Surgery for Metastatic Melanoma: an Evolving Concept

Role of Surgery in Metastatic Melanoma and Review of Melanoma Molecular Characteristics

We aimed to review the molecular characteristics of metastatic melanoma and the role of surgery in metastasectomy for metastatic melanoma. We performed a systematic literature search on PubMed to identify relevant studies focusing on several mutations, including NRAS, BRAF, NF1, MITF, PTEN, TP53, CDKN2A, TERT, TMB, EGFR, and c-KIT. This was performed in the context of metastatic melanoma and the role of metastasectomy in the metastatic melanoma population. A comprehensive review of these molecular characteristics is presented with a focus on their prognosis and role in surgical metastasectomy.

Current Status and Molecular Mechanisms of Resistance to Immunotherapy in Oral Malignant Melanoma

Immune checkpoint inhibitors (ICIs), including anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and anti-programmed death-1 (PD-1) antibodies, have initiated a new era in the treatment of malignant melanoma. ICIs can be used in various settings, including first-line, adjuvant, and neo-adjuvant therapy. In the scope of this review, we examined clinical studies utilizing ICIs in the context of treating oral mucosal melanoma, a rare disease, albeit with an extremely poor prognosis, with a specific focus on unraveling the intricate web of resistance mechanisms. The absence of a comprehensive review focusing on ICIs in oral mucosal melanoma is notable. Therefore, this review seeks to address this deficiency by offering a novel and thorough analysis of the current status, potential resistance mechanisms, and future prospects of applying ICIs specifically to oral malignant melanoma. Clarifying and thoroughly understanding these mechanisms will facilitate the advancement of effective therapeutic approaches and enhance the prospects for patients suffering from oral mucosal melanoma.

Personalizing neoadjuvant immune-checkpoint inhibition in patients with melanoma

Neoadjuvant immune-checkpoint inhibition is a promising emerging treatment approach for patients with surgically resectable macroscopic stage III melanoma. The neoadjuvant setting provides an ideal platform for personalized therapy owing to the very homogeneous nature of the patient population and the opportunity for pathological response assessments within several weeks of starting treatment, thereby facilitating the efficient identification of novel biomarkers. A pathological response to immune-checkpoint inhibitors has been shown to be a strong surrogate marker of both recurrence-free survival and overall survival, enabling timely analyses of the efficacy of novel therapies in patients with early stage disease. Patients with a major pathological response (defined as the presence of ≤10% viable tumour cells) have a very low risk of recurrence, which offers an opportunity to adjust the extent of surgery and any subsequent adjuvant therapy and follow-up monitoring. Conversely, patients who have only a partial pathological response or who do not respond to neoadjuvant therapy still might benefit from therapy escalation and/or class switch during adjuvant therapy. In this Review, we outline the concept of a fully personalized neoadjuvant treatment approach exemplified by the current developments in neoadjuvant therapy for patients with resectable melanoma, which could provide a template for the development of similar approaches for patients with other immune-responsive cancers in the near future.

Can patients with gallbladder adenocarcinoma and liver metastases obtain survival benefit from surgery? A population-based study

According to international guidelines, surgical treatment is not recommended for gallbladder adenocarcinoma with liver metastases (GCL), and research on the clinical implications of surgery in GCL is very scarce. In this study, we aimed to investigate whether surgery is an effective means to improve survival in GCL. Data were collected from the Surveillance, Epidemiology, and End Results database. A total of 612 people diagnosed with GCL were identified. According to their treatment, patients were categorised into 4 groups: synchronous resection of the primary tumour and liver metastases (SPL), synchronous primary site and other resection (SPO), single resection of the primary site (SPS), and no resection (NR). Our study findings showed that 34 (5.6%) patients received SPL, 18 (2.9%) had SPO, 185 (30.2%) underwent SPS, and 375 (61.3%) received NR. Our analysis showed that surgical treatment was an independent protective prognostic factor for gallbladder cancer cause-specific survival. Groups who underwent SPL, SPO, and SPS showed gradually decreasing survival benefit compared with the NR group (median survival: 9, 5, 4, and 2 months, respectively). Notably, mortality in the SPL, SPO, and SPS groups were significantly different compared with NR group, and the hazard ratio were gradually increased, which were 0.402 (95% confidence interval [CI] 0.264-0.611), 0.463 (95% CI 0.274-0.784), and 0.597 (95% CI 0.457-0.779), respectively (all P < 0.05). Survival in patients with GCL was significantly improved via surgery of the primary site with simultaneous metastasectomy. Among them, SPL and SPO showed greater survival advantages in carefully selected patients with GCL. Registered at researchregistery.com: Trial registration number is researchregistry6915.

