Tumor-specific VEGF-A and VEGFR2 in postmenopausal breast cancer patients with long-term follow-up : Implication of a link between VEGF pathway and tamoxifen response

• Vascular endothelial growth factor (VEGF-A) is considered a prognostic indicator for clinical outcome in breast cancer. Conflicting results nevertheless exist and there is a need for larger studies including untreated patients in order to clarify the importance of tumor-specific VEGF-A regarding prognosis as well as potential links to predictive treatment information. VEGF-A and its receptor, vascular endothelial growth receptor 2 (VEGFR2), were therefore analyzed by immunohistochemistry in postmenopausal breast cancers enrolled in a clinical trial where patients were randomized to adjuvant tamoxifen treatment (n=124) for 2 years or no treatment (n=127) with a median follow-up of 18 years. The tumors were arranged in a tumor tissue microarray system enabling parallell analysis of the angiogenic factors and hormone receptor status. Tumor-specific expression of VEGFR2 correlated strongly with expression of VEGF-A and progesterone receptor (PR) negativity, whereas VEGF-A was not associated with hormone receptor status. Among patients with estrogen receptor (ER) positive (fraction > 10%) tumors, there was a statistically significant tamoxifen response in VEGF-A negative tumors at both 10-year and 18-year disease-free survival (DFS), contrasting to VEGF-A positive tumors who had no beneficial effect of tamoxifen. A treatment-interaction variable indicated a marked difference in tamoxifen response depending on VEGFA-status in terms of DFS at 10 and 18 years of follow-up, p=0.046 and p=0.039, respectively. VEGFR2 status did not yield significant predicitve information for tamoxifen response in patients with ER fraction > 10%, whereas in patients with ER fraction > 90% both VEGF-A and VEGFR2 status were associated with tamoxifen treatment effect.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Aged

Antineoplastic Agents; Hormonal/*pharmacology/*therapeutic use

Breast Neoplasms/*drug therapy/*pathology

Chemotherapy; Adjuvant

Female

Follow-Up Studies

Humans

Immunohistochemistry

Middle Aged

Postmenopause

Prognosis

Tamoxifen/*pharmacology/*therapeutic use

Treatment Outcome

Tumor Markers; Biological/*analysis

Vascular Endothelial Growth Factor A/*blood

Vascular Endothelial Growth Factor Receptor-2/*blood

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)