Not Your Mother's Breast Cancer Treatment-Or Outlook
Cassell, Dana, Drug Topics
Breast cancer is in transition-from an acute disease that killed quickly to a chronic disease that can be managed, much like diabetes or heart disease. In an April 2007 report, the biotech intelligence firm BioSeeker Group reported that three million women in the United States are living with breast cancer-with living the key word. Although the breast cancer diagnosis rate remains high, the overall breast cancer death rate has dropped steadily, at about 2% per year since the early 1990s.
Today's longer survival rates have come about using mostly "old-fashioned" drugs. With the recent emergence of more targeted "smart" drugs, the outlook is for even greater emphasis on maintenance treatment, meaning ever greater pharmacy involvement, from community to hospital to specialty pharmacists.
Treatment by stages
Breast cancer treatment is discussed in terms of stages. Early-stage (stage I, II, or III) means the cancer is within the breasts or regional lymph nodes, according to Thehang Luu, M.D., an oncologist at City of Hope Cancer Center, Duarte, Calif. "Those cancers we treat to cure," she explained. Surgery, radiation, and drugs may be used during earlystage. Late-stage (stage IV) means the cancer has spread (metastasized) to other organs of the body. "Those we cannot cure, so we try to prolong life and preserve the quality of life with drug treatments."
For early-stage breast cancer, the current standard treatment is breast conservation surgery. "We remove only the tumor itself, a procedure called lumpectomy or segmentectomy. And then we radiate around that," Luu said. For most women with stage I or II breast cancer, breast conservation therapy is as effective as mastectomy in terms of putting off local recurrence.
About 15% of women with breast cancer are not candidates for breast conservation, so mastectomy is their only surgical option, according to Cynthia Drogula, M.D., medical director and breast surgeon at Baltimore Washington Medical Center. "The reasons a woman might need a mastectomy include: a very large tumor in a smallish breast; multifocal disease-tumors in more than one location in the same breast; inability to get clear surgical margins; or contraindications to adjuvant radiation therapy." (A surgical margin is healthy tissue around the tumor removed for examination.) Also, she said, some women who actually are candidates for lumpectomy choose to have a mastectomy for personal reasons.
What oncologists worry about, Luu said, is distant recurrence, or the cancer returning in other parts of the body. About two-thirds of the recurrences are distant. "That's why we introduce adjuvant drug therapy." Three different categories of drugs are considered for adjuvant therapy: chemotherapeutic, hormonal, and targeted.
In most cases, adjuvant therapy works best when combinations of drugs are used together. While studies have shown which combinations are most effective, decisions about specific drugs for any given patient will depend upon prognostic factors, the woman's menopausal status, her general health and personal preference, ongoing clinical trials, and the medical center providing treatment. "Best" drug combinations also continue to change with new drug approvals and research findings.
Luu explained some of these changes and options for chemotherapy: "In the 1970s and 1980s we did CMF-cyclophosphamide, methotrexate, and 5-fluorouracil (5-FU). In the '80s we moved to doxorubicin, which is an anthracydine, and cyclophosphamide. Then during the '90s we introduced the taxanes-paclitaxel or Taxotere (docetaxel, Sanofi-Aventis) on top of Adriamycin/Cytoxan [AC]."
Luu added, "Some of us like to use AC followed by Taxol. You can do this every three weeks, four treatments each. Or you can do it every two weeks as a dose-dense treatment, and with the introduction of Neulasta (pegfilgrastim, Amgen) or Neupogen (filgrastim, Amgen)." (Neulasta and Neupogen are growth factors that accelerate recovery from neutropenia following chemotherapy. …