6 Common Cancers - Breast Cancer

Elizabeth Edwards, wife of presidential candidate John Edwards, does not let a recurrence of breast cancer slow her down.
Photo: AP Photo/Brett Flashnick

Breast Cancer

Breast cancer is a malignant (cancerous) growth that begins in the tissues of the breast. The American Cancer Society estimates that over the course of a lifetime, one in eight women will be diagnosed with breast cancer. When detected early, before the cancer has spread (called localized cancer), the 5-year survival rate for women with breast cancer is now 98 percent, compared to only 26 percent if the cancer has already spread.

Screening and Diagnosis

All women should check their breasts for lumps or other changes in texture; this self-examination process is a key personal screening tool. Your doctor may also check each breast for lumps and look for other problems. If you have a lump, your doctor will feel its size, shape, and texture. A hard, oddly shaped lump that feels firmly attached within the breast is more likely to be cancer.

Your doctor may order a mammogram (an X-ray picture of the breast) to view the tissues inside the breast. NCI recommends that women 40 years of age and older should have a screening mammogram at least every two years. Other breast imaging tools include magnetic resonance imaging (MRI) scans for detailed pictures of breast tissue and ultrasound, which sends out sound waves that bounce off tissues to create a picture. If your doctor finds something suspicious with any of these imaging methods, you may need to have a biopsy (testing of a tiny portion of breast tissue) to look for cancer cells.

Treatment

In recent years, two therapies have revolutionized breast cancer treatment: tamoxifen (Nolvadex) and trastuzumab (Herceptin). Bernard Fisher, M.D., of the University of Pittsburgh, and Dennis J. Slamon, M.D., of UCLA, pioneered these treatments. (See a related story on the inside front cover of this issue.)

Dr. Fisher's research into how cancer spreads paved the way for today's understanding that cancer is a disease of the entire body and that its spread is not predictable. Dr. Fisher went on to show the effectiveness of adjuvant (supportive) chemotherapy and hormonal therapy with tamoxifen in treating breast cancer. Tamoxifen blocks the activity of the female hormone estrogen in the breast and can stop the growth of some breast tumors.

Dr. Slamon and his colleagues developed trastuzumab (Herceptin). Trastuzumab, a monoclonal antibody, was the first treatment to target the specific molecular changes in cells that make them cancerous. Because it targets only the cancer cells, trastuzumab causes fewer side effects than standard chemotherapy drugs, which can kill both cancer cells and normal cells.

Today, breast-conserving surgery (lumpectomy), followed by localized radiation therapy has replaced mastectomy (removal of the entire breast) as the preferred surgical approach for treating women with early-stage breast cancer. Combination chemo (therapy with more than one drug) has also become standard in the treatment of women with early stage breast cancer.

Research: What's New

Sentinel lymph node biopsy, followed by surgery: The sentinel lymph node is the first place where cancer is likely to spread from the tumor. A surgeon removes this node and examines it under a microscope. If there are no cancer cells, the surgeon can usually remove just the tumor and not additional lymph nodes.
Hormone Replacement Therapy: Age-adjusted breast cancer incidence rates in women in the United States fell 6.7 percent in 2003, according to a recent study. At the same time, prescriptions for hormone replacement therapy (HRT) declined rapidly, following reports from NIH's Women's Health Initiative (WHI) study that showed an increased risk of breast cancer, heart disease, stroke, blood clots, and urinary incontinence among postmenopausal women who were using HRT that included estrogen and progestin. This study does not prove a link between HRT and breast cancer incidence. WHI researchers are expected to release a follow-up report later this year that should provide a much higher level of evidence about HRT and breast cancer incidence rates.
Aromatase inhibitors: Dr. Matthew Ellis and Dr. John Olson of the American College of Surgeons Oncology Group and their colleagues are running clinical trials at sites throughout the United States on breast cancer that grows in response to the hormone estrogen. Women with this kind of breast cancer often benefit from treatment with drugs known as aromatase inhibitors (AIs). AIs block the ability of an enzyme called aromatase to make estrogen. The NCI-funded researchers are comparing AI therapy and chemotherapy before surgery for breast cancer. They hope to discover whether this therapy can shrink tumors enough to allow women to have breast-sparing surgery instead of mastectomy.
MRIs and the other breast: When a woman is newly diagnosed with cancer in one breast, there is up to a 10 percent chance that clinical exams and mammography will miss a tumor growing in the opposite breast. For that reason, some women choose a double mastectomy rather than live with the worry that the second breast may develop cancer. A new study funded by NCI found that magnetic resonance imaging (MRI) improved the detection of cancer in the opposite breast at the time of initial diagnosis — better than through a standard mammogram.

Read More "6 Common Cancers" Articles
Lung Cancer / Breast Cancer / Prostate Cancer / Colorectal Cancer / Skin Cancer / Gynecologic Cancers

Spring 2007 Issue: Volume 2 Number 2 Page 9