ESTRO meets Asia 2024 - Abstract Book

S181

Interdisciplinary – Head & neck

ESTRO meets Asia 2024

292

Proffered Paper

Correlation of cf DNA with response in head & neck cancer treated with definitive chemoradiotherapy

Madhup Rastogi 1 , Ajeet K Gandhi 1 , Sourajit Parida 2 , Vachaspati Mishra 1 , Rohini Khurana 1 , Rahat Hadi 1 , Nuzhat Husain 3 1 Radiation Oncology, RMLIMS, Lucknow, India. 2 Radiation Oncology, AIIMS, Bubaneshwar, India. 3 Pathology, RMLIMS, Lucknow, India

Purpose/Objective:

Changes in circulating free DNA (cfDNA) levels after treatment have been correlated with response of treatment in various malignancies. We intended to correlate cfDNA levels with treatment response and to evaluate it as a potential biomarker in the patients of locally advanced head and neck squamous cell carcinomas (LAHNSCC) treated with 2 cycles of induction chemotherapy (IC) followed by definitive chemoradiotherapy.

Material/Methods:

This was a prospective study of 34 LAHNSCC patients (stage III-IVA, AJCC 8th edition) conducted between February 2018 to June 2021. All patients received 2 cycles of taxane based IC followed by definitive chemoradiotherapy (66 70Gy in 33-35 fractions using 3-dimensional conformal plan with weekly concurrent cisplatin (40mg/m2). Serum cfDNA levels were quantified by qPCR in blood samples collected prior to treatment (S1), 2 weeks after IC (S2), post 20 fractions of RT (S3) and 3 months post treatment completion (S4). Response assessment was done 3 months post treatment completion based on WHO response criteria. Statistical analysis was done with statistical package for social sciences (SPSS, version 23.0, IBM). Correlation between S3-S1 and response was evaluated by Spearman’s rank order correlation. P value of < 0.05 was considered statistically significant.

Results:

Table 1 Showing the Patient Characteristics

Patient characteristics

Distribution (n=34)

Median Age (range)

55 years (range 32-67 years)

Male: Female

31:3

Median KPS (range)

90 (range 80-90)

Differentiation (Well: Moderate: Poor)

3(8.8%):24(70.6%):7(20.6%)

Primary Site

Oropharynx: Hypopharynx: Larynx

5(14.7%):19(55.9%):10(29.4%)

T size T1:T2: T3:T4a

1(2.9%): 10(29.4%):12(35.3%):11(32.4%)

N status N0:N1: N2

5(14.8%):6(17.6%):23(67.6%)

Stage III: IVA

9(26%):25(74%)