Fink, Stephanie

Abstract Background: Multiple myeloma (MM) has been studied by conventional cytogenetics and fluorescence in situ hybridization using DNA probes (FISH) on interphase nuclei and metaphase cells, but the relative clinical significance of proliferating (metaphase) versus non-proliferating (interphase) cells at diagnosis is poorly understood. We investigated a consecutive series of 154 patients (pts) with newly diagnosed untreated MM, and compared results for metaphase and interphase cells with survival. Methods: Bone marrow within 30 days of diagnosis was analyzed by standard cytogenetics. Leftover cells were stored at −70°C. Interphase and metaphase FISH was done using probes for IGH, FGFR3, CCND1, c-MAF, D13S319, LAMP1, p53 and D17Z1 to detect t(4;14), t(11;14), t(14;16) and chromosome 13 or 17 anomalies, respectively. We analyzed <10 metaphases and 200 unselected interphase nuclei for each FISH probe set for each pt. Survival rates were estimated using Kaplan-Meier and differences in survival curves compared using log-rank test. Results: 61 (39.6%) pts had abnormal metaphases by cytogenetics (43 pts) and/or FISH (46 pts): 12 (19.7%) had t(11;14) by cytogenetics (3 pts) and/or FISH (11 pts), 11 (18.0%) had t(4;14) by FISH but not cytogenetics, and 3 (4.9%) had t(14;16) by FISH but not cytogenetics. Metaphases with 13q- were seen in 30 pts (49.2%). Interphase FISH results were abnormal for 133 (86.3%) pts: mean percent neoplastic nuclei was 26.9 ± 21.6 (3.9 to 99.0). Mean percent plasma cells was 54.7 ± 24.6 (3.0 to 99.0). Each of the 61 pts with abnormal metaphases was also abnormal in interphase nuclei. Median survival for pts with ≥50% (20 pts) abnormal nuclei was 202 days vs. 1351 days for pts with <50% (134 pts) (p<0.001). Median survival for pts with abnormal metaphases (61 pts) was 587 days vs. 1404 days for pts with normal metaphases (93 pts) (p=0.002). Median survival was 381 days for 30 pts with 13q- metaphases compared with 1404 days for 38 pts with normal metaphases and 13q- interphase nuclei (p<0.001). Metaphase and interphase analysis along with other potential risk factors (hemoglobin <10, serum calcium ≥11, serum creatinine ≥2, plasma cell labeling index and percent bone marrow plasma cells) were evaluated by multivariate analysis using a stepwise selection in a Cox proportional hazards model. Only the observation of 13q- in metaphases or ≥50% abnormal interphase nuclei were significant predictors of survival. Conclusions: Analysis of metaphases at diagnosis is important to detect proliferating disease which is a strong indicator of poor prognosis. Metaphase FISH is a necessary adjunct to conventional cytogenetics to detect cryptic t(4;14) and t(14;16), and accurately detect prognostic chromosome anomalies such as 13q-. Observing a 13q- in metaphase cells is a strong predictor of survival compared with observing 13q- in only interphase nuclei. At diagnosis, analysis of interphase nuclei is efficient, identifies an abnormal clone in 86% of pts and defines a subset of patients with ≥50% nuclei that have a poor prognosis. Since analysis of metaphases gives better prognostic information, interphase FISH is not a substitution in the cytogenetic work up of patients with MM.

Abstract Background: Using fluorescent in-situ hybridization (FISH), a number of investigators have identified specific cytogenetic abnormalities that identify CLL patients with a more aggressive (17p-, 11q-) or indolent (13q-) disease course. Some have suggested patients who initially have a normal karyotype may acquire new chromosome abnormalities during the course of their disease. Since patients with specific cytogenetic abnormalities (17p-, 11q-) are less likely to respond to purine nucleoside analogues, such clonal evolution has potential implications for treatment as well as prognosis. No study has prospectively investigated the frequency of clonal evolution in a cohort of patients with newly diagnosed untreated CLL. Methods: Between 1994 and 2000, we enrolled 167 patients with previously untreated CLL seen at Mayo Clinic in a prospective trial evaluating the prognostic importance of cytogenetic abnormalities and clonal evolution detected by FISH. All patients provided a baseline blood specimen for FISH testing and follow-up specimens over the following 24 months. Other research samples from later timepoints were tested where available. Study participants were contacted by mail in 2004 to update vital and treatment status. Of 83 living responders, 70 (84%) indicated they would be willing to provide an additional follow-up sample for cytogenetic analysis of whom 48 have returned a sample to date. Results of clinical FISH testing during the follow-up interval were also abstracted. FISH was performed on interphase nuclei from blood as we have previously described (BJH 121:287). Results: Median age at diagnosis was 64. Median time from diagnosis to study enrollment was 3.3 months. 94% of patients had early stage disease at enrollment (88 Rai 0; 48 Rai I, 18 Rai II, 2 Rai III; 8 Rai IV). Median follow-up time from diagnosis for all 164 eligible study participants was 8.5 years (range: 0.33–22.9 yrs). As of last follow-up, 48% of patients have received treatment and 57 (35%) have died. 75% of patients had chromosome abnormalities on FISH testing at baseline. The frequency of individual cytogenetic abnormalities on baseline FISH analysis along with overall survival by hierarchical FISH risk category are shown in Table I. 106 patients had sequential samples for FISH analysis at least 2 years apart, 61 had samples at least 5 years apart, and 22 had samples at least 10 years apart. 15 patients had evidence of clonal evolution during follow up as evidenced by a new FISH anomaly not present on the baseline specimen. No clonal evolution was observed in the first 2 years of follow-up (n=106), however of 61 patients with samples at least 5 years apart, 14 (23%) had evidence of clonal evolution. Median time for development of a new cytogenetic abnormality among these patients was 9.3 years. Conclusions: Clonal evolution occurs during the course of disease for approximately 25% of patients with early stage CLL. Clonal evolution appears to occur at low frequency during the first 2 years of follow-up but increases in frequency after 5 years. This finding has potentially significant implications for prognosis and treatment of patients with CLL. FISH Risk Category* N (Baseline) Median Overall Survival (Years) * Difference between groups significant p=0.0038 13q- x 1 37 14.4 13q- x2 35 17 Normal Karyotype 40 13.2 12+ 24 11.1 11q- 12 8.6 17p- 10 10.5 6q- 2 4.1 Other 2 Not reached