Table 1.

Common cancers with ctDNA detection.

Type of Cancer with ctDNA Detection	Results	References
Breast cancer	ctDNA-based detection preceded clinical detection of metastasis in 86% of patients	[47]
Breast cancer	55 non-metastatic breast cancer patients on neo-adjuvant chemotherapy; in the immediate post-operative period, 19% of available patients had detectible ctDNA, representing minimal residual disease (MRD), and 86% of these women went on to relapse during the study period	[40,48]
Colorectal cancer	metastatic colorectal cancer demonstrated 100% diagnostic sensitivity and specificity for mutant BRAF detection and 92% sensitivity/98% specificity for seven tested KRAS point mutations	[41]
Lung cancer	With tumor tissue DNA used as a reference, ctDNA demonstrated a specificity of 86% for PI3KCA exon 9, 88% for EGFR exon 19, and 100% for other measured amplicons, with an 87% (62%–96%) overall average specificity. Certain PIK3CA and EGFR hot-spot mutations were detected in ctDNA but not in the tissue DNA	[49]
Prostate cancer	Tumor DNA samples from the blood of 97 patients with castration-resistant prostate cancer at different times during the course of treatment with abiraterone revealed androgen receptor amplifications were present from the beginning and correlated with abiraterone resistance	[50,51]