Program: Oral and Poster Abstracts
Session: 623. Lymphoma: Chemotherapy, excluding Pre-Clinical Models: Poster III
From 2004 to 2013, a total of 61 de novo MCL patients assessed by PET were included. For each patient, were collected at baseline, the whole body SUVmax site, the presence of a bone marrow (BM) uptake, total metabolic tumour volume (TMTV) and total tumour glycolysis (TLG). The interim PET response after 3 or 4 cycles of induction treatment was assessed using the Deauville score and the quantitative variation of SUV between the baseline PET and the PET performed after 4 cycles of immunochemotherapy (ΔSUV).
Patient’s median age was 64 years [38 - 84]. At diagnosis, 92% presented a disseminated disease (stage III-IV). Mean MCL International Prognostic Index (MIPI) was 6.09 [5.89 - 6.29]. All patients received a first-line induction treatment. Twenty-eight (46%) received an autologous stem cell transplantation as consolidation treatment and 10 (16%) a rituximab maintenance. The baseline FDG uptake intensity was low (median SUVmax: 6.93 [2.5 - 25]) leading to consider that baseline PET was informative and suitable for a further PET reassessment in 40 (93%) patients. 72% of the patients with an informative baseline PET, had a SUVmax < 10 making the metabolic quantitative analyses (TMTV, TLG, ΔSUV) uninformative. Among the 46 (75%) patients with histologically proven BM involvement, only 14% of them had BM FDG uptake. After 3 to 4 cycles of induction treatment, 27 (75%) patients achieved a negative PET. With a median follow up of 27 months, a shorter PFS was related to a disseminated disease (stage III-IV) on the basis of baseline PET (2y-PFS: 47% vs 80% p = 0.03) and an insufficient interim metabolic response according to the Deauville score (score ≥ 4) (16% vs 64% p<0.01). However, in multivariate analysis, using the MIPI, the stage and the interim PET response as covariates, only a score of Deauville ≥ 4 (p = 0.0018, HR = 32.6 IC 95% [3.7 - 286.82]) and a MIPI>=6 (p = 0.04, HR = 7.1 IC 95% [1.1 - 46]) retained an independent negative impact on PFS.
FDG avidity of LCM is usually low. PET underestimates BM involvement at diagnosis in 86 % of patients, compared with cytological and histological techniques, and has no independent prognostic value. The interim metabolic response assessed using the Deauville criteria is a prognosis factor independent from MIPI in patients with MCL.
Disclosures: Salles: Calistoga Pharmaceuticals, Inc.; Celgene Corporation; Genentech, Inc.; Janssen Pharmaceutica Products, L.P.; Roche: Consultancy ; Celgene Corporation; Roche and Gilead Sciences: Research Funding ; Celgene Corporation; Roche: Speakers Bureau . Casasnovas: Gilead: Consultancy ; Takeda: Consultancy ; Roche: Consultancy , Research Funding .
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