Hepatic arterial infusion pump chemotherapy combined with systemic chemotherapy for borderline resectable and unresectable colorectal liver metastases: phase II feasibility study

BACKGROUND

Hepatic arterial infusion pump chemotherapy combined with systemic chemotherapy (HAIP-SYS) for liver-only colorectal liver metastases (CRLMs) has shown promising results but has not been adopted worldwide. This study evaluated the feasibility of HAIP-SYS in the Netherlands.

METHODS

This was a single-arm phase II study of patients with CRLMs who received HAIP-SYS consisting of floxuridine with concomitant systemic FOLFOX or FOLFIRI. Main inclusion and exclusion criteria were borderline resectable or unresectable liver-only metastases, suitable arterial anatomy and no previous local treatment. Patients underwent laparotomy for pump implantation and primary tumour resection if in situ. Primary end point was feasibility, defined as ≥70% of patients completing two cycles of HAIP-SYS. Sample size calculations led to 31 patients. Secondary outcomes included safety and tumour response.

RESULTS

Thirty-one patients with median 13 CRLMs (i.q.r. 6-23) were included. Twenty-eight patients (90%) received two HAIP-SYS cycles. Three patients did not get two cycles due to extrahepatic disease at pump placement, definitive pathology of a recto-sigmoidal squamous cell carcinoma, and progressive disease. Five patients experienced grade 3 surgical or pump device-related complications (16%) and 11 patients experienced grade ≥3 chemotherapy toxicity (38%). At first radiological evaluation, disease control rate was 83% (24/29 patients) and hepatic disease control rate 93% (27/29 patients). At 6 months, 19 patients (66%) had experienced grade ≥3 chemotherapy toxicity and the disease control rate was 79%.

CONCLUSION

HAIP-SYS for borderline resectable and unresectable CRLMs was feasible and safe in the Netherlands. This has led to a successive multicentre phase III randomized trial investigating oncological benefit (EUDRA-CT 2023-506194-35-00). Current trial registration number: clinicaltrials.gov (NCT04552093).

Local treatment in metastatic GIST patients: A multicentre analysis from the Dutch GIST Registry

BACKGROUND

The added value of local treatment in selected metastatic GIST patients is unclear. This study aims to provide insight into the usefulness of local treatment in metastatic GIST by use of a survey study and retrospective analyses in a clinical database.

METHODS

A survey study was conducted among clinical specialists to select most relevant characteristics of metastatic GIST patients considered for local treatment, defined as elective surgery or ablation. Patients were selected from the Dutch GIST Registry. A multivariate Cox-regression model for overall survival since time of diagnosis of metastatic disease was estimated with local treatment as a time-dependent variable. An additional model was estimated to assess prognostic factors since local treatment.

RESULTS

The survey's response rate was 14/16. Performance status, response to TKIs, location of active disease, number of lesions, mutation status, and time between primary diagnosis and metastases, were regarded the 6 most important characteristics. Of 457 included patients, 123 underwent local treatment, which was associated with better survival after diagnosis of metastases (HR = 0.558, 95%CI = 0.336-0.928). Progressive disease during systemic treatment (HR = 3.885, 95%CI = 1.195-12.627) and disease confined to the liver (HR = 0.269, 95%CI = 0.082-0.880) were associated with worse and better survival after local treatment, respectively.

CONCLUSION

Local treatment is associated with better survival in selected patients with metastatic GIST. Locally treated patients with response to TKIs and disease confined to the liver have good clinical outcome. These results might be considered for tailoring treatment, but should be interpreted with care because only specific patients are provided with local treatment in this retrospective study.

Oncological Outcome After Lymph Node Dissection for Cutaneous Squamous Cell Carcinoma

BACKGROUND

Although cutaneous squamous cell carcinoma (cSCC) is common, lymph node metastases are relatively rare and are usually treated with lymph node dissection (LND). The aim of this study was to describe the clinical course and prognosis after LND for cSCC at all anatomical locations.

METHODS

A retrospective search at three centres was performed to identify patients with lymph node metastases of cSCC who were treated with LND. Prognostic factors were identified by uni- and multivariable analysis.

RESULTS

A total of 268 patients were identified with a median age of 74. All lymph node metastases were treated with LND, and 65% of the patients received adjuvant radiotherapy. After LND, 35% developed recurrent disease both locoregionally and distantly. Patients with more than one positive lymph node had an increased risk for recurrent disease. 165 (62%) patients died during follow-up of whom 77 (29%) due to cSCC. The 5-year OS- and DSS rate were 36% and 52%, respectively. Disease-specific survival was significantly worse in immunosuppressed patients, patients with primary tumors >2cm and patients with more than one positive lymph node.

CONCLUSIONS

This study shows that LND for patients with lymph node metastases of cSCC leads to a 5-year DSS of 52%. After LND, approximately one-third of the patients develop recurrent disease (locoregional and/or distant), which underscores the need for better systemic treatment options for locally advanced cSCC. The size of the primary tumor, more than one positive lymph node, and immunosuppression are independent predictors for risk of recurrence and disease-specific survival after LND for cSCC.

A Nationwide Prospective Clinical Trial on Active Surveillance in Patients With Non-intraabdominal Desmoid-type Fibromatosis: The GRAFITI Trial

OBJECTIVE

To assess tumor behavior and the efficacy of active surveillance (AS) in patients with desmoid-type fibromatosis (DTF).

SUMMARY OF BACKGROUND DATA

AS is recommended as initial management for DTF patients. Prospective data regarding the results of AS are lacking.

METHODS

In this multicenter prospective cohort study (NTR4714), adult patients with non-intraabdominal DTF were followed during an initial AS approach for 3 years. Tumor behavior was evaluated according to Response Evaluation Criteria in Solid Tumors. Cumulative incidence of the start of an active treatment and progression-free survival (PFS) were calculated using the Kaplan-Meier method. Factors predictive for start of active treatment were assessed by Cox regression analyses.

