Invasive, can infrequently cause significant morbidity |
Minimally invasive |
Monitoring treatment response/disease course with multiple biopsies generally not feasible |
Monitoring treatment response/disease course with multiple samples relatively easily achieved |
High likelihood of obtaining adequate tissue for analysis |
CTCs can be hard to isolate or may be missed |
Relatively cheap |
Expensive |
No specialised analytical equipment required |
Specialised analytical equipment required |
Can be performed at the vast majority of treatment centres |
Can only be performed in certain laboratories equipped for CTC analysis |
Interpretation of IHC (+/− FISH) assessment of tumor tissue standardised for ER, PgR, HER2 |
Further validation of best method for interpretation of HER2 or ER expression on CTCs needed |
Clinical impact of treatment decisions based on tissue biopsy biomarker assessment uncertain |
Clinical impact of treatment decisions based on CTC biomarker assessment uncertain |