Discontinuation of imatinib in patients with oligometastatic gastrointestinal stromal tumour who are in complete radiological remission: a prospective multicentre phase II study.

INTRODUCTION: Metastatic gastrointestinal stromal tumour (GIST) is considered incurable, and life-long treatment with tyrosine kinase inhibitors is recommended. We investigated whether selected patients with metastatic GIST may remain in durable remission despite imatinib discontinuation. PATIENTS: In this 1-group, prospective, multicentre phase II trial selected patients with oligometastatic (≤3 metastases) GIST discontinued imatinib treatment. Eligible patients had been treated with imatinib >5 years without progression and had no radiologically detectable metastases after metastasectomy, radiofrequency ablation (RFA) or complete response to imatinib. The primary endpoint was progression-free survival (PFS) 3-years after stopping imatinib. Overall survival (OS) and quality of life (QoL) were secondary endpoints. RESULTS: The trial closed prematurely due to slow accrual. Between January 5, 2017, and June 5, 2019, 13 patients were enrolled, of whom 12 discontinued imatinib. The median follow-up time was 55 months (range, 36 to 69) after study entry. Five (42%) of the 12 eligible patients remained progression free, and seven (58%) progressed with a median time to progression 10 months. Median PFS was 23 months and the estimated 3-year PFS 41%. Six of the seven patients who progressed restarted imatinib, and all six responded. Three-year OS was 100%, and all patients were alive at the time of the study analysis. QoL measured 5 and 11 months after discontinuation of imatinib demonstrated improvement compared to the baseline. INTERPRETATION: A substantial proportion of selected patients with oligometastatic GIST treated with imatinib and metastasis surgery/RFA may remain disease-free for ≥3 years with improved QoL after stopping of imatinib.

Denosumab induction and Zoledronic acid maintenance therapy for recurrent unresectable giant cell tumour of the distal tibia: A case report with sustained tumour control after drug withdrawal.

A 31-year-old woman was diagnosed with a recurrent and rapidly growing giant cell tumour of distal tibia with skin ulceration after intralesional curettage. The patient started on Denosumab 120 mg subcutaneously, once per month with additional loading doses on Days 8 and 15 attempting to avoid below-knee amputation. Twelve doses of Denosumab were administered in 9 months, resulting in resolution of pain, reduction of tumour size and calcification. Hence, the local surgical treatment was delayed and bisphosphonate maintenance therapy was initiated as skin healing was incomplete. The patient was given Zoledronic acid infusions at a dose of 4 mg. After the third infusion, the skin healed. As tumour remained stable, it was decided to continue maintenance. Overall, six doses of Zoledronic acid at 6 months intervals were administrated over 3 years. At the end of the maintenance, the patient experienced no pain and satisfied with her limb function. Since the lesion remained stable over 3 years after Denosumab discontinuation, it was suggested to stop further medical treatment and proceed to active surveillance. The patient's disease is still stable clinical remission with no serious adverse events 41 months after Denosumab cessation and 10 months after the last bisphosphonate infusion. The present case confirmed the high effectiveness of denosumab as induction therapy in advanced recurrent giant cell tumour. We speculate that following the Denosumab-induced tumour ossification, high Zoledronic acid uptake in lesion may prevent tumour reactivation due to its improved pharmacodynamics with an assumed irreversible anti-tumoral effect on residual mutated cells. This hypothesis requires confirmation in future studies.

Outcome of rare primary malignant bone sarcoma treated with multimodal therapy: Results from the EUROpean Bone Over 40 Sarcoma Study (EURO-B.O.S.S.).

BACKGROUND: Rare primary malignant bone sarcomas (RPMBS) account for 5%-10% of primary high-grade bone tumors and represent a major treatment challenge. The outcome of patients with RPMBS enrolled in the EUROpean Bone Over 40 Sarcoma Study (EURO-B.O.S.S) is presented. METHODS: Inclusion criteria were as follows: age from 41 to 65 years and a diagnosis of high-grade spindle cell, pleomorphic, or vascular RPMBS. The chemotherapy regimen included doxorubicin 60 mg/m2 , ifosfamide 9 g/m2 , and cisplatin 90 mg/m2 ; postoperative methotrexate 8 g/m2 was added in case of a poor histologic response. Version 2.0 of the Common Terminology Criteria for Adverse Events, Kaplan-Meier curves, log-rank tests, and univariate Cox regression models were used. RESULTS: In total, 113 patients were evaluable for analysis. The median patient age was 52 years (range, 40-66 years), and 67 patients were men. Eighty-eight tumors were categorized as undifferentiated pleomorphic sarcomas (UPS), 20 were categorized as leiomyosarcomas, three were categorized as fibrosarcomas, and two were categorized as angiosarcomas. Eighty-three of 113 tumors were located in the extremities. Ninety-five of 113 patients presented with no evidence of metastases. After a median follow-up of 6.8 years (interquartile range [IQR], 3.5-9.8 years), the 5-year overall survival rate for patients with localized disease was 68.4% (IQR, 56.9%-77.5%), and it was 71.7% (IQR, 58.1%-81.6%) for patients with UPS and 54.9% (IQR, 29.5%-74.5%) for patients with leiomyosarcoma. Grade III-IV hematologic toxicity was reported in 81% patients; 23% had grade II-III neurotoxicity, and 37.5% had grade I-II nephrotoxicity. Five-year overall survival was significantly better for patients with localized disease, for patients who obtained surgical complete remission, and when the primary tumor was located in the extremities. CONCLUSIONS: The survival of patients who had RPMBS in the current series was similar to that of age-matched patients who had high-grade osteosarcoma treated according to the same protocol. An osteosarcoma-like chemotherapy may be proposed in patients who have RPMBS.

Effect of Intraperitoneal 224Radium-Labelled Microparticles on Compartmentalized Inflammation After Cytoreductive Surgery and Hypertherm Intraperitoneal Chemotherapy.

Despite extensive treatment with surgery and chemotherapy many patients with peritoneal metastases from colorectal cancer experience intraperitoneal disease relapse. The α-emitting 224radium-labelled microparticle radionuclide therapeutic Radspherin® is being explored as a novel treatment option for these patients. Radspherin® is specially designed to give local radiation to the surface of the peritoneal cavity and potentially kill remaining attached micrometastases as well as free-floating cancer cells, thus preventing future relapse. The effect of Radspherin® on the immune system is not known. Systemic and local inflammatory responses were analyzed in plasma, intraperitoneal fluid and urine collected prospectively as part of a phase 1 dose-escalation study of intraperitoneal instillation of the α-emitting therapeutic radiopharmaceutical Radspherin®, at baseline and the first 7 postoperative days from nine patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. All patients additionally received intraperitoneal instillation of Radspherin® on postoperative day 2. Complement activation products C3bc and the terminal complement complex were analyzed using enzyme-linked immunosorbent assay. Cytokines (n = 27), including interleukins, chemokines, interferons and growth factors, were analyzed using multiplex technique. The time course and magnitude of the postoperative cytokine response after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy displayed a modest systemic response in plasma, in contrast to a substantial local intraperitoneal response. After administration of Radspherin®, a significant increase (P < 0.05) in TNF and MIP-1ß was observed in both plasma and peritoneal fluid, whereas IL-9 increased only in plasma and IFNγ and IL1-RA only in peritoneal fluid. Only minor changes were seen for the majority of the inflammatory markers after Radspherin® administration. Our study showed a predominately local rather than systemic inflammatory response to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Radspherin® had overall modest impact on the inflammation.

ALPL-1 is a target for chimeric antigen receptor therapy in osteosarcoma.

Osteosarcoma (OS) remains a dismal malignancy in children and young adults, with poor outcome for metastatic and recurrent disease. Immunotherapies in OS are not as promising as in some other cancer types due to intra-tumor heterogeneity and considerable off-target expression of the potentially targetable proteins. Here we show that chimeric antigen receptor (CAR) T cells could successfully target an isoform of alkaline phosphatase, ALPL-1, which is highly and specifically expressed in primary and metastatic OS. The target recognition element of the second-generation CAR construct is based on two antibodies, previously shown to react against OS. T cells transduced with these CAR constructs mediate efficient and effective cytotoxicity against ALPL-positive cells in in vitro settings and in state-of-the-art in vivo orthotopic models of primary and metastatic OS, without unexpected toxicities against hematopoietic stem cells or healthy tissues. In summary, CAR-T cells targeting ALPL-1 show efficiency and specificity in treating OS in preclinical models, paving the path for clinical translation.

Psychological and social challenges of patients with locally advanced and metastatic gastrointestinal stromal tumours (GIST) on long-term treatment with tyrosine kinase inhibitors: a qualitative study with patients and medical oncologists.

PURPOSE: Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of locally advanced and metastatic gastrointestinal stromal tumours (GISTs). Patients are experiencing prolonged survival but often at the expense of their health-related quality of life. It is not only the physical side effects that impact GIST patients' daily lives but also the psychological and social challenges they have to deal with. This qualitative study aimed to explore the psychological and social life challenges of GIST patients with locally advanced and metastatic disease on ≥ 5 years TKI treatment. METHODS: Semi-structured interviews with 15 locally advanced and/or metastatic GIST patients and 10 medical oncologists with experience of delivering care to this specific patient group were conducted. Thematic analysis was used to interpret the data. RESULTS: Psychological challenges expressed by participants concerned fears, scanxiety, negative change in emotion and mood, doubts about their treatment and follow-up, living with uncertainty, lack of understanding from others or healthcare professionals, and constantly being reminded of their illness. Challenges regarding social health included financial difficulties, challenges in relationships, concerns about fertility and parenting, work, and impact on social activities. CONCLUSION: The reported psychological and social challenges can significantly hamper the overall quality of life of GIST patients. Some challenges were clearly underreported and hardly recognized by medical oncologist, as they may tend to focus on the physical side effects and clinical outcomes of treatment. Therefore, it is essential to take the patient's perspective into account in research and clinical practice to ensure optimal care for this patient group.

Exploring the Patient Perspective of Bone Sarcoma Survivors Who Have Undergone Particle Radiotherapy Abroad.

BACKGROUND/AIM: Sarcoma patients' experiences of their health-related quality of life and late effects following particle therapy are sparse. Such knowledge is essential to optimize treatment compliance and follow-up care related to this rapidly developing, but still centralized treatment modality. PATIENTS AND METHODS: This qualitative study has an explorative design and applies a phenomenological and hermeneutical approach based on semi-structured interviews with 12 bone sarcoma patients who had undergone particle therapy abroad. The data were interpreted using thematic analysis. RESULTS: Several of the participants called for more information about how the treatment would be carried out, its acute side effects and late complications. Most participants had positive experiences from the treatment and their stay abroad, but several struggled with late effects and other challenges. Themes that emerged from the analysis were "importance of being prepared", "treatment and stay abroad", "basically healthy, but with health problems and challenges". CONCLUSION: Oncologists who inform and refer patients to particle therapy abroad must have sufficient experience of this treatment modality, prognoses, acute side effects, and late complications. Findings derived from this study may improve treatment preparation and compliance, enhance understanding of individual patient challenges to reduce stress and worry, and lead to better follow-up care and consequently quality of life of this selected group of bone sarcoma patients.

First experience with 224Radium-labeled microparticles (Radspherin®) after CRS-HIPEC for peritoneal metastasis in colorectal cancer (a phase 1 study).

Background: Peritoneal metastasis (PM) from colorectal cancer carries a dismal prognosis despite extensive cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). With a median time to recurrence of 11-12 months, there is a need for novel therapies. Radspherin® consists of the α-emitting radionuclide radium-224 (224Ra), which has a half-life of 3.6 days and is adsorbed to a suspension of biodegradable calcium carbonate microparticles that are designed to give short-range radiation to the serosal peritoneal surface linings, killing free-floating and/or tumor cell clusters that remain after CRS-HIPEC. Methods: A first-in-human phase 1 study (EudraCT 2018-002803-33) was conducted at two specialized CRS-HIPEC centers. Radspherin® was administered intraperitoneally 2 days after CRS-HIPEC. Dose escalation at increasing activity dose levels of 1-2-4-7-MBq, a split-dose repeated injection, and expansion cohorts were used to evaluate the safety and tolerability of Radspherin®. The aim was to explore the recommended dose and biodistribution using gamma-camera imaging. The results from the planned safety interim analysis after the completion of the dose-limiting toxicity (DLT) period of 30 days are presented. Results: Twenty-three patients were enrolled: 14 in the dose escalation cohort, three in the repeated cohort, and six in the expansion cohort. Of the 23 enrolled patients, seven were men and 16 were women with a median age of 64 years (28-78). Twelve patients had synchronous PM stage IV and 11 patients had metachronous PM [primary stage II; (6) and stage III; (5)], with a disease-free interval of 15 months (3-30). The peritoneal cancer index was median 7 (3-19), operation time was 395 min (194-515), and hospital stay was 12 days (7-37). A total of 68 grade 2 adverse events were reported for 17 patients during the first 30 days; most were considered related to CRS and/or HIPEC. Only six of the TEAEs were evaluated as related to Radspherin®. One TEAE, anastomotic leakage, was reported as grade 3. Accordion ≥3 grade events occurred in a total of four of the 23 patients: reoperation due to anastomotic leaks (two) and drained abscesses (two). No DLT was documented at the 7 MBq dose level that was then defined as the recommended dose. The biodistribution of Radspherin® showed a relatively even peritoneal distribution. Conclusion: All dose levels of Radspherin® were well tolerated, and DLT was not reached. No deaths occurred, and no serious adverse events were considered related to Radspherin®.Clinical Trial Registration: Clinicaltrials.gov, NCT03732781.

Radiation safety considerations for the use of radium-224-calciumcarbonate-microparticles in patients with peritoneal metastasis.

Aim: Two ongoing phase I studies are investigating the use of radium-224 adsorbed to calcium carbonate micro particles (224Ra-CaCO3-MP) to treat peritoneal metastasis originating from colorectal or ovarian cancer. The aim of this work was to study the level of radiation exposure from the patients to workers at the hospital, carers and members of the public. Method: Six patients from the phase 1 trial in patients with colorectal cancer were included in this study. Two days after cytoreductive surgery, they were injected with 7 MBq of 224Ra-CaCO3-MP. At approximately 3, 24 and 120 h after injection, the patients underwent measurements with an ionization chamber and a scintillator-based iodide detector, and whole body gamma camera imaging. The patient was modelled as a planar source to calculate dose rate as a function of distance. Scenarios varying in duration and distance from the patient were created to estimate the potential effective doses from external exposure. Urine and blood samples were collected at approximately 3, 6, 24, 48 and 120 h after injection of 224Ra-CaCO3-MP, to estimate the activity concentration of 224Ra and 212Pb. Results: The patients' median effective whole-body half-life of 224Ra-CaCO3-MP ranged from 2.6 to 3.5 days, with a mean value of 3.0 days. In the scenarios with exposure at the hospital (first 8 days), sporadic patient contact resulted in a range of 3.9-6.8 µSv per patient, and daily contact resulted in 4.3-31.3 µSv depending on the scenario. After discharge from the hospital, at day 8, the highest effective dose was received by those with close daily contact; 18.7-83.0 µSv. The highest activity concentrations of 224Ra and 212Pb in urine and blood were found within 6 h, with maximum values of 70 Bq/g for 224Ra and 628 Bq/g for 212Pb. Conclusion: The number of patients treated with 224Ra-CaCO3-MP that a single hospital worker - involved in extensive care - can receive per year, before effective doses of 6 mSv from external exposure is exceeded, is in the order of 200-400. Members of the public and family members are expected to receive well below 0.25 mSv, and therefore, no restrictions to reduce external exposure should be required.

Particle Therapy in Adult Patients with Pelvic Ewing Sarcoma-Tumor and Treatment Characteristics and Early Clinical Outcomes.

PURPOSE: To report dosimetric characteristics and early clinical outcomes in patients with pelvic Ewing sarcoma undergoing particle therapy. METHODS: Patients ≥ 18 years old with pelvic Ewing sarcoma treated in adjuvant or definitive settings were considered for this retrospective analysis. Proton therapy was carried out with 45-60 Gy (RBE) (1.5-2 Gy (RBE) per fraction) and carbon ion therapy for recurrent disease with 51 Gy (RBE) (3 Gy (RBE) per fraction). Local control (LC), disease control (DC) and overall survival (OS) were calculated using the Kaplan-Meier method. RESULTS: For our sample, 21 patients were available, 18 of whom were treated for primary, 3 for locally recurrent and 16 for inoperable disease. The median CTV and PTV were 1215 cm3 and 1630 cm3. Median Dmean values for the PTV, bladder and rectum and median V40 Gy for the bowel for patients undergoing proton therapy were 56 Gy (RBE), 0.6 Gy (RBE), 9 Gy (RBE) and 15 cm3, respectively. At the end of particle therapy, G 1-2 skin reactions (n = 16/21) and fatigue (n = 9/21) were the main reported symptoms. After a median follow-up of 21 months, the 2-year LC, DC and OS were 76%, 56% and 86%, respectively. CONCLUSIONS: Particle therapy in adult pelvic Ewing sarcoma is feasible and provides excellent dosimetric results. First clinical outcomes are promising; however, further long-term follow-up is needed.

Targeted alpha therapy with the 224Ra/212Pb-TCMC-TP-3 dual alpha solution in a multicellular tumor spheroid model of osteosarcoma.

Osteosarcoma patients with overt metastases at primary diagnosis have a 5-year survival rate of less than 20%. TP-3 is a murine IgG2b monoclonal antibody with high affinity for an epitope residing on the p80 osteosarcoma cell surface membrane antigen. The tumor-associated antigen p80 is overexpressed in osteosarcomas, and has very low normal tissue expression. We propose a novel dual alpha targeting solution containing two radionuclides from the same decay chain, including the bone-seeking 224Ra, and cancer cell-surface seeking 212Pb-TCMC-TP-3 for the treatment of osteoblastic bone cancers, circulating cancer cells and micrometastases. In this in vitro study, the cytotoxic effects of 212Pb-TCMC-TP-3 (single alpha solution) and 224Ra/212Pb-TCMC-TP-3 (dual alpha solution) were investigated in a multicellular spheroid model mimicking micrometastatic disease in osteosarcoma. OHS spheroids with diameters of 253 ± 98 µm treated with 4.5, 2.7, and 3.3 kBq/ml of 212Pb-TCMC-TP-3 for 1, 4, and 24 h, respectively, were disintegrated within 3 weeks. The 212Pb-TCMC-TP-3 induced a 7-fold delay in spheroid doubling time compared to a 28-times higher dose with the non-specific 212Pb-TCMC-rituximab. The 224Ra/212Pb-TCMC-TP-3 completely disintegrated spheroids with diameters of 218-476 µm within 3 and 2 weeks after 4 and 24 h incubation with 5 kBq/ml, respectively. Treatment with 1 kBq/ml of 224Ra/212Pb-TCMC-TP-3 for 24 h caused an 11.4-fold reduction in spheroid viability compared with unconjugated 224Ra/212Pb. The single and dual alpha solutions with TP-3 showed cytotoxicity in spheroids of clinically relevant size, which warrant further testing of the dual alpha solution using in vivo osteosarcoma models.

Real-world evidence on perioperative chemotherapy in localized soft tissue sarcoma of the extremities and trunk wall; a population-based study.

BACKGROUND: Data from the real-world setting on perioperative chemotherapy in high-risk, localized soft tissue sarcoma (STS) is limited. Real-world data (RWD) includes data derived from patients treated outside clinical trials and often captures long-term follow-up not recorded in clinical trials. The aim of this study was to provide population-based, real-world evidence on perioperative chemotherapy in localized STS. MATERIAL AND METHODS: Adult patients with localized STS in the extremities or trunk wall treated at Oslo University Hospital, Oslo, Norway from 1998 to 2017 were included in the study. Data were extracted from a prospectively maintained database, supplemented by retrospective review of medical records. RESULTS: The total study cohort included 806 patients, of whom 154 (19%) received perioperative chemotherapy. A regimen with anthracycline and ifosfamide was given in 141 of 154 cases (92%). During long-term follow-up two patients developed secondary malignancies, cardiac toxicity was registered in 11 patients (7%) and renal toxicity in 12 patients (8%). Seventy-one of 154 patients (46%) were treated outside of clinical trials and constituted the RWD cohort. The median age at surgery was slightly lower and there were more synovial sarcomas and fewer myxofibrosarcomas in the RWD cohort. No difference in chemotherapy dose intensity was observed. The estimated 5-year metastasis-free survival (MFS) in all patients receiving perioperative chemotherapy was 58%. In the RWD cohort 5-year MFS was 53% and in the clinical study cohort 61% (HR 1.24; 95% CI 0.77-2.00). CONCLUSION: Long-term outcome after perioperative chemotherapy was comparable for patients treated in routine clinical practice to those in clinical trials. Secondary malignancy and cardiac toxicity were observed. The risk of serious late side effects should be included in the decision process on perioperative chemotherapy.

Factors Influencing the Therapeutic Efficacy of the PSMA Targeting Radioligand 212Pb-NG001.

This study aimed to determine the influence of cellular PSMA expression, radioligand binding and internalization, and repeated administrations on the therapeutic effects of the PSMA-targeting radioligand 212Pb-NG001. Cellular binding and internalization, cytotoxicity, biodistribution, and the therapeutic efficacy of 212Pb-NG001 were investigated in two human prostate cancer cell lines with different PSMA levels: C4-2 (PSMA+) and PC-3 PIP (PSMA+++). Despite 10-fold higher PSMA expression on PC-3 PIP cells, cytotoxicity and therapeutic efficacy of the radioligand was only 1.8-fold better than for the C4-2 model, possibly explained by lower cellular internalization and less blood-rich stroma in PC-3 PIP xenografts. Mice bearing subcutaneous PC-3 PIP xenografts were treated with 0.2, 0.4, and 0.8 MBq of 212Pb-NG001 that resulted in therapeutic indexes of 2.7, 3.0, and 3.5, respectively. A significant increase in treatment response was observed in mice that received repeated injections compared to the corresponding single dose (therapeutic indexes of 3.6 for 2 × 0.2 MBq and 4.4 for 2 × 0.4 MBq). The results indicate that 212Pb-NG001 can induce therapeutic effects at clinically transferrable doses, both in the C4-2 model that resembles solid tumors and micrometastases with natural PSMA expression and in the PC-3 PIP model that mimics poorly vascularized metastases.

Outcomes from a mechanistic biomarker multi-arm and randomised study of liposomal MTP-PE (Mifamurtide) in metastatic and/or recurrent osteosarcoma (EuroSarc-Memos trial).

The phase III clinical study of adjuvant liposomal muramyl tripeptide (MTP-PE) in resected high-grade osteosarcoma (OS) documented positive results that have been translated into regulatory approval, supporting initial promise for innate immune therapies in OS. There remains, however, no new approved treatment such as MTP-PE for either metastatic or recurrent OS. Whilst the addition of different agents, including liposomal MTP-PE, to surgery for metastatic or recurrent high-grade osteosarcoma has tried to improve response rates, a mechanistic hiatus exists in terms of a detailed understanding the therapeutic strategies required in advanced disease. Here we report a Bayesian designed multi-arm, multi-centre, open-label phase II study with randomisation in patients with metastatic and/or recurrent OS, designed to investigate how patients with OS might respond to liposomal MTP-PE, either given alone or in combination with ifosfamide. Despite the trial closing because of poor recruitment within the allocated funding period, with no objective responses in eight patients, we report the design and feasibility outcomes for patients registered into the trial. We demonstrate the feasibility of the Bayesian design, European collaboration, tissue collection with genomic analysis and serum cytokine characterisation. Further mechanistic investigation of liposomal MTP-PE alone and in combination with other agents remains warranted in metastatic OS.

Hope as a Lifeline: Imatinib Discontinuation in Patients With Oligometastatic Gastrointestinal Stromal Tumours.

