561 Metastasectomy for Stage IV Melanoma in the Effective Systemic Treatment Era

Aim

Historically, a diagnosis of Stage IV melanoma was a dire one, with low survival rates and ineffective treatment. The only beneficial treatment option was metastasectomy in very selected cases. The recent introduction of the effective systemic therapy agents (EST) (immunotherapy and BRAF inhibitors) dramatically changed this. This research’s aim is to determine if EST + Metastectomy significantly improves OS. And if so, should be considered as the main therapeutic approach to stage IV melanoma patients.

Method

Single-centre retrospective cohort study from the Melanoma Unit at Calvary Mater Hospital in Australia was conducted, approved by the ethics committee. Inclusion criteria was Stage IV Melanoma patients who received EST from 2009-2019. OS of those who received EST alone are compared to EST + Metastasectomy. The 2 groups were compared retrospectively based on their disease characteristics, using probability score weighting analysis and survival curve.

Results

This is a preliminary analysis for the first 200 patients, data collection is ongoing. Mean OS is 2 years. Several combinations of immunotherapy treatments were identified. Of the 200 patients, 35% underwent metastasectomy. Mean survival for those who had surgery is 3 years, as oppose to 2 years for those who had EST alone. OS in the Metastasectomy group was higher than those who had EST alone, of 47.1% and 42.3% respectively. The Kaplan Meier curve also shows increase survival in the metastasectomy group, up to year 6 post diagnosis.

Conclusions

Metastasectomy for stage iv melanoma in the EST era appears to offer a survival benefit in selected patients

Loss of capillary pericytes and the blood-brain barrier in white matter in poststroke and vascular dementias and Alzheimer's disease

White matter (WM) disease is associated with disruption of the gliovascular unit, which involves breach of the blood–brain barrier (BBB). We quantified pericytes as components of the gliovascular unit and assessed their status in vascular and other common dementias. Immunohistochemical and immunofluorescent methods were developed to assess the distribution and quantification of pericytes connected to the frontal lobe WM capillaries. Pericytes with a nucleus were identified by collagen 4 (COL4) and platelet‐derived growth factor receptor‐β (PDGFR‐β) antibodies with further verification using PDGFR‐β‐specific ELISA. We evaluated a total of 124 post‐mortem brains from subjects with post‐stroke dementia (PSD), vascular dementia (VaD), Alzheimer’s disease (AD), AD‐VaD (Mixed) and post‐stroke non‐demented (PSND) stroke survivors as well as normal aging controls. COL4 and PDGFR‐β reactive pericytes adopted the characteristic “crescent” or nodule‐like shapes around capillary walls. We estimated densities of pericyte somata to be 225 ±38 and 200 ±13 (SEM) per COL4 mm² area or 2.0 ± 0.1 and 1.7 ± 0.1 per mm capillary length in young and older aging controls. Remarkably, WM pericytes were reduced by ~35%–45% in the frontal lobe of PSD, VaD, Mixed and AD subjects compared to PSND and controls subjects (P < 0.001). We also found pericyte numbers were correlated with PDGFR‐β reactivity in the WM. Our results first demonstrate a reliable method to quantify COL4‐positive pericytes and then, indicate that deep WM pericytes are decreased across different dementias including PSD, VaD, Mixed and AD. Our findings suggest that downregulation of pericytes is associated with the disruption of the BBB in the deep WM in several aging‐related dementias.

Sigmoidoscopic neurosurgery? Treatment of an unusual complication of ventriculoperitoneal shunting

A 16-year-old male with acute hydrocephalus due to bilateral acoustic neuromata was treated successfully with a ventriculoperitoneal shunt before formal neuroma resection. However, 2 years postoperatively, he noticed the distal shunt per rectum while defaecating. Subsequent removal was successfully performed using a flexible sigmoidoscope.

Liver Biopsies Following Ileogastrostomy

Patients who have had ileogastrostomy for the treatment of morbid obesity require close, long-term follow-up. One concern in patients undergoing any form of intestinal bypass surgery is that of possible liver damage. To assess for possible liver damage in morbidly obese patients undergoing ileogastrostomy, we undertook a prospective study of liver biopsies in 12 consecutive patients. Preoperative and 2-year postoperative biopsies of the liver were planned. There were six liver biopsies available for comparison both pre- and post-operatively. The biopsies showed changes of fatty infiltration both pro- and post-operatively. There were no differences in the degree of fatty infiltration, or of other histological parameters which we measured. There were no cases of cirrhosis of the liver recorded.