Molecular Detection of Mycobacterium tuberculosis in Urinary Bladder FFPET Samples Could be a Proposed Specific Entity Of Bladder Carcinoma.
Authors: Tarish Hashim Raheem , Aljanabi Asaad , Abdul-Hussein Zina Mohammed 
Published: March 2023

Background: Bladder cancer is one of the most common human cancers in Iraq and the world. While smoking, age, gender, and occupational exposure to aromatic amines are the most prominent among the risk factors identified, long term Inflammation and chronic infection may largely play some role in urinary bladder cancer (UBC) development. The association between bacterial inflammation and cancer appears to be stronger especially in chronic type of infection, many studies mentioned the role of chronic Escherichia coli (E. coli) infection and UBC but there was no study mentioned the role of chronic Mycobacterium tuberculosis (MTB) infection in association with UBC. There are many cellular and immune responses that occur during chronic Mycobacterial infection such as irritation, long term inflammatory cytokine production and DNA damaging due to bacterial metabolic products are some factors that may give chance for UB neoplastic changes. In the present study we worked on urinary bladder cancer and noncancerous Formalin-Fixed Paraffin Embedded (FFPE) Tissue specimens of Iraqi patients, the current study used polymerase chain reaction (PCR) for detection of Mycobacterium tuberculosis genome.
Objectives: investigation for the role of Mycobacterium tuberculosis and its association with urinary bladdercancer.
Methodology: The current study used urinary bladder cancer (UBC) formalin-fixed paraffin embedded tissues(FFPET) specimens of Iraqi patients collected of several private histopathology labs in AL-Najaf Governorate, the specimens were 50 samples of UBC patients and 25 different noncancerous pathological bladder samples. 84% of UBC cases were male and the predominant age group was 61-80 years (60%) for both gender. low grade cases were the most common which recorded (64%) and they were mostly TaN0M0 staging (42%). Large part of the study was performed at the Medical Education Research Facility (MERF)/ Carver collage of medicine/ University of Iowa/ United States of America. Samples of DNA were extracted and DNA quantitation was performed using Nanodrop DNA quality was evaluated using human β-globin gene amplification.
Results: human β-globin gene amplification used in DNA quality evaluation, PCR results showed that 80% of samples were β-globin positive and many samples showed appearance of multiple copies. Detection of Mycobacterium tuberculosis complex (MTBC) DNA using IS6110-PCR amplification showed 33% of UBC samples with positive results and 4% of noncancerous samples showed positive result, with high significant difference P<0.01. Identification of MTB subspecies was performed using Internal Transcribed Spacer Regions PCR (ITS-PCR), 55.56% of UBC IS6110-PCR positive cases were ITS-PCR positive.
Conclusions: A high percentage of MTBC and MTB detected among patients with UBC in comparison to noncancerous cases, suggesting that MTBC- associated bladder carcinoma is a proposed specific entity of bladder cancer which need to be more clarified.
Recommendations: Modern techniques should be used for MTBC and MTB detection in laboratories andfurther study for the relationship between chronic MTB infection and UBC.