Early responder myeloma: kinetic studies identify a patient subgroup characterized by very poor prognosis

The prognostic role of 1q21 gain/amplification in newly diagnosed multiple myeloma: The faster, the worse

BACKGROUND

The prognostic value of additional copies of chromosome 1q (1q gain/amplification [amp]) in multiple myeloma (MM) remains controversial. In the meantime, the kinetics of the response to MM therapy has long been an area of debate. Few studies have pointed out the relationship of response kinetics with cytogenetic abnormalities (CAs) in MM.

METHODS

The authors retrospectively analyzed the data of 1068 real-world newly diagnosed MM patients from a Chinese national medical center.

RESULTS

Overall, 405 (51.9%) patients had 1q gain/amp, with aggressive clinical characteristics and significant inferior survival. The variation in copy number (CN) of 1q (CN = 3 or CN >3) had no significant impact on the survival of MM patients with 1q abnormalities. No difference was found in the outcome of 1q gain/amp patients treated with doublet or triplet regimens. Upfront autologous stem cell transplantation could eliminate the adverse prognostic effect of 1q gain but not 1q amp. The duration from diagnosis to the first time achieving very good partial response (VGPR) or better was significantly shorter in patients with 1q gain/amp (77 days vs. 100 days, p = .001). Finally, multifactor regression analysis was performed to construct a new risk stratification model in MM patients with 1q gain/amp, which was validated in the Multiple Myeloma Research Foundation CoMMpass study cohort and worked better than the Revised International Staging System and Second Revision of the International Staging System (Harrell's concordance index: 0.631 vs. 0.598 and 0.537).

CONCLUSIONS

In the setting of novel therapy, 1q gain/amp still acts as an independent adverse prognostic factor. Patients with 1q gain/amp achieved VGPR rapidly but had inferior survival.

Early versus late response to daratumumab-based triplet therapies in patients with multiple myeloma: a pooled analysis of trials POLLUX, CASTOR and MAIA

In multiple myeloma (MM), it is unclear whether early and late responders to daratumumab have similar outcomes. We pooled individual-level data from phase 3 trials and divided them into early and late response groups based on median time to response. Altogether 670 and 213 patients achieved very good partial response (VGPR) or better and minimal residual disease (MRD) negativity, respectively. Among VGPR or better, there was no significant difference of modified progression-free survival (mPFS, hazard ratio [HR] 1.00, 95% confidence interval [CI] 0.69-1.44) or duration of response (DOR) (HR 1.02, 95%CI 0.68-1.53). Among relapsed/refractory MM (RRMM) achieving MRD negativity, late responders had significantly longer mPFS (p = 0.038) and DOR (p = 0.043). These results support that for patients who failed to achieve an early response to daratumumab, therapies should be continued with the goal of achieving ongoing and stepwise improvement of response.

Kinetics of response to first- and second-line therapies in multiple myeloma: Assessment by both M-spikes and light chains

OBJECTIVES

The prognostic value of kinetics of response to multiple myeloma (MM) therapy is controversial. We aimed to expand the knowledge on this topic by reviewing the kinetics of response to both first- and second-line MM therapy, utilizing a homogeneously treated cohort and analyzing separately both M-spike and light chain (LC) responses for each patient.

METHODS

We reviewed all patients who received first-line cyclophosphamide, bortezomib and dexamethasone induction followed by autologous transplant with melphalan and lenalidomide maintenance in our center between 2007 and 2019.

RESULTS

Analyzing 360 patients, we observed no correlation between response kinetics to first- versus second-line therapy at the individual patient level. Time to best response to first-line therapy was not a predictor of outcome; however, longer time to best response was highly predictive of a favorable outcome in the second-line setting, independent of other factors. Patients with IgA-MM cleared their M-spike faster than IgG-MM, probably reflecting different half-lives of these isotypes rather than disease biology, as the clearance of LC in both subtypes was similar.

CONCLUSIONS

Analyzing both M-spike and LC responses in a homogenously treated cohort, we identified important insights regarding the prognostic value of kinetic patterns. Prospective analysis may shed more light on unsolved questions.

