Evaluation of the prognostic impact of postoperative adjuvant radiotherapy on head and neck mucosal melanoma: a meta-analysis

Abstract

BackgroundHead and neck mucosal melanoma (HNMM) is a rare type of malignant tumor that frequently exhibits postoperative recurrence and distant metastasis. Many clinicians administer postoperative adjuvant radiotherapy to improve patient prognosis and enhance quality of life; however, the effects of this treatment remain controversial. Therefore, in this study, a meta-analysis was performed to evaluate the practical value of postoperative adjuvant radiotherapy for head and neck mucosal melanoma.MethodsArticles in the PubMed, MEDLINE, Cochrane Library, Web of Science and EMBASE databases were systematically retrieved. Analyses were conducted to compare the impact of treatments involving postoperative radiotherapy with treatments entailing surgery alone on patient overall survival time, local recurrence and distant metastasis. The hazard ratio (HR) was used to evaluate the time-to-event data employing RevMan version 5.2 and Stata/SE version 13.0 software according to the principles specified for systematic reviews of interventions in the Cochrane handbook.ResultsTwelve cohort studies involving 1593 patients satisfied the desired conditions. In comparing surgery alone with postoperative radiotherapy, there was no significant difference regarding a decrease in the death risk in HNMM patients (HR, 1.07; 95 % CI, 0.95–1.2; p = 0.903; low heterogeneity, I2 = 0); this was also the case for sinonasal melanoma after subgroup meta-analysis (HR, 1.04; 95 % CI, 0.8–1.36; p = 0.983; low heterogeneity, I2 = 0 %). A sensitivity analysis and subgroup meta-analysis showed that disease progression was the main source of the instability in the results. Surgery combined with postoperative radiotherapy reduced the risk of local recurrence (HR, 0.51; 95 % CI, 0.35–0.76; p = 0.155) but did not reduce the risk of distant metastasis (HR, 2.26; 95 % CI, 1.01–5.05; p = 0.006).ConclusionsThis study demonstrated that for HNMM patients surgery is recommended if indicated, and surgery combined with postoperative radiotherapy is also recommended for dramatically improved local control of the tumor bed. For patients not suitable for surgical treatment, radiotherapy is still advised. To control distant metastasis and finally lower the risk of death, immunological therapy is another potential option whose therapeutic effect needs to be proved with more data from clinical trials.

Sinonasal Mucosal Melanoma: A Clinicopathological Review

“…However, its effect on the long term survival is doubtful. [7] Conventional radiotherapy as a primary modality of treatment has been shown to achieve a 5-year local control rate of 13%, while postoperative radiotherapy achieves a rate of 30%. [20] Liao JJ et al studied the effects of fast neutron radiotherapy on primary mucosal melanoma and found an overall local control rate of 79%.…”

“…[20] Other modalities of radiotherapy like intensity modulated radiotherapy, proton therapy and carbon ion therapy have shown promising results in clinical trials. [7] Further validation with a large sample size is required to assess the effectiveness of these modalities. Chemotherapy has been mostly used for palliation and dacarbazine has been used as the standard chemotherapeutic agent.…”

“…Studies show that 75% of cutaneous melanoma arising from the sun exposed areas carry mutations in BRAF oncogene, which is rare in the mucosal variants (Approximately 2%). [2,7] Mucosal melanomas mostly carry C-KIT expression (88%) with 5-20% of tumours carrying active C-KIT mutations. [2] C-KIT is a key regulator involved in the proliferation, migration and differentiation of melanocytes.…”

“…Clinical trials with Vemurafenib (A selective BRAF inhibitor) and Imatinib (Therapeutic agent targeting C-KIT mutation) have shown promising results. [7] Immunobiological therapy involving transfer of Lymphokine Activated Killer (LAK) cells has shown to increase the 5-year survival rate in patients. [7,21] These newer modalities of treatment provides an interesting field for further research and may open up newer horizons in the treatment of this rare disease.…”

Local control in sinonasal malignant melanoma: Comparing conventional to hypofractionated radiotherapy

“…Evidence for the addition of postoperative radiotherapy (RT) in the treatment of mucosal head and neck melanoma is based on retrospective series. To our knowledge, 9 series with at least 15 patients who underwent adjuvant RT after surgery have been published in the last 25 years . A meta‐analysis showed an average relative risk reduction of 45% for local control with the addition of postoperative RT after complete or incomplete surgical resection .…”