Mutation of KRAS and NRAS gene in the right-sided and left-sided colorectal cancer of patients treated with surgery in KBC Split between 2014 and 2017

Abstract

Cilj istraživanja: karcinom debelog crijeva jedan je od najčešćih tumora na kojeg otpada 9,7% svih zloćudnih bolesti. Cilj ovog diplomskog rada je istražiti postoji li statistički značajna razlika pojavnosti mutacije gena KRAS i NRAS u desnostranom i ljevostranom karcinomu debelog crijeva bolesnika operiranih u Kliničkom bolničkom centru Split čija je mutacija određena u Kliničkom zavodu za patologiju, citologiju i sudsku medicinu na parafinskim uzorcima tumorskog tkiva u periodu od 2014. do 2017. godine. Ispitanici i metode: U istraživanje je uključeno 136 bolesnika s karcinomom debelog crijeva operiranih u Kliničkom bolničkom centru Split, kojima je nakon operativnog zahvata provedena molekularna analiza mutacije KRAS i NRAS gena iz parafinskih uzoraka tumorskog tkiva u razdoblju od siječnja 2014. godine do kraja veljače 2017. godine. Podaci su prikupljeni pretraživanjem baze podataka Laboratorija za kliničku i sudsku medicinu i Odjela za patologiju Kliničkog zavoda za patologiju, sudsku medicinu i citologiju te arhive Klinike za kirurgiju Kliničkog bolničkog centra Split. Svakom bolesniku prikupljeni su i analizirani podaci o spolu, dobi, lokalizacija bolesti( desno ili lijevo) i postojanje KRAS i NRAS mutacije. Svim ispitanicima (n=136) je određena mutacija gena KRAS. Ispitanicima s negativnim nalazom mutacije gena KRAS i jednom ispitaniku s dokazanom mutacijom gena KRAS (n=73) rađena je analiza mutacije gena NRAS. Rezultati: Od ukupnog broja bolesnika analiziranih na KRAS i NRAS mutaciju (n=136), na muškarce otpada 92 (67,65%), a na žene 44 (32,35%), što ukazuje na 2 puta učestalije obolijevanje kod muškaraca nego kod žena. Prosječna dob bolesnika je 62,32 godina (raspon 37-79). Analiza je pokazala da najviše bolesnika ima između 50. i 64. godina (42,32 %). Od ukupnog broja bolesnika ljevostranu lokalizaciju karcinoma debelog crijeva ima njih 99 (72,79%), a desnostranu 37 (27,21%). Od ukupnog broja bolesnika njih 64 (47,06%) ima, a 72 (52,94%) nema mutaciju gena KRAS. Mutacija NRAS gena testirana je kod 73 (53,68%) ispitanika, od kojih njih 11 (15,07%) ima, a 62 (84,93%) nema mutaciju gena NRAS. Analiza statistički značajne razlike KRAS i NRAS mutacija desnostranog i ljevostranog karcinoma debelog crijeva provjerena je χ2 testom te je p=0,6613 (p<0,05 postavljen kao statistički značajan). Zaključci: Broj bolesnika kojima je određena mutacija gena KRAS i NRAS je veći svake godine. Veći je udio bolesnika muškog spola od onih ženskog spola. KRAS i NRAS mutacije su negativni prognostički faktori. Njihova aktivacija predviđa loš odgovor na terapiju monoklonalnim anti-EGFR protutijelima u naprednom karcinomu debelog crijeva. Pojedina istraživanja pokazala su da postoji bitna razlika u pojavnosti KRAS i NRAS mutacije između ljevostranog i desnostranog karcinoma debelog crijeva. U ovom istraživanju kod većine ispitanika karcinom debelog crijeva lokaliziran je lijevo, dok manji dio ima desnostrani karcinom debelog crijeva. Postotak ispitanika bez mutacije gena KRAS je veći u odnosu na postotak ispitanika koji imaju mutaciju. I postotak ispitanika bez mutacije gena NRAS je veći u odnosu na postotak ispitanika koji imaju mutaciju. Mutaciju oba analizirana gena (KRAS ili NRAS) ima da nešto veći postotak ispitanika, od onih koje je nemaju. Nije utvrđena statistički značajna razlika u pojavnosti mutacije analiziranih gena RAS uspoređujući desnostrane i ljevostrane karcinoma debelog crijeva.Research Objective: Colorectal cancer is one of the most common tumors, which accounts for 9.7% of all malignant diseases (6). The aim of this thesis is to investigate whether there is a statistically significant difference in occurrence between the mutation of KRAS and NRAS genes in the right-sided and left-sided colorectal cancer of patients treated with surgery at the University hospital of Split, whose mutation was determined in the Clinical Institute of Pathology, Cytology and Judicial Medicine on paraffin tumor tissue patterns in the period from 2014 to 2017. Subjects and Methods: The study included 136 patients with colorectal cancer treated with surgery at the University hospital of Split, who after the operation were analysed on mutations of KRAS and NRAS genes from paraffin tumor tissue samples from January 2014 to the end of February 2017 year. Data was collected by searching the database of the Clinical and Judicial Medicine Laboratory and Department of Pathology of the Clinical Institute of Pathology, Judicial Medicine and Cytology and the Clinic for Surgery of the University hospital of Split. All patients were collected and analyzed on gender, age, localization of the disease (right or left) and the existence of KRAS and NRAS mutations. All patients (n = 136) were analyzed on mutation of KRAS gene. Patients with a negative mutation finding of KRAS gene and one patients with proven mutation of KRAS gene (n = 73) were analyzed to a NRAS mutation analysis. Results: Of the total number of patients analyzed on KRAS and NRAS mutation (n = 136), men were 92 (67.65%) and women 44 (32.35%), which indicates a twice-frequent incidence of males rather than women. The average age of the patient was 62.32 years (range 37-79). The analysis showed that most patients were between 50 and 64 years (42.32%). Out of the total number of patients the number of left-sided tumor was 99 (72.79%), and right-sided 37 (27.21%). Out of the total number of patients there were 64 (47.06%) who had mutation, and 72 (59.84%) did not have KRAS mutations. The mutation of NRAS genes was tested in 73 (53.68%) patients, of whom 11 (15.07%) had mutation and 62 (84.93%) did not have NRAS mutation. Statistically significant differences KRAS and NRAS mutations of right and left colorectal cancer were checked by the χ2 test in which p = 0.6613 (p <0.05 set as statistically significant). Conclusions: The number of patients with KRAS and NRAS mutations is getting higher every year. There wass a higher percentage of male patients than female. KRAS and NRAS mutations are negative prognostic factors. Their activation predicts poor response to monoclonal anti-EGFR antibodies therapy in advanced colorectal cancer. In this study, most colorectal cancer were left-sided, while less patients had right-sided colorectal cancer. The percentage of patients with no mutation of KRAS genes was higher than the percentage of patients with mutation. Also, the percentage of patients without NRAS mutation was higher than the percentage of patients who had a mutation. The mutation of both analyzed genes (KRAS or NRAS) had a slightly higher percentage of pozitive patients than those who did not have mutation. There was no statistically significant difference in the occurrence of RAS mutations by comparing right-sided and left-sided colorectal cancer