BACKGROUND: To investigate the role of the phosphoinositide 3-kinase (PI3K) pathway activation in human epidermal growth factor receptor 2 (HER2)-targeted therapy. METHODS: We evaluated the predictive roles of PI3K, catalytic alpha (PIK3CA), and phosphatase and tensin homolog (PTEN) in HER2-based therapy (either trastuzumab or lapatinib). PTEN expression and PIK3CA mutation were analyzed using immunohistochemistry and pyrosequencing. RESULTS: Forty-eight patients received trastuzumab (n = 39) or lapatinib (n = 9) combination chemotherapy. PTEN loss was found in 47.9% (n = 23), but no PIK3CA mutations were identified. Twenty-six (54.1%) patients responded to HER2-based therapy, without a significant difference between patients with PTEN loss and those without (52.2 vs. 56.0%). Among the patients with responsive disease, time to best response did not differ by PTEN status, but the duration of response was significantly shorter for patients with PTEN loss (median 4.2 vs. 6.1 months, p = 0.04). In addition, patients with PTEN loss had a significantly shorter progression-free survival time (median 4.9 vs. 7.3 months, p = 0.047). CONCLUSIONS: PTEN deficiency is an important predictive marker for early resistance to HER2 inhibitor treatment in gastric cancer patients. This finding may be useful for the development of drug combinations and identification of patients who need a modified treatment strategy.
BACKGROUND: To investigate the role of the phosphoinositide 3-kinase (PI3K) pathway activation in humanepidermal growth factor receptor 2 (HER2)-targeted therapy. METHODS: We evaluated the predictive roles of PI3K, catalytic alpha (PIK3CA), and phosphatase and tensin homolog (PTEN) in HER2-based therapy (either trastuzumab or lapatinib). PTEN expression and PIK3CA mutation were analyzed using immunohistochemistry and pyrosequencing. RESULTS: Forty-eight patients received trastuzumab (n = 39) or lapatinib (n = 9) combination chemotherapy. PTEN loss was found in 47.9% (n = 23), but no PIK3CA mutations were identified. Twenty-six (54.1%) patients responded to HER2-based therapy, without a significant difference between patients with PTEN loss and those without (52.2 vs. 56.0%). Among the patients with responsive disease, time to best response did not differ by PTEN status, but the duration of response was significantly shorter for patients with PTEN loss (median 4.2 vs. 6.1 months, p = 0.04). In addition, patients with PTEN loss had a significantly shorter progression-free survival time (median 4.9 vs. 7.3 months, p = 0.047). CONCLUSIONS:PTEN deficiency is an important predictive marker for early resistance to HER2 inhibitor treatment in gastric cancerpatients. This finding may be useful for the development of drug combinations and identification of patients who need a modified treatment strategy.
Authors: Asunción Díaz-Serrano; Barbara Angulo; Carolina Dominguez; Roberto Pazo-Cid; Antonieta Salud; Paula Jiménez-Fonseca; Ana Leon; Maria Carmen Galan; Maria Alsina; Fernando Rivera; J Carlos Plaza; Luis Paz-Ares; Fernando Lopez-Rios; Carlos Gómez-Martín Journal: Oncologist Date: 2018-04-26
Authors: A Lambert; J Salleron; M Lion; M Rouyer; N Lozano; A Leroux; J L Merlin; Alexandre Harlé Journal: Pathol Oncol Res Date: 2018-11-13 Impact factor: 3.201