BACKGROUND/AIM: This study explored how highly selected oligometastatic gastrointestinal stromal tumour (GIST) patients subjectively experienced the discontinuation of imatinib (IM) treatment. PATIENTS AND METHODS: Being an exploratory qualitative study, we applied a phenomenological and hermeneutical approach. We conducted in-depth semi-structured interviews with nine oligometastatic GIST patients who were in long-term clinical remission. The gathered data were interpreted using a thematic analysis. RESULTS: The analysis of the interview data revealed four main themes; getting one's life back, fear of recurrence, hope as a lifeline and the pros/cons of participating in this clinical trial. The participants disclosed that hope of being cancer free and without the side-effects of IM was essential for both participating in this study and enduring the uncertainty of drug discontinuation. CONCLUSION: Use of a qualitative approach in clinical trials can result in a better understanding of patients' perspectives and therefore lead to improved clinical practice.

Dual targeting with 224Ra/212Pb-conjugates for targeted alpha therapy of disseminated cancers: A conceptual approach.

Metastases are the primary cause of death among cancer patients and efficacious new treatments are sorely needed. Targeted alpha-emitting radiopharmaceuticals that are highly cytotoxic may fulfill this critical need. The focus of this paper is to describe and explore a novel technology that may improve the therapeutic effect of targeted alpha therapy by combining two radionuclides from the same decay chain in the same solution. We hypothesize that the dual targeting solution containing bone-seeking 224Ra and cell-directed complexes of progeny 212Pb is a promising approach to treat metastatic cancers with bone and soft tissue lesions as well as skeletal metastases of mixed lytic/osteoblastic nature. A novel liquid 224Ra/212Pb-generator for rapid preparation of a dual targeting solution is described. Cancer cell targeting monoclonal antibodies, their fragments, synthetic proteins or peptides can all be radiolabeled with 212Pb in the 224Ra-solution in transient equilibrium with daughter nuclides. Thus, 224Ra targets stromal elements in sclerotic bone metastases and 212Pb-chelated-conjugate targets tumor cells of metastatic prostate cancer or osteosarcoma. The dual targeting solution may also be explored to treat metastatic breast cancer or multiple myeloma after manipulation of bone metastases to a more osteoblastic phenotype by the use of bisphosphonates, denosumab, bortezomib or hormone therapy prior to treatment. This may improve targeting of bone-seeking 224Ra and render an augmented radiation dose deposited within metastases. Our preliminary preclinical studies provide conceptual evidence that the dual 224Ra-solution with bone or tumor-targeted delivery of 212Pb has potential to inhibit cancer metastases without significant toxicity. In some settings, the use of a booster dose of purified 212Pb-conjugate alone could be required to elevate the effect of this tumor cell directed component, if needed, e.g., in a fractionated treatment regimen, where the dual targeting solution will act as maintenance treatment.

Multimodal functional imaging for early response assessment in patients with gastrointestinal stromal tumor treated with tyrosine kinase inhibitors.

BACKGROUND: Several imaging modalities are used in the early work-up of patients with gastrointestinal stromal tumor (GIST) receiving tyrosine kinase inhibitor (TKI) treatment and there is a need to establish whether they provide similar or complimentary information. PURPOSE: To compare 18F-fluorodeoxyglucose positron emission tomography (FDG PET), computed tomography (CT) and magnetic resonance imaging (MRI) as early predictors of three-month outcomes for patients with GIST receiving TKI treatment. MATERIAL AND METHODS: Thirty-five patients with advanced GIST were prospectively included between February 2011 and June 2017. FDG PET, contrast-enhanced CT (CECT), and MRI were performed before and early after onset of TKI treatment (range 8-18 days). Early response was categorized according to mRECIST (CT), the Choi criteria (CECT), and PERCIST (FDG PET/CT). For MRI, volumetry from T2-weighted images and change in apparent diffusion coefficient (ADC) from diffusion-weighted imaging was used. The reference standard for early assessment was the three-month mRECIST evaluation based on CT. At three months, both stable disease (SD) and partial response (PR) were categorized as response. Clinical usefulness was defined as agreement between early and three-month assessment. RESULTS: At the three-month assessment, 91% (32/35) were responders, 37% (13/35) PR, 54% (19/35) SD, and 9% (3/35) had progressive disease (PD). Early assessment correctly predicted three-month response in 93% (27/29) for MRI, 80% (28/35) for PERCIST, 74% (26/35) for Choi, and 23% (8/35) for mRECIST. Six patients had non-FDG-avid tumors. For the FDG-avid tumors, PET/CT correctly predicted three-month response in 97% (28/29). CONCLUSION: MRI was superior to CECT for early assessment of TKI-treatment response in GIST. If the tumor was FDG-avid, PET and MRI were equally good. Changes in functional parameters were superior to changes in longest tumor diameter (mRECIST).

