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Fig. 2 | BMC Medicine

Fig. 2

From: Utility of circulating tumor DNA in cancer diagnostics with emphasis on early detection

Fig. 2

Each patient depicted in this figure has a fetus (far left patient) or a tumor (rest of the patients) of a different mass, decreasing from left to right. Data from Table 4 was plotted and sizes are not to scale. The fetus/tumors secrete DNA into the blood stream in quantities proportional to their masses; the ratio of tumor/fetal DNA (in italics) to total DNA secreted from healthy cells (in bold) is shown underneath a dividing line for each patient. As tumor size decreases, the ratio of circulating tumor DNA to total circulating DNA decreases proportionally. Thus, it becomes increasingly difficult for a test to extract these miniscule amounts of tumor DNA from the rest of the circulating DNA, compromising its effectiveness in detecting small, early stage tumors. For more details see text and Table 4

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