Variations in the definition and perceived importance of positive resection margins in patients with colorectal cancer - an EYSAC international survey.

INTRODUCTION: Microscopically positive resection margins (R1) are associated with poorer outcomes in patients with colorectal cancer. However, different definitions of R1 margins exist. It is unclear to what extent the definitions used in everyday clinical practice differ within and between nations. This study sought to investigate variations in the definition of R1 margins in colorectal cancer and the importance of margin status in clinical decision-making. MATERIALS AND METHODS: A 14-point survey was developed by members of The European Society of Surgical Oncology (ESSO) Youngs Surgeons and Alumni Club (EYSAC) Research Academy targeting all members of the multidisciplinary team (MDT) treating patients with colorectal cancer. The survey was distributed on social media, in ESSO's monthly newsletter and via national societies. RESULTS: In total, 137 responses were received. Most respondents were from Europe (89.7%), with the majority from Denmark (56.9%). Less than 2/3 of respondents defined R1 margins as the presence of viable cancer cells ≤1 mm of the margin. Only 60% reported that subdivisions of R1 margins (primary tumour vs tumour deposit vs metastatic lymph node) are routinely available. More than 20% of respondents reported that pathology reports are not routinely reviewed at MDT meetings. Less than half of respondents considered margin status in decision-making for type and duration of adjuvant chemotherapy in Stage III colon cancer. CONCLUSION: The definitions and perceived clinical importance of microscopically positive margins in patients with colorectal cancer appear to vary. Adoption of an international dataset for pathology reporting may help to standardise current practices.

Elevated preoperative serum interleukin-6 level is predictive for worse postoperative outcome after soft tissue sarcoma surgery.

BACKGROUND: The pro-inflammatory cytokine interleukin-6 (IL-6) plays a role in cancer development and progression, but research into the predictive value of IL-6 on postoperative outcome in soft tissue sarcoma (STS) is scarce. The purpose of this study is to investigate the predictive value of serum IL-6 level for the achievement of assumed (post)operative outcome after STS surgery, the so-called textbook outcome. METHODS: Preoperative IL-6 serum levels were collected in all patients with a STS at first presentation between February 2020 and November 2021. Textbook outcome was defined as a R0 resection, no complications, no blood transfusions, no reoperation within the postoperative period, no prolonged hospital stay, no hospital readmission within 90-days, and no mortality within 90-days. Factors associated with textbook outcome were determined by multivariable analysis. RESULTS: Among 118 patients with primary, non-metastatic STS, 35.6% achieved a textbook outcome. Univariate analysis showed that smaller tumor size (p = 0.026), lower tumor grade (p = 0.006), normal hemoglobin (Hb, p = 0.044), normal white blood cell (WBC) count (p = 0.018), normal C-reactive protein (CRP) serum level (p = 0.002) and normal IL-6 serum level (p = 1.5 × 10-5) were associated with achieving textbook outcome after surgery. Multivariable analysis showed that elevated IL-6 serum level (p = 0.012) was significantly associated with not achieving a textbook outcome. CONCLUSIONS: Increased IL-6 serum level is predictive for not achieving a textbook outcome after surgery for primary, non-metastatic STS.

Cellular Radiosensitivity of Soft Tissue Sarcoma.

Currently, all soft tissue sarcomas (STS) are irradiated by the same regimen, disregarding possible subtype-specific radiosensitivities. To gain further insight, cellular radiosensitivity was investigated in a panel of sarcoma cell lines. Fourteen sarcoma cell lines, derived from synovial sarcoma, leiomyosarcoma, fibrosarcoma and liposarcoma origin, were submitted to clonogenic survival assays. Cells were irradiated with single doses from 1-8 Gy and surviving fraction (SF) was calculated from the resulting response data. Alpha/beta (α/ß) ratios were inferred from radiation-response curves using the linear-quadratic (LQ)-model. Cellular radiosensitivities varied largely in this panel, indicating a considerable degree of heterogeneity. Surviving fraction after 2 Gy (SF2) ranged from 0.27 to 0.76 with evidence of a particular radiosensitive phenotype in only few cell lines. D37% on the mean data was 3.4 Gy and the median SF2 was 0.52. The median α/ß was 4.9 Gy and in six cell lines the α/ß was below 4 Gy. A fairly homogeneous radiation response was observed in myxoid liposarcoma cell lines with SF2 between 0.64 and 0.67. Further comparing sarcomas of different origin, synovial sarcomas, as a group, showed the lowest SF2 values (mean 0.35) and was significantly more radiosensitive than myxoid liposarcomas and leiomyosarcomas (P = 0.0084 and 0.024, respectively). This study demonstrates a broad spectrum of radiosensitivities across STS cell lines and reveals subtype-specific radiation responses. The particular cellular radiosensitivity of synovial sarcoma cells supports consideration of the different sarcoma entities in clinical studies that aim to optimize sarcoma radiotherapy.

Management of meningeal solitary fibrous tumors/hemangiopericytoma; surgery alone or surgery plus postoperative radiotherapy?

INTRODUCTION: A meningeal solitary fibrous tumor (SFT), also called hemangiopericytoma, is a rare mesenchymal malignancy. Due to anatomic constrains, even after macroscopic complete surgery with curative intent, the local relapse risk is still relatively high, thus increasing the risk of dedifferentiation and metastatic spread. This study aims to better define the role of postoperative radiotherapy (RT) in meningeal SFTs. PATIENTS AND METHODS: A retrospective study was performed across seven sarcoma centers. Clinical information was retrieved from all adult patients with meningeal primary localized SFT treated between 1990 and 2018 with surgery alone (S) compared to those that also received postoperative RT (S + RT). Differences in treatment characteristics between subgroups were tested using independent samples t-test for continuous variables and chi-square tests for proportions. Local control (LC) and overall survival (OS) rates were calculated as time from start of treatment until progression or death from any cause. LC and OS in groups receiving S or S + RT were compared using Kaplan-Meier survival curves. RESULTS: Among a total of 48 patients, 7 (15%) underwent S and 41 (85%) underwent S + RT. Median FU was 65 months. LC was significantly associated with treatment. LC after S at 60 months was 60% versus 90% after S + RT (p = 0.052). Furthermore, R1 resection status was significantly associated with worse LC (HR 4.08, p = 0.038). OS was predominantly associated with the mitotic count (HR 3.10, p = 0.011). CONCLUSION: This retrospective study, investigating postoperative RT in primary localized meningeal SFT patients, suggests that combining RT to surgery in the management of this patient population may reduce the risk for local failures.

The value of lymph node ultrasound and whole body 18F-FDG PET/CT in stage IIB/C melanoma patients prior to SLNB.

BACKGROUND: Stage IIB/IIC (8th AJCC) melanoma patients are known to have high-risk primary tumors, however they follow the same routine to sentinel lymph node biopsy (SLNB) as more low risk tumors. Guidelines are not conclusive regarding the use of preoperative imaging for these patients. The aim of this pilot study was to assess the value of ultrasound (US) and 18F-FDG PET/CT prior to lymphoscintigraphy (LSG) and SLNB for stage IIB/C melanoma patients. METHODS: From 2019-04 till 2020-01, all stage IIB/C melanoma patients underwent US of the regional lymph nodes and whole body 18F-FDG PET/CT before their planned LSG and SLNB. Suspected metastases were confirmed with fine needle aspiration (FNA), prior to surgery. RESULTS: In total 23 patients were screened: six had metastases detected by imaging, two by US, one by 18F-FDG PET/CT and three were detected by both imaging modalities. All metastases were nodal and therefore treatment was altered to lymph node dissection and all but one also received adjuvant therapy. Eight (47%) of the 17 patients without macroscopic disease, still had a positive SN. Sensitivity, specificity and false negative rate for US and 18F-FDG PET/CT were 36%, 89%, 64% and 29%, 100% and 71%, respectively. CONCLUSION: Preoperative negative imaging does not exclude the presence of SN metastases, therefore SLNB cannot be foregone. However, US detected metastases in 22% of patients, altering their treatment, which suggests it is effective in the work-up of stage IIB/C melanoma. Staging with 18F-FDG PET/CT is not of added value prior to LSG and SLNB and should therefore not be used.

COX-2 expression in chondrosarcoma: a role for celecoxib treatment?

Chondrosarcomas are resistant to conventional chemo- and radiotherapy. A subset of chondrosarcomas arises secondarily in the benign tumour syndromes enchondromatosis (EC) and multiple osteochondromas (MO), and prevention of tumour development would greatly improve prognosis. We therefore investigated the effect of selective COX-2 inhibition on chondrosarcoma growth. COX-2 expression was studied in central- and peripheral cartilaginous tumours. The effect of COX-2 inhibition was assessed in four high-grade chondrosarcoma cell lines using celecoxib and NS-398 treatment. COX-2 activity (prostaglandin E(2) (PGE(2)) ELISA) and cell viability were measured. The (prophylactic) effect of celecoxib on chondrosarcoma growth in vivo was studied for 8 weeks using a xenograft model of cell line CH2879 in immunoincompetent nude mice. High COX-2 protein expression was mainly found in solitary peripheral chondrosarcoma and in enchondromatosis-related central chondrosarcoma, which was confirmed by qPCR. After 72h of celecoxib treatment, a significant decrease in cell viability was observed in three chondrosarcoma cell lines. In vivo, celecoxib initially slowed tumour growth in chondrosarcoma xenografts; however, after prolonged treatment relapsed tumour growth was observed. Tumour volume was negatively associated with celecoxib serum levels, and seemed smaller in the high-dose prophylactic treatment group. We confirmed the expression of COX-2 in 65% of chondrosarcomas, and COX-2 inhibition by celecoxib diminished cell viability in vitro. The initial response and the decrease in tumour volume with increased celecoxib serum levels in vivo supported a role for celecoxib, although relapsed tumour growth after 6 weeks was worrisome. Also the role of high-dose prophylactic celecoxib in preventing the development of benign and malignant cartilage tumours in EC and MO patients deserves further investigation.

Myxoid tumours of soft tissue: the so-called myxoid extracellular matrix is heterogeneous in composition.

AIM: Myxoid tumours of soft tissue are characterized by their so-called 'myxoid' extracellular matrix. The aim was to investigate the composition and possible function of this matrix which is poorly understood. METHODS AND RESULTS: Using Alcian Blue staining with and without pretreatment with hyaluronidase and application of the critical electrolyte concentration method followed by densitometry, the glycosaminoglycan composition of three different myxoid tumours was studied. The composition of glycosaminoglycans varied with tumour type and grade, despite their general characterization as myxoid tumours. Intramuscular myxoma contained similar amounts of the various glycosaminoglycans as grade I myxofibrosarcoma; grade III myxofibrosarcoma contained less hyaluronic acid and more heparan sulphate, whereas extraskeletal myxoid chondrosarcoma contained predominantly chondroitin-4 and -6 sulphates. Western blot identified albumin as a major protein in tumour lysates, and its presence in the extracellular matrix and cytoplasm of the majority of tumours was demonstrated by immunohistochemistry; production of albumin by the tumour cells was confirmed by quantitative polymerase chain reaction. CONCLUSIONS: The extracellular matrix of myxoid tumours of soft tissue has a heterogeneous composition consisting of, amongst others, glycosaminoglycans and albumin, which appear to play an active role in their morphogenesis.