Breast Cancer Stage IV

Stage IV breast cancer has traditionally been considered an incurable cancer. In the mid to late 1980's the average patient with stage IV breast cancer treated with low-dose chemotherapy survived 8-10 months before their cancer relapsed and less than 5% of patients could expect to survive 5 years without their cancer recurring. In 1988, the results of a small clinical trial treating 22 women with stage IV breast cancer treated with high-dose chemotherapy and autologous stem cell transplant were published. Fourteen percent of these patients treated with high-dose chemotherapy survived without their cancer recurring beyond 5 years.

By 1997, these patients had been observed over 10 years and the original 14% remain alive without a relapse of their cancer and appear cured of their disease. It is important to understand that because over 50% of patients with stage IV breast cancer relapse, it is not useful to compare the response rate to chemotherapy, the average duration of survival or time to relapse. When evaluating treatment strategies in stage IV breast cancer, patients should compare the percent of patients alive with or without relapse 3-5 years from treatment to determine whether a treatment is truly superior.

In general, women who have advanced breast cancer at the time of diagnosis live approximately 18 months after diagnosis (median survival rate). Those who are still alive five years after their diagnosis of advanced breast cancer can live an additional 3.5 years (median survival rate) according to the American Cancer Society.

The 3-year survival rates were 38% for those receiving the standard chemotherapy, and 32% for those receiving the high-dose chemotherapy. Twelve percent of those in the standard-dose group had no progression of disease, compared with only 6% in the high-dose group. Furthermore, there were more side effects in the high-dose therapy group, including one treatment-related death.

High-dose chemotherapy and autologous stem cell transplant treatment for previously untreated stage IV breast cancer appears safe; however, the benefit of this treatment approach is currently unknown. It is known that many factors may influence an individual patient's potential outcome if treated with high-dose chemotherapy. Patients without prior treatment, those with small amounts of cancer, and those whose cancer responds to conventional chemotherapy all do better.

The main reason patients with breast cancer fail treatment is relapse. Relapse of breast cancer occurs because the high-dose chemotherapy is either unable to kill all the cancer cells in the patient and/or because cancer cells "contaminating" the stem cells are infused back into the patient. The majority of relapses occur because all the cancer cells were not destroyed by the high-dose chemotherapy treatment. However, some relapses may be due to infusion of breast cancer contaminated stem cells. Doctors are performing clinical trials designed to improve the treatment of breast cancer with high-dose chemotherapy that include the following approaches alone or in combination:

North American white women have the highest rates of breast cancer in the world, but the 5-year survival rate for all stages (Stage 1, Stage 2, Stage 3, and Stage 4) combined is 88% for the U.S. A recent study found European countries have lower 5-year breast cancer survival rates, with England at 77.8% and Ireland at 76.2% (Lancet Oncology).