Circulating tumor DNA analysis of the phase III VOYAGER trial: KIT mutational landscape and outcomes in patients with advanced gastrointestinal stromal tumor treated with avapritinib or regorafenib.

BACKGROUND: The current treatment paradigm of imatinib-resistant metastatic gastrointestinal stromal tumor (GIST) does not incorporate KIT/PDGFRA genotypes in therapeutic drug sequencing, except for PDGFRA exon 18-mutant GIST that is indicated for avapritinib treatment. Here, circulating tumor DNA (ctDNA) sequencing was used to analyze plasma samples prospectively collected in the phase III VOYAGER trial to understand how the KIT/PDGFRA mutational landscape contributes to tyrosine kinase inhibitor (TKI) resistance and to determine its clinical validity and utility. PATIENTS AND METHODS: VOYAGER (N = 476) compared avapritinib with regorafenib in patients with KIT/PDGFRA-mutant GIST previously treated with imatinib and one or two additional TKIs (NCT03465722). KIT/PDGFRA ctDNA mutation profiling of plasma samples at baseline and end of treatment was assessed with 74-gene Guardant360® CDx. Molecular subgroups were determined and correlated with outcomes. RESULTS: A total of 386/476 patients with KIT/PDGFRA-mutant tumors underwent baseline (pre-trial treatment) ctDNA analysis; 196 received avapritinib and 190 received regorafenib. KIT and PDGFRA mutations were detected in 75.1% and 5.4%, respectively. KIT resistance mutations were found in the activation loop (A-loop; 80.4%) and ATP-binding pocket (ATP-BP; 40.8%); 23.4% had both. An average of 2.6 KIT mutations were detected per patient; 17.2% showed 4-14 different KIT resistance mutations. Of all pathogenic KIT variants, 28.0% were novel, including alterations in exons/codons previously unreported. PDGFRA mutations showed similar patterns. ctDNA-detected KIT ATP-BP mutations negatively prognosticated avapritinib activity, with a median progression-free survival (mPFS) of 1.9 versus 5.6 months for regorafenib. mPFS for regorafenib did not vary regardless of the presence or absence of ATP-BP/A-loop mutants and was greater than mPFS with avapritinib in this population. Secondary KIT ATP-BP pocket mutation variants, particularly V654A, were enriched upon disease progression with avapritinib. CONCLUSIONS: ctDNA sequencing efficiently detects KIT/PDGFRA mutations and prognosticates outcomes in patients with TKI-resistant GIST treated with avapritinib. ctDNA analysis can be used to monitor disease progression and provide more personalized treatment.

Intraoperative motive for incomplete resection in primary retroperitoneal sarcoma.

INTRODUCTION: Surgical resection is the current standard of care for retroperitoneal sarcoma (RPS). Recent data suggests that up to 5% of patient have incomplete (R2) resection. The exact reason why patients scheduled for surgery with a curative intent to treat ended up with an R2 resection is largely unknown. AIM OF THE STUDY: To identify intraoperative findings responsible for incomplete (R2) resection in primary RPS. METHODS: All records of consecutive patients scheduled for a non-metastatic primary RPS surgery between 1995 and 2020 in a tertiary care sarcoma centre were retrospective analyzed. RESULTS: Among the 347 patients scheduled for surgery, 13 (3.7%) had an incomplete (R2) resection. The reasons for incomplete surgery were intraoperative finding of vascular involvement of great vessels in 5 patients, previously undetected peritoneal metastases in 5 patients, invasion of contralateral kidney/ureter in 2 patients and the need to preserve both kidneys in 1 patient because of his past medical history. Among these patients, 3 had a laparotomy without resection and 10 had a partial resection (i.e. debulking surgery). Severe postoperative complications occurred in 5 patients. The median length of stay in hospital was 19days. After a median follow-up of 12months, the median survival of patients after incomplete resection was 18months. The 1-y, 5-y and 8-y overall survival (OS) for these patients were 46%, 14%, and 7%, respectively. CONCLUSION: Incomplete (R2) resection for a primary RPS surgery is rare in specialized sarcoma center. The next steps should be to identify the preoperative criteria that lead to this accurate selection and to define the best practice in front of a peroperative discovery of an unresectable RPS. LEVEL OF EVIDENCE: III.