RESULTS

A total of 105 patients started with AS. Median tumor size at baseline was 4.1cm (interquartile range 3.0-6.6). Fifty-seven patients had a T41A CTNNB1 mutation; 14 patients a S45F CTNNB1 mutation. At 3 years, cumulative incidence of the start of active treatment was 30% (95% confidence interval [CI] 21-39) and PFS was 58% (95% CI 49-69). Median time to start active treatment and PFS were not reached at a median follow-up of 33.7 months. During AS, 32% of patients had stable disease, 28% regressed, and 40% demonstrated initial progression. Larger tumor size (≥5 cm; hazard ratio = 2.38 [95% CI 1.15-4.90]) and S45F mutation (hazard ratio = 6.24 [95% CI 1.92-20.30]) were associated with the start of active treatment.

CONCLUSIONS

The majority DTF patients undergoing AS do not need an active treatment and experience stable or regressive disease, even after initial progression. Knowledge about the natural behavior of DTF will help to tailor the follow-up schedule to the individual patient.

The oncological outcomes of isolated limb perfusion and neo-adjuvant radiotherapy in soft tissue sarcoma patients - A nationwide multicenter study

INTRODUCTION

Patients with locally extensive high-grade extremity soft tissue sarcomas (eSTS) are often presented in multidisciplinary teams to decide between ablative surgery (amputation) or limb-salvage surgery supplemented with either neo-adjuvant radiotherapy (RT) or induction isolated limb perfusion (ILP). In The Netherlands, ILP typically aims to reduce the size of tumors that would otherwise be considered irresectable, whereas neo-adjuvant RT aims mainly at improving local control and reducing morbidity of required marginal margins. This study presents a 15-year nationwide cohort to describe the oncological outcomes of both pre-operative treatment strategies.

METHODS

All consecutive patients with locally extensive primary high-grade eSTS surgically treated between 2000 and 2015 at five tertiary sarcoma centers that received neo-adjuvant ILP or RT were included. 169 patients met the inclusion criteria (89 ILP, 80 RT). Median follow-up was 7.3 years.

RESULTS

Limb salvage was achieved in 84% of cases in the ILP group (80% for patients with amputation indication) and 96% of cases in the RT group. 5-Year overall survival was 47% in the ILP group, 69% in the RT group. 5-Year local recurrence rate was 14% in the ILP group, 10% in the RT group. Distant metastasis rate was 55% in the ILP group, 36% in the RT group.

CONCLUSION

We find oncological outcomes and limb salvage rates in line with existing literature for both treatment modalities. Whether the tumor was locally advanced with an indication for induction therapy to prevent amputation or morbid surgery appeared to be the main determinant in choosing between neo-adjuvant ILP or RT.

Single agent Talimogene Laherparepvec for stage IIIB-IVM1c melanoma patients: A systematic review and meta-analysis

Single-agent Talimogene Laherparepvec (T-VEC) was developed for treatment of unresectable and injectable stage III-IV melanoma. Since its approval and reimbursement, studies have reported varying response rates. The purpose of this systematic review and meta-analysis was to investigate the efficacy and safety of T-VEC. Of 341 publications that were identified, eight studies with a total of 642 patients were included. In patients with stage IIIB-IVM1a, the pooled complete- and overall response rate (CRR and ORR) were 41% and 64%, respectively. In patients with stage IIIB-IVM1c, the pooled CRR and ORR were 30% and 44%, respectively. In patients with stage IVM1b and IVM1c, the pooled CRR and ORR were 4% and 9%, respectively. Adverse events (AEs) were seen in 41-100% of all patients and 0-11% of AEs were severe. In conclusion, single agent T-VEC achieves the highest response rates in patients with early metastatic melanoma and is well-tolerated with generally only mild toxicities.

Neoadjuvant Systemic Therapy (NAST) in Patients with Melanoma: Surgical Considerations by the International Neoadjuvant Melanoma Consortium (INMC)

Exciting advances in melanoma systemic therapies have presented the opportunity for surgical oncologists and their multidisciplinary colleagues to test the neoadjuvant systemic treatment approach in high-risk, resectable metastatic melanomas. Here we describe the state of the science of neoadjuvant systemic therapy (NAST) for melanoma, focusing on the surgical aspects and the key role of the surgical oncologist in this treatment paradigm. This paper summarizes the past decade of developments in melanoma treatment and the current evidence for NAST in stage III melanoma specifically. Issues of surgical relevance are discussed, including the risk of progression on NAST prior to surgery. Technical aspects, such as the definition of resectability for melanoma and the extent and scope of routine surgery are presented. Other important issues, such as the utility of radiographic response evaluation and method of pathologic response evaluation, are addressed. Surgical complications and perioperative management of NAST related adverse events are considered. The International Neoadjuvant Melanoma Consortium has the goal of harmonizing NAST trials in melanoma to facilitate rapid advances with new approaches, and facilitating the comparison of results across trials evaluating different treatment regimens. Our ultimate goals are to provide definitive proof of the safety and efficacy of NAST in melanoma, sufficient for NAST to become an acceptable standard of care, and to leverage this platform to allow more personalized, biomarker-driven, tailored approaches to subsequent treatment and surveillance.

Survival data of PRADO: A phase 2 study of personalized response-driven surgery and adjuvant therapy after neoadjuvant ipilimumab (IPI) and nivolumab (NIVO) in resectable stage III melanoma

9501

Background: In the OpACIN-neo study, 2 cycles neoadjuvant (neoadj) IPI 1mg/kg + NIVO 3mg/kg (I1N3) have been identified as most favorable dosing scheme with a pathologic response rate (pRR) of 77% and 20% grade 3-4 irAEs. After 24.6 months median follow-up (FU), the 2-year (2y) RFS was 96.9% for patients (pts) with pathologic response versus 35.5% for non-responders (>50% viable tumor; pNR). These data raised the question whether therapeutic lymph node dissection (TLND) could be safely omitted in pts achieving a major pathologic response (MPR; ≤10% viable tumor) in their index node (ILN; largest LN metastasis at baseline), and if additional adjuvant (adj) therapy could improve the outcome of pNR pts. Methods: PRADO is an extension cohort of the phase 2 OpACIN-neo study aiming to confirm the pRR and safety of neoadj I1N3 and to test response-driven subsequent therapy. Pts with stage III melanoma were included to receive 2 cycles neoadj I1N3 after marker placement in the ILN. ILN resection was planned at week 6. Pts that achieved MPR in the ILN did not undergo TLND; pts with partial response (pPR; >10 – ≤50% viable tumor) underwent TLND; and pts with pNR underwent TLND and received adj NIVO or dabrafenib plus trametinib (D+T) for 52 weeks ±radiotherapy (RT). Primary endpoints were pRR in the ILN and RFS at 2y. The 2y RFS rates were calculated using a Kaplan Meier based method. Results: Between Nov 2018 and Jan 2020, 99 patients were enrolled and treated with at least 1 cycle of neoadj I1N3. We previously showed a pRR of 72% (95% CI 62 - 80), including 60 (61%) pts with MPR and 11 (11%) pts with pPR. TLND omission in MPR pts resulted in significant reduced surgical morbidity and improved quality of life. There were 27 non-responders of whom 6 developed distant metastasis before ILN resection. Of the other 21 pNR pts, 7 received adj NIVO, 10 adj D+T, 3 no adj therapy, and 1 was lost to FU. After a median FU of 27.9 months (data cutoff Jan 31, 2022), the estimated 2y RFS rate for MPR pts was 93.3% (95% CI 87.2 – 99.9), with 4/60 pts developing a regional relapse. Distant metastasis-free survival (DMFS) was 100%. Of the 11 pPR pts, 4 developed a relapse (all distant), resulting in a 2y RFS and DMFS rate of 63.6% (95% CI 40.7 – 99.5). The 2y RFS rate of the pNR pts was 71.4% (95% CI 54.5 – 93.6), and DMFS 76.2%. At data cutoff, relapse occurred in 2/7 pNR pts with adj NIVO and 3/10 with adj D+T. Final data cutoff is planned mid Feb, 2022. Conclusions: MPR pts in whom TLND was omitted showed a 2y RFS rate of 93.3% and DMFS of 100%, indicating that the ILN procedure and omitting adj therapy could become a safe approach in these pts. Adj systemic therapy in pNR pts seems to improve RFS as compared to historic control (OpACIN-neo), thus should be considered in this unfavorable pNR group. The DMFS rate of 63.6% observed in the pPR group advocates the consideration of adj therapy also for this subgroup in the future. Clinical trial information: NCT02977052.

Use of Merlin Assay to identify patients with a low-risk for SN metastasis in a prospective multicenter Dutch study of a primary melanoma gene-signature (CP-GEP model) to predict sentinel node status during COVID-19

9571

Background: Approximately 70%-85% of patients who undergo sentinel lymph node biopsy (SLNb) show no nodal metastasis in the sentinel node (SN). The clinicopathological and gene expression profile (CP-GEP) model ( Merlin Assay) was developed and validated to identify patients that may forgo the SLNb surgery due to their low risk for for nodal metastasis This study was initiated during the first wave of Covid-19 pandemic to allow for surgical triage on SLNb and evaluate the implementation of the Merlin assay in clinical practice. Methods: This study was conducted in four designated melanoma centers in the Netherlands. Patients (age > 18y) with newly diagnosed melanoma of the skin, eligible to undergo SLNb were screened for study inclusion. Main exclusion criteria was prior history of primary melanoma ( > T1b) in the past 5 years. After enrollment, tissue sections of the primary melanoma were centrally reviewed at the Erasmus MC Cancer Institute to determine Breslow thickness at primary diagnosis. FFPE tumor tissue was dispatched for molecular analysis of eight target genes known to play a role in cancer development. In combination with age, Breslow thickness, and GEP outcome, risk of having nodal metastasis was calculated. Results were binary presented as 'CP-GEP low risk' and 'CP-GEP high risk'. SLNb status was used as gold standard for comparison. Results: A total of 177 patients were analyzed using the CP-GEP model. Median age was 64 years (IQR 52-73) Median Breslow thickness was 1.4mm (IQR 1.0-2.4). Of all patients 28.2% was diagnosed with T1, 40.7% with T2 and 20.9% with T3 melanoma. Corresponding positivity rate was 7%, 14% and 29% respectively. A total of 24 out of 177 patients had a positive SLNb. Median turn-around time from inclusion to CP-GEP result was 15 days. Overall 37.1.% of patients had a CP-GEP low risk profile. The CP-GEP model had a NPV of 94.6%. Conclusions: This is the first prospective multicenter implementation study for the Merlin assay. Results are in line with previous validation studies. The CP-GEP model could accurately identify patients at low risk for SN metastasis. Implementation in clinical practice is feasible based on current turn-around time. In the future, using the Merlin assay to deselect patients for SLNB may allow for a reduction of surgery in patients with melanoma.

Postoperative radiotherapy in Merkel cell carcinoma (MCC)

9575

Background: MCC is a rare and aggressive neuroendocrine malignancy of the skin. Postoperative radiotherapy (PORT) is recommended by current guidelines to reduce recurrences and improve survival in patients with locoregional MCC. However, evidence supporting these recommendations is conflicting and deviations from the protocol occur frequently, due to the generally elderly and frail patient population. We aim to evaluate the influence of PORT on survival in stage I-III MCC patients treated in the Netherlands. Methods: All patients with stage I-III MCC treated in three referral centers between 2013 and 2018 were included retrospectively. Recurrence free survival (RFS) and disease specific survival (DSS, including death from unknown causes) were compared between patients with and without PORT. Prognostic factors for DSS were analyzed using Kaplan-Meier curves, logrank test and cox regression. Since sentinel node biopsies (SN) are frequently omitted in this patient population, analyses were performed in patients with clinical (SN not performed) stage I/II (c-I/II-MCC), pathologic (SN negative) stage I/II (p-I/II-MCC) and stage III MCC (III-MCC), separately. Propensity score matching (PSM) was performed to assess possible confounding by indication. Results: In total 219 patients were included, of whom 54 had p-I/II-MCC, 82 had c-I/II-MCC and 83 had III-MCC. Median follow up time was 53.4 (IQR 32.8-62.4), 28 (11.8-43.3) and 30.8 (19.5-50.0) months, respectively. PSM identified no confounding by indication, analyses were therefore performed in the unmatched cohort. Majority of recurrences were regional in p-I/II-MCC (77.8%) and c-I/II-MCC (74.2%), and distant in III-MCC (61.7%). RFS was significantly different across all stages (p<0.001), DSS was similar for patients with c-I/II-MCC and III-MCC, which was significantly worse compared to patients with p-I/II-MCC (p=0.003). Survival times are shown in table. PORT did not improve RFS and DSS in patients with p-I/II-MCC and c-I/II-MCC. In patients with III-MCC, PORT was associated with improved RFS, but not with DSS. Multivariable analysis identified male gender (hazard ratio (HR) 1.94, p=0.030), performance status (PS) of 3 (HR 3.87, p=0.014) and an unknown PS (HR 5.45, p=0.004), primary tumor on the trunk (HR 2.67, p=0.008), c-I/II-MCC (HR 5.38, p=0.001) and III-MCC (HR 6.44, p<0.001) as predictors for DSS. Effect of PORT was not significant. Conclusions: In this retrospective cohort PORT did not show a DSS benefit in patients with stage I-III MCC. RFS was improved by PORT in III-MCC. PSM showed no confounding by indication.[Table: see text]

Validation of a clinicopathological and gene expression profile model for sentinel lymph node metastasis in primary cutaneous melanoma

BACKGROUND

The Clinicopathological and Gene Expression Profile (CP-GEP) model was developed to accurately identify patients with T1-T3 primary cutaneous melanoma at low risk for nodal metastasis.

OBJECTIVES

To validate the CP-GEP model in an independent Dutch cohort of patients with melanoma.

METHODS

Patients (aged ≥ 18 years) with primary cutaneous melanoma who underwent sentinel lymph node biopsy (SLNB) between 2007 and 2017 at the Erasmus Medical Centre Cancer Institute were eligible. The CP-GEP model combines clinicopathological features (age and Breslow thickness) with the expression of eight target genes involved in melanoma metastasis (ITGB3, PLAT, SERPINE2, GDF15, TGFBR1, LOXL4, CXCL8 and MLANA). Using the pathology result of SLNB as the gold standard, performance measures of the CP-GEP model were calculated, resulting in CP-GEP high risk or low risk for nodal metastasis.

RESULTS

In total, 210 patients were included in the study. Most patients presented with T2 (n = 94, 45%) or T3 (n = 70, 33%) melanoma. Of all patients, 27% (n = 56) had a positive SLNB, with nodal metastasis in 0%, 30%, 54% and 16% of patients with T1, T2, T3 and T4 melanoma, respectively. Overall, the CP-GEP model had a negative predictive value (NPV) of 90·5% [95% confidence interval (CI) 77·9-96.2], with an NPV of 100% (95% CI 72·2-100) in T1, 89·3% (95% CI 72·8-96·3) in T2 and 75·0% (95% CI 30·1-95·4) in T3 melanomas. The CP-GEP indicated high risk in all T4 melanomas.

CONCLUSIONS

The CP-GEP model is a noninvasive and validated tool that accurately identified patients with primary cutaneous melanoma at low risk for nodal metastasis. In this validation cohort, the CP-GEP model has shown the potential to reduce SLNB procedures in patients with melanoma.

Limitations in resectability of colorectal liver metastases 2020 - A systematic approach for clinicians and patients

Colorectal liver metastases (CRLM) affect over 50 % of all patients with colorectal cancer, which is the second leading cause of cancer in the western world. Resection of CRLM may provide cure and improves survival over chemotherapy alone. However, resectability of CLRM has to be decided in multidisciplinary tumor boards and is based on oncological factors, technical factors and patient factors. The advances of chemotherapy lead to the abolition of contraindications to resection in favor of technical resectability, but somatic mutations and molecular subtyping may improve selection of patients for resection in the future. Technical factors center around anatomy of the lesions, volume of the remnant liver and quality of the liver parenchymal. Multiple strategies have been developed to overcome volume limitations and they are reviewed here. The least investigated topic is how to select the right patients among an elderly and frail patient population for the large variety of technical options specifically for bi-lobar CRLM to keep 90-day mortality as low as possible. The review is an overview over the current state-of-the art and a systematic guide to the topic of resectability of CRLM for both clinicians and patients.

Safety and Feasibility of Additional Tumor Debulking to First-Line Palliative Combination Chemotherapy for Patients with Multiorgan Metastatic Colorectal Cancer

Introduction

Local treatment of metastases is frequently performed in patients with multiorgan metastatic colorectal carcinoma (mCRC) analogous to selected patients with oligometastatic disease for whom this is standard of care. The ORCHESTRA trial (NCT01792934) was designed to prospectively evaluate overall survival benefit from tumor debulking in addition to chemotherapy in patients with multiorgan mCRC. Here, we report the preplanned safety and feasibility evaluation after inclusion of the first 100 patients.

Methods

Patients were eligible if at least 80% tumor debulking was deemed feasible by resection, radiotherapy and/or thermal ablative therapy. In case of clinical benefit after three or four cycles of respectively 5‐fluorouracil/leucovorin or capecitabine and oxaliplatin ± bevacizumab patients were randomized to tumor debulking followed by chemotherapy in the intervention arm, or standard treatment with chemotherapy.