Impact of early response on outcomes in AL amyloidosis following treatment with frontline Bortezomib

The outcomes in systemic AL amyloidosis are dependent on the depth of haematologic response. However, there is limited data on the impact of the speed of response on outcomes. Here we report the impact of speed of response in a cohort of AL patients treated with upfront Bortezomib. Patients seen from February 2010 until August 2019 are included in the present analysis. 1194 & 1133 patients comprised the ITT and 1-month landmark cohorts. In the landmark cohort, 137 (11.5%), 270 (22.6%), 252 (21.1%) and 352 (31.1%) patients had a CR, VGPR, PR and NR at 1-month. Patients with ≥ VGPR at 1-month had significantly better survival (median not reached; at the end of 1, 2, 5,10 years, 87%/92%, 83%/87%, 68%/72% and 63%/58% of patients in CR/VGPR, respectively, were alive) compared to those with a PR (median OS 60 months) or NR (median OS 32 months) (p < 0.005). At 1-month, patients with CR and iFLC < 20 mg/l had a significantly better survival compared to CR and iFLC > 20 mg/l (p = 0.005). Reaching ≥ VGPR at 1-month significantly improved survival in all Mayo disease stages. In conclusion, patients achieving an early deep haematologic response have a significantly superior survival irrespective of cardiac involvement.

Proliferation to Apoptosis Tumor Cell Ratio as a Biomarker to Improve Clinical Management of Pre-Malignant and Symptomatic Plasma Cell Neoplasms

Proliferation and apoptosis of neoplastic cells are prognostic biomarkers in plasma cell neoplasms (PCNs). The prognostic capacity of proliferation to apoptosis ratio (Ratio-PA) in the era of immunomodulatory treatments is re-evaluated in 316 gammopathy of undetermined significance (MGUS), 57 smoldering multiple myeloma (SMM), and 266 multiple myeloma (MM) patients. Ratio-PA of 0.77 ± 0.12, 1.94 ± 0.52, and 11.2 ± 0.7 (p < 0.0001) were observed in MGUS, SMM, and MM patients. Ten-year overall survival (10y-OS) rates for patients with low/high Ratio-PA were 93.5%/77.3% p < 0.0001) for MGUS, 82.5%/64.7% (p < 0.05) for SMM, and 62.3%/47.0% (p < 0.05) for MM. For patients with low, intermediate, and high risk, 10y-OS for low/high Ratio-PA were 95.5%/72.9% (p < 0.0001), 74.2%/50.4% (p < 0.0001), and 35.3%/20.0% (p = 0.836), respectively. Ratio-PA was an independent prognostic factor for OS (HR = 2.119, p < 0.0001, Harrell-C-statistic = 0.7440 ± 0.0194) when co-analyzed with sex, age, and standard risk. In patients with Ratio-PA^high, only first-line therapy with VRd/VTd, but not PAD/VCD, coupled with ASCT was associated with high 10y-OS (82.7%). Tumor cell Ratio-PA estimated at diagnosis offers a prognostic biomarker that complements standard risk stratification and helps to guide the clinical management of pre-malignant and symptomatic PCNs. Every effort should be made to provide first-line therapies including VTd or VRd associated with ASCT to patients with Ratio-PA^high at higher risk of progression and death.

The impact of response kinetics for multiple myeloma in the era of novel agents

Rapid remission by induction therapy has long been recognized as an important predictor for long-time survival in acute leukemia. However, the impact of response kinetics on multiple myeloma (MM) seems to be different and remains unexplored. The relationship between response kinetics and outcome were assessed in 626 patients with newly diagnosed MM who were included in a prospective, nonrandomized clinical trial (BDH 2008/02). Patients were assigned to either immunomodulatory drug- or proteasome inhibitor-based therapy. The response depth, time to best response (T_BR) and duration of best response (D_BR) were collected. Depth of response was associated with superior outcomes, consistent with findings from other studies. However, the early responders (defined as T_BR ≤3 months) showed significantly worse survival compared with late responders. We found that patients with rapid complete remission experienced inferior survivals comparable to those attaining a gradual partial remission. Moreover, 4 distinct response kinetics patterns were identified. Patients with gradual and sustained remission ("U-valley" pattern) experienced superior outcomes, whereas poor outcomes were observed in rapid and transient responders ("roller coaster" pattern) (median overall survival, 126 vs 30 months). The effects of response patterns on survival were confirmed in patients at different stages of disease and cytogenetic risk, including transplant-eligible patients and those attaining different extents of response depth. Collectively, our data indicated that slow and gradual response is a favorable prognostic factor in MM. In addition to response depth, the kinetic pattern of response is a simple and powerful predictor for survival even in the era of novel agents.

Serum free light chain response after 2 courses of induction chemotherapy predicts prognosis in myeloma patients

BACKGROUND

The aim of this study was to investigate the prognostic effect of serum free light chain (sFLC) response after 2 cycles of first-line chemotherapy (CT) in multiple myeloma (MM) patients.

MATERIALS AND METHODS

The data of 78 newly diagnosed MM patients who had sFLC levels at diagnosis and after 2 cycles of first-line CT were included in the study. The prognostic effect of sFLCs were evaluated with normalization of sFLC κ/λ ratio after 2 cycles of CT and involved/uninvolved (i/u) sFLCs.

RESULTS

At the end of follow-up the probability of overall survival (OS) was 95.7% versus 68.5% in patients with and without normalized sFLC κ/λ ratio, respectively (P = .072). The probability of OS with i/u sFLC assessment was 97.4% versus 55.8% with regard to i/u sFLC ≤ 10 and > 10, respectively (P = .001). In univariate and multivariate analysis including sFLC ratio, age, sex, and International Staging System, i/u sFLC ratio > 10 after 2 cycles of CT was identified as an independent risk factor for OS (P = .015; hazard ratio [HR], 13.2; 95% confidence interval [CI], 1.668-104.65 vs. P = .011; HR, 15.17; 95% CI, 1.85-123.89).

CONCLUSION

Early response assessment in terms of sFLC after 2 courses of induction CT seems to have a prognostic effect in MM patients. The methodology and timing of the evaluation based on sFLCs needs to be validated in prospective studies.

Long-term disease control in patients with newly diagnosed multiple myeloma after suspension of lenalidomide therapy

There are no systematic data regarding nonmaintained induction for those patients with multiple myeloma (MM) who do not receive consolidative autologous stem cell transplantation. Of 173 patients with newly diagnosed MM treated with lenalidomide and dexamethasone (LenDex) as primary therapy, 31 patients had their lenalidomide discontinued for reasons other than progression or alternate therapy. Median progression free survival (PFS) from the time of discontinuing lenalidomide was longer in patients who received lenalidomide ≥ 1 year (39 vs. 13 months, P < 0.05); there was no difference in PFS for those treated for 1-2 years as compared to ≥ 2 years. Among those taking lenalidomide for ≥ 1 year PFS was superior in patients who were in very good partial response (VGPR) or better as compared to those with partial response (48.4 versus 14.8 months, P < 0.05). All patients who progressed and were rechallenged with LenDex responded. These analyses illustrate that discontinuation of lenalidomide after 1 year among those patients achieving a ≥VGPR can result in long-term disease control.

Implications of continued response after autologous stem cell transplantation for multiple myeloma

Patients undergoing autologous stem cell transplantation (ASCT) for multiple myeloma (MM) undergo disease assessment approximately 100 days later. Some patients continue to have a decline in their serum or urine monoclonal protein after day 100 in the absence of additional therapy. We evaluated 430 MM patients who underwent ASCT within 12 months of their diagnosis and had not achieved a complete remission at day 100. Of these patients, 167 (39%) had a continued response after day 100 without additional therapy. When compared with patients who did not (n = 263), those who had a continued response had a longer progression-free survival (35 vs 13 months, P < .001), time to next therapy (43 vs 16 months, P < .001), and overall survival (96 vs 57 months, P < .001). This phenomenon of a continued response maintained prognostic value in a multivariable analysis and should be considered when interpreting posttransplant responses.

