Patients with
acute myeloid leukemia who have abnormal chromosomes in bone marrow
cells at remission are twice as likely to relapse
Patients with acute myeloid leukemia who enter
remission with abnormal chromosomes in bone marrow cells are twice
as vulnerable to recurrence of disease as patients with normal bone
marrow cells at remission, according to an article in the June 15th
issue of the Journal of Clinical Oncology.
“For the first time, we have shown in a relatively
large group of patients that someone with acute myeloid leukemia
who has abnormal chromosomes early during remission will relapse,
even if blood counts and other parameters are favorable,” said lead
author Guido Marcucci, MD.
Since 1990, physicians have considered patients
with acute myeloid leukemia to be in complete remission following
treatment if their blood count was normal and their bone marrow
contained fewer than 5 percent blast cells. By that definition,
60 to 70 percent of patients achieve complete remission, but only
30 percent to 40 percent of those patients remain in remission long
enough to be considered completely cured.
“Achieving complete remission is an important
step for a successful treatment,” Marcucci said, “but it does not
predict who will do well in the long run and who will relapse. We
need additional diagnostic indicators like the presence of abnormal
chromosomes.”
Chromosomal abnormalities are seen at diagnosis
in about 55 percent of all patients. The presence of chromosomal
abnormalities at diagnosis has long proven to be one of the most
important prognostic factors for acute myeloid leukemia. Furthermore,
the sensitive technology and methods needed for cytogenetic testing,
which were formerly found mainly in research laboratories, are now
widely available for use in clinical tests.
The current, retrospective study examined
the outcomes of 118 patients who had received cytogenetic testing
at the time of diagnosis and at the first day of complete remission.
Of the total, 103 patients had abnormal chromosomes at diagnosis
and normal chromosomes at complete remission. These patients were
compared with 15 others who had abnormal chromosomes at both diagnosis
and at complete remission.
The results showed that patients with abnormal
chromosomes at remission had a significantly shorter survival with
twice the risk for relapse and death.
Based on their findings, the researchers
concluded that converting from abnormal chromosomes to normal chromosomes
at remission is an import predictor of long-term outcome in acute
myeloid leukemia and thus cytogenetic testing should become routine
as a criterion for remission. Marcucci said, “These findings indicate
that the old definition of remission isn’t good enough. We need
to include cytogenetic complete remission as a criterion for complete
remission in acute myeloid leukemia.”
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