Results

Twelve patients dropped out prior to randomization for various reasons. Eighty‐eight patients were randomized to the standard (n = 43) or intervention arm (n = 45). No patients withdrew after randomization. Debulking was performed in 82% (n = 37). Two patients had no lesions left to treat, five had progressive disease, and one patient died prior to local treatment. In 15 patients (40%) 21 serious adverse events related to debulking were reported. Postoperative mortality was 2.7% (n = 1). After debulking chemotherapy was resumed in 89% of patients.

Conclusion

Tumor debulking is feasible and does not prohibit administration of palliative chemotherapy in the majority of patients with multiorgan mCRC, despite the occurrence of serious adverse events related to local treatment.

Implications for Practice

This first prospective randomized trial on tumor debulking in addition to chemotherapy shows that local treatment of metastases is feasible in patients with multiorgan metastatic colorectal cancer and does not prohibit administration of palliative systemic therapy, despite the occurrence of serious adverse events related to local treatment. The trial continues accrual, and overall survival (OS) data and quality of life assessment are collected to determine whether the primary aim of >6 months OS benefit with preserved quality of life will be met. This will support evidence‐based decision making in multidisciplinary colorectal cancer care and can be readily implemented in daily practice.

The ORCHESTRA trial was designed to prospectively evaluate overall survival benefit from tumor debulking in addition to chemotherapy in patients with multi‐organ metastatic colorectal cancer. This article reports the preplanned safety and feasibility evaluation after inclusion of the first 100 patients.

First safety and efficacy results of PRADO: A phase II study of personalized response-driven surgery and adjuvant therapy after neoadjuvant ipilimumab (IPI) and nivolumab (NIVO) in resectable stage III melanoma

10002

Background: OpACIN-neo tested 3 dosing schemes of neoadjuvant (neoadj) IPI+NIVO and identified 2 cycles of IPI 1mg/kg + NIVO 3mg/kg (I1N3) as the most favorable with a pathologic (path) response rate (pRR) of 77% and 20% grade 3-4 irAEs. After 17.6 months median FU, 1/64 (2%) patients (pts) with path response vs 13/21 (62%) of the non-responders ( > 50% viable tumor cells; pNR) had relapsed. We hypothesized that therapeutic lymph node dissection (TLND) could be omitted in pts achieving a complete or near-complete path response (≤10% viable tumor cells; major path response, MPR) in the index node (largest LN metastasis: ILN), whereas additional adjuvant (adj) therapy might improve the outcome of pNR pts. Methods: PRADO is an extension cohort of the multi-center phase 2 OpACIN-neo study that aims to confirm the pRR and safety of neoadj I1N3 and to test response-driven subsequent therapy. Pts with RECIST 1.1 measurable clinical stage III melanoma were included to receive 2 cycles of neoadj I1N3 after marker placement in the ILN. ILN resection was planned at wk 6. Pts that achieved MPR in the ILN did not undergo TLND; pts with pPR ( > 10 – ≤50% viable tumor cells) underwent TLND; and pts with pNR underwent TLND and received adj NIVO or targeted therapy (TT) for 52 wks +/- radiotherapy (RT). Primary endpoints were pRR in the ILN and 24-month RFS. Estimated toxicity rates at wk 12 were calculated using a Kaplan Meier based method. Results: Between Nov 16, 2018 and Jan 3, 2020, 99 of 114 screened pts were eligible and enrolled. So far, 86 pts had ≥12 wks FU. 70/99 pts achieved a path response in the ILN (pRR 71%, 95% CI 61% - 79%); 60 (61%) had MPR. TLND was omitted in 58 (97%) of the MPR pts. There were 28 non-responders; 7 developed distant metastasis before ILN resection. To date, 8 of the 21 pNR pts had adj NIVO, 7 had adj TT and 7 had adj RT. The estimated grade 3-4 irAE rate at wk 12 was 24%. Due to toxicity, 10 pts (10%) received only 1 cycle I1N3 and in 3 pts ILN resection was not performed: 2 of these pts underwent TLND at wk 9 and one pt was not evaluated for path response. At data cutoff, the surgery-related grade 1,2 and 3 AE rates were 29%, 10% and 0% in pts who underwent ILN resection only vs 21%, 30% and 9% in pts who underwent subsequent TLND (p = 0.004). At ASCO 2020 all pts will have reached ≥12 wks FU. Conclusions: Neoadj I1N3 treatment induced a high pRR with tolerable toxicity. TLND was omitted in a major subset of pts, reducing surgical morbidity. Longer FU is needed to report safety and RFS when TLND is omitted in MPR pts. Clinical trial information: NCT02977052.

Upregulation of intratumoral HLA class I and peritumoral Mx1 in ulcerated melanomas

Before the era of immune checkpoint blockade, a meta-analysis encompassing fifteen trials reported that adjuvant IFN-α significantly reduces the risk of relapse and improves survival of ulcerated melanoma (UM) with no benefit for higher doses compared to lower doses. IFNa2b affects many cell intrinsic features of tumor cells and modulates the host innate and cognate immune responses. To better understand the biological traits associated with ulceration that could explain the efficacy of prophylactic type 1 IFN, we performed immunohistochemical analysis of various molecules (major histocompatibility complex class I and class II, MX Dynamin Like GTPase 1 (MX1), inducible Nitric-Oxide Synthase (iNOS) or CD47) in two retrospective cohorts of melanoma patients, one diagnosed with a primary cutaneous melanoma (1995-2013, N = 172, among whom 49% were ulcerated melanoma (UM)) and a second one diagnosed with metastatic melanoma amenable to lymph node resection (EORTC 18952 and 18991 trials, N = 98, among whom 44% were UM). We found that primary and metastatic UM exhibit higher basal expression of MHC class I molecules, independently of Breslow thickness, histology and lymphocytic infiltration compared with NUM and that primary UM harbored higher constitutive levels of the antiviral protein Mx1 at the border of tumor beds than NUM. These findings suggest that UM expand in a tumor microenvironment where chronic exposure to type 1 IFN could favor a response to exogenous IFNs.

