Table 2.
Studies assessing HER2 discordance between primary tumor and HER2 on CTCs in recurrent breast cancer. ^ Includes only patients with metastatic breast cancer; * includes only patients with known HER2 primary tumor status. FISH: fluorescence in situ hybridization; IF: immunofluorescence; Immunomag: immunomagnetic technique; RT-PCR: real-time reverse transcription polymerase chain reaction.
| Author [ref.] | Year | No. of pts ^ | No. (%) with CTCs | CTC analysis | HER2 assessment | Rate of discordance* | |
|---|---|---|---|---|---|---|---|
| HER2+→HER2− | HER2−→HER2+ | ||||||
| de Albuquerque [66] | 2012 | 32 | 24 (75%) | Immunomag | RT-PCR | 8/9 (89%) | 4/15 (27%) |
| Fehm [67] | 2007 | 77 | 21 (27%) | Immunomag | IF and FISH, some with RT-PCR | 2/3 (67%) | 4/12 (33%) |
| Fehm [48] | 2010 | 254 | 122 (48%) | CellSearch® | IF | 13/31 (42%) | 25/76 (33%) |
| 229 | 90 (39%) | AdnaTest® | RT-PCR | 13/22 (59%) | 28/57 (49%) | ||
| Flores [68] | 2010 | 75 | 75 (100%) | CellSearch® | FISH | 1/45 (2%) | 10/30 (33%) |
| Ignatiadis [37] | 2011 | 39 | 23 (59%) | CellSearch® | IF | 1/2 (50%) | 13/21 (61%) |
| Ligthart [65] | 2013 | 103 | 90 (87%) | CellSearch® | IF (automated) | 29% | 9% |
| Meng [41] | 2004 | 24 | 24 (100%) | Immunomag | FISH | - | 9/24 (38%) |
| Munzone [60] | 2010 | 76 | 57 (75%) | CellSearch® | IF | 2/15 (13%) | 6/42 (14%) |
| Pestrin [38] | 2009 | 66 | 40 (61%) | CellSearch® | IF | 5/12 (42%) | 8/28 (29%) |
| Punnoose [34] | 2010 | 38 | 29 (76%) | CellSearch® | IF | 3/12 (25%) | 2/17 (12%) |
| Somlo [69] | 2011 | 22 | 18 (81%) | MACS | IF | 3/5 (60%) | 3/13 (23%) |
| Tewes [14] | 2009 | 42 | 22 (52%) | AdnaTest | RT-PCR | 3/5 (60%) | 5/17 (29%) |