Table 2.
ctDNA in early breast cancer.
| Authors [Reference] | Study Design | Method | Findings |
|---|---|---|---|
| Beaver, J.A., et al., 2014 [47] | PIK3CA in pre- and post-surgery plasma samples | ddPCR | ctDNA detectable in plasma. Of 15 PIK3CA mutations detected in tumors, 14 were detected in pre-surgery plasma. No mutations detected in wild-type PIK3CA plasma. Sensitivity: 93.3%, specificity: 100% |
| Riva, F., et al., 2017 [48] | ctDNA in TNBC before NACT, after 1 cycle, pre-surgery, post-surgery | ddPCR | ctDNA detected in 75% of patients at baseline. ctDNA decreased during NACT. Minimal decrease in ctDNA level during NACT associated with shorter DFS and OS. |
| Phallen, J., et al., 2017 [49] | ctDNA at primary diagnosis | TEC-Seq | ctDNA detected in 56% stage I-III BC patients. ctDNA detected had high concordance with alterations detected in tumor tissue. |
| Cohen, J.D., et al., 2018 [50] | ctDNA at primary diagnosis | QIASymphony CancerSEEK |
33% sensitivity in breast cancer. |
| Garcia-Murillas, I., et al., 2019 [51] | ctDNA before, during, and after NACT | ddPCR | ctDNA detected at baseline associated with RFS. ctDNA detected during follow-up associated with increased risk of relapse. |
| Garcia-Murillas, I., et al., 2015 [52] | ctDNA after NACT | ddPCR | ctDNA detected at post-surgical time point or during follow-ups increased risk of relapse. Serial ctDNA predicted relapse with median lead time of 7.9 months over clinical relapse. |
| Rothe, F., et al., 2019 [54] | ctDNA before, at week 2, and after NACT in HER2+ patients | ddPCR | ctDNA detected in 41% of patients at baseline. ctDNA detected in 20% of patients at week 2. ctDNA detected in 5% of patients post-NACT. ctDNA detected at baseline associated with decreased pCR. |
| Zhang, X., et al., 2019 [55] | ctDNA before and after adjuvant chemotherapy | AmpliSeq | ctDNA detected after surgery associated with increased lymph node metasis. ctDNA positivity decreased after chemotherapy in TNBC and HER2+. ctDNA positivity persistent after chemotherapy in ER+. |
| Rodriguez, B.J., et al., 2019 [56] | TP53 and PIK3CA in plasma and tissue at diagnosis | SafeSEQ | Matched plasma and tumor mutations detected in 27.6% of patients at diagnosis. Four ctDNA mutations identified in plasma but not in tumor tissue. Clinicopathological features significantly associated with ctDNA detection. |
| Chen, Y.H., et al., 2017 [57] | ctDNA in patients with residual disease after NACT | Oncomine Research Panel | Mutations identified in tumor tissue of 33/38 patients. ctDNA detected in 4/33 patients. All 4 patients relapsed (100% specificity). 13 patients in total relapsed (31% sensitivity). ctDNA detected in patients with residual disease associated with decreased DFS. |
| McDonald, B.R., et al., 2019 [60] | ctDNA before, during, and after NACT | TARDIS | ctDNA detected in 100% of patients before treatment. ctDNA concentrations decreased during treatment and were lower overall for patients who achieved pCR. |
ctDNA, circulating tumor DNA; ddPCR, digital drop polymerase chain reaction; NACT, neoadjuvant chemotherapy; pCR, pathologic complete response; TARDIS, targeted digital sequencing; TNBC, triple-negative breast cancer.