Assessment of Minimal Residual Disease in Ewing Sarcoma

Table 1

Summary of Key Studies Using RT-PCR for MRD Detection in Ewing Sarcoma.

Author  [Reference]	N (pts)	Key Findings
Peter [9]	36	31% had MRD in either blood or marrow at diagnosis at diagnosis
Pfeiderer [13]	16	38% had MRD in BM, while only 6% had CTC at diagnosis
West [12]	28	25% of newly diagnosed localized pts had MRD in blood or marrow, compared to 50% with relapsed/metastatic disease
Fagnou [11]	67	26% of patients had MRD in blood at diagnosis, but this was not correlated with clinical features or outcome.33% of patients had BM MRD, with worse outcome
De Alava [6]	28	MRD in blood and/or marrow developed prior to clinical progression
Zoubek [14]	35	7/23 (30%) had BM MRD at diagnosis, but this did not predict relapse
Thomson [3]	9	Survival was correlated with speed of clearance of MRD in blood and BM
Sumerauer [10]	22	MRD in marrow found in 31% of localized and 50% of metastatic pts
Merino [15]	12	Quantitative RT-PCR can be used to measure efficacy of stem cell purging methods
Schleiermacher [2]	172	MRD in blood or BM at diagnosis is associated with worse survival in patients with otherwise localized disease
Avigad [5]	26	43% of pts had marrow MRD at diagnosisMRD developed prior to clinical recurrence in 10 of 11 patients
Yaniv [16]	11	Tumor cells frequently contaminate stem cell harvests, and are associated with relapse after transplantation.Relapse is preceded by MRD in BM and/or blood

MRD, minimal residual disease; BM, bone marrow.