NEWS

In Brief

The American Society of Clinical Oncology held its 39th annual meeting last month. More than 3,500 abstracts were included in the meeting. Some highlights are summarized below. The abstracts for the studies are available at http://www.asco.org.

Chemo-Cetuximab Combo Studied in Patients With Metastatic Colorectal Cancer

A new study suggests that the cancer drug cetuximab (Erbitux) in combination with irinotecan more effectively shrinks tumors and delays tumor progression compared with the standard treatment alone.

Cetuximab is a monoclonal antibody that targets the epidermal growth factor receptor. Preliminary studies of the drug were promising, but in 2001, the U.S. Food and Drug Administration rejected New York-based Imclone System Inc.’s application for cetuximab, citing problems with the study design.

In the current study (abstract 1012), David Cunningham, M.D., of the Royal Marsden Hospital in Sutton, England, and his colleagues randomly assigned 329 patients with refractory colorectal cancer to receive either cetuximab and irinotecan, or cetuximab alone. The combined treatment shrunk tumors by half in 22.9% of the patients, compared with 10.8% of patients treated with cetuximab alone. In addition, the combined treatment delayed tumor progression by an average of 4.1 months, compared with 1.5 months for patients treated with cetuximab alone. Median survival time was 8.6 months for patients who received the combined therapy, compared with 6.9 months for patients who received the monotherapy.

See also News, Vol. 94, No. 24, p. 1824, "Erbitux Trial Flawed From the Beginning, Committee Finds" and Vol. 94, No. 5, p. 326, "Biotech Firm Faces Challenges from FDA, Falling Stock Prices."

Gene Expression Profiling May Help Predict Response to Chemotherapy

An analysis of breast tumors using DNA microarrays suggests that the technology may be able to predict whether a patient will respond to a chemotherapy regimen commonly given before surgery for early-stage breast cancer.

Lajos Pusztai, M.D., of the University of Texas M. D. Anderson Cancer Center, Houston, and his colleagues (abstract 1) analyzed tumor samples taken from 24 early-stage breast cancer patients at the time of diagnosis and noted the subsequent response of these patients to preoperative chemotherapy (paclitaxel followed by 5-fluorouracil, doxorubicin, and cyclophosphamide, or T/FAC). They used microarrays to examine the expression profiles of more than 19,000 genes and used this information to develop a 74-gene test.

The researchers used this test to examine gene expression in a test set of 21 patients. Overall, the presence or absence of the genetic markers predicted the outcome in 15 of 21 patients (71%). The test had a positive predictive value of 75%; the test predicted fourcomplete responses, and three of four patients actually had complete responses.

In a discussion of the study in the plenary session at the 39th Annual Meeting of the American Society of Clinical Oncology, Larry Norton, M.D., of Memorial Sloan-Kettering Cancer Center, New York, pointed out that there are some flaws in the study, such as a very small sample size and an end point that may not be the best measurement of outcome. "What these investigators have done is a critical step in the right direction," Norton said. "We’ve made enormous progress in clinical oncology" because of the work in gene expression profiling, but he added that "we have to add a new level of computational biology and biostatistics" to such analyses.

See also News, Vol. 95, No. 5, p. 350, "Microarray Studies Challenge Theories of Metastasis", Vol. 94, No. 14, p. 1052, "Gene Profiles May Help Predict Response to Chemotherapy", and Vol. 93, No. 15, p. 1126, "Comparing Microarray Data: What Technology Is Needed?"

Statins May Reduce Risk of Cancer

Statins, a class of drugs used to lower cholesterol levels, may reduce the risk of cancer, according to a retrospective case-control study in The Netherlands (abstract 3400).

Statins block cholesterol synthesis by inhibiting an enzyme called 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. This enzyme also regulates a cell signaling pathway that may play a role in cancer development. Laboratory work has suggested that some statins can trigger apoptosis of cancer cells.

Researchers at the University of Amsterdam used a record linkage system to identify Dutch patients who had one or more prescriptions for cardiovascular drugs between 1985 and 1998. Their study population included 3,080 patients with cancer, 144 of whom were statin users. Patients were matched to 16,711 control patients, of which 986 were statin users. The investigators found that statin use was associated with an estimated 20% relative cancer risk reduction. The largest reduction was observed in patients who had used statins for 4 or more years.

The authors note that the patients in the study population took a variety of statin drugs—79.6% took simvastatin, 6.6% took pravastatin, 2.5% took fluvastatin, 0.4% took atorvastatin, and 10.9% took a combination of statin drugs. "[Because] the inhibitory potency of different statins is not equal, the results of this study may not be generalized to the use of other statins," said lead investigator Matthijs Graaf, Pharm.D.

See also News, Vol. 95, No. 12, p. 844, "Of Cancer and Cholesterol: Studies Elucidate Anticancer Mechanisms of Statins".

    —Linda Wang and Katherine Arnold



             
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