patterns vary among different melanoma subtypes, and efficacy of ...immune-checkpoint inhibitors differs depending on the subtype of melanoma. In spite of the recent revolution of systemic therapies for advanced melanoma, access to innovative agents is still restricted in many countries. This review article aimed to describe the epidemiology and current status of systemic therapies for melanoma in Japan, where melanoma is rare, but access to innovative agents is available. Acral and mucosal melanomas, which are common in Asian populations, predominantly occur in sun-protected areas and share several biological features. Both the melanomas harbor KIT mutation in approximately 15% of the cases; BRAF or NRAS mutation is found in approximately 10–15% of acral melanoma, but these mutations are less frequent in mucosal melanoma. Combined use of BRAF and MEK inhibitors is one of the standards of care for patients with advanced BRAF-mutant melanoma. In patients with melanoma harboring KIT mutation in exon 11 or 13, KIT inhibitors can be a treatment option; however, none of them have been approved in Japan. Immune-checkpoint inhibitors are expected to be less effective against acral and mucosal melanomas because their somatic mutation burden is lower than those in non-acral cutaneous melanomas. A recently completed phase II trial of nivolumab and ipilimumab combination therapy in 30 Japanese patients with melanoma, including seven with acral and 12 with mucosal melanoma, demonstrated an objective response rate of 43%. Regarding oncolytic viruses, canerpaturev (C-REV, also known as HF10) and talimogene laherparepvec (T-VEC) are currently under review in early phase trials. In the adjuvant setting, dabrafenib plus trametinb combination, nivolumab monotherapy, and pembrolizumab monotherapy were approved in July, August, and December 2018 in Japan, respectively. However, most of the adjuvant phase III trials excluded patients with mucosal melanoma. A phase III trial of adjuvant therapy with locoregional interferon (IFN)-β versus surgery alone is ongoing in Japan (JCOG1309, J-FERON), in which IFN-β is injected directly into the site of the primary tumor postoperatively, so that it would be drained through the untreated lymphatic route to the regional node basin. After the recent approval of these new agents, the JCOG1309 trial will be revised to focus on patients with stage II disease. In conclusion, acral and mucosal melanomas have been treated based on the available medical evidence for the treatment of non-acral cutaneous melanomas. Considering the differences in genetic backgrounds and therapeutic efficacy of immunotherapy, specialized therapeutic strategies for these subtypes of melanoma should be established in the future.
The distribution and incidence of melanoma vary among different races and ethnic groups. This study aimed to investigate the characteristics of cutaneous melanoma, mucosal melanoma, uveal melanoma, ...and melanoma of unknown primary (MUP) origin in a Japanese population. We studied these four types of melanoma in patients registered in Hospital Based Cancer Registries in Japan from 2011 to 2013. A total of 5566 patients with melanoma were identified. The distribution of sex, age, primary site, and clinical stage was analyzed. The number of patients, proportion in comparison with all melanoma cases, and crude incidence rate per 100 000 person-year of each melanoma type were 4481, 80.5%, and 1.24 in invasive cutaneous; 821, 14.8%, and 0.32 in mucosal; 163, 2.9%, and 0.064 in uveal; and 101, 1.8%, and 0.039 in MUP origin, respectively. Including the patients with in-situ cutaneous melanoma and stage unknown cutaneous melanoma, the crude incidence rate of cutaneous melanoma increased at 1.75. Almost half of the cutaneous melanomas were located in the lower limb. Cutaneous melanoma was the most common, but less frequent than that in western countries. Mucosal melanoma was quite rare, but its proportion and crude incidence rate were higher than those in western countries. Uveal melanoma was particularly rare, and its crude incidence rate was lower than that in western countries. MUP origin was also particularly rare, but it had almost the same incidence rate as that in other countries. Melanoma in Japan was heterogeneous among the four melanoma types and shares some attributes with that in western countries.
Abstract
In the eighth edition of the American Joint Committee on Cancer Staging Manual, several modifications were made for melanoma. These modifications were aimed at improving the prognosis ...prediction accuracy of the staging system. The main modifications are as follows: the cutoff value of the T1 category has been changed, and there are new classifications of stage IIID and of M1d (metastasis of the central nervous system). These changes will allow for more accurate stratification of melanoma prognosis. However, it is necessary to validate the new modifications through future clinical research.
We summarized the changes in the eighth edition of the American Joint Committee on Cancer Staging Manual for melanoma. These changes will allow for a more accurate stratification of melanoma prognosis.
An anti-programmed cell death protein 1 monoclonal antibody, nivolumab, is one of the most effective drugs for advanced melanoma. Tumor cell-derived or immune cell-derived markers and clinical ...predictors such as serum lactate dehydrogenase (LDH) and cutaneous adverse events, have already been described as prognostic factors for advanced melanoma treated with nivolumab. We sought to identify further clinical predictors that can be determined in routine clinical practice.
