ICHNO-ECHNO 2022 - Abstract Book

S39

ICHNO-ECHNO 2022

PO-0070 Cisplatin total dose: a novel prognostic factor in locally advanced nasopharyngeal carcinoma

O. Nouri 1 , W. Mnejja 1 , N. Fourati 1 , F. Dhouib 1 , W. Siala 1 , I. Charfeddine 2 , A. Khanfir 3 , L. Farhat 4 , J. Daoud 4

1 Habib Bourguiba University Hospital, Department of Oncology Radiotherapy, Sfax, Tunisia; 2 Habib Bourguiba University Hospital, Department of Oto Rhino Laryngology, Sfax, Tunisia; 3 Habib Bourguiba University Hospital, Department of Medical Oncology, Sfax, Tunisia; 4 Habib Bourguiba university Hospital, Department of Oncology Radiotherapy, Sfax, Tunisia Purpose or Objective The value of cisplatin concomitant dose in predicting nasopharyngeal carcinomas’ (NPC) outcomes is well established. Adding induction chemotherapy (IC) to concomitant chemo radiotherapy (CCR) is the new standard of care for locally advanced NPC. Total cisplatin dose, including both induction and concomitant cisplatin, has rarely been reported. The aim of this study was to evaluate the impact of total cisplatin dose with this new treatment protocol. Materials and Methods We retrospectively reviewed the data of 52 patients with NPC treated between 2016 and 2019. All patients received 3 cisplatin-based IC courses (TPF) followed by CCR with intensity modulated radiotherapy (IMRT) and weekly cisplatin (40 mg/m ² ). IMRT was delivered with integrated simultaneous boost of 33 daily fractions at a total dose of 69.96 Gy. ROC curves were used to determine the cut-off value of cisplatin total dose. Survival analysis was performed according to Kaplan-Meier’s method. Log-rank test and Cox method were used to compare factors that may influence overall survival (OS), disease free survival (DFS), metastatic free survival (MFS) and loco regional free survival (LRFS). Results Forty-five tumours (86.5%) were classified as stages III-IV according to the 2017 UICC TNM classification. Forty-seven patients (90.4%) received 75 mg/m ² of cisplatin per course while five patients (9.6%) received 60 mg/m ² /course. Forty- three patients (82%) had at least four courses of concomitant cisplatin. The median total cisplatin dose was 425 mg/m ² [305-505]. Thirteen patients (25%) received less than 380 mg/m ² . After a median follow up of 48 months [31-70], 5-year OS, DFS, MFS and LRFS were 67.8%, 56.8%, 63.5% and 85.9% respectively. Cumulative concomitant cisplatin dose did not impact outcomes. Cut-off value of cisplatin total dose was 380 mg/m ² . The 5-year OS was 73.4% for patients receiving more than 380 mg/m ² total cisplatin dose versus 40.4% for the others (p=0.012). The 5-year DFS was 64.2% and 34.6% for the patients receiving more and less than 380 mg/m ² respectively (p=0.01). Cisplatin total dose significantly impacted 5-year MFS (p=0.003) and LRFS (p=0.03) as well (Table 1). In multivariate analysis, total cisplatin dose was found to be a significant factor for OS (p=0.003), DFS (p=0.001), MFS (p=0.003) and LRFS (p=0.005).

Conclusion Adding IC to CCR reduced the impact of concomitant cisplatin dose in predicting NPC’s outcomes. However, cisplatin total dose appears to be a powerful prognosis factor for all survivals. Further studies are needed to define high risk patients that might benefit from systemic treatment intensification.

PO-0071 Awareness of HPV-associated oropharyngeal cancer among GPs in The Netherlands: cross-sectional study

F. Mulder 1 , I. Demers 2 , F. Verhees 1 , L. Schouten 3 , J. Muris 4 , B. Kremer 1 , E. Speel 2

1 Maastricht University Medical Center, Otorhinolaryngology and Head & Neck Surgery, Maastricht, The Netherlands; 2 Maastricht University Medical Center, Pathology, Maastricht, The Netherlands; 3 Maastricht University, Epidemiology, Maastricht, The Netherlands; 4 Maastricht University, Health, Medicine and Life Sciences, Maastricht, The Netherlands Purpose or Objective The incidence of human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) is increasing in high-income countries. Knowledge on HPV-associated OPC among primary care professionals is essential for disease recognition and early start of treatment. The objective of this study was to examine the knowledge on HPV-associated OPC among general practitioners (GPs) in The Netherlands. Materials and Methods In a cross-sectional postal survey among GPs in The Netherlands, a twelve-item questionnaire was sent to 900 randomly selected general practices. Outcome measures included awareness of the link between HPV and OPC, epidemiological trends and patient characteristics. Data were statistically analyzed for gender, years after graduation, and self-rated knowledge of OPC.