By Amy D'Orazio, PhD & Kavita Maung, PhD

Breast Cancer

Stopping Breast Cancer in Its Tracks
For many years, tamoxifen (Nolvadex®) was the only therapy with proven ability to prevent breast cancer from recurring.

But tamoxifen has its drawbacks, including the fact that some patients develop resistance to it. Doctors are uncertain how this happens, but it appears the breast cancer cell changes the way it sees tamoxifen. Instead of a stop sign, the breast cancer sees a go signal and begins to grow again.

As of September 2002, breast cancer patients have a new option for adjuvant (postsurgical) hormonal therapy: Arimidex®. Developed as an alternative antiestrogen therapy, Arimidex leads to an almost complete shutdown of estrogen production, which in turn leads to “starvation” of any breast cancer cells that remain in the patient’s body after surgery. Arimidex was approved by the U.S. Food and Drug Administration (FDA) in September 2000 for use in patients with advanced breast cancer.

The effectiveness of Arimidex in preventing breast cancer recurrence after surgery has been explored in a number of trials that have shown that for postmenopausal women, initial analysis suggests that Arimidex is at least as good if not better than tamoxifen. The ATAC (Arimidex or Tamoxifen Alone and in Combination) trial compared the two agents in postmenopausal women who had completed their initial treatment (surgery, radiation therapy, and chemotherapy). The preliminary results showed that Arimidex was more effective than tamoxifen in lowering the risk of relapsing or developing a new tumor in the opposite breast. Arimidex also had a lower incidence of some side effects such as hot flashes, vaginal bleeding, weight gain, blood clot formation, and endometrial cancer. Much longer follow-up is needed to determine the ultimate safety and efficacy of Arimidex after breast surgery.

Visit www.arimidex.com to learn more about Arimidex.

Sisters Get Into the Act
Much attention has been given to hereditary factors that increase a woman’s chance of developing breast cancer, but few studies have been conducted to determine what role environment, overall health, biology, and lifestyle play in this disease. That will soon change as the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health (NIH), begins enrolling 50,000 volunteers ages 35 to 74 for a large study of the nonhereditary factors that influence the development of breast cancer.

The NIEHS is specifically seeking cancer-free sisters of women with breast cancer. Women whose sisters have had breast cancer have twice the risk of developing breast cancer in their lifetime. Volunteers will be studied annually for 10 or more years to determine the reasons why they did not get breast cancer when their sisters did. There will be no fees, diagnostic tests, or treatments required as part of this study.

Visit www.sisterstudy.org or call 877-4SISTER (747837) for more information.

Lung Cancer

Speeding Up Approval for Iressa™
In September 2002 the Oncologic Drugs Advisory Committee (ODAC) voted 11-3 to recommend the accelerated approval by the Food and Drug Administration (FDA) of Iressa for patients with lung cancer whose disease had relapsed after responding to two prior chemotherapy regimens. Granting accelerated approval means more patients will have access to the drug sooner. ODAC, which serves as an advisory committee to the FDA, reviewed phase II trial data of Iressa in patients with lung cancer who had already been treated with chemotherapy. Iressa was found to yield disease shrinkage in about one-tenth of patients and to improve quality of life.

The issue of whether or not Iressa should be given the accelerated status, which is granted only to drugs that benefit terminally ill patients, was muddied recently by the early results of phase III trials that showed that Iressa, in combination with standard chemotherapy, did not prolong survival. ODAC decided that this finding, although disappointing, did not rule out the fact that when Iressa is given alone to patients whose other treatment options have failed, it does appear to provide some benefit. Some members of ODAC are recommending that further trials be conducted to investigate the benefit of single-agent Iressa in lung cancer patients given two prior chemotherapy treatments. The FDA has yet to confer final approval for Iressa for lung cancer.

To learn more, visit www.iressa.com.

Find It Small, Find It Early
For the estimated 90 million smokers and former smokers in the United States, the question is always there: Will I get lung cancer? Lung cancer causes more cancer-related deaths than breast, prostate, colon, and pancreatic cancer combined, mainly because at the time of diagnosis, most patients have disease that has spread beyond the lungs.

Selected screening methods have had a significant impact on many tumor types. For example, the routine use of mammograms has been associated with a decline in breast cancer mortality. For prostate cancer, the widespread use of PSA screening has led to a significant increase in the number of men who are diagnosed at a stage when their tumors can be removed by surgery. Now, researchers at the National Cancer Institute are hoping to do the same with lung cancer using spiral computed tomography (CT) scanning, a highly sensitive method of detecting very small tumors. This trial carries high importance, because, despite the many advances in the treatment of lung cancer in recent years, deaths due to lung cancer have still not declined, suggesting that finding tumors early is important in reaching a cure.

The National Lung Cancer Screening Trial will enroll 50,000 current or former smokers ages 55 to 74 who do not and have never had lung cancer. The trial will be conducted at 30 locations throughout the United States. Patients will be randomly assigned to receive either a conventional chest X-ray, which can detect tumors about 1-2 cm in size, or the newer spiral CT, which can detect tumors much smaller than 1 cm. The hope is that by finding smaller tumors, disease will be less advanced and more curable. The study opened in fall 2002 and is expected to continue through 2009.

To learn more about this trial, contact the NCI at 800-4-CANCER or visit www.cancer.gov/nlst.