Systemic treatment in advanced phyllodes tumor of the breast: a multi-institutional European retrospective case-series analyses.

BACKGROUND: We aimed at investigating outcome of systemic treatments in advanced breast PT. METHODS: All cases of advanced breast PT treated with systemic treatments from 1999 to 2019, in one of the referral sarcoma centers involved in the study, were retrospectively reviewed. RESULTS: 56 female patients were identified. Median age was 52 (range of 25-76) years. Patients received a median number of 2 systemic treatments (range of 1-4). Best responses according to RECIST were 1 (3.7%) CR, 11 (40.7%) PR, 6 (22.2%) SD, 9 (33.3%) PD with anthracyclines plus ifosfamide (AI); 2 (16.7%) PR, 4 (33.3%) SD, 6 (50.0%) PD with anthracycline alone; 3 (18.8%) PR, 4 (25.0%) SD, 9 (56.3%) PD with high-dose ifosfamide given as a continuous infusion (HD-IFX); 3 (20.0%) SD, 12 (80.0%) PD with a gemcitabine-based regimen (with 2 patients not evaluable); 1 (8.3%) PR, 2 (16.7%) SD, 9 (75.0%) PD with trabectedin (with 1 patient not evaluable); 1 (16.7%) PR, 1 (16.7%) SD, 4 (66.7%) PD with tyrosine-kinase inhibitors (TKI). The median PFS were 5.7 (IQR 2.5-9.1) months with AI; 3.2 (IQR 2.2-5.0) months with anthracycline alone; 3.4 (IQR 1.4-6.7) months with HD-IFX; 2.1 (IQR 1.4-5.2) months with gemcitabine-based chemotherapy; 1.8 (IQR 0.7-6.6) months with trabectedin; 3.4 (IQR 3.1-3.8) months with TKI. With a median follow-up of 35.3 (IQR 17.6-66.9) months, OS from the start of first-line systemic treatment was 15.2 (IQR 7.6-39.6) months. CONCLUSION: In this series of advanced PT (to our knowledge, the largest reported so far), AI was associated with a high rate of responses, however, with a median PFS of 5.7 months. Other systemic treatments were poorly active.

A randomized phase III trial comparing trabectedin to best supportive care in patients with pre-treated soft tissue sarcoma: T-SAR, a French Sarcoma Group trial.

BACKGROUND: The French Sarcoma Group assessed the efficacy, safety, and quality of life (QoL) of trabectedin versus best supportive care (BSC) in patients with advanced soft tissue sarcoma (STS). PATIENTS AND METHODS: This randomized, multicenter, open-label, phase III study included adults with STS who progressed after 1-3 prior treatment lines. Patients were randomized (1 : 1) to receive trabectedin 1.5 mg/m2 every 3 weeks or BSC, stratified into L-STS (liposarcoma/leiomyosarcoma) and non-L-STS groups (other histotypes). Patients from the BSC arm were allowed to cross over to trabectedin at progression. The primary efficacy endpoint was progression-free survival (PFS) confirmed by blinded central review and analyzed in the intention-to-treat population. RESULTS: Between 26 January 2015 and 5 November 2015, 103 heavily pre-treated patients (60.2% with L-STS) from 16 French centers were allocated to receive trabectedin (n = 52) or BSC (n = 51). Median PFS was 3.1 months [95% confidence interval (CI) 1.8-5.9 months] in the trabectedin arm versus 1.5 months (0.9-2.6 months) in the BSC arm (hazard ratio = 0.39, 95% CI 0.24-0.64, P < 0.001) with benefits observed across almost all analyzed subgroups, but particularly in patients with L-STS (5.1 versus 1.4 months, P = 0.0001). Seven patients (13.7%) in the trabectedin arm (all with L-STS) achieved a partial response, while no objective responses were observed in the BSC arm (P = 0.004). The most common grade 3/4 adverse events were neutropenia (44.2% of patients), leukopenia (34.6%), and transaminase increase (32.7%). Health-related 30-item core European Organization for the Research and Treatment of Cancer Quality-of-Life Questionnaire evidenced no statistical differences between the arms for any domain and at any time point. After progression, 91.8% of patients crossed over from BSC to trabectedin. CONCLUSION: Trabectedin demonstrates superior disease control to BSC without impairing QoL in patients with recurrent STS of multiple histologies, with greater impact in patients with L-STS.

Long-Term Outcome After Surgery for a Localized Retroperitoneal Soft Tissue Sarcoma in Elderly Patients: Results from a Retrospective, Single-Center Study.

BACKGROUND: To evaluate short- and long-term results after curative surgery for a retroperitoneal sarcoma (RPS) in elderly patients. METHODS: We retrospectively analyzed data of all patients operated in our single, tertiary care center for a nonmetastatic RPS and identified patients aged 70 years and older. RESULTS: Among 296 patients with an RPS treated between 1994 and 2015, 60 (20%) were aged 70 years and older (median age 74 years; range 70-85). The median tumor size was 24 cm (range 6-46). Forty-six patients (77%) had mass-related symptoms at the time of diagnosis. The most frequent histological subtypes were de-differentiated liposarcoma (53%, n = 32) and well-differentiated liposarcoma (35%, n = 21). Twenty-two patients (37%) had perioperative radiotherapy and/or chemotherapy. Fifty-eight patients (97%) had macroscopically complete resection. The postoperative mortality was 8% and severe morbidity (Dindo/Clavien ≥ 3) was 32%. A reoperation was required for ten patients (17%). After a median follow-up of 20 months (range 1-121), the 5-year overall survival (OS) rate was 90% (95% confidence interval [CI] 79-100%), and median OS was not reached. The cancer-specific death rate was 88%. No prognostic factor for disease-specific survival was detected. The 5-year disease-free survival (DFS) rate was 52% (95% CI 33-84%) and 5-year locoregional recurrence-free survival rate was 52% (95% CI 33-84%). Median DFS was 94 months (95% CI 35-NA). Reoperation after inappropriate surgery and postoperative morbidity were independent predictive factors of locoregional relapse. No predictive factors of distant metastasis were found. CONCLUSIONS: Curative surgery is feasible in selected elderly patients but with higher mortality and morbidity rates than in younger patients. It enables a prolonged survival. Future studies should focus on selection process to minimize postoperative mortality and morbidity.

Improved survival using specialized multidisciplinary board in sarcoma patients.

BACKGROUND: Sarcomas are rare but aggressive diseases. Specialized multidisciplinary management is not implemented for all patients in most countries. We investigated the impact of a multidisciplinary tumor board (MDTB) presentation before treatment in a nationwide study over 5 years. PATIENTS AND METHODS: NETSARC (netsarc.org) is a network of 26 reference sarcoma centers with specialized MDTB, funded by the French National Cancer Institute to improve the outcome of sarcoma patients. Since 2010, presentation to an MDTB and second pathological review are mandatory for sarcoma patients in France. Patients' characteristics and follow-up are collected in a database regularly monitored and updated. The management and survival of patients presented to these MDTB before versus after initial treatment were analyzed. RESULTS: Out of the 12 528 patients aged ≥15 years, with a first diagnosis of soft tissue and visceral sarcoma obtained between 1 January 2010 and 31 December 2014, 5281 (42.2%) and 7247 (57.8%) were presented to the MDTB before and after the initiation of treatment, respectively. The former group had generally worse prognostic characteristics. Presentation to a MDTB before treatment was associated with a better compliance to clinical practice guidelines, for example, biopsy before surgery, imaging, quality of initial surgery, and less reoperations (all P < 0.001). Local relapse-free survival and relapse-free survival were significantly better in patients presented to a MDTB before initiation of treatment, both in univariate and multivariate analysis. CONCLUSION: The compliance to clinical practice guidelines and relapse-free survival of sarcoma patients are significantly better when the initial treatment is guided by a pre-therapeutic specialized MDTB.

