Osteosarcoma Working Group (OWG)

Maria Ambatzidou

Antonios Kattamis

Nikolaos Katzilakis

Eleni Dana

Apostolos Pourtsidis

Kyriaki Kotsoglanidou

Georgios Totikidis

Athanasios Tragiannidis
Efthymia Rigatou

Kondylia Antoniadis

Dimitrios Doganis

Xenia Loseva

Margarita Baka

Evgenia Papakonstantinou

The scope of the scientific object of the Osteosarcoma Working Group includes:

Management of patients with osteosarcoma in terms of diagnosis, treatment with chemotherapy and surgery, diagnosis and treatment of recurrence. The incidents of the last decade are recorded for the creation of a pan-Hellenic registry, study of epidemiology with an emphasis on demographic data, characterization of the disease, treatment, outcome and follow-up. Preoperative preparation and support of patients, end-stage palliative care. The main objectives of the group are to propose new therapeutic modalities and protocols, to define guidelines, to provide supportive care. It also aims to find molecular studies and encourages the development of new diagnostic tests and molecular therapies.
An important role of the Group is to promote collaboration between researchers.
After diagnosis, a multidisciplinary team works together to manage the patient. First, radiological examinations raise the suspicion of osteosarcoma and biopsy confirms the diagnosis after histological evaluation. Radiological tests are done for staging. After Neoadjuvant Chemotherapy, PET assesses response. Frozen tissue is stored after surgery and NGS in some cases. Adjuvant chemotherapy is followed by metastasectomy if indicated and then follow-up. Oncologists, Radiologists, Orthopedic Surgeon, Psychiatric team, Rehabilitation Physiotherapists, Thoracic Surgeons are the main contributing specialties.

Ιnitiatives corresponding research/ scientific proposals:

• Administration of off-label TKI treatment upon request in the electronic drug pre-authorization system according to clinical studies conducted in Europe. In particular, treatment with Lenvatinib is administered according to OLIE, Regorafenib according to REGOMAIN protocol.
• In collaboration with Medical Oncologists EOPE, initiation of a multicenter, open-label Phase IV study, for patients over 12 years of age (until May 2025), on the efficacy of Cabozantinib in advanced osteosarcoma recurring after initial treatment.
• We are in the process of designing FOSTER-CabOS a FOSTER group protocol with first-line TKI administration as maintenance therapy. Our immediate goals are joining the new protocol.

In 2022 we had the following actions:

1. We attended the SIOP 2022 conference with a posted announcement on standard practices in relation to patient management.

2. Participation in the EEPAO conference with a posted announcement on osteosarcoma recurrences

3. Participation in the EEPAO conference with a presentation by E. Papakonstantinou on “Newest data on targeted therapies in osteosarcoma”.

4. A lecture was presented in the framework of the EEPAO educational program by E. Papaconstantinou on the topic “Osteosarcoma – Lessons from the past, challenges for the future”.

5. Participation in the 5th masterclass on sarcomas at the Acropolis Museum of Athens on December 9-10, 2022 of the EOSSO with a presentation by E. Papakonstantinou on the topic “Osteosarcoma and what tomorrow brings”.

6. Creation of a pan-Hellenic registry recording patients of the last decade with the aim of including 20-year cases.

7. Forming an estimation of how patients with osteosarcoma are treated in the Pediatric Oncology Departments of the EEPAO after completing a questionnaire.

8. Participation in the European FOSTER osteosarcoma study group with national representative E. Papakonstantinou. The Greek representatives in the FOSTER consortium are 9 pediatric oncologists (Maria Ambatzidou, Antonios Kattamis, Nikolaos Katzilakis, Eleni Dana, Apostolos Pourtsidis, Athanassios Tragiannidis, Efthymia Rigatou, Dimitrios Doganis, Eugenia Papakonstantinou), 6 oncologists, 1 orthopedic surgeon. In the FOSTER group we are represented by Mr. Pourtsidis in the WP7 of far-reaching consequences.

9. The Greek way of working was presented to the FOSTER consortium by E. Papakonstantinou at the Seminar within the framework of WP8 on 28/11/2022.

The relevant protocols supported and promoted by our Group:

• According to the trends prevailing in Europe we support the following protocols: OLIE, REGOSTA, REGOMAIN, IMMUNOSARC II.
• Off-label TKI treatment is already provided on request in the electronic drug pre-authorization system according to clinical trials conducted in Europe. In particular, treatment with Lenvatinib is administered according to OLIE, Regorafenib according to REGOMAIN.
• In addition, the FOSTER group initiated a protocol design process with drug administration in the first line of treatment as maintenance therapy. We participate in the design of the protocol with proposals and regular online meetings. Our immediate future goals include joining the new protocol.

Σε εθνικό επίπεδο υπάρχει συνεργασία με την ομάδα σαρκωμάτων, συνδρόμου Ewing, AYA της ΕΕΠΑΟ και την Ελληνική Ομάδα σαρκωμάτων και Σπανίων όγκων ΕΟΣΣΟ. Στην ομάδα ΕΟΣΣΟ εκπροσωπούμαστε από Ε. Παπακωνσταντίνου και κ. Κατζηλάκη.
Σε διεθνές επίπεδο υπάρχει συνεργασία με την Ευρωπαϊκή ομάδα FOSTER στην οποία 9 άτομα από την ομάδα οστεοσαρκώματος αποτελούν μέλη που έχουν γραφτεί στα Work Packages (WP). Στο FOSTER έχουν εγγραφεί κατόπιν αιτήματός μου ως Εθνικής εκπροσώπου της Ελλάδας για το οστεοσάρκωμα και 6 Ογκολόγοι Παθολόγοι της ΕΟΠΕ και 1 Ορθοπεδικός.
Συνεργαζόμαστε ως μέλη και με άλλες διεθνείς ομάδες όπως SIOP, SIOPE, INFORM, ERN PaedCan, PanCare, EpSSG. Στην ομάδα SIOPE συμμετέχουμε μέσω του FOSTER. Στο INFORM αποστέλλεται κατεψυγμένος ιστός σε ασθενείς με υποτροπιάζον οστεοσάρκωμα για ανεύρεση κατάλληλης στοχευμένης θεραπείας.