Year: 2023 | Month: December | Volume: 10 | Issue: 12 | Pages: 9-19
DOI: https://doi.org/10.52403/ijrr.20231202
Prevalence of PIK3CA Mutation Based on Tumour Locations Among Colorectal Cancer Patients in Bali
Nyoman Rama Aditya Kurniawan1, Agus Eka Darwinata2, Ni Putu Ekawati3, I Made Mulyawan4, Ni Nyoman Ayu Dewi5
1Magister Program in Anti-Aging Medicine, 2Departement of Microbiology, 3Department of Pathology, 4Department of Surgery, 5Department of Biochemistry;
Faculty of Medicine, Udayana University, Denpasar, Bali, Indonesia
Corresponding Author: Ni Nyoman Ayu Dewi
ABSTRACT
Colorectal tumour location is important in determining therapeutic strategies because the location of the tumour will affect the histological and molecular characteristics of the cancer. Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) is a gene known to be associated with colorectal cancer location. The prevalence of PIK3CA mutations in colorectal cancer (CRC) ranges from 10-20%. Although the prevalence is small, this gene has a potential as a predictive and prognostic biomarker in the management of CRC. 80% of PIK3CA mutations occur in exon 9 (codon 542 and 545) and exon 20 (codon 1047). This study aimed to determine the prevalence of PIK3CA gene mutations based on tumour location among colorectal cancer patients in Bali, especially in Prof. dr. I G.N.G. Ngoerah Hospital, Denpasar, Bali. DNA was isolated from formalin-fixed-paraffin embedded (FFPE) blocks of colorectal cancer samples which were stored in the Department of Pathology of Prof. dr. I G.N.G. Ngoerah Hospital. Mutation was detected using polymerase chain reaction (PCR) and direct sequencing. Data on age, gender, and tumour location were recorded from patient medical records.
Our findings on 31 colorectal cancer samples showed 26 samples (96.3%) were found with heterozygous mutation in exon 9 with AC genotype, but no mutation was found on exon 20. Based on tumor location, among 26 samples with mutation, 16 samples (61.5%) were left colorectal cancer and 10 samples (38.5%) were right colorectal cancer. Further studies are needed to identify the association of this mutation with colorectal cancer location and the other clinicopathological aspects of CRC.
Keywords: Colorectal cancer, PIK3CA gene mutation, PIK3CA exon 9, PIK3CA exon 20, colorectal cancer location, left-sided colorectal cancer, right-sided colorectal cancer
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