Sick bodies adjust their internal chemistry, and this change is showed in the form of tiny gases that float around us. A growing number of studies imply that people with canc3r smell different due to volatile organic compounds (VOCs) that gather in their bl00d, urine, or breath. These molecules work as chemical fingerprints that, in minimal concentrations, operate sensitive olfactory receptors.
In this article, we will explore the biochemistry of VOCs, olfactory experiments with animals and electronic sensors, and the current status of urine- or breath-based biosensors.
VOCs: Chemical Fingerprints of the Tumor
Canc3r reprograms cellular metabolism. In doing so, it produces free radicals that decompose lipids and proteins, releasing aldehydes, ketones, and short-chain alkanes.
The review by Janfaza et al. (2019) finds more than 1,300 compounds related with lung, breast, colon, and pancreatic tumors. Aldehydes such as hexanal, ketones such as 2-butanone, and terpene alcohols appear in concentrations higher than those of healthy individuals. These compounds, despite their low mass, have penetrating and characteristic odors.
Body sources of VOCs
- Breath: Pulmonary gas exchange carries volatile metabolites to the outside. GC-MS and ion flow spectrometry studies have spotted p-xylene and toluene in the breath of lung canc3r patients.
- Urine: The kidneys concentrate soluble metabolites. Giró Benet et al. (2022) displayed that a urinary VOC pattern classified breast canc3r with 92% accuracy.
- Sweat and sebum: Lipophilic compounds such as oxygenated squalene are released through the skin and can alter body scent.
Advantages and limits of biological smell
- Pro: Fast learning, low cost, holistic detection of complex combinations.
- Cons: fatigue, mood swings, need for constant training, inability to connect what specific molecule one smells.
- Towards electronic sensors: e-noses and biosensors
Factors that modify the oncological aroma
Not all odor comes from the tumor. Diet, medications, microbiota, and smoking habits change the volatilome. Methylnitrosamine-1-butanol (NNAL), a tobacco metabolite, interferes with urinary signatures of bladder canc3r. Therefore, modern protocols request controlled fasting and dietary records prior to sample collection.
The state of the immune system also plays a key role. Tumor inflammation declares nitric oxide and interleukins that induce oxidative enzymes responsible for odorous aldehydes. Understanding these pathways will help reduce false positives.
Regulatory and ethical challenges
- Multicenter validation: Studies with thousands of participants and restriction of environmental confounders are needed.
- Smell privacy: Volatilomas could spot not only canc3r but also drug use or infections; an ethical framework for use is required.
- Accessibility: Make sure that new tests do not increase gaps between high- and low-income health systems.