Feasibility of a national expert panel to determine resectability in patients with initially unresectable colorectal cancer liver metastases (CRLM)

3562

Background: Decision on optimal treatment strategy for CRLM remains complex because uniform (un)resectability criteria are lacking. We hypothesize that the use of an expert panel can improve the identification of patients with potentially resectable CRLM. The Dutch Colorectal Cancer Group (DCCG) Expert Panel was established in conjunction with the CAIRO5 study (Huiskens J et al. BMC Cancer 2015), a multicenter, randomized, phase-3 trial, investigating optimal systemic induction treatment in patients with initially unresectable CRLM. Here, we present the feasibility of this panel. Methods: The DCCG Expert Panel consists of 13 liver surgeons and 4 radiologists. Consensus was reached on predefined (un)resectability criteria at baseline. An online platform allowed resectability-assessment by 3 surgeons in case of inter-surgeon agreement, and 5 surgeons if they disagreed. CRLM were assessed as 1) resectable 2) potentially resectable, or 3) permanently unresectable. Patients with initially unresectable CRLM were evaluated at baseline and subsequently every 2 months as long as CRLM were considered potentially resectable. Results: Overall, 397 panel evaluations in 183 patients were analyzed. Median time to panel conclusion was 7 days (IQR 5-11 days) and 204 (51%) evaluations showed inter-surgeon disagreement, with major disagreement (resectable versus permanently unresectable) in 24 (14%) and 12 (29%) evaluations after 2 and 4 months of systemic treatment. Ultimately, 84 (79%) patients with resectable CRLM underwent resection and 23 (27%) resections included portal vein embolization or 2-stage procedures. In resectable CRLM with inter-surgeon agreement versus disagreement, R0 resection was achieved in 39 (75%) versus 28 (52%) patients, p = 0.013. Median time to recurrence was similar between resections with panel agreement versus disagreement, 8 versus 6 months, p = 0.447. Conclusions: This study shows the feasibility of a national Liver Expert Panel for prospective resectability assessment of patients with initially unresectable CRLM. High inter-surgeon disagreement supports the use of a panel. We aim to further validate the panel with outcome parameters. Clinical trial information: NCT02162563.

Surgical and medical management of small bowel gastrointestinal stromal tumors: A report of the Dutch GIST registry

BACKGROUND

A cohort of 201 patients with small bowel gastrointestinal stromal tumors (GIST) treated between January 1st, 2009 and December 31st, 2016 in five GIST expertise centers in the Netherlands was analyzed. Goal of this study was to describe the clinical, surgical and pathological characteristics of this rare subpopulation of GIST patients, registered in the Dutch GIST registry.

METHODS

Clinical outcomes and risk factors of patients with small bowel GIST who underwent surgery or treated with systemic therapy were analyzed. A classification was made based on disease status at diagnosis (localized vs. metastasized).

RESULTS

201 patients with small bowel GIST were registered of which 138 patients (69%) were diagnosed with localized disease and 63 patients (31%) with metastatic disease. Approximately 19% of the patients had emergency surgery, and in 22% GIST was an accidental finding. In patients with high risk localized disease, recurrence occurred less often in patients who received adjuvant treatment (4/32) compared to patients who did not (20/31, p < 0.01). Disease progression during palliative imatinib treatment occurred in 23 patients (28%) after a median of 20.7 (range 1.8-47.1) months. Ongoing response was established in 52/82 patients on first line palliative treatment with imatinib after a median treatment time of 30.6 (range 2.5-155.3) months.

CONCLUSION

Patients with small-bowel GIST more frequently present with metastatic disease when compared to patients with gastric GIST in literature. We advocate for Prospective registration of these patients and investigate the use of surgery in patients with limited metastatic disease.

Elderly patients with gastrointestinal stromal tumour (GIST) receive less treatment irrespective of performance score or comorbidity - A retrospective multicentre study in a large cohort of GIST patients

OBJECTIVE

Although gastrointestinal stromal tumours (GIST) predominantly occur in older patients, data on treatment patterns in elderly GIST patients are scarce.

METHODS

Patients registered in the Dutch GIST Registry (DGR) from January 2009 until December 2016 were included. Differences in treatment patterns between elderly (≥75 years) and younger patients were compared. Multivariate analyses were conducted using logistic regression.

RESULTS

Data of 145 elderly and 665 non-elderly patients were registered (median age 78 and 60 years respectively). In elderly patients, performance score (WHO-PS) and age-adjusted Charlson comorbidity index (ACCI) were significantly higher (p < 0.05; p < 0.001), and albumin level significantly lower (p = 0.04). Hundred-and-nine (75.2%) elderly and 503 (75.6%) non-elderly patients had only localised disease. Surgery was performed in 57% of elderly versus 84% of non-elderly patients (p = 0.003, OR: 0.26, 95% CI: 0.11-0.63). No differences in surgery outcome or complications were found. Thirty-eight percent of elderly with an indication for adjuvant treatment did receive imatinib versus 68% of non-elderly (p = 0.04, OR: 0.47, 95% CI: 0.23-0.95). Thirty-six elderly and 162 non-elderly patients had metastatic disease. Palliative imatinib was equally given (mean dose 400 mg) and adverse events were mostly minor (p = 0.71). In elderly, drug-related toxicity was in 32.7% reason to discontinue imatinib versus 5.1% in non-elderly (p = 0.001, OR 13.5, 95% CI: 2.8-65.0). Median progression-free survival (PFS) was 24 months in elderly and 33 months in non-elderly (p = 0.10). Median overall survival (OS) was 34 months and 59 months respectively (p = 0.01).

CONCLUSIONS

Elderly GIST patients with localised disease receive less surgery and adjuvant treatment, irrespective of comorbidity and performance score. Drug-related toxicity results more often in treatment discontinuation. This possibly results in poor outcome.

