Page 73 - SDIR5 Abstract book 21 12 2021.

POSTER PRESENTATIONS

P33

Association between TGFB1 C-509T polymorphism and acute toxicity after radiotherapy for
prostate cancer

1
1,2
3,4
Emina Mališić , Nina Petrović , Marina Nikitović , Tatjana Stanojković 1
1 Institute for Oncology and Radiology of Serbia, Department of Experimental Oncology, Belgrade, Serbia
2 “VINČA“ Institute of Nuclear Sciences-National Institute of the Republic of Serbia, University of Belgrade,
Belgrade, Serbia
3 Institute for Oncology and Radiology of Serbia, Department of Radiation Oncology, Belgrade, Serbia
4 Faculty of Medicine, University of Belgrade, Belgrade, Serbia

Background: Radiotherapy (RT) for prostate cancer (PCa) is associated with a spectrum of side effects
(toxicity) in the surrounding normal tissues. TGFB1 is a key cytokine associated with inflammation and
fibrosis, but its role in acute toxicity is unclear. The presence of T allele at −509 bp of the promoter region
of TGFB1 gene is related to higher concentrations of TGFB1 than C allele. We aimed to investigate
association between C-509T polymorphism (rs1800469) and RT-induced acute toxicity. Patients and
methods: Eighty six patients who had a localized or locally advanced PCa were treated with radical (72
Gy)(n=49) or postoperative/salvage (66 Gy)(n=37) RT without previous hormonal therapy. TGFB1 C-509T
was determined by PCR-RFLP analysis on DNA from PBMC. The differences in the distribution of genotypes
between patients with or without acute genitourinary (GU) or gastrointestinal (GI) toxicity were tested by
χ2 and Fisher’s exact test. P values ≤0.05 were considered statistically significant. The genotype-specific
associations with toxicity were estimated as odds ratios (OR) with 95% confidence intervals (CIs) for
dominant, recessive, codominant and overdominant genetic model. Results: Heterozygote carriers of
TGFB1 C-509T had statistically significant lower rate of acute GU and GI toxicity then homozygotes (CC plus
TT) (p=0.048; p=0.047). Additionally, the OR indicated lower risk for acute toxicity development in
heterozygote than homozygote patients (OR (95%CI) were: 0.12 (0.01- 1.11) for GU and 0.19 (0.03- 1.02)
for GI). Conclusion: The obtained data indicate that CT genotype of TGFB1 C-509T could be potential
biomarkers of lower risk for acute RT-induced toxicity.
Keywords: polymorphism, prostate cancer, radiotherapy, toxicity

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