Blockade of growth factor receptors in ductal carcinoma in situ inhibits epithelial proliferation.
BACKGROUND
Ductal carcinoma in situ (DCIS) expresses c-erbB-2 receptor and epidermal growth factor receptor (EGFR). The aim of this study was to determine whether blocking of c-erbB-2 receptor with a humanized monoclonal antibody, 4D5 (HerceptinTM), or of EGFR with an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), ZD1839 (IressaTM), would decrease epithelial proliferation in DCIS.


METHODS
DCIS tissue from 18 women undergoing surgery was implanted into 16 to 20 athymic nude mice per experiment (eight xenografts per mouse). Treatment commenced 2 weeks after implantation and consisted either of twice-weekly intraperitoneal injections of 4D5 10 mg/kg or of daily gavage with ZD1839 at 100-200 mg/kg for 14 days; appropriate controls were included. Xenografts were removed on days 14, 21 and 28. Proliferation was assessed by counting 1000 epithelial cells after Ki67 immuno- staining.


RESULTS
ZD1839 inhibited proliferation compared with that in controls after 14 days (P < 0.01), whereas 4D5 did not.


CONCLUSIONS
Proliferation in DCIS was decreased by EGFR tyrosine kinase inhibition but not by c-erbB-2 receptor blockade. ZD1839, an orally active and selective EGFR-TKI, has potential as adjuvant therapy in DCIS.
Chan
K C
KC
Department of Surgery, University Hospital of South Manchester, Manchester, UK.
Knox
W F
WF
Gandhi
A
A
Slamon
D J
DJ
Potten
C S
CS
Bundred
N J
NJ
D000328:Adult; D000368:Aged; D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000473:pathology / Q000628:therapy*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology / Q000628:therapy*; D002455:Cell Division; D066246:ErbB Receptors / Q000037:antagonists & inhibitors*; D005260:Female; D000077156:Gefitinib; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D009368:Neoplasm Transplantation; D011799:Quinazolines / Q000627:therapeutic use*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors*; D014183:Transplantation, Heterologous; D000068878:Trastuzumab; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D066246:ErbB Receptors; D000077156:Gefitinib; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab