June 21, 2010, 3:03PM

By Mike Miller and Linda Perrett

Posted in: Clinical trials | breast cancer | treatment

Tags: axillary node, breast, chemotherapy, clinical, drug, radiation, sentinel node, therapy, treatment

Results from four separate clinical trials presented at the annual meeting of the American Society of Clinical Oncology this year should change clinical practice and could spare many women the side effects of some common cancer therapies.  The four trials discussed at the ASCO breast cancer treatment session are excellent examples of well-designed and well-conducted trials that are providing true benefit to women, will positively affect their quality of life, and will provide cost-savings to society.  Based on these trial findings, most women can now be spared axillary lymph node dissection (ALND) and elderly women can be spared radiation therapy if the drug tamoxifen is provided first.  In summarizing the value of these studies, William Wood, M.D., Emory University, Atlanta, the discussant for this session, said, “ I [have] the privilege of discussing these four presentations: the results of four NCI-supported clinical trials with clinically important results. Offhand, I can’t remember a series of four reports in a row at ASCO with as clear conclusions that were consequential for practice as the four that we have just heard very well presented.”   He went on to observe that, when taken together, the results of the studies presented practice-changing paradigms for the treatment of breast cancer.

Results from these studies will be of particular interest to older women.  According to NCI’s Epidemiology and End Results (SEER) program statistics, approximately 42 percent of breast cancers occur in women 65 or older, with incidence of breast cancer rising steadily for women up until the age of 80.

Studies Overview

Among the highlights from this set of trials were these findings:

• NSABP B-32: Axillary lymph node dissection does not add benefit to sentinel node biopsy alone in clinically node-negative patients. Axillary lymph nodes are located under the arm. Axillary node dissection is performed to determine if cancer has spread beyond the breast. If cancer cells are found in the dissected lymph nodes, the cancer may have spread to other parts of the body and the patient may need more aggressive treatment.  David N. Krag, M.D., Vermont Cancer Center, noted that this was the largest randomized trial to date of this surgical choice.  “When the sentinel node is negative, sentinel node surgery alone with no further axillary dissection is an appropriate, safe, and effective therapy for breast cancer patients with clinically negative lymph nodes,” he said.  This is clear evidence of a study that adds benefit to a woman’s quality of life and is also cost-saving.

• ACOSOG Z0011: removal of the axillary nodes does not improve survival for women with clinically node-negative disease who will receive whole breast radiation followed by chemotherapy.

• ACOSOG Z0010:  cells of sentinel lymph nodes examined by a microscope and found to have no signs of cancer that were also tested using a method of detecting the presence of specific proteins in cells or tissues (called immunohistochemistry, or IHC) adds no prognostic information.

• CALGB 9343:  This study was presented as part of this session, but is a follow-up result of an earlier reported  study of 636 women, 70 years of age or older, with stage I, estrogen receptor–positive breast cancer that had not spread to the lymph nodes after lumpectomy.  One group was given tamoxifen plus radiation therapy and another received tamoxifen alone. Initially reported in 2004, study investigators now have ten years of follow-up data to examine and found that freedom from further breast cancer was 96 percent for women who had taken tamoxifen alone compared to 98 percent for women who had taken tamoxifen plus radiation therapy.

The breast cancer-specific and overall survival rates at 10 years were 98 percent and 63 percent, respectively for the tamoxifen group, compared to 96 percent and 61 percent for the radiation therapy group. ASCO presenter and coauthor of the study, Kevin Hughes, M.D., co-director of the Avon Comprehensive Breast Evaluation Center at Massachusetts General Hospital, Boston, said a large number of women in this study died because they were older and that most died of causes unrelated to cancer.

Based on these follow-up results, researchers concluded, as they did in 2004, that lumpectomy plus tamoxifen alone was a good option for the treatment of women 70 years of age or older with early stage cancer but that these results should not be used to make treatment decisions for women younger than 70.  This trial definitively demonstrates that women in this cohort can be spared unnecessary radiation, a finding that should increase their quality of life and provide a real cost-savings.

NCI Supported Programs and Clinical Trials on Breast Cancer Treatment for Older Women

Clinical trials are not the only means of determining benefit or harm from various treatment or other breast cancer therapy modalities.  NCI supports programs and clinical trials relevant to older women with breast cancer in the areas of:

• Biology—age-related factors in carcinogenesis, factors that contribute to the increased incidence of breast cancer in older women and/or affect treatment outcome.

• Clinical Medicine— prevention and treatment issues such as screening, early detection, diagnosis, preoperative and/or postoperative management, adverse physical influences on surgical outcome, and influence of age on physician/surgeon treatment decisions for operative risk.

• Epidemiology—studies in the context of aging and/or old age that investigate risk factors in cancer etiology; evaluate methods of prevention; explain the pattern of breast cancer as an illness for patients; and improve clinical effectiveness of the diagnostic and management processes for older-aged women breast cancer patients.

• Behavioral and Social Sciences—special concerns include health behaviors and beliefs about aging and breast cancer, interactions between health professionals and older people, effects of breast cancer on psychosocial and physical functioning, socio-demographic factors related to breast cancer prevention in older women, long-term care for older women with breast cancer.

To learn more about NCI’s breast cancer research portfolio, please visit: http://www.cancer.gov/cancertopics/types/breast.