Summary of the Evidence for PC-SPES
To assist readers in evaluating the results of human studies of complementary and alternative medicine (CAM) treatments for cancer, the strength of the evidence (i.e., the levels of evidence) associated with each type of treatment is provided whenever possible. To qualify for a level of evidence analysis, a study must:
- Be published in a peer-reviewed scientific journal.
- Report on therapeutic outcome or outcomes, such as tumor response, improvement in survival, or measured improvement in quality of life.
- Describe clinical findings in sufficient detail that a meaningful evaluation can be made.
The lack of consistent composition of PC-SPES due to varying concentrations of adulterants makes it difficult to determine the effects of PC-SPES in humans; therefore, no level of evidence analysis is possible for this treatment. At this time, the use of PC-SPES as a treatment for cancer cannot be recommended outside the context of well-designed clinical trials.
For additional information about levels of evidence analysis, refer to Levels of Evidence for Human Studies of Cancer Complementary and Alternative Medicine.