ICHNO-ECHNO 2022 - Abstract Book

S10

ICHNO-ECHNO 2022

However, it has become clear that further improvement can only be accomplished by implementing biological classifiers. In this respect, promising data have recently been reported in relation to genetic determinants (e.g., SMAD4 loss in pancreatic cancer, PBRM1 mutation in renal cancer), epigenetic modifiers (e.g., 14q23-encoded microRNAs), and tumour- host interactions (immune response). In head and neck cancer, the most prognostically favourable group comprises patients presenting with an oligorecurrence of human papillomavirus (HPV)-positive oropharyngeal cancer in the lungs. Of note, oligorecurrence represents a state of metachronous dissemination in which oligometastases develop in patients with a controlled local or locoregional disease who are at least 3 – 6 months after the primary diagnosis. Therefore, post-treatment follow-up has a decisive role, and although current guidelines do not recommend routine radiological examinations in all head and neck cancer survivors, they can be justified in those potentially presenting with curable oligometastases. Besides that, in patients receiving systemic therapy for polymetastatic cancer, there are further clinical scenarios sharing some of the hallmarks of oligometastases. They include oligoprogression if few distant lesions evade disease control and start growing and oligopersistence if a complete response is achieved except for few persisting lesions which are either stable or partially decrease in size. Importantly, the same local techniques, typically surgical resection, stereotactic body radiotherapy, or radiofrequency ablation, can be employed in these settings, albeit not with a curative intent but rather to prolong survival or delay a change or reinitiation of systemic treatment. Taken together, despite providing intriguing options to improve patient care, the concept of oligometastatic disease is still far from being fully understood and furnishes thus ample research opportunities in the areas of disease biology, workup, and treatment. Gaining a better insight into the biological basis of an oligometastatic phenotype together with finetuning its clinical determinants will be indispensable for developing reliable composite prognostic models and proper patient selection. This will probably not be possible without simultaneous advances in imaging modalities, such as using molecular imaging with novel positron emission tomography (PET) tracers, or introducing liquid biopsy to clinical practice as part of residual disease monitoring and early recurrence detection. Finally, investigational treatment strategies seek to address various issues encompassing development of new drugs (e.g., epigenetic modifiers reversing polymetastatic to oligometastatic phenotype), technologies (e.g., improvements in external and internal radiotherapy), combinations of local and systemic therapies (especially with immune checkpoint inhibitors), treatment sequencing, innovative approaches to clinical trial design (e.g., adjusted endpoints, patient-reported outcomes), and other. Importantly, some of these new concepts hold the promise of becoming site-agnostic tools, thus of interest also to the head and neck cancer field, while other are more specific such as circulating Epstein-Barr virus (EBV) DNA monitoring in metastatic nasopharyngeal cancer or still experimental measurements of cell-free plasma HPV DNA in oropharyngeal cancer.

Keynote lecture: Intraoperative margin analysis

SP-0023 Intraoperative margin analysis

R.J. Baatenburg de Jong 1

1 Erasmus Medical Center, Dept. of Otorhionolaryngology, Rotterdam , The Netherlands

Abstract Text The goal of head and neck oncological surgery is complete tumor resection with adequate resection margins while preserving acceptable function and appearance. For oral cavity squamous cell carcinoma (OCSCC), different studies showed that only 15%-26% of all resections are adequate. A major reason for the low number of adequate resections is the lack of information during surgery; the margin status is only available after the final histopathologic assessment, days after surgery. The surgeons and pathologists at the Erasmus MC University Medical Center in Rotterdam started the implementation of specimen-driven intraoperative assessment of resection margins (IOARM) in 2013, which became the standard of care in 2015. This method enables the surgeon to turn an inadequate resection into an adequate resection by performing an additional resection during the initial surgery. Intraoperative assessment is supported by a relocation method procedure that allows accurate identification of inadequate margins (found on the specimen) in the wound bed. The implementation of this protocol resulted in an improvement of adequate resections from 15%-40%. The protocol for specimen-driven IOARM and the relocation method will be presented in detail, supplemented with data on disease free and overall survival, as well as the decrease in need for postoperative radiation.

Proffered papers: Innovative highlights 2

OC-0024 Pre-treatment lymphocyte count predicts cisplatin benefit with radiotherapy in oropharynx cancer

J. Price 1 , H. Mistry 2 , G. Betts 3 , E. Cheadle 4 , L. Dixon 1 , K. Garcez 1 , T. Illidge 1 , Z. Iyizoba-Ebozue 5 , L. Lee 1 , A. McPartlin 1 , S. Papageorgiou 4 , R. Prestwich 5 , D. Pritchard 5 , A. Sykes 1 , C. West 4 , D. Thomson 1 1 The Christie NHS Foundation Trust, Clinical Oncology, Manchester, United Kingdom; 2 The University of Manchester, Division of Cancer Sciences, MANCHESTER, United Kingdom; 3 Manchester Foundation Trust, Histopathology, MANCHESTER, United Kingdom; 4 The University of Manchester, Division of Cancer Sciences, Manchester, United Kingdom; 5 Leeds Cancer Centre, Clinical Oncology, Leeds, United Kingdom Purpose or Objective There is a need to refine the selection of patients with oropharynx squamous cell carcinoma (OPSCC) for treatment de- escalation. We investigated whether pre-treatment absolute lymphocyte count (ALC) predicted overall survival benefit from the addition of concurrent cisplatin to radiotherapy.