Cancer treatment is improving—saving lives and extending survival for people with cancers at many sites, including breast, colon, bladder, lung, prostate, ovary, and kidney, and for people with leukemias, lymphomas, and pediatric cancers.
Clinical trials are the major avenue for evaluating the benefits of new therapies. However, a relatively small percentage of all adult cancer patients (aged 20 years and older) participate in clinical trials. The exact percentage is unknown because NCI-sponsored trials and industry-sponsored trials are tracked separately. However, it is estimated to be less than 5 percent for most types of cancer. It is important to increase physician and patient awareness of, and participation in, clinical trials if we are to examine new treatments, find more effective treatments more rapidly, and broaden the options available to patients.
For treatments already in use, trends in patterns of care have been examined for major cancers, including breast, colorectal, prostate, lung, bladder, and ovarian cancers. Patterns of care at specific points in time, generally in relationship to the release of new guidance on care, have been documented for additional cancers, including cervical, endometrial, head and neck, non-Hodgkin lymphoma, and melanoma. These studies have been supported through the NCI Patterns of Care/Quality of Care and Surveillance, Epidemiology, and End-Results (SEER)-Medicare projects.
Research results on breast cancer treatment have shown that the use of breast-conserving surgery increased markedly from 1992 to 2002. From 1998 to 2002 the proportion of women receiving breast-conserving surgery who also received radiation treatment declined modestly. The use of recommended adjuvant chemotherapy increased substantially from 1987 to 1995. However, the increase has slowed between 1995 and 2005. Similarly, the receipt of adjuvant chemotherapy for stage III colon cancer increased markedly following the publication in 1989 of clinical recommendations for this treatment with a moderate increase from 1990 to 2005. Paclitaxel was unavailable in 1991, but following its introduction and approval by the Food and Drug Administration (FDA), its use among patients with stage III or IV ovarian cancer rose steadily until peaking in 1996 at 67 percent. The use of paclitaxel and chemotherapy of any type decreased in 2002.
The studies also show that older individuals and members of racial/ethnic minority groups are less likely to receive these treatments. More investigation is required to determine if these differences in treatments received constitute disparities in quality of care that need to be addressed through policy or organizational interventions. Women with node-positive breast cancer are less often given chemotherapy if they are aged 65 years or older. However, past clinical trials have included few older women, and there are no clear guidelines for women aged 70 years or older. Although chemotherapy has been reported to improve survival and palliation of lung change patients with stage IIIB or IV, patients aged 80 years or older receive chemotherapy less than half as often as patients under the age of 70. Some of these differences have decreased over time; for example, the treatment gap between White and Black patients with stage III colon cancer closed between 1995 and 2000.
NCI is working with many Federal and private partners to improve methods and data systems for tracking the quality of cancer care. For prostate cancer, a major study on quality-of-life outcomes among 3,500 men following diagnosis has provided important new information that will help men and their families and physicians to make more informed decisions about treatment. An ongoing NCI study, the Cancer Care Outcomes Research and Surveillance Consortium, will provide more detailed information on how to link quality-of-care measures to outcomes important to colorectal and lung cancer patients. Other similar initiatives are being supported by major professional organizations, as well as by NCI.
These and other ongoing studies will provide much new information on treatment. Future editions of the Cancer Trends Progress Report will include treatment trends for cancer sites for which there are definitive treatment guidelines based on rigorous evidence of benefit to patients.