Poor survival rates in some cancers related to lack of clinical trial participation

In a new study Archie Bleyer, M.D. of the M. D. Anderson Cancer Centre in Houston and colleagues have discovered that mortality and poor survival rates among young adults and older adolescents with some cancers may be explained in part by the lack of participation in clinical trials.

The study, to be published in the May 1, 2005 issue of CANCER, found that age-dependent survival rates among patients with sarcomas - except Kaposi Sarcoma (KS) - correlated with clinical trial participation rates.

Over the last 25 years survival rates among all ages have shown vast improvements but unfortunately the same is not true for patients between 15-45 years. This has previously been explained by differences in physical tolerances to therapy, tumour biology, treatment options, health insurance coverage, and availability of new treatments and protocols. Studies investigating individual cancer types, such as leukaemia, have also shown that age-dependent survival may be linked to rates of participation in and availability of clinical trials. The 15-45 year age group is one of the least studied and also the least likely to be treated at a large health care institution that offers clinical trials. Participation in cancer clinical trials has been shown to improve survival.

Participation in a clinical trial was found to correlate with survival improvement in both KS and non-KS sarcomas. For soft-tissue and bone sarcomas, patients between 15 and 45 years demonstrated the least improvement. In this group, the lowest clinical trial participation rates were also noted in the group between 20-44 years. In contrast, for KS, patients between 30 and 44 years demonstrated the greatest survival increase. In this group, the greatest clinical trial participation rates were also identified in the group between 35-44 years.

Bleyer and colleagues were investigating whether KS and non-KS sarcoma survival and mortality rates were related to participation in clinical trials and concluded in their study, and from others in leukemias, brain tumours, and cancer in general, that the lack of clinical trial participation (and of the increased knowledge of tumour biology that derives from modern clinical trials) offers one explanation for the poor cancer survival improvements in young adults.