The role of quantitative polymerase chain reaction in the management of follicular lymphoma patients.
OBJECTIVE
In order to increase the prognostic significance of polymerase chain reaction (PCR) data it has been suggested that quantitative PCR can be used to measure tumor burden. However, this option has not yet been definitely supported or refuted in patients with follicular lymphoma (FL). We decided to evaluate whether knowledge of the quantitative level of minimal residual disease and its variations can be of use in the management of FL patients.


METHODS
We used qualitative and competitive PCR to study 11 patients with refractory or relapsed FL harboring the t(14;18) translocation who underwent autologous (nine patients) or allogeneic (two patients) stem cell transplantation (SCT). Competitive PCR was performed with a multiple competitor carrying specific sequences including Bcl2/IgH MBR and mcr, and the beta-globin gene.


RESULTS
After a median post-SCT follow-up of 44 months (range, 12-62), overall survival was 91% and disease-free survival 82%. The quantitative PCR data showed that: 1) effective chemotherapy before SCT substantially (1-2 log) reduced the tumor burden in the bone marrow (BM); 2) the increase in rearranged DNA detected in BM was associated with disease progression and relapse; 3) a PCR-negative autograft seemed to lead to lasting molecular remission even when it was performed in patients with a low level of BM infiltration before transplant; and 4) allo-SCT made and maintained the BM PCR negative even in the presence of a greater tumor burden before SCT. Six of the nine patients having CR after SCT (four auto and two allo) are in continuous molecular remission.


CONCLUSIONS
In FL patients qualitative and quantitative PCR may provide data that can be helpful for the prognostic evaluation of tumor progression and the early detection of impending relapse by highlighting biological features such as the quality of the infused material, the tumor burden at transplant, and the behavior of tumor cells after transplant.
Perego
Roberto A
RA
Department of Experimental and Environmental Medicine and Medical Biotechnologies, School of Medicine, Milano-Bicocca University, Monza, Milan, Italy. roberto.perego@unimib.it
Cairoli
Roberto
R
Cornacchini
Giorgia
G
Bianchi
Cristina
C
Corizzato
Matteo
M
Tresoldi
Elisabetta
E
Morra
Enrica
E
D000328:Adult; D001483:Base Sequence; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008224:Lymphoma, Follicular / Q000235:genetics* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D033581:Stem Cell Transplantation; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous