NEW ORLEANSIn a retrospective, observational study of nearly 4,000 patients
in northern Israel, statin use for at least 5 years reduced the risk of
colorectal cancer by 46%, after adjustment for known protective factors,
including use of aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs). The
effects seen do not appear to be the result of a reduction in cholesterol
levels. While the investigators, from the Molecular Epidemiology of Colorectal
Cancer (MECC ) Study Group, cautioned that it is premature to change either the
standard of care for colorectal cancer or the indications for statins, they
said statins merit further investigation in this area.
Jenny N. Poynter, MPH, of the University of Michigan, presented the study
results at the 40th Annual Meeting of the Society of Clinical Oncology
(abstract 1), on behalf of the MECC Study Group. MECC is led by Stephen B.
Gruber, MD, PhD, MPH, director of clinical cancer genetics, University of
Michigan Comprehensive Cancer Center, and Gadi Rennert, MD, director of the
National Cancer Control Center for Clalit Health Services, Israel’s largest
The MECC study, initiated in 1999 with a $4.8 million grant from the
National Cancer Institute and additional funding from the Irving Weinstein and
Ravitz Foundations, explores how genes, diet, exercise, and other factors
interact to produce colon cancer.
Given that the descendants of Ashkenazi Jews have unusually high rates of
colon cancer (with a novel cancer susceptibility allele, APC I1307K, identified
in 6% and appearing to double colorectal cancer risk), the researchers believed
an Israeli-based population study including this ethnic group, as well as Arab
patients and Jews of non-Ashkenazi ethnicity, might provide interesting
information about possible nongenetic factors influencing development of this
Statins were assessed in this population, Ms. Poynter said, "because they
inhibit HMG CoA reductase, which is overexpressed in colorectal cancer cell
lines, and induce apoptosis in colorectal cancer cell lines at physiologically
relevant concentrations. They have also been shown to reduce tumor formation in
animal models of colorectal cancer."
Eligible patients were those diagnosed with colon or rectal cancer between
1998 and 2004 (n = 1,814 cases). Controls (n = 1,959) were matched to cases
based on age, sex, and Jewish vs non-Jewish ethnicity. The researchers also
performed matched analyses on 1,570 perfectly matched case-control pairs.
Medication use, including statins, was assessed in a structured in-person
interview. Classified as "statin users" were those reporting use of any statin
for at least 5 years; nonusers had no reported statin use. Regular statin use
(prescriptions filled more than three times per year) was validated from
prescription records from the Clalit Health System database for the majority of
patients who reported using these drugs. All pathology was independently
confirmed by a single pathologist at the University of Michigan.