Health-Related Quality of Life Issues Experienced by Thoracic and Breast Sarcoma Patients: A Rare and Understudied Group.

Thoracic and breast sarcomas constitute a rare subgroup within the sarcoma population. There is limited knowledge about their health-related quality of life (HRQoL) and a valid disease-specific HRQoL instrument is lacking. This qualitative study aimed to investigate the HRQoL issues experienced by a small group of thoracic and breast sarcoma patients. Semi-structured interviews with 19 thoracic and four breast sarcoma patients were conducted and thematically analysed. Physical issues mentioned by both groups were fatigue, sleep disturbances, pain, wound infections, and symptoms related to chemotherapy and radiotherapy. Tightness in the back and restrictions in performing tasks above arm height were specific physical issues for breast sarcoma patients, whereas respiratory problems were only mentioned by thoracic sarcoma patients. Body image issues, changes in mood, fear of recurrence, and living with uncertainty were important mental health issues for both subgroups. Social issues in both groups included challenges in work and relationships, financial difficulties, loss of independence, and limitations in social activities. The identified physical, mental, and social health challenges can significantly impact thoracic and breast sarcoma patients' HRQoL. Results of this qualitative study will guide personalised supportive care for breast and thoracic sarcoma patients and help in determining the best possible HRQoL measurement strategy for sarcoma patients with different primary sarcoma locations.

Early immunohistochemical detection of pulmonary micrometastases in dogs with osteosarcoma.

BACKGROUND: Despite decades of research, the early phases of metastatic development are still not fully understood. Canine osteosarcoma (OS) is a highly aggressive cancer, with a high metastatic rate (> 90%), despite a low overt metastatic prevalence at initial diagnosis (< 15%). Canine OS is generally regarded as a good clinically relevant model for human OS. The aim of this hypothesis-generating study was to evaluate a method to detect pulmonary micrometastases and study their prevalence in dogs with OS without macroscopic metastases. We prospectively enrolled dogs with OS that received no cancer-specific treatment (n = 12) and control dogs without cancer (n = 2). Dogs were necropsied and sampled immediately after euthanasia. The OS dogs were classified as having macroscopic metastases (n = 2) or not (n = 10). We immunohistochemically stained one tissue sample from each of the seven lung lobes from each dog with a monoclonal antibody (TP-3) to identify micrometastases (defined as clusters of 5-50 tumour cells), microscopic metastases (> 50 tumour cells) and TP-3 positive single cells (< 5 tumour cells). RESULTS: We showed that pulmonary micrometastases easily overseen on routine histology could be detected with TP-3. Pulmonary micrometastases and microscopic metastases were present in two dogs with OS without macroscopic metastases (20%). Micrometastases were visualised in three (43%) and four (57%) of seven samples from these two dogs, with a mean of 0.6 and 1.7 micrometastases per sample. Microscopic metastases were present in one (14%) and four (57%) of seven samples from the same two dogs, with a mean of 0.14 and 1.0 microscopic metastases per sample. There were four (57%) and two (29%) samples with neither microscopic metastases nor micrometastases for each of these two dogs. The prevalence of pulmonary micrometastases (20%) was significantly lower than expected (> 90%) based on commonly expected metastatic rates after amputation (P < 0.0001). There was no statistically significant difference in the number of TP-3 positive single cells in between groups (P = 0.85). CONCLUSIONS: Pulmonary micrometastases could be detected with TP-3 immunohistochemistry in a subset of dogs with OS before macroscopic metastases had developed. We propose that dogs with spontaneous OS represent clinically relevant models to study early micrometastatic disease.