According to a recent study published in the Annals of Internal Medicine, high-dose chemotherapy followed by an autologous stem cell transplant may prolong survival in women with advanced ovarian cancer. Women who have advanced ovarian cancer are often treated with surgery followed by combination chemotherapy consisting of paclitaxel plus cisplatin or paclitaxel plus carboplatin. Although advanced-stage ovarian cancer is highly responsive to initial therapy, most patients ultimately experience a cancer recurrence and succumb to the disease. Improved treatment strategies are urgently needed to improve long-term, disease-free survival for patients with ovarian cancer.
Cancer of the ovary, or ovarian cancer, is a common malignancy occurring in women in the United States with about 25,000 new cases diagnosed each year. The ovaries are small female reproductive organs that reside in the pelvis. The ovaries make female hormones and store all of the egg cells that are released once a month during ovulation. The majority of cancerous ovarian tumors originate from the cells that are part of the outer lining of the ovaries (epithelium) and are collectively called epithelial cancers. Since ovarian cancers begin deep in the pelvis, they often do not cause any symptoms and therefore go undetected until they are at an advanced stage. At the time of initial diagnosis of ovarian cancer, the majority of patients have cancer that has spread to different sites in the body. Currently, very few women with advanced ovarian cancer are cured. In an effort to increase survival time for women with ovarian cancer, continuing research for the development of new therapies and/or strategies is ongoing.
Chemotherapy targets and kills rapidly dividing cells such as cancer cells. High-dose chemotherapy (HDC) kills more cancer cells than lower-dose conventional chemotherapy. Unfortunately, HDC also kills more normal cells, especially the blood-producing stem cells in the bone marrow. This treatment strategy utilizing stem cell transplantation is an attempt to restore the blood-producing stem cells after HDC has reduced them to dangerously low levels.
Stem cells are immature cells produced in the bone marrow, which is the spongy material inside bones. Stem cells eventually become either red blood cells, which provide oxygen to tissues, white blood cells; which fight infection; or platelets, which aid in blood clotting. HDC destroys cancer as well as bone marrow stem cells. When bone marrow is destroyed, stem cell stores are depleted, which leads to low levels of circulating blood cells. When these cells reach critically low levels, complications such as anemia, infection and bleeding can occur. These complications may result in death, thus, it is imperative to restore stem cell levels as quickly as possible. In autologous stem cell transplantation, the patient’s own stem cells are collected before chemotherapy treatment, frozen, and infused back into the patient after treatment to “rescue” the bone marrow.
Researchers from the Autologous Blood and Marrow Transplant Registry evaluated over 400 women with advanced ovarian cancer who received HDC and autologous stem cell transplantation as part of their treatment. Two years following treatment, the overall survival rate for patients in this study was 35%. There was a subgroup of these patients who had a survival rate of 55% after two years. These women were younger and in otherwise good health, possessed a certain microscopic type of cancer cell (non-clear cell), and were treated with HDC and stem cell transplantation during their first remission.
The results from this study indicate that survival time may be improved for patients with advanced ovarian cancer with the utilization of HDC and autologous stem cell transplantation, particularly when this treatment strategy is used early in a patient’s treatment course. Women with ovarian cancer may wish to speak with their physician about the risks and benefits of HDC and stem cell transplantation and/or participation in a clinical trial utilizing other promising new treatments. (Annals of Internal Medicine, Vol 133, No 7, pp 504-515, 2000)