[phil]

FISH is a measure of how strongly the cancer cells overexpress the her2 gene. you would have had this or some other test for her2 strength at initial diagnosis. ask your doc how strong you her2 overexpression is. the FISH scale is 1- 10 , with anything over 3 indicating trying kadcyla. so a 6 is plenty strong enough . the her2 cancer is very aggressive , but the flip side of that is it seems to be easier to find tx.'s that could kill it. starting with Herceptin in the late 80's. no her23 targeted drug is a 100 % killer yet , but it is easier to target her2 than triple neg. / triple pos. that is changing ( too slowly in this 20th century testing system ) as we speak . I know a tdm-1 ( kad. ) - like, antibody drug conjugate is showing promise with triple neg. sacituzumab/govetican . and drugs like pembro ( keytruda) are being tested with kad. in trials for er + .
So - a normal breast tissue cell has about 20,000 her2 cells on exterior. the mutant cancer cells have as many 2 million her2 gene receptors ! my theory is the higher the overexpression of her2 only - the better target for Herceptin to bring the emtansine chemo to those cells. more chemo - more mutant cell death !
also Mtngrl - I know that infections can distort testing. Lorraine had sepsis from stents in her kidney , bile duct prior to t dm-1. they did chest cts and her lungs had spots every where ! the er doc scared the crap out of us " cancer or emboli " but our onc came in and said " I don't believe it " . she was right . sepsis cleared and spots disappeared .