Phase II trial of trastuzumab in women with advanced or recurrent, HER2-positive endometrial carcinoma: a Gynecologic Oncology Group study.
OBJECTIVE
This study evaluated efficacy of single-agent trastuzumab against advanced or recurrent HER2-positive endometrial carcinoma (EC), and explored predictors for HER2 amplification.


METHODS
Eligible patients had measurable stage III, IV, or recurrent EC. There was no limit on prior therapy although total prior doxorubicin dose was limited to 320 mg/m(2). Tumors were required to have HER2 overexpression (2+ or 3+ immunohistochemical staining) or HER2 amplification (FISH HER2/CEP 17 ratio >2.0). Trastuzumab was administered intravenously at a dose of 4 mg/kg in week 1, then 2 mg/kg weekly until disease progression. The primary endpoint was tumor response.


RESULTS
Of the 286 tumors centrally screened by LabCorp, 33 (11.5%) were HER2-amplified. Three of 8 clear (38%) cell carcinomas and 7 of 25 serous carcinomas (28%) screened exhibited HER2 amplification compared with 7% (2/29) of endometrioid adenocarcinomas. HER2 overexpression was correlated with HER2 amplification (r=0.459; p<0.0001). Thirty-four women were enrolled; 1 was excluded (refused treatment); and 18 had tumors with known HER2 amplification. No major tumor responses were observed. Twelve women experienced stable disease, 18 had increasing disease, and 3 were indeterminate for tumor response. Neither HER2 overexpression nor HER2 amplification appeared to be associated with progression-free survival or overall survival.


CONCLUSIONS
Trastuzumab as a single agent did not demonstrate activity against endometrial carcinomas with HER2 overexpression or HER2 amplification, although full planned accrual of women with HER2 amplified tumors was not achieved due to slow recruitment. Serous and clear cell endometrial carcinomas appear to be more likely to demonstrate HER2 amplification.
University of Chicago Medical Center, 5841 South Maryland Avenue, MC 2115, Chicago, IL 60637, USA. gfleming@medicine.bsd.uchicago.edu
Gini F
GF
Fleming
Michael W
MW
Sill
Kathleen M
KM
Darcy
D Scott
DS
McMeekin
J Tate
JT
Thigpen
Lisa M
LM
Adler
Jonathan S
JS
Berek
Julia A
JA
Chapman
Paul A
PA
DiSilvestro
Ira R
IR
Horowitz
James V
JV
Fiorica
D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D016889:Endometrial Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D005260:Female; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics; D000068878:Trastuzumab
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab