Prevalence and clinical implications of bone marrow involvement in pediatric anaplastic large cell lymphoma.
Anaplastic large cell lymphoma (ALCL) harbors the reciprocal chromosomal translocation t(2;5)(p23;q35) in approximately 80% of the cases. The genes involved are nucleophosmin (NPM) and anaplastic lymphoma kinase (ALK) and the resulting chimeric NPM-ALK protein is thought to play a key role in the pathogenesis of t(2;5) positive ALCL. Few data on bone marrow (BM) involvement in ALCL have been published and they mostly rely on morphological examination of BM smears. We studied 52 ALCL for NPM-ALK expression by RT-PCR: 47/52 biopsies were positive. In 41 of the 47 cases we obtained the BM at diagnosis and investigated the prevalence of minimal BM infiltration by RT-PCR and real-time PCR. Minimal disseminated disease was positive in 25/41 patients (61%), of whom six had morphologically infiltrated BM. Survival analysis demonstrated a 5-year progression-free survival of 41 +/- 11% for patients with molecularly positive BM vs 100% for patients with negative BM (P = 0.001). These results suggest that minimal BM involvement at diagnosis is a common event in pediatric ALCL and that minimal BM disease monitoring could identify patients at risk of relapse.
Mussolin
L
L
Clinica di Oncoematologia Pediatrica, Azienda Ospedaliera-Università di Padova, Padova, Italy.
Pillon
M
M
d'Amore
E S
ES
Santoro
N
N
Lombardi
A
A
Fagioli
F
F
Zanesco
L
L
Rosolen
A
A
D000293:Adolescent; D001853:Bone Marrow / Q000378:metabolism* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007223:Infant; D016403:Lymphoma, Large B-Cell, Diffuse / Q000175:diagnosis* / Q000235:genetics* / Q000378:metabolism; D008297:Male; D018365:Neoplasm, Residual; D009687:Nuclear Proteins / Q000235:genetics; D000090243:Nucleophosmin; D011446:Prospective Studies; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis
C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D000090243:Nucleophosmin; C107023:p80(NPM-ALK) protein; D011505:Protein-Tyrosine Kinases