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Tumor Discovery Volatile organic compounds for cancer screening

Despite these promising results, little is known are varied, with some countries adopting population-
about the mechanism of production of VOCs specific based screening, while other countries reserving screening
to prostate cancer, and a reliable VOC profile for investigations for specific high-risk subgroups dependent
prostate cancer has not yet been described. Peng et al. on endemic incidence. Early diagnosis and treatment of
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examined the exhaled VOC profiles of healthy controls gastric cancer results in decreased mortality. However,
(n = 22) compared with patients with biopsy-confirmed early-stage gastric cancer is most often asymptomatic or
malignancy (breast (n = 22), lung (n = 30), colorectal with symptoms similar to gastritis. 56-58 Owing to the silent
(n = 26), prostate (n = 18). They describe several VOCs or ambiguous presentation of early gastric cancer, effective
that, when measured, showed no overlap between screening investigations are important to ensure early
controls and patients with prostate cancer (toluene, gastric cancer diagnosis.
2-amino-5-isopropyl-8-methyl-1-azulenecarbonitrile, The primary method of detecting gastric cancer in the
p-xylene, and 2,2-dimethyl-decane). However, this early 20 century was X-ray imaging. With the ingestion
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th
study was limited by a small sample size, and their model of barium contrast media, the GI tract could be assessed
failed to reach statistical significance for their VOC 59
profile for prostate cancer. The molecule sarcosine has for abnormalities with minimal risk to patients.
previously been proposed as a biomarker of aggressive However, the sensitivity of the single-contrast barium
tumor biology in prostate cancer, and interestingly, examination in the diagnosis of gastric carcinoma ranged
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higher levels are reported in the urine of patients with from 54% to an average of 75%. In the late 1960s,
biopsy-confirmed prostate cancer (n = 44) compared Japanese physicians developed the gas-barium double-
contrast method of X-ray imaging, which involved the
to healthy controls (n = 51). However, the receiver ingestion of CO gas-producing granules in conjunction
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operator characteristic (ROC) for sarcosine was modest 2 60-63
(0.71 for urine sediments; 0.67 for supernatants), which with a barium suspension. This method permitted
limits its potential for clinical application. 50 visualization of the enhanced barium-saturated mucous
membrane of the stomach, which was subsequently
In vitro studies report elevated acetaldehyde inflated with air to assess its elasticity. Over time,
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dehydrogenase activity in tumor cells, a molecule that specific techniques involving rotating the patient and
catalyzes the oxidation of exogenous and endogenous timings for spot films were developed to optimize the
aldehyde substrates into carboxylic acids, which may mucosal coating of the stomach and to permit assessment
explain the finding of decreased aldehyde levels in prostate of the stomach in its entirety. Sensitivity with the double
cancer VOC profiles. 46,51-54 This finding is not, however, contrast barium study ranged from an average of 76
specific to prostate cancer and has been described in colon, – 96%; however, it has been established as superior to
gastric, and breast cancer as well. 54,55 Similarly, Liu et al. conventional computed tomography in localizing the
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describe 2-ethyl-1-hexanol in their prostate cancer VOC diagnosis. 60,61,64
profile as a known metabolite of diethylhexyl phthalate with
a role in the induction of apoptosis previously implicated The flexible design of the fiberoptic endoscope
in the VOC profile of several other malignancies. 46,53-55 created in 1957 allowed for the examination of the entire
Nevertheless, VOC for prostate cancer screening and stomach, overcoming the limitations of its predecessor,
detection is promising, with excellent sensitivity and the rigid gastroscope. 57,65 In the early 1960s, the utility
specificity profiles in studies using VOCs detected in the of endoscopy in the diagnosis of gastric cancer was
headspace of urine samples (Figure 1). Given the current realized as it enabled direct visualization of the gastric
limitations of PSA screening, further study is warranted to mucosa and allowed for biopsies to be carried out on
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explore the role of VOC analysis as a non-invasive test for ulcers and other suspicious areas of the stomach. The
prostate cancer screening. sensitivity of endoscopy in the diagnosis of gastric cancer
ranged from 92% to 99%, and therefore, endoscopy
5. Gastric cancer rapidly gained popularity for its superior diagnostic
accuracy as compared to the single contrast barium meal
Gastric cancer is the fifth most common cancer worldwide, (Figure 1). 59-61 Ultimately, endoscopy was accepted as
with approximately 1.09 million new cases of gastric cancer the superior test for gastric cancer screening due to its
diagnosed in 2020. Globally, it is the fourth leading cancer better accuracy. 57,58,66,67 Today, endoscopy and endoscopic
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cause of death, responsible for 7.7% of all cancer-related biopsy are accepted as the gold standard for the diagnosis
deaths in 2020. The incidence and prevalence of gastric 64
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cancer have significant variability worldwide, with most of gastric cancer.
new cases of gastric cancer occurring in Eastern Asia. Helicobacter pylori infection was identified as a major
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As a result, recommendations for gastric cancer screening risk factor for gastric cancer in the 1980s, resulting in

Volume 3 Issue 2 (2024) 7 doi: 10.36922/td.2061