Effect of surgical treatment for anorectal melanoma: a propensity score-matched analysis of the Surveillance, Epidemiology, and End Results programme data

OBJECTIVE

Anorectal melanoma (AM) is a rare but aggressive tumour with limited information in the existing literature. This study aimed to assess the effect of surgical treatment for AM and predict the prognosis of affected patients.

DESIGN

A retrospective cohort study.

SETTING

Data of patients diagnosed with AM between 1975 and 2016 in the USA were collected from the Surveillance, Epidemiology, and End Results (SEER) database.

PARTICIPANTS

This study enrolled a total of 795 patients with AM from the SEER database and the validation cohort comprised 40 patients with AM enrolled from Chinese institutes.

PRIMARY AND SECONDARY OUTCOME MEASURES

Overall survival (OS) and AM-specific survival (AM-SS).

RESULTS

A total of 795 patients with AM diagnosed between 1975 and 2016 were enrolled in this study. Data over the past four decades showed a trend of increase in incidence rate. A nomogram based on a multivariate Cox regression model was generated to predict AM-SS. The C-index of the nomogram was 0.74 (95% CI 0.71 to 0.77) on internal verification. In the validation cohort, the C-index of the nomogram was 0.72 (95% CI 0.68 to 0.76). The results of propensity score matching (PSM) analysis showed that patients who underwent surgical treatment achieved significant survival (OS: log-rank=17.41, p<0.001; AM-SS: log-rank=14.55, p<0.001). Patients who underwent surgery were stratified into local and extended surgery subgroups. AM-SS and OS were also compared after PSM, but the results were not significantly different between the two surgery subgroups (all p>0.05).

CONCLUSIONS

The nomogram based on the analysis of SEER data showed good performance in predicting OS and AM-SS. Patients with AM can benefit from surgery; however, extensive surgery and appendectomy may not improve AM-SS or OS.

Proposed Quality Performance Indicators (QPI's) for axillary lymphadenectomy in metastatic cutaneous melanoma

INTRODUCTION

Axillary lymph node clearance (ALNC) continues to play a central role in the management of melanoma. However, what defines an adequate lymphadenectomy remains unclear. We aimed to propose Quality Performance Indicators (QPIs) for ALNC and to determine if the number of lymph nodes (LNs) removed impacts survival.

METHODS

We reviewed patients who underwent ALNC for melanoma at the Waitemata District Health Board and Melanoma Unit between February 2005 and October 2019, performed by two surgeons with standardized technique and surveillance.

RESULTS

105 patients with stage III melanoma were included, of which 73 had clinically evident disease and 32 had clinically occult disease. The mean total number of LNs excised was 29 (SD 10.90, range 10-76). On multivariate analysis, lymph node ratio (HR 4.48, 95% CI 1.55-12.93, p = 0.006), extracapsular spread (HR 2.53, 95% CI 1.06-6.05, p = 0.036) and distant recurrence (HR 11.24, 95% CI 3.79-33.31, p < 0.001) were significant predictors of mortality. The number of LNs removed did not predict survival outcomes, while the lymph node ratio did significantly predict survival outcomes. The regional recurrence rate was 3.8%.

DISCUSSION

We propose that QPIs for ALNC in melanoma include a 90th percentile LN yield of greater than 15, a mean LN yield of 20, a regional recurrence rate of less than 10%, and an overall complication rate of less than 50%.

CONCLUSION

The establishment of QPIs can help ensure that surgical oncology patients receive the highest quality of care.

Observation policy for sentinel node metastasis of melanoma: Comparative study with completion lymph node dissection in Japanese patients

Based on the results of international multicenter randomized trials, completion lymph node dissection for patients with sentinel lymph node-positive melanoma is no longer routinely recommended. However, clinicians should take into consideration racial and medical resource differences when applying this evidence to clinical practice in Japan. To evaluate the clinical validity of the observation policy of omitting completion lymph node dissection, we retrospectively surveyed patients with sentinel lymph node-positive melanoma between 2002 and 2020 at Niigata Cancer Center Hospital. A total of 59 patients were categorized into the observation group (n = 19) and completion lymph node dissection group (n = 40). Newly developed anticancer agents, including targeted therapy and immunotherapy, were more commonly used in the observation group than in the completion lymph node dissection group as either adjuvant therapy (31.6% vs. 5.0%) or post-recurrence therapy (100% vs. 34.8%). The median overall survival in the observation group (not reached) was significantly longer than that in the completion lymph node dissection group (95.0 months; p = 0.02), which was mainly attributed to the difference in post-recurrence overall survival. There was no significant difference in recurrence-free survival between the two groups (p = 0.63). Although the use of new anticancer agents leads to bias, this study demonstrates that observation without prompt completion lymph node dissection provides a favorable overall survival without increasing the risk of recurrence compared with completion lymph node dissection. The observation policy for patients with sentinel lymph node-positive melanoma patients is considered to be clinically valid in real-world medical practice.

High level of TILs is an independent predictor of negative sentinel lymph node in women but not in men

Factors that are most associated with positive lymph node status in melanoma are Breslow thickness and ulceration. However, there are other factors that have been little explored and could help in the identification of "at risk patients" harbouring occult metastasis. The objective of this study was to determine whether intensity of tumour-infiltrating lymphocytes (TILs) in a cohort study (N = 4133) is an independent predictor of sentinel lymph node (SLN) status in patients with primary cutaneous melanoma. Of the patients with cutaneous melanoma who resulted negative for nodal metastasis, 50.7% had moderate/marked TILs versus 27.7% among those patients who resulted positive for nodal metastasis. In the multivariate analysis, controlling for sex, age, mitotic rate, ulceration and Breslow, high levels of TILs in primary invasive melanoma was associated with a lower risk of developing SLN metastasis (OR 0.46; 95% CI 0.23-0.95, p = 0.037). When the analysis was stratified by sex, the protective effect of moderate/marked TIL remained only for women (OR 0.30; 95% CI 0.10-0.93, p = 0.037) but not for men (OR 0.51; 95% CI 0.19-1.34, p = 0.172). Other independent predictors of negative lymph node were low Breslow thickness (≤ 2.0 mm) and low mitotic rate. Besides predicting a negative lymph node response, TILs were also associated with a decreased risk of 10-year mortality among females with positive lymph node. Our findings suggest that high level of TILs is an independent predictor of negative SLN status among women. Further research is warranted to confirm our findings.

Trend and socioeconomic disparities in survival outcome of metastatic melanoma after approval of immune checkpoint inhibitors: a population-based study

BACKGROUND

The approval of immune checkpoint inhibitors (ICI) for metastatic melanoma in 2011 has changed the treatment landscape of this disease. However, current trend of the population-based survival remains unclear.

METHODS

8078 patients with metastatic melanoma diagnosed in the pre-ICI (2005-2010) and post-ICI period (2011-2016) were enrolled from the Surveillance, Epidemiology, and End Results (SEER) program for survival comparison. Propensity score matching (PSM) was performed to reduce selection bias. Cox proportional hazards model was applied for identifying survival-related factors and constructing a prognostic nomogram. The accuracy of the nomogram was determined by concordance index (C-index), calibration curves, and validated by an internal cohort.

RESULTS

Patients in the post-ICI period had a significantly longer median overall survival (OS) than those in the pre-ICI period, even after performing PSM between the two periods. We also found socioeconomic disparities in the survival improvement. Significant differences in OS between the two periods were only observed in cases with medical insurance and patients living in urban or low-poverty area, but not uninsured cases and patients from rural or high-poverty area. For patients in the post-ICI period, multivariate analysis demonstrated that socioeconomic and insurance status were independent prognostic factors, which can be combined with other clinical variates into a nomogram for OS prediction with promising C-index of 0.672 and 0.650 in the training- and testing cohort, respectively.

CONCLUSION

An overall trend to favorable survival at the population level and socioeconomic disparities in the survival trend are observed in metastatic melanoma after the ICI approval. The proposed nomogram is available for prognostication in the current melanoma management.