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Tumor Discovery Volatile organic compounds for cancer screening

7.1. Standardization highly sensitive and specific in detecting breast cancer,
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The results of VOC testing are sensitive to the method of and Dragonieri et al. demonstrated a VOC analysis
sample collection, patient physiology, and test environment. protocol highly accurate for the detection of lung cancer,
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When measuring VOCs in exhaled breath, multiple a study by Ge et al. discovered that VOC analysis had
respiratory factors may influence the concentration of low sensitivity in detecting pancreatic cancer. Moreover,
certain molecules within the breath sample. There are, the histologic subtype of the cancer may also influence
for example, international recommendations for the the VOC profile of the malignancy, in turn affecting the
standardized measurement of nitric oxide within breath sensitivity and specificity of the diagnostic test. VOC
analysis has been shown to have higher accuracy in
samples published by the American Thoracic Society and
the European Respiratory Society, which in turn have detecting adenocarcinomas than squamous cell
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supported the adoption of this metric as a diagnostic carcinoma in lung cancer. Similarly, the VOC profile
1,98
tool in clinical practice. A similar framework must be of ovarian cancer varies by histological type, whereby
proposed and implemented across all VOC screening serous tumors have a different VOC profile compared
to endometrioid tumors. The tumor’s location within
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tools to ensure the standardization and reliability of the
measurements. Quality control measures will need to be the affected organ may also impact the accuracy of
implemented with established guidelines for calibration the VOC analysis. The VOC profile of gastric cancer
procedures, and accurate quantification analyses of VOC has been shown to vary by the location of the primary
tumor within the stomach, whereby tumors located in
samples will be required to ensure reliable, high-quality, the antrum produce a different VOC profile compared to
reproducible testing. The detection limits of instruments 107
used in clinical settings for trace VOC measurements will those discovered in the body of the stomach. Similarly,
need to be specified. higher concentrations of VOCs are produced by lung
tumors in the central airways compared to peripheral
7.2. Limitations tumors. 108
• The use of chemotherapy and radiation therapy
There are several tumor factors that influence the sensitivity will also influence the accuracy of VOC analysis, as
and specificity of VOC for cancer screening and detection, adjuvant therapy changes VOC profiles produced by
which in turn may impact the implementation of this tumors. VOC analysis has shown lower accuracy in
technology in clinical practice. Tumor volume and stage, detecting oral cancer in patients who have received
for example, are critical considerations when applying chemotherapy or radiation therapy. The VOC
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VOC analysis to cancer screening and detection. The profile of cancer has also been shown to change during
sensitivity and specificity of VOC analysis for colorectal adjuvant therapy, which may affect the accuracy of
cancer detection have been shown to be affected by VOC analysis in detecting residual disease. 110,111
tumor size, whereby larger tumors release higher VOC • The metabolic activity of cancer cells is different at
concentrations, increasing the accuracy of VOC analysis. different stages of lung cancer, leading to different
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VOC analysis has been shown to have a higher accuracy in VOC profiles, and several recent studies have shown
detecting early-stage breast cancer compared to advanced- that the cancer stage influences the sensitivity and
stage cancer, and as such, the impact of tumor volume specificity of VOC analysis for cancer detection. 112
may also vary by cancer type. 99,100 Larger tumors produce The VOC profiles of early-stage lung and colon cancer
more volatile compounds, leading to a more complex patients differ significantly from those of late-stage
VOC profile and making it more difficult to detect specific patients, and the sensitivity of VOC analysis for early-
biomarkers. The accuracy of VOC analysis for cancer stage lung cancer detection is higher than that of late-
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detection can also be influenced by other factors related stage cancer. 112-114 A study by Cao et al. investigated
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to tumor volumes, such as necrosis and inflammation. the use of VOC analysis for early detection of gastric
A study by Angioli et al. reported that necrosis in cancer and discovered that the sensitivity of the
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ovarian cancer could affect the VOC profile and lead to technique was higher for early-stage tumors than for
inaccurate results in cancer detection. Similarly, a study by advanced-stage tumors. Similarly, a study by Saorin
Rodriguez-Miguelez et al. discovered that inflammation et al. reported that VOC analysis had higher
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in breast cancer can influence the VOC signature and lead accuracy in detecting early-stage ovarian cancer
to false positives. compared to advanced-stage cancer.
In addition, some malignancies may be better • The use of VOC analysis for cancer screening and
candidates for screening through VOC analysis. While detection is still in its early stages, and further
Haick et al. confirmed that VOC analysis could be research is needed to fully understand the impact of
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Volume 3 Issue 2 (2024) 10 doi: 10.36922/td.2061