ICHNO-ECHNO 2022 - Abstract Book

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ICHNO-ECHNO 2022

Results OCT4 expression in HNSCC tumors was associated with radioresistance. However, combination therapy with cisplatin was found to overcome this radioresistance in OCT4- expressing HNSCC tumors. The results were validated by using several independent patient cohorts. Furthermore, CRISPRa-based OCT4 overexpression in the HNSCC cell line resulted in apoptosis resistance, and cisplatin was found to downregulate OCT4 protein expression in vitro . Ex vivo drug sensitivity analysis of HNSCC tumors confirmed the association between OCT4 expression and cisplatin sensitivity.

Conclusion This study introduces OCT4 immunohistochemistry as a simple and cost-effective diagnostic approach for clinical practice to identify HNSCC patients who can be treated with radiation therapy alone and on the other hand the patients who has radiotherapy resistant cancer and need cisplatin for radiosensitation.

PO-0120 Prognostic Factors Associated with Successful Salvage Surgery in Recurrent Oral Cancer

M. Szewczyk 1 , W. Golusi ń ski 2

1 Poznan University of Medical Sciences, Head and Neck Surgery, Pozna ń , Poland; 2 Pozna ń University of Medical Sciences, Head and Neck Surgery, Pozna ń , Poland Purpose or Objective To determine the parameters associated with poor outcomes in recurrent oral cancer and the risk stratification factors of patients most likely to benefit from salvage surgery for recurrent disease. Materials and Methods Retrospective study of 261 patients treated with primary surgery. The following clinical parameters were assessed: age at diagnosis; disease stage; T status; N status; perineurial invasion; lymphovascular invasion; extranodal extension; and intraoperative and final margin status. The type of recurrence (local, regional, and/or distant) or second primary tumour was registered. Disease-free survival (DFS) and overall survival (OS) rates were calculated. A multivariate analysis was performed. Results On the multivariate analysis, three variables—positive surgical margins, nodal disease, and perineural invasion (PNI)—were associated with a significant increase in recurrence risk. Of the 108 patients with recurrent disease, 36 (33%) were eligible for salvage surgery. Three variables were significantly associated with suitability for salvage surgery: no primary neck disease (N0), no positive margins in the primary resection, and no adjuvant radiotherapy following primary resection. The only variable significantly associated with improved salvage outcomes was negative margin status. Conclusion The findings of this study show that N0 disease, no adjuvant treatment, and free surgical margins are the main factors in the primary surgery associated with successful salvage surgery. Assessment of these factors could help to better stratify patients to determine the likelihood of successful salvage surgery, thus avoiding the negative impact of unsuccessful surgery on quality of life, in patients with a low probability of success.

PO-0121 Radical radiation with Tomotherapy in carcinoma Oropharynx, Larynx & Hypopharynx: Indian experience.

Y. Sreenija 1 , P. K U 1 , A. R 1 , D. Dutta 1

1 Amrita Institute of Medical Sciences, Radiation Oncology, Kochi, India

Purpose or Objective Audit of outcomes of Radical Radiation (RT) in Carcinoma Oropharynx (OPX), Larynx (LX), Hypopharynx (HPX) treated with Tomotherapy. Materials and Methods During 2016-2019, consecutive oropharyngeal, laryngeal and hypopharyngeal cancer patients treated with radical intent RT with Tomotherapy were evaluated. RT dose of 70Gy/33 fr for primary PTV and high risk nodal PTV; 66Gy/33fr for intermediate risk nodal PTV and 56.1Gy/33fr for low risk nodal PTV. Node positive and bulky primary (T3/T4) patients received concomitant chemotherapy (CTRT). Acute toxicities, feeding pattern and response to treatment were evaluated. Results 102 consecutive patients were analyzed [Median age 66 years (30-82 yrs), male-97(95%), OPX-42(41%), LX-31(30%), HPX- 29(29%). Stages I-2(2%), II-10(10%), III-28 (27%), IVA-47(46%), IVB-15 (15%)]. At RT start, 94 were on oral feeds, 4 on Nasogastric tube (NG) feeds, 3 PEG tube feeds and 1 had jejunostomy. 76 received CTRT, 26 received RT alone. Among the CTRT group, 58 received concomitant cisplatin-40mg/m2, weekly (46) and 100 mg/m2, three weekly (12), 17 carboplatin and 1 cetuximab. At median follow up (FU) of 25.5 months, mean overall all survival (OS) for entire cohort was 26 months (SD14.7; range 2-85 months; 1-year: 81.6%, 2-year: 73.6%). Mean OS in oropharyngeal: 25.3 months (1-year:79.3%), laryngeal: 24.9 months (1-year: 80.1%), and hypopharyngeal: 28 months (1-year: 86.2%). At last follow up, 52 (51%) were