Neo-adjuvant chemotherapy followed by surgery versus surgery alone in high-risk patients with resectable colorectal liver metastases: The CHARISMA randomized multicenter clinical trial

TPS790

Background: Colorectal carcinoma is a leading cause of cancer death worldwide, mostly as a consequence of metastatic disease. If metastases are confined to the liver, surgical resection is the only therapy providing potential for cure. Efforts to improve the outcome of hepatectomy for colorectal liver metastases (CRLM) by combining surgery with chemotherapy have failed to demonstrate overall survival (OS) benefit. This may partly be explained by the fact that previous trials on this subject involved strict inclusion criteria. Consequently, patients with a high oncological risk profile - who might benefit the most from chemotherapy – might have been underrepresented in previous trials. Several Clinical Risk Scores (CRS) have been developed predicting patients’ prognosis after resection of CRLM. The most widely used and validated CRS was described by Fong et al., which characterizes 2 risk groups (high versus low) based on 5 independent clinicopathologic prognostic variables. Each variable is assigned 1 point. Multiple retrospective observations showed that neo-/adjuvant chemotherapy induced significant OS benefit in patients with a high-risk profile (CRS of 3 to 5 points). The CHARISMA trial evaluates the impact of neo-adjuvant chemotherapy in patients with high-risk, primarily resectable liver-only colorectal metastases. We hypothesize that adding neo-adjuvant chemotherapy to surgery improves OS in this high-risk patient group. Methods: The CHARISMA trial is a randomized (1:1) phase III trial. Patients receive either surgery only for CRLM (arm A) or 6 cycles of neo-adjuvant Oxaliplatin + Capecitabine, followed by surgery (arm B). The primary endpoint is OS. On basis of retrospective data, the expected hazard ratio for arm B is 0.60. With an expected 5-year OS of 25% in arm A, a two-sided significance level α = 0.05 and power 1 - β = 0.8, 224 patients have to be recruited. Major eligibility criteria are: liver-only metastases, primarily resectable CRLM, high-risk patients (CRS 3-5). The trial is currently accruing in 10 Dutch liver centers and is registered in the “Dutch Trial Register”: NTR4893 ( www.trialregister.nl ). Clinical trial information: NTR4893.

The ORCHESTRA trial: A phase III trial of adding tumor debulking to systemic therapy versus systemic therapy alone in multi-organ metastatic colorectal cancer (mCRC)

TPS788

Background: In the current multidisciplinary approach of mCRC, local treatment of oligometastases is common practice. Results of large case series of selected patients treated with complete surgical resection of metastatic lesions suggest that this approach substantially improves survival rates to around 30-60%. Other techniques such as radiofrequency or microwave ablation (RFA, MWA), transarterial chemoembolization (TACE) or radiotherapy can also be applied in local treatment. Curative treatment options are generally not available for patients with extensive hepatic and/or extrahepatic mCRC. These patients primarily receive palliative systemic treatment consisting of combination chemotherapy as well as targeted agents. So far, reports on the benefit of local treatment for metastases in multi-organ mCRC have major limitations, including being small, non-randomized, single-center and retrospective. The benefit from local treatment of metastases for these patients should be established to allow for interruption of the standard systemic therapy and exposure to possible adverse events from local treatment. Methods: The ‘ORCHESTRA’ trial is a randomized multicenter clinical trial for patients with multi-organ mCRC, comparing the combination of chemotherapy and maximal tumor debulking versuschemotherapy alone (NCT01792934). We will examine the interplay of both efficacy and toxicity for the combination of systemic chemotherapy and locoregional therapy. Our study design incorporates systemic as well as local therapy in the experimental arm and combines local treatment modalities to pursue maximal tumor debulking. We aim to improve overall survival of patients with multi-organ mCRC by maximal tumor debulking after induction chemotherapy with at least six months. A total of 478 patients will be included to meet the primary endpoint (power 80%, type I error rate 5%). We define local treatments feasible when they can be performed within a 3-month time period to prevent extensive delay of systemic therapy. Currently, 60 patients are included in 22 participating Dutch hospitals. Clinical trial information: NCT01792934.

Favorable overall survival in stage III melanoma patients after adjuvant dendritic cell vaccination

Melanoma patients with regional metastatic disease are at high risk for recurrence and metastatic disease, despite radical lymph node dissection (RLND). We investigated the immunologic response and clinical outcome to adjuvant dendritic cell (DC) vaccination in melanoma patients with regional metastatic disease who underwent RLND with curative intent. In this retrospective study, 78 melanoma patients with regional lymph node metastasis who underwent RLND received autologous DCs loaded with gp100 and tyrosinase and were analyzed for functional tumor-specific T cell responses in skin-test infiltrating lymphocytes. The study shows that adjuvant DC vaccination in melanoma patients with regional lymph node metastasis is safe and induced functional tumor-specific T cell responses in 71% of the patients. The presence of functional tumor-specific T cells was correlated with a better 2-year overall survival (OS) rate. OS was significantly higher after adjuvant DC vaccination compared to 209 matched controls who underwent RLND without adjuvant DC vaccination, 63.6 mo vs. 31.0 mo (p = 0.018; hazard ratio 0.59; 95%CI 0.42-0.84). Five-year survival rate increased from 38% to 53% (p < 0.01). In summary, in melanoma patients with regional metastatic disease, who are at high risk for recurrence and metastatic disease after RLND, adjuvant DC vaccination is well tolerated. It induced functional tumor-specific immune responses in the majority of patients and these were related to clinical outcome. OS was significantly higher compared to matched controls. A randomized clinical trial is needed to prospectively validate the efficacy of DC vaccination in the adjuvant setting.

Long-term results of the "liver first" approach in patients with locally advanced rectal cancer and synchronous liver metastases

BACKGROUND

There are no reports available on the long-term outcome of patients with the "liver first" approach.

OBJECTIVES

The aim of this study was to present the long-term results of the "liver first" approach in our center.

DESIGN

This study is a retrospective analysis.

SETTING

This study was conducted at a tertiary referral center.

PATIENTS

Patients from May 2003 to March 2009 were included.

INTERVENTIONS

Patients with locally advanced rectal cancer and synchronous liver metastases were first treated for their liver metastases. If the treatment was successful, patients underwent neoadjuvant chemoradiotherapy and surgery for the rectal cancer. If metastases could not be resected, resection of the rectal primary was not routinely performed.

MAIN OUTCOME MEASURES

The primary outcome measured was long-term results of the "liver first" approach.

RESULTS

Of the 42 patients included (median age, 61 years), all but one (98%) started with neoadjuvant chemotherapy. In total, 31 (74%) patients completed the "liver first" approach. In 11 patients, curative therapy was not possible because of unresectable metastases; in 10 of these patients (91%), the primary tumor was not resected.

LIMITATIONS

This study was limited because it was a retrospective analysis without a control group.

CONCLUSIONS

By applying the "liver first" approach, the majority of this group of patients (74%) could undergo curative treatment of both metastatic and primary disease in combination with optimal neoadjuvant therapy. This strategy may avoid unnecessary rectal surgery in patients with incurable metastatic disease. In this selected patient group, long-term survival may be achieved with a 5-year survival rate of 67%.

Morbidity and prognosis after therapeutic lymph node dissections for malignant melanoma

Melanoma patients with clinically evident regional lymph node metastases are treated with therapeutic lymph node dissections (TLNDs). The aim of this study was to evaluate morbidity and mortality following TLND in our institution. Moreover, disease-free (DFS) and overall (OS) survival were evaluated and factors that influence prognosis after TLND were assessed. Between 1982 and 2005, 236 patients underwent a TLND. Patients, who received a palliative LND or a sentinel node procedure, were not included. The median Breslow thickness was 2.4mm. Ulceration was present in 23% of patients and unknown in 66%. 37 patients had unknown primary tumors. There were 129 ilio-inguinal, 50 axillary and 61 cervical dissections performed. 37% of the patients experienced at least one operation related complication. The most frequently seen complications were wound infections/necrosis and chronic lymph edema. Ilio-inguinal dissection patients experienced significantly more complications and a longer duration of hospitalization compared to axillary or cervical patients. The duration of hospitalization has been reduced in recent years from 12 to 5days. The mean follow-up was 29months. Kaplan-Meier estimated 5-year regional control was 79%, 5-year DFS was 19% and 5-year OS was 26%. The number of positive lymph nodes, the site of the primary tumor and extra capsular extension (ECE) were independent prognostic factors for DFS and only site and ECE for OS. In conclusion, TLND for stage III melanoma is accompanied with considerable short-term complications, and can achieve regional control and potential curation in approximately one in every four patients.

Outcome and prognostic factor analysis of 217 consecutive isolated limb perfusions with tumor necrosis factor-α and melphalan for limb-threatening soft tissue sarcoma

BACKGROUND

Extensive and mutilating surgery is often required for locally advanced soft tissue sarcoma (STS) of the limb. As it has become apparent that amputation for STS does not improve survival rates, the interest in limb-preserving approaches has increased. Isolated limb perfusion (ILP) with tumor necrosis factor-alpha (TNF) and melphalan is successful in providing local tumor control and enables limb-preserving surgery in a majority of cases. A mature, large, single-institution experience with 217 consecutive ILPs for STS of the extremity is reported.

METHODS

At a prospectively maintained database at a tertiary referral center, 217 ILPs were performed from July 1991 to July 2003 in 197 patients with locally advanced STS of the extremity. ILPs were performed at mild hyperthermic conditions with 1-4 mg of TNF and 10-13 mg/L limb-volume melphalan (M) for leg and arm perfusions, respectively.

RESULTS

The overall response rate was 75%. Limb salvage was achieved in 87% of the perfused limbs. Median survival post-ILP was 57 months and prognostic factors for survival were Trojani grade of the tumor and ILP for single versus multiple STS. The procedure could be performed safely, with a perioperative mortality of 0.5% in all patients with no age limit (median age, 54 yrs; range, 12-91). Systemic and locoregional toxicity were modest and easily manageable.

CONCLUSION

TNF+M-based ILP can provide limb salvage in a significant percentage of patients with locally advanced STS and has therefore gained a permanent place in the multimodality treatment of STS.

The palliative value of tumor necrosis factor α-based isolated limb perfusion in patients with metastatic sarcoma and melanoma

BACKGROUND

Both patients with soft tissue sarcoma (STS) and patients with melanoma have limited treatment possibilities once the tumor has metastasized systemically. In patients with extremity STS or bulky melanoma in-transit metastases, the local tumor burden may be so problematic that, even in patients with systemically metastasized disease, an amputation may be inevitable. Isolated limb perfusion (ILP) has proven to be an excellent, local, limb-saving treatment option in patients with locally advanced extremity tumors. In this study, the authors investigated the palliative value of the ILP procedure to avoid amputation in patients who had Stage IV STS and melanoma.

METHODS

From 1991 to 2003, of 339 tumor necrosis factor alpha (TNF)-based ILPs, 51 procedures were performed for either Stage IV STS (n = 37 patients) or Stage IV melanoma (n = 14 patients). All patients underwent an ILP with TNF and melphalan of the upper limb (n = 4 patients) or the lower limb (n = 47 patients) with 26-140 mg melphalan and 2-4 mg TNF.

RESULTS

The overall response in patients with Stage IV STS was 84%, and their median survival was 12 months after ILP. Limb salvage was achieved in 36 of 37 patients, with 1 patient undergoing amputation due to treatment toxicity. In the patients with Stage IV melanoma, the complete response rate was 43%. All patients with melanoma preserved their limb during a median survival of 7 months.

CONCLUSIONS

TNF-based ILP is an excellent procedure that provided tumor control and limb salvage for the short survival of patients with metastasized, very bulky, limb-threatening tumors of the extremity.