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Jul 15, 2017 07:03AM
Kiss - It is very interesting to hear about your experience. Everything I have read suggests cfDNA is very accurate. I'll keep posting as I research and pursue this test. Analysis of Circulating Tumor DNA to Monitor Metastatic Breast Cancer
CT and Circulating Biomarkers for Tumor Monitoring
We compared the performance of circulating biomarkers with CT scans in 20 patients with measurable disease (as defined by RECIST21) and for whom circulating biomarker data were available at 3 or more time points over a period of more than 100 days of follow-up. Circulating tumor DNA was detected and showed serial changes in 19 of 20 women (95%) with fluctuations in circulating tumor DNA generally correlating with treatment responses seen on imaging (Figure 4A
women with high levels of CA 15-3 had fluctuations corresponding to responses on imaging but with a smaller dynamic range (Figure 4A and 4B) than cfDNA. In patients with levels of CA 15-3 of 50 U or less per milliliter (8 of 19 patients [42%]), no consistent serial changes in CA 15-3 levels were seen (Figure 4C).
Progressive disease was documented on CT (as defined by RECIST) in 19 of 20 women during the follow-up period; CA 15-3 data were available for 18 of these women (95%). Increases in circulating tumor DNA levels reflected progressive disease in 17 of the 19 women (89%). In these women, on average, circulating tumor DNA levels increased by a factor of 505 (range, 2 to 4457) from the nadir before the establishment of progressive disease.
CA 15-3 levels increased in 9 of 18 women (50%). In 10 of the 19 patients (53%), levels of circulating tumor DNA increased at one or more consecutive time points, on average 5 months (range, 2 to 9) before the establishment of progressive disease by means of imaging (Figure 4D). In 2 women (Patients 9 and 22), increasing levels of circulating tumor DNA did not reflect the presence of progressive disease as assessed on CT.
This article is interesting for people trying to understand their CA 15-3 results. For women like me with a CA15-3 of less that 50 U/ml, increases in CA15-3 did not correlate with progression. For women with CA 15-3 greater than 50U/ml, increases in CA15-3 did predict progression.
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12/28/2015, IDC, Left, 4cm, Stage IV, metastasized to bone/liver, Grade 3, ER+/PR-, HER2-
1/17/2016 Femara (letrozole)
2/2/2016 Ibrance (palbociclib)