CYTOGENETIC ANALYSIS IS NON-INFORMATIVE FOR ASSESSING THE REMISSION RATE IN CHRONIC MYELOID-LEUKEMIA (CML) PATIENTS ON INTERFERON-ALPHA (IFN-ALPHA) THERAPY
Mc. Coxfroncillo et al., CYTOGENETIC ANALYSIS IS NON-INFORMATIVE FOR ASSESSING THE REMISSION RATE IN CHRONIC MYELOID-LEUKEMIA (CML) PATIENTS ON INTERFERON-ALPHA (IFN-ALPHA) THERAPY, Cancer genetics and cytogenetics, 84(1), 1995, pp. 15-18
Cytogenetic analysis is considered pivotal for assessing the remission
rate in CML patients on IFN therapy. On the basis of general agreemen
t, at least 25 metaphases should be analyzed in each case. The main li
mitations to this approach are: 1) the small number of analyzable meta
phases generally found in cytogenetic preparations from IFN-a-treated
patients; and 2) the inability of this technique for scoring interphas
e cells. We compared the results of cytogenetic analysis and double-co
lor FISH detection of bcr/abl genes fusion in 13 CML patients on IFN-a
therapy (marrow sampling for cytogenetic and FISH analysis was carrie
d out after 12 months in all patients and repeated after 18 months of
IFN therapy in patients 4, 6, and 8). In five specimens, 20 to 25 cell
s were evaluable for cytogenetic examination, in another five no analy
zable metaphases were scored, and in the remaining six samples two to
14 cells could be analyzed. With FISH detection at least 100 cells wer
e easily scored in each specimen (mean number, 175). Comparing the res
ults carried out with the two methods in different samples it emerged
that cytogenetic analysis led to improper conclusions as regards the r
ate of Ph positivity, even in those patients where 213-25 metaphases w
ere analyzed. Although many more cases have to be studied to establish
the role of FISH analysis in Ph-positive patients, we are of the opin
ion that cytogenetic analysis is unfit for easily and accurately asses
sing the actual quality of remission in IFN-treated subjects.