Octreotide reduces the kinetic index, proliferating cell nuclear antigen-maximum proliferative index, in patients with colorectal cancer.
BACKGROUND
Somatostatin has been shown to inhibit in vitro and xenograft growth of human colon cancer. The kinetic index, proliferating cell nuclear antigen (PCNA), has previously been used to measure the effects of manipulation of growth of normal rectal epithelium.


METHODS
Twenty-five patients with distal colorectal cancer were considered for entry in a presurgical study of Sandostatin (Sandoz, East Hanover, NJ) 1 mg every 8 hours. Biopsies were performed pretreatment, during treatment (14 days), and day of surgical resection (2 days off treatment). A control series of 16 patients underwent endoscopic and subsequent surgical biopsy. A kinetic index was created called PCNA-maximum proliferative index (PCNA-MPI), which was reproducible within one biopsy and between two separate biopsies. Multiple biopsies were taken from the growing edge of tumors, the most cellular and best-stained fields selected, and the highest 6 of 10 separate counted fields were used to produce PCNA-MPI.


RESULTS
A significant decline in PCNA-MPI was observed in 6 of the 10 treated patients for whom all three biopsies were available, followed by a significant elevation on withdrawal of treatment. Changes in PCNA-MPI in the control group were less frequent and smaller.


CONCLUSIONS
Sandostatin causes a reduction in PCNA-MPI in patients with human colorectal cancer.
Stewart
G J
GJ
University of New South Wales Department of Surgery, St. George Hospital, Kogarah, Sydney, Australia.
Connor
J L
JL
Lawson
J A
JA
Preketes
A
A
King
J
J
Morris
D L
DL
D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology*; D001706:Biopsy; D002455:Cell Division / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D004361:Drug Tolerance; D004724:Endoscopy; D006131:Growth Inhibitors / Q000494:pharmacology; D006801:Humans; D015282:Octreotide / Q000494:pharmacology*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011446:Prospective Studies
D018931:Antineoplastic Agents, Hormonal; D006131:Growth Inhibitors; D018809:Proliferating Cell Nuclear Antigen; D015282:Octreotide