ESTRO 2024 - Abstract Book

S1295

Clinical - Head & neck

ESTRO 2024

1452

Poster Discussion

Prognostic ability of TGF- β and IL -6 in patients with HNSCC treated with RT.

Laura Montezuma 1 , Xavier Leon-Vintró 2 , Katarina Majerčáková 1 , Joan Julià 1 , Nuria Farré 1 , Jady Rojas 1 , Saba Rabi 1 , Scarlet Crespo 1 , Gemma Calvet 1 , Mercedes Camacho 3 , Gemma Sancho 1 1 Hospital de la Santa Creu I Sant Pau, Radiation Oncology, Barcelona, Spain. 2 Hospital de la Santa Creu I Sant Pau, Otorhinolaryngology Service, Barcelona, Spain. 3 Hospital de la Santa Creu I Sant Pau, Biomedical Research Institute, Barcelona, Spain

Purpose/Objective:

Transforming growth factor- β (TGF - β) and interleukin -6 (IL-6) are cytokines that have been independently associated with increased tumor aggressiveness and treatment resistant head and neck squamous cell carcinoma (HNSCC) [1,2] . The aim of our study is to correlate TGF-B and IL-6 transcriptional expression with local tumor control in a cohort of patients treated with radiotherapy (RT).

Material/Methods:

Retrospective study from biopsies obtained from 160 patients with HNSCC located in oral cavity, oro-hypopharynx or larynx, treated with radical intent during the period 2005-2012, , including patients treated with RT (n=60), chemo-radiotherapy (n=84) or bio-radiotherapy (n=16). RT treatment consisted in administration of 70Gy to primary disease and positive lymph nodes, and elective 50 Gy in regions of risk of microscopic tumor dissemination according to international consensus guidelines. 84% of patients were treated with normofractionation dose (2Gy/fraction, 1 fraction/day, 5 days/week). 16% patients were treated with hyper-fractionated regimen (1.2Gy/ fraction, 2 fractions/day, 5 days / week). All patients had a minimum follow-up of 3 years. Transcriptional expression of TGF- β and IL6 was determined by RT -PCR and categorized by recursive partitioning analysis. Evaluation of local recurrence-free survival was performed according to the three risk categories obtained based on high and low transcriptional expression of TGF- β and IL6. During the follow-up period, local tumor recurrence occurred in 54 patients (33.8 %). Patients with local recurrence had significantly higher TGF- β expression levels (P=0.041). Recursive partitioning analysis yielded a classification tree with three terminal nodes, with a first partition dependent on TGF- β expression, and a second partition for patients with high TGF- β expression dependent on IL -6 expression. Patients with low TGF- β expression (Group 1, n=62) had a low risk of local recurrence; patients with high TGF- β/low IL -6 expression (Group 2, n=36) an intermediate risk of local recurrence; and patients with high TGF- β/elevated IL -6 expression (Group 3, n=62) a high risk of recurrence Figure 1 . The 5-year local recurrence-free survival for Group 1, 2 and 3 patients was 85.4% (95% CI: 76.0-94.8%), 67.8% (95% CI: 52.1-83.5%) and 41.7% (95% CI: 29.2-54.2%), respectively. There were significant differences in local recurrence-free survival according to TGF- β/IL -6 expression (P=0.0001) Figure 2 . According to the result of a multivariate analysis, considering Group 1 patients as the reference category, Group 2 patients had a 2.5-fold Results: