Monday, March 30, 2009

Standard treatment

Standard treatment is the best known treatment for a specific type of cancer. For
instance, in 2002, the standard treatment for intermediate-risk ALL is combination
chemotherapy for two to three years. The standard treatment for high-risk ALL
includes more drugs and may include cranial radiation and/or stem cell transplant
for very high-risk groups.
As results from ongoing and completed clinical trials are analyzed, more knowledge
is accumulated and standard treatments evolve. In the 1980s, most children with
ALL received cranial radiation as standard care. Carefully controlled clinical trials
established that the majority of children with ALL do not require cranial radiation.
The standard-of-care was changed.
Most clinical trials divide patients into two or more groups (“arms” of the trial). One
arm is the standard-of-care (best treatment known), and the other arms are the
experimental portions, which scientists hope will prove to be more effective or less
toxic than the standard treatment. The trial is designed to compare the experimental
arms to the standard arm, to determine whether patients will benefit.
In the early 1990s, my daughter’s clinical trial for high-risk ALL had
three arms. One arm was the standard treatment of four drug rotations of
chemotherapy with a delayed intensification and consolidation, and 1,800
rads of cranial radiation. The second arm was identical except radiation
was replaced with more frequent doses of intrathecal methotrexate. The
third arm was for children who had CNS disease at diagnosis or who
were slow responders to initial therapy. They received a very aggressive
chemotherapy regimen plus cranial radiation.
The purpose of the study was to compare response to treatment,
duration of disease control, and side effects. The investigators hoped to be
able to eliminate radiation from the standard care for high-risk ALL.