Adding the chemotherapy drug topotecan to a standard first-line chemotherapy regimen in women with advanced ovarian cancer offers no benefit, according to the final results of an international phase III clinical trial published in the August 2 Journal of the National Cancer Institute. Patients who received topotecan also had higher grade hematological side effects such as low platelet and red blood cell levels.

Combined with similarly disappointing findings in other phase III trials assessing different chemotherapy regimens, these results suggest that standard cytotoxic chemotherapy drugs have run their course in ovarian cancer.

Many solid tumors appear to have a small population of stem cells that are partially resistant to chemotherapy and can perpetuate themselves indefinitely. These cancer stem cells thus far have been isolated from breast and brain tumors as well as blood. The exact origin of these cancer stem cells remains to be defined.

With mounting evidence to support the hypothesis that genetic alterations in tissue stem cells may represent the origins of some cancers, the time is right to more vigorously explore the properties, mechanisms, and vulnerabilities of this subset of cells. The presence of such cells, first demonstrated in acute myeloid leukemia patients, provides a different and exciting model with which to further explore cancer biology. Read more  

The NCI Cancer Bulletin is produced by the National Cancer Institute (NCI). NCI, which was established in 1937, leads the national effort to eliminate the suffering and death due to cancer. Through basic, clinical, and population-based biomedical research and training, NCI conducts and supports research that will lead to a future in which we can identify the environmental and genetic causes of cancer, prevent cancer before it starts, identify cancers that do develop at the earliest stage, eliminate cancers through innovative treatment interventions, and biologically control those cancers that we cannot eliminate so they become manageable, chronic diseases. For more information on cancer, call 1-800-4-CANCER or visit http://www.cancer.gov. NCI Cancer Bulletin staff can be reached at ncicancerbulletin@mail.nih.gov.