We retrospectively analyzed clinical findings of 98 consecutive patients with unresectable stage III or IV melanoma treated with nivolumab, at the National Cancer Center Hospital or at Keio University Hospital, in Tokyo, Japan, between July 2014 and July 2016. These patients had been administered nivolumab at a dose of 2mg/kg every 3 weeks.
As for pretreatment prognostic factors, ECOG performance status (PS) ≥1, maximum tumor diameters of ≥30mm, elevated LDH and elevated C-reactive protein were significantly associated with poor overall survival (OS) (hazard ratio HR 0.29 P<0.001, HR 0.40 p=0.003, HR 0.29 P<0.001, HR 0.42 P=0.004, respectively) on univariate analysis. Among these factors, PS and LDH were identified as independent variables by multivariate analysis. As for early markers examined during therapy, patients with absolute lymphocyte count (ALC) ≥ 1000/μl (Week3: HR 0.40 P=0.004, Week6: HR 0.33 P=0.001) and absolute neutrophil count (ANC) <4000/μl (Week3: HR 0.46 P=0.014, Week6: HR 0.51 P=0.046) had significantly better OS.
ALC≥1000/μl and ANC<4000/μl during treatment appear to be early markers associated with OS. Nivolumab might have minimal efficacy in patients with a massive tumor burden.
Skin cancer is most frequently diagnosed in the White population. However, its subtypes and epidemiology in Japan are understudied. We aimed to elucidate skin cancer incidence in Japan based on the ...National Cancer Registry, a new nationwide integrated population‐based registry. Data from patients diagnosed with skin cancer in 2016 and 2017 were extracted and classified by cancer subtypes. Data were analyzed using the World Health Organization and General Rules tumor classifications. Tumor incidence was calculated as the number of new cases divided by the corresponding total person‐years. Overall, 67,867 patients with skin cancer were included. The percentage of each subtype was as follows: basal cell carcinoma, 37.2%; squamous cell carcinoma, 43.9% (18.3% of which, in situ); malignant melanoma, 7.2% (22.1% of which, in situ); extramammary Paget's disease, 3.1% (24.9% of which, in situ); adnexal carcinoma, 2.9%; dermatofibrosarcoma protuberans, 0.9%; Merkel cell carcinoma, 0.6%; angiosarcoma, 0.5%; and hematologic malignancies, 3.8%. The overall age‐adjusted incidence of skin cancer was 27.89 for the Japanese population model and 9.28 for the World Health Organization (WHO) model. The incidences of basal cell carcinoma and squamous cell carcinoma were the highest (3.63 and 3.40 per 100,000 persons, respectively, in the WHO model) among skin cancers, whereas the incidences of angiosarcoma and Merkel cell carcinoma were the lowest (0.026 and 0.038 per 100,000 persons, respectively, in the WHO model). This is the first report to provide comprehensive information on the epidemiological status of skin cancers in Japan using population‐based NCR data.
The Japan NCR yielded data from 67,867 patients with skin cancer. The incidence of BCC and SCC was the first and second highest, respectively. The study may guide the development of needed treatments for skin cancers in Japan.
With consideration of the ongoing developments in treatment options for cutaneous melanoma, the Japanese Skin Cancer Society published the first guidelines for cutaneous melanoma in 2007 and later ...revised them in 2015. Here, we report on an English version of the 2019 Japanese Melanoma Guidelines. In this latest edition, all processes were carried out according to the Grading of Recommendations, Assessment, Development and Evaluation system. A comprehensive published work search, systematic review and determination of recommendations in each clinical question were performed by a multidisciplinary expert panel consisting of dermatologists, a plastic and reconstructive surgeon, and a radiation oncologist. The advent of novel agents, such as immune checkpoint inhibitors and molecular‐targeted agents, has drastically changed the nature of treatment for adjuvant and advanced‐stage diseases among melanoma patients worldwide. Additionally, recent reports of clinical trials regarding surgical procedures and a better understanding of molecular biology and tumor immunology in clinical types of melanoma have had an impact on clinical practise. Based on these viewpoints, eight relevant clinical questions were raised in this report that aim to help clinicians select the appropriate therapeutic approach.
We conducted a retrospective investigation of the efficacy and safety of dabrafenib and trametinib combination therapy in Japanese patients with BRAF V600 mutation‐positive advanced melanoma in ...real‐world clinical practise. The study analyzed 50 patients who received dabrafenib and trametinib combination therapy for BRAF V600 mutation‐positive advanced melanoma in our hospital (26 men and 24 women, aged 21–86 years, inclusive; median age, 53 years). The response rate was 72.3%, with complete response (CR) achieved in eight cases (17.0%), partial response in 26 (55.3%), stable disease in nine (19.1%) and progressive disease in four (8.5%). Median progression‐free survival (PFS) was 12 months, and median overall survival (OS) was 23 months. Disease progression occurred in 29 of the 50 patients during the study period, and 25 patients died. Baseline lactate dehydrogenase and the number of organs with metastasis were important predictive factors for PFS and OS, and CR to combination therapy was a predictive factor for long‐term remission. Adverse events occurred in 88% of cases; 16% were grade 3 or worse. The adverse events observed in 50% of more of patients were rash (56%) and pyrexia (52%). The efficacy of dabrafenib and trametinib combination therapy in Japanese patients was similar to that reported in global studies, and the same adverse events were generally reported; however, rash tended to occur more frequently in the patients in our study.
Cutaneous angiosarcomas is a rare cancer with poor prognoses. The common radiotherapy techniques that have been reported so far are two pairs of lateral X-ray and electron fields. However, it is ...quite difficult to irradiate scalp angiosarcomas (SAs) homogeneously with this technique. In this study, safety, effectiveness, and risk factors were assessed for localized SAs ≥ 5 cm treated with intensity-modulated radiotherapy (IMRT) or volumetric modulated arc therapy (VMAT) with boluses. Sixty-eight angiosarcoma patients who had received radiotherapy in our institution between January 2007 and November 2020 were retrieved from our radiotherapy database. Of these patients, 27 localized SA patients were included in the retrospective analysis. The 2-year overall survival, local progression-free rate, and distant metastases-free survival were 41.8%, 48.4%, and 33.1%. All the patients experienced acute radiation dermatitis ≥ grade 2, with18 (66.7%) ≥ grade 3. No nodule lesion was a significant unfavorable predictive factor of acute radiation dermatitis ≥ grade 3. Tumor bleeding at the initiation of radiotherapy and tumor invasion to the face were significant predictive factors of overall survival, and tumor bleeding at the initiation of radiotherapy was also a significant predictive factor of local progression-free rate.
Malignant melanoma (MM) is usually resistant to radiotherapy. Brachytherapy may be an option in patients with bleeding or pain, and those in whom surgery is difficult. Brachytherapy has few side ...effects and can be used in combination with external beam radiotherapy or chemotherapy. We summarize the demographic and clinical characteristics of 15 patients who received brachytherapy for MM at our hospital and describe two of these representative cases. Patient 1 had an approximately 10‐mm, dark‐red nodule near the external urethral meatus. Excision was not performed to preserve urethral function. A gradual improvement was observed after 48 Gy of remote afterloading system (RALS) brachytherapy and nivolumab therapy. Patient 2 had a 38‐mm, black tumor on the vagina. Post‐resection, RALS brachytherapy was administered to treat the residual black macule and a lesion quickly disappeared. In all 15 cases, nine patients received radiotherapy for local control and six patients received palliative radiotherapy to reduce symptoms such as bleeding and pain. The irradiation site was the vagina in six patients, lymph node metastasis in five, head and neck in two, skin or subcutaneous metastases in two, and the anus in one. Treatment effect for local control and palliative care was 75% and 83% of patients, respectively. In particular, disappearance of the tumor or disappearance of symptoms was observed in half of the cases of brachytherapy to the vagina. On the other hand, brachytherapy was not very effective for lymph node metastases. Immediately after radiotherapy, eight (53%) patients experienced dermatitis or mucositis. Due to the histological and structural characteristics of mucosal melanoma of the luminal organs, brachytherapy may be an effective therapy. Hence, widespread use of brachytherapy with an appropriate irradiation technique aiming for local control and palliative care in case of unresectable MM should be considered.
Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine carcinoma that tends to show local recurrence and metastasis. Typically, MCC is polyomavirus (MCPyV)‐associated and cytokeratin 20 ...(CK20) positive. However, little is known about this tumor and its origins. Here, we aimed to determine the developmental origins of MCC and to identify prognostic clinicopathologic factors. Initial examinations revealed that CK20 and MCPyV expression (CK20+, MCPyV+ (60%); CK20+, MCPyV− (10%); CK20−, and MCPyV− (30%)) did not affect overall survival. With RB1 gene sequencing of FFPE specimens, which covered an entire exon, all RB1 mutation‐positive cases showed positive regional lymph node and/or distant metastases (8/8 cases, 100%), whereas the frequency of the metastasis was statistically significantly lower in RB1 mutation‐negative cases, (10/16 cases, 62%, P = 0.033). The results were also confirmed with immunohistochemistry, and either RB1 alterations, entire exon sequencing, or immunohistochemistry was associated with the metastasis (P = 0.007). RB1 alterations may be used to access the aggressive clinical course of MCC.