Do we know why....

[AlaskaAngel]

Phosphorylated HER-2 tyrosine kinase and Her-2/neu gene amplification as predictive factors of response to trastuzumab in patients with HER-2 overexpressing metastatic breast cancer (MBC).

Giuliani R, Durbecq V, Di Leo A, Paesmans M, Larsimont D, Leroy JY, Borms M, Vindevoghel A, Jerusalem G, D'Hondt V, Dirix L, Canon JL, Richard V, Cocquyt V, Majois F, Reginster M, Demol J, Kains JP, Delree P, Keppens C, Sotiriou C, Piccart MJ, Cardoso F

Translational Research Unit, Jules Bordet Institute, 125, Boulevard de Waterloo, 1000 Brussels, Belgium.AIM:

Trastuzumab (T), a humanised monoclonal antibody against HER-2, is active in HER-2-positive MBC patients. However, nearly 60% of the patients do not benefit from T, stressing the need for additional predictive markers. The following markers could be implicated in response to T: (1) the magnitude of Her-2 gene amplification; (2) the co-expression of the other HER family receptors, possibly responsible for HER-2 trans-activation; (3) the activated status of HER-2; (4) the activated status of downstream effectors as mitogen-activated protein kinases (MAPKs), p38 and p27. METHODS: Medical files of patients with MBC treated with T either as a single agent or in combination with chemotherapy (CT) were reviewed. HER family members (EGFR, HER-2, HER-3, HER-4), the phosphorylated forms of EGFR (p-EGFR), HER-2 (p-HER-2) and of the downstream effectors were evaluated in the archival tumours. The correlation between clinical outcome and the expression of these markers was investigated.

RESULTS: (1) Increasing values of Her-2 amplification were associated with a higher probability of achieving an objective response; (2) no statistical significant correlation between the expression of the HER family receptors was found; (3) p-HER-2 was predictive of response in patients treated with T+CT; (4) a statistically significant correlation between p-ERK 1/2, p-p38 and p-HER-2 emerged, pointing to the activated vertical pathway p-HER-2-->p-MAPKs.

CONCLUSIONS: p-HER-2 and the magnitude of Her-2 amplification were predictive of response to T and their role deserves to be analysed in larger and more homogenous T-treated populations such as those from large phase III trials.

Published <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com[img] /><st1:date Year=[/img]25 January 2007</st1:date> in Eur J Cancer.

[Lani]

this means lapatinib may work for some of those that herceptin doesn't work for

[rinaina]

Thank you to all for your responses and help with this.

[michele u]

Steph and all,

yes i did check for PTEN. It was positive, so i have it to help the Herceptin. It was after the fact. I already had treatment and was done. I was just curiuos. I've never checked the TOPOII. Does anyone know if there is any thing out yet that could give PTEN to one that is negativae and have Herceptin help? I have a friend that failed Herceptin and Tykerb. Now she is on Taxotere. It is in her bone and lymph node in neck. she relapsed after 18months.