טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentAmal Haitham
SubjectThe Uniqe Chemical Signature of Cancer in Exhaled
Breath
DepartmentDepartment of Chemical Engineering
Supervisor Professor Hossam Haick
Full Thesis textFull thesis text - English Version


Abstract

Cancer is a major public health problem in the United States and many other parts of the world. Cancer is a class of diseases characterized by out-of-control cell growth. There are over 100 different types of cancer, and each is classified by the type of cell that is initially affected. Many studies have shown the correlation of volatile organic compounds (VOCs; organic compounds that have a high vapour pressure at ordinary, room-temperature conditions) that evaporate from cancerous cell reaching the exhaled breath with a specific cancer disease conditions. The biochemical mechanism of the VOC emission and relation with the different cancer conditions is still under debate. Oxidative stress is the main source of the straight hydrocarbons in the body, causing lipid peroxidation of polyunsaturated fatty acids in cell membranes, and generating hydrocarbons.  A large and diverse group of oxidase enzymes are probably responsible for the emission of part of the VOCs.


             In this thesis, we have conducted several individual projects showing that the cancer disease has different and unique breath fingerprint from its control group. This was done on gastric cancer, colorectal cancer, ovarian cancer and head & neck cancer.


Furthermore, a meta-Analysis (with more than 1500 breath samples) have provided an evidence that a different kinds of cancer (gastric, colorectal, ovarian, head and neck, lung, prostate, kidney and bladder cancer) have distinctive breath volatolome when compared one to the other and not only when compared to the control groups. The breath samples were analysed by gas chromatography linked mass spectrometry (GC-MS) in order to understand the nature of the compositions associated with the different states. In parallel we have analysed the samples also by a sensitive nanomaterials based sensors for the collective sensing of the obtained mixtures. Distinguishable differences were shown between the cancer groups in the GC-MS and the sensors analysis indicating that each disease has a distinctive breath fingerprint. These valuable results will lead the breath analysis field towards global evidence of breath volatolomics of cancer.