Hepatitis B virus reactivation in patients with solid tumors receiving systemic anticancer treatment.

BACKGROUND: Hepatitis B virus (HBV) reactivation is a well-known risk during chemotherapy for hematological malignancies with reported rates ranging between 14% and 72%. However, there is a paucity of data regarding HBV infection management and reactivation risk in patients receiving systemic treatments for solid tumors. DESIGN: We conducted a PubMed search for publications from January 1990 until May 2016 related to HBV reactivation. The search terms were 'hepatitis B reactivation', cross-referenced with 'chemotherapy', then 'hepatitis B' cross-referenced with International Non-proprietary Name of each of the most used chemotherapy drugs in solid tumors. RESULTS: From these data, a grading of HBV reactivation risk and recommendations for management are given for most frequently used anticancer drugs in solid tumors. CONCLUSION: Most drugs used for the treatment of solid tumors can induce hepatitis B reactivation in HBs antigen-positive patients. HBV screening can be recommended before systemic treatment initiation. Pre-emptive antiviral treatment can reduce the risk of HBV reactivation and prevent chemotherapy disruption.

Variation in transplacental transfer of tyrosine kinase inhibitors in the human perfused cotyledon model.

BACKGROUND: The use of tyrosine kinase inhibitors (TKis) during pregnancy in humans remains rare, and little data are available on their transplacental passage. Erlotinib and gefitinib are the first-line targeted therapy in case of stage IV nonsmall-cell lung cancer with an EGFR-activating mutation. There are no data available regarding the comparative use of these TKis in pregnant patients. We aimed to compare the transplacental transfer of gefitinib, imatinib and erlotinib, using the ex vivo method of human perfused cotyledon, and to determine the placental accumulation of TKis. MATERIALS AND METHODS: Term placentas were perfused after delivery with gefitinib, imatinib and erlotinib at targeted maternal concentrations around the steady-state plasma trough concentration (i.e. 500, 1000 and 1500 ng/ml, respectively). Samples from fetal and maternal circulations were collected in order to monitor TKis concentrations. Main transfer parameters such as fetal transfer rate (FTR), clearance index (CI) and placental uptake were assessed. RESULTS: Mean FTR of gefitinib, imatinib and erlotinib were 16.8%, 10.6% and 31.4%, respectively. Mean CI of gefitinib, imatinib and erlotinib were 0.59, 0.48 and 0.93, respectively. Placental uptake in cotyledon was 0.030% %, 0.010% and 0.003% for gefitinib, imatinib and erlotinib, respectively, corresponding to a mean mass of 27.7 µg for gefitinib, 15.7 µg for imatinib and 6.8 µg for erlotinib. CONCLUSION: The results suggest that TKis cross the placenta at therapeutic level. Particularly, erlotinib crosses the placenta at a higher rate than gefitinib or imatinib. All of them have a very low placental uptake. These data may suggest that gefitinib should be preferred to erlotinib for the treatment of pregnant woman with lung cancer harboring an EGFR-activating mutation, during the second and third trimesters of pregnancy.

Low skeletal muscle is associated with toxicity in patients included in phase I trials.

BACKGROUND: Low muscle mass has been associated with chemotherapy toxicity. We conducted this prospective study to evaluate the effects of body composition on the occurrence of toxicity in phase I trials. PATIENTS AND METHODS: Patients were consecutively enrolled irrespective of the type of tumor or the type of drug. The Skeletal Muscle Index (SMIndex) and visceral and subcutaneous adipose tissue were assessed with computed tomography imaging by measuring cross-sectional areas of the tissues (cm(2)/m(2)). Dose-limiting toxicity (DLT) corresponded to toxicities occurring during the 1(st) cycle that necessitated dose reduction, postponement or interruption of drug administration and severe toxicity events (STE) corresponded to DLT or permanent treatment withdrawal due to toxicity. RESULTS: 93 patients were evaluated. Ten percent of patients experienced DLT and had a lower SMIndex: 40.8 ± 4.6 vs. 48.1 ± 9.6 cm(2)/m(2) (p = 0.01). STE occurred in 14 % of the patients. The only factor associated with STE was a low SMIndex: 42.4 ± 5.8 vs. 48.4 ± 9.7 cm(2)/m(2) (p = 0.02). STE were observed in 25.5 % of the patients when the SMIndex was below the median value compared to 6.5 % of patients with a high SMIndex (p = 0.02). CONCLUSION: Muscle mass is a critical predictor of severe toxicity events in phase I patients, suggesting that sarcopenia may be considered in assessing patients for eligibility of phase-1 studies.

Sarcopenia and body mass index predict sunitinib-induced early dose-limiting toxicities in renal cancer patients.

BACKGROUND: Little is known on factors predicting sunitinib toxicity. Recently, the condition of low muscle mass, named sarcopenia, was identified as a significant predictor of toxicity in metastatic renal cell cancer (mRCC) patients treated with sorafenib. We investigated whether sarcopenia could predict early dose-limiting toxicities (DLTs) occurrence in mRCC patients treated with sunitinib. METHODS: Consecutive mRCC patients treated with sunitinib were retrospectively reviewed. A DLT was defined as any toxicity leading to dose reduction or treatment discontinuation. Body composition was evaluated using CT scan obtained within 1 month before treatment initiation. RESULTS: Among 61 patients eligible for analysis, 52.5% were sarcopenic and 32.8% had both sarcopenia and a body mass index (BMI)<25 kg m(-2). Eighteen patients (29.5%) experienced a DLT during the first cycle. Sarcopenic patients with a BMI<25 kg m(-2) experienced more DLTs (P=0.01; odds ratio=4.1; 95% CI: (1.3-13.3)), more cumulative grade 2 or 3 toxicities (P=0.008), more grade 3 toxicities (P=0.04) and more acute vascular toxicities (P=0.009). CONCLUSION: Patients with sarcopenia and a BMI<25 kg m(-2) experienced significantly more DLTs during the first cycle of treatment.

Advanced chondrosarcomas: role of chemotherapy and survival.

BACKGROUND: There are limited data about the role of chemotherapy in patients with advanced chondrosarcomas. METHODS: The medical charts of 180 patients with advanced chondrosarcomas having received chemotherapy in 15 participating institutions between 1988 and 2011 were reviewed. RESULTS: Median age was 52 years. Sixty-three percent of patients had conventional chondrosarcoma and 88% had metastatic disease. Combination chemotherapy was delivered in 98 cases (54.5%). One hundred and thirty-one patients (73%) received an anthracycline-containing regimen. Using RECIST, the objective response rate was significantly different according to histological subtype, being 31% for mesenchymal chondrosarcoma, 20.5% for dedifferentiated chondrosarcoma, 11.5% for conventional chondrosarcoma and 0% for clear-cell chondrosarcoma (P = 0.04). Median progression-free survival (PFS) was 4.7 months [95% confidence interval (CI) 3-6.5]. Performance status (PS) ≥2, number of metastatic sites ≥1 and single-agent regimen were independently associated with poor PFS. Median overall survival (OS) was 18 months (95% CI 14.5-21.6). PS, number of metastatic sites and palliative surgery were independently associated with OS. CONCLUSIONS: Conventional chemotherapy have very limited efficacy in patients with advanced chondrosarcoma, the highest benefit being observed in mesenchymal and dedifferentiated chondrosarcoma. These data should be used as a reference for response and outcome in the assessment of investigational drugs in advanced chondrosarcoma.