According to results presented at the 2003 San Antonio Breast Cancer Symposium, the presence of even one cancer cell in a sample of bone marrow predicts for a worse outcome in patients with early breast cancer.
One area of research that is currently receiving much time and attention is the identification of specific disease or patients characteristics that may help predict the prognostic of a patient with cancer. It is the hope that these prognostic factors will help to individualize treatment therapies and ultimately improve outcomes for patients with various cancers, including breast cancer. Results from previous studies have indicated an association between the presence of cancer cells in the bone marrow and a poor prognosis in breast cancer. Bone marrow is the spongy material inside large bones, where immature blood cells are formed. It is thought that cancer cells found in the bone marrow indicate that cancer has spread in the body, and may result in increased recurrence rates and reduced survival. Physicians currently assess certain factors of breast cancer to determine optimal therapy, such as the spread of cancer to tissues in the breast or the rest of the body, the spread of cancer to lymph nodes under the arm (axillary nodes), hormone-receptor status of the cancer, aggressiveness of the cancer and human epidermal receptor-2 (HER2) status.
Researchers from Norway recently conducted a clinical trial to evaluate the potential clinical utility of detecting the presence of cancer cells in the bone marrow in patients with early breast cancer. This trial included 356 patients with early breast cancer; the majority of whom had no spread of cancer to axillary lymph nodes. Patients underwent initial surgery to remove the cancer, during which a bone marrow sample was taken (BM1) and analyzed for the presence of one or more cancer cells. Three years following initial surgery, patients underwent a second bone marrow sample (BM2) that was also analyzed for the presence of one or more cancer cells. All patients were considered cancer free according to clinical evaluation. Approximately 2 years following BM2, the rate of patients who had not experienced a cancer recurrence was as follows: 93% for those with no cancer cells found on BM1 and BM2; 92.6% for patients with cancer cells on BM1, but not on BM2; 87.9% for patients with no cancer cells found on BM1, but cancer cells found on BM2; and 70.6% for patients with cancer cells found in both BM1 and BM2.
The researchers concluded that bone marrow samples evaluating for the presence of one or more cancer cells may help to provide further indication of the prognosis of a patient, as well as monitor disease response to therapy. Patients with cancer cells in the bone marrow may be considered appropriate candidates or chemotherapy, even with early stage disease. These results lend further confirmation to results from previous studies evaluating this issue. Patients with breast cancer may wish to speak with their physician about the risks and benefits of bone marrow sampling in their individual situation.
Wiedswang G, Borgen E, Karensen R, et al. The presence of isolated tumor cells in bone marrow three years after diagnosis in disease free breast cancer patients predicts an unfavourable outcome. Proceedings from the 2003 San Antonio Breast Cancer Symposium. December 2003. Abstract #8.