Tumour mutation status and melanoma recurrence following a negative sentinel lymph node biopsy

The role of micrometastasis in high-risk skin cancers

The propensity to metastasize is the most important prognostic indicator for solid cancers. New insights into the mechanisms of early carcinogenesis have revealed micrometastases are generated far earlier than previously thought. Evidence supports a synergistic relationship between vascular and lymphatic seeding which can occur before there is clinical evidence of a primary tumour. Early vascular seeding prepares distal sites for colonisation while regional lymphatics are co-opted to promote facilitative cancer cell mutations. In response, the host mounts a global inflammatory and immunomodulatory response towards these cells supporting the concept that cancer is a systemic disease. Cancer staging systems should be refined to better reflect cancer cell loads in various tissue compartments while clinical perspectives should be broadened to encompass this view when approaching high-risk cancers. Measured adjunctive therapies implemented earlier for low-volume, in-transit cancer offers the prospect of preventing advanced disease and the need for heroic therapeutic interventions. This review seeks to re-appraise how we view the metastatic process for solid cancers. It will explore in-transit metastasis in the context of high-risk skin cancer and how it dictates disease progression. It will also discuss how these implications will influence our current staging systems and its consequences on management.

Lack of Influence of Non-Overlapping Mutations in BRAF, NRAS, or NF1 on 12-Month Best Objective Response and Long-Term Survival after Checkpoint Inhibitor-Based Treatment for Metastatic Melanoma

BACKGROUND

Non-overlapping somatic mutations in BRAF, NRAS, or NF1 genes occur in 85% of metastatic melanoma patients. It is not known whether these mutations affect immunotherapy outcome.

MATERIALS AND METHODS

Next-Gen sequencing of 324 oncogenes was performed in 73 metastatic melanoma patients. A retrospective review of immunotherapy outcome was performed.

RESULTS

BRAF fusions/internal rearrangements, BRAF V600E, NRAS, NF1 mutations, and triple-negative genotypes occurred in 6.9%, 30.1%, 17.8%, 32.9%, and 12.3% of patients, respectively. Median potential follow-up was 41.0 months. Patients with BRAF fusion/rearrangement had decreased progression-free and overall survival (p = 0.015). The other genotypes each had similar progression-free and overall survival. Patients who achieved a complete best objective response at 12 months (n = 36, 49.3%) were found to have significantly improved survival compared those who failed to achieve remissions (n = 37, 50.7%, p < 0.001).

CONCLUSIONS

The most important determinant of long-term survival was achievement of a complete response by 12 months following immunotherapy. PR and SD were not a stable type of response and generally resulted in progression and death from melanoma. Rare patients with BRAF fusions or rearrangements had decreased progression-free and overall survival following initial immunotherapy. Other BRAF, NRAS, or NF1 mutations were not associated with significant differences in outcome.

A General Framework for Identifying Hierarchical Interactions and Its Application to Genomics Data

The analysis of hierarchical interactions has long been a challenging problem due to the large number of candidate main effects and interaction effects, and the need for accommodating the "main effects, interactions" hierarchy. The two-stage analysis methods enjoy simplicity and low computational cost, but contradict the fact that the outcome of interest is attributable to the joint effects of multiple main factors and their interactions. The existing joint analysis methods can accurately describe the underlying data generating process, but suffer from prohibitively high computational cost. And it is not straightforward to extend their optimization algorithms to general loss functions. To address this need, we develop a new computational method that is much faster than the existing joint analysis methods and rivals the runtimes of two-stage analysis. The proposed method, HierFabs, adopts the framework of the forward and backward stagewise algorithm and enjoys computational efficiency and broad applicability. To accommodate hierarchy without imposing additional constraints, it has newly developed forward and backward steps. It naturally accommodates the strong and weak hierarchy, and makes optimization much simpler and faster than in the existing studies. Optimality of HierFabs sequences is investigated theoretically. Simulations show that it outperforms the existing methods. The analysis of TCGA data on melanoma demonstrates its competitive practical performance.

Progression of untreated gastric and pulmonary metastasis in a patient with resected acral melanoma

We report a man in his 80s who presents with epigastric abdominal pain and fatigue for 2 weeks. His medical history was significant for left toe acral melanoma (excised 6 years prior) and a lung mass, further workup for which was declined at the time by the patient. On presentation, he had iron deficiency anaemia and esophagogastroduodenoscopy revealed a gastric mass. Histopathological analysis of gastric and subsequently, pulmonary, lesions were consistent with metastatic melanoma. This case demonstrates the unique slow progression of untreated pulmonary metastasis in metastatic melanoma.

Predictive and Prognostic Value of BRAF and NRAS Mutation of 159 Sentinel Lymph Node Cases in Melanoma-A Retrospective Single-Institute Study

PURPOSE

To assess the prognostic role of sentinel lymph node status (SLN) in melanoma patients, a statistical comparison was performed with the application of already known prognostic factors, mutational occurrence of BRAF and NRAS in the primary tumor, as well as disease outcome.

METHODS

Our retrospective single-center study involved 159 melanoma cases, who underwent SLN biopsy. The following clinico-pathological data were collected: age, gender, location of primary tumor, Breslow thickness, ulceration degree, histological subtype, mitosis count, lymphovascular and perineural invasion, presence of tumor-infiltrating lymphocytes, regression signs, mutations of BRAF and NRAS of the primary tumors, and SLN status.

RESULTS

From the studied clinico-pathological factors, only Breslow thickness increased the risk of SLN positivity (p = 0.025) by multivariate analysis, while neither BRAF nor NRAS mutation of the primary tumor proved to be a predictor of the SLN status. While the NRAS-mutant subgroup showed the most unfavorable outcome for progression-free and distant metastasis-free survival, their rate of positive SLNs proved to be relatively lower than that of patient groups with BRAF mutation and double-wild-type phenotypes.

CONCLUSION

Similarly to the importance of SLN positivity, NRAS mutation of the primary tumor proved to be an independent prognostic factor of progression. Therefore, despite negative SLN, this NRAS-mutant subgroup of patients still requires closer monitoring to detect disease progression.

Proposed quality performance indicators of sentinel lymph node biopsy for cutaneous melanoma

BACKGROUND

Melanoma is a leading cause of morbidity and mortality in Australia and New Zealand. New Zealand has the highest melanoma incidence in the world alongside Australia at 54 per 100 000 persons. The aim of this study is to conduct a retrospective quality audit of sentinel lymph nodal biopsy (SLNB) practices from 2007 to 2019 of a high-volume melanoma surgeon. Primary outcome was false negative rate (FNR). Secondary outcomes were sentinel node (SN) identification and removal rate, and complication rates.

METHODS

A database was maintained, containing n = 553 consecutive SLNB's for cutaneous melanoma from 31 August 2007 to 31 August 2019. Patient characteristics and details of the primary lesion, sentinel lymph node biopsy, recurrence and complications were recorded.

RESULTS

SN's were successfully identified in 444 (99.6%) out of 446 patients with an FNR of 9.1%. Positive SN's were identified in 70 (12.7%) SLNB's. Complications occurred in 76 out of 553 (13.7%) SLNB's. A review of internationally published literature reveals an SN identification rate of 94.4-99.5% with an FNR of 4.0-37.5%. SLNB is the best staging tool for melanoma and gives potential access to adjuvant systemic treatment if >1 mm deposits are found. It is a day-stay procedure with a low-complication rate.

CONCLUSION

SLNB is a safe and reliable procedure utilized for cutaneous melanoma. We propose our data should be used alongside international SN series to establish Quality Performance Indicators to improve melanoma management.

Study of cutaneous melanoma recurrences after sentinel node biopsy: Patterns of dissemination and use of complementary test in follow-up

OBJECTIVES

To investigate the patterns of melanoma recurrence in the local population, including factors that may influence in this event and timing of relapse, and to determine the mode of detection of them.

METHODS

This is a retrospective cohort study of patients with melanoma who underwent sentinel lymph node biopsy at the Complejo Hospitalario de Navarra (Spain) from 2002 to 2012. The following data were collected of each patient: age, gender, date of diagnosis, location of melanoma, histological subtype, Breslow thickness, ulceration, mitosis, sentinel node status, AJCC 8th edition stage, site of first diagnosed metastasis, mode of relapse, date of first relapse and time of death.

RESULTS

Of 308 patients, 30% people suffered metastasis. The mean follow-up time was 68.63 months. 51.1% of relapses were locoregional and 48.9% haemato-visceral. Sentinel node status was the only variable associated with higher risk of haemato-visceral metastasis (p < 0.001). The mean time between diagnosis of melanoma and recurrence was 2.7 years. Most recurrences were detected by the patient himself or had any type of symptoms and were consequently selected for a complementary test.

CONCLUSION

It is important to follow-up all patients with diagnosis of cutaneous melanoma, essentially during the first 5 years after diagnosis.

Clinicopathological features of granulomatous lobular mastitis and mammary duct ectasia

Granulomatous lobular mastitis (GLM) and mammary duct ectasia (MDE) are inflammatory diseases. However, only a limited number of studies have focused on characterizing their clinicopathological features. The aim of the present study was to investigate the etiology, clinicopathological characteristics and diagnosis of GLM and MDE. The clinical information and treatment of 118 female patients with pathologically-proven GLM or MDE were retrospectively analyzed in the present study. A total of 29 cases had GLM, 77 had MDE and 12 had GLM accompanied by MDE. GLM tends to occur in patients who have had their last birth within 5 years and are usually <40 years of age. GLM masses were usually larger than MDE masses and suppurated or ulcerated more easily. Histopathologically, GLM was characterized by a significant granulomatous inflammatory reaction centered on lobules. Compared with MDE, GLM had a higher incidence of granuloma and microabscess formation within the lobules and surrounding tissue. More multinucleated giant cells within granuloma were observed in patients with GLM than in those with MDE, while MDE was characterized by significant dilatation of the duct terminals and inflammatory changes in the duct wall and periductal tissues. When compared with patients with GLM, foam cells within the duct epithelium or surrounding stroma were more common in patients with MDE. The present study demonstrated that GLM and MDE had distinct clinicopathological characteristics. Further research is required in order to identify more appropriate treatment strategies for these specific types of breast inflammation.