Reduction in plasma cell proliferation after initial therapy in newly diagnosed multiple myeloma measures treatment response and predicts improved survival

Standard myeloma treatment response criteria are determined principally by changes in the monoclonal protein. Reduction in the size of the proliferative component of malignant plasma cells may be an additional metric of assessing response to therapy. We retrospectively analyzed 176 patients with newly diagnosed myeloma with a measurable plasma cell labeling index (PCLI) at diagnosis and repeat measurement 4 months after initiation of therapy. PCLI response was defined as a ≥ 60% reduction. Baseline PCLI is an independent prognostic factor; therefore, we categorized patients into 3 groups: PCLI ≥ 3% (high), ≥ 1% (intermediate), and < 1% (low). Patients achieving a greater PCLI response had improved median overall survival of 54 months compared with 29 months in nonresponders (P = .02). Improved median overall survival with PCLI response occurred in the high initial PCLI group (28 vs 7 months; P = .003) and intermediate group (64 vs 24 months; P = .002). The application of PCLI response and serum M-spike response together provided further prognostic information. On multivariate analysis, the prognostic value of PCLI response was independent of β(2)-microglobulin, elevated creatinine, serum M-spike response, and baseline PCLI. We conclude that a significant reduction in plasma cell proliferation in patients with newly diagnosed myeloma is an important predictor of survival.

Advances in biology of multiple myeloma: cell kinetics, molecular biology and immunology

Bone marrow plasma cell proliferative activity has been evaluated in a large series of multiple myeloma (MM) patients. This kinetic parameter has been shown to be a useful tool for patient management, and contributes to a correct diagnosis and a selection of high-risk patients who can be offered high-dose chemotherapy. The role of ras oncogenes has been evaluated in the pathogenesis of MM. A point-mutated and activated H-ras oncogene, introduced in a human lymphoblastoid cell line, was able to induce neoplastic transformation and differentiation to plasma cell. Indeed, mutated alleles of ras genes have been detected in a high percentage of myeloma patients in relapse phase. Phenotypical and functional studies have been carried out in T-lymphocyte subsets and an impaired cellular immunity has been detected. Such an impairment was related to the disease status: marked alterations were detected in relapse phase, whereas a partial recovery was observed during remission phase.

The Merlini, Waldenström, Jayakar staging system revisited

At present, none of the routinely used staging systems is entirely satisfactory, since all of them require some reconsideration to account for the most recent prognostic factors. Among these, serum beta-2 microglobulin (S-beta-2M) has proved to be a powerful prognostic test assessable in most centers. In order to improve the Merlini, Waldenström, Jayakar (MWJ) staging system, we have determined the prognostic significance of several factors in an independent population of 345 retrospective myeloma patients seen at our institution from 1973 to 1988. The Cox regression hazards method showed that S-Creatinine, S-Albumin levels and percentage of bone marrow plasma cells accounted for 94% of total chi 2 achieved with all eight variables (including also: paraprotein index, S-Calcium, S-M-component, bone lesions and hemoglobin). The same analysis, applied to patients in whom S-beta-2M was available at presentation, selected S-beta-2M, S-Creatinine and percentage of bone marrow plasma cells (accounting for 92% of total chi 2), followed by platelet count, S-Albumin and S-M-component. The best discriminatory level of S-beta-2M was found to be 4 mg/l. However, the prognostic power of S-beta-2M when used with binary values was remarkably reduced with respect to its application as a continuous variable. In patients with MWJ stage 1 and 2 disease, S-beta-2M had an independent prognostic significance. Grouping stage I and II patients with S-beta-2M less than or more than 4 mg/l presented a median survival of 70 and 40 months, respectively. In stage 3 patients S-beta-2M did not contribute additional prognostic information.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term results of thalidomide in refractory and relapsed multiple myeloma with emphasis on response duration

OBJECTIVE

Thalidomide administered as a single agent produces a response rate of about 40% in patients with refractory or relapsed multiple myeloma (MM). The aim of our study was to determine the quality and duration of such responses.

PATIENTS AND METHODS

Forty-two consecutive patients with refractory (20) or relapsed (22) MM were given thalidomide as a single agent at our institution. Most of them (70%) had previously received two or more lines of therapy, and 38% had undergone autologous stem cell transplantation.

RESULTS

Eighteen patients (43%) responded to thalidomide [11 minimal responses (MR) and seven partial responses (PR)] according to the European Marrow Transplant Registry (EBMT) criteria. The median time to response was 3 months and the median duration of therapy in responding patients was 9 months. Treatment was discontinued because of toxicity in 10 responding patients. The toxicity mainly led to peripheral neuropathy and fatigue. At the time of this analysis, all responding patients had progressed except one who remains in continued stable PR. The median time to progression was 15.6 months (range 1.3 to 70+), with a trend towards a longer duration for patients who achieved PR vs. MR (21.2 vs. 11.2 months, P = 0.11). The median duration of response was 12.4 months (range: 0.3-67+) (17.2 months for PR vs. 9.7 months for MR, P = 0.11).

CONCLUSION

These results show that the effect of thalidomide in refractory/relapsed MM can be sustained, particularly in patients who achieve a greater degree of response, and support the finding that this drug can be used for maintenance therapy.

Evaluation of plasma cell propidium-iodide and annexin-V indices: their relation to prognosis in multiple myeloma

In a group of 117 patients with multiple myeloma (MM) examined at the time of diagnosis, i.e. excluding previous chemotherapy, we analysed the levels of propidium-iodide (proliferative) - PC-PI/CD(138) and annexin-V (apoptotic) - PC-AI/CD(138) indices of myeloma plasmocytes using the method of flow-cytometry to determine their relationship to prognosis. It was revealed that patients with high values of PC-PI/CD(138) had substantially worse overall survival than those with low values. Patients with a level of propidium-iodide index > or = 2,8 % exprimed a median survival of 13 months only in comparison with 42 months in patients with levels < 2,8 % (p = 0,0005). In the PC-AI/CD(138) index a reverse trend was registered. Patients with PC-AI/CD(138) > or = 4,0 % had long overall survival (median was not assessable at the time of evaluation), whereas patients with low apoptosis values < 4,0 % had median overall survival 16 months only (p = 0,01). Based on the sequentional graphic analysis of the curves of overall survival was found that the optimal discrimination level sequestering patients with good and poor prognosis was, in the case of PC-PI/CD(138) value 2,8 %, whereas in the case of PC-AI/CD(138) value 4,0 %. Among patients with good prognosis, there were no statistically significant differences in overall survival according to different levels of proliferative and apoptotic index. We conclude that evaluation of the propidium-iodide and annexin-V index using flow-cytometry is a quick, useful, and easily accessible method for the evaluation of plasma cell kinetics and thus prognosis of the disease, multiple myeloma.

Soluble syndecan-1 level at diagnosis is an independent prognostic factor in multiple myeloma and the extent of fall from diagnosis to plateau predicts for overall survival

Syndecan-1 (CD138) is a heparin sulphate proteoglycan that is over expressed on the surface of both normal and malignant plasma cells and actively shed from the cell surface (soluble syndecan-1). Soluble syndecan-1 has been shown to be an independent prognostic factor in myeloma but its role in prognostic classification requires further investigation. We have retrospectively measured soluble syndecan-1 in 324 presentation samples and 154 plateau phase samples from the UK Medical Research Council Myeloma VIth trial. Log-rank analysis showed that the presentation value of soluble syndecan-1 is a highly significant prognostic factor when assessing survival from entry (chi2=14.92, P<0.0001) and remains an important independent prognostic factor when considered in Cox regression models (P<or=0.02) with known independent factors. The magnitude of fall in soluble syndecan-1 from presentation to plateau also had prognostic value when assessing overall survival from plateau (chi2=3.79, P=0.05). In conclusion, this large study confirms that soluble syndecan-1 level is a powerful independent prognostic factor both at diagnosis and at plateau phase.

Early response to therapy and survival in multiple myeloma

Whether the response to chemotherapy is a prognosticator in multiple myeloma (MM) is still not known. Therefore, the relationship between survival and the rate of monoclonal protein (M-protein) decrement during the first cycles of therapy was prospectively assessed in 262 patients with newly diagnosed MM that were included in a phase III trial (HOVON-16). M-proteins were collected monthly during melphalan-prednisone therapy (MP: melphalan 0.25 mg/kg, prednisone 1.0 mg/kg orally for 5 d every 4 weeks). Patients with light chain disease (n = 18), immunoglobulin M (IgM)-MM (n = 1) and no immunotyping (n = 1) were excluded. Of the 242 patients studied, 75% had IgG M-protein and 25% IgA; MM stages: I: 1%, II: 35% and III: 64%. The median M-protein decrease after the first cycle of MP was 21% for IgG and 27% for IgA, and declined to < 5% after four cycles. An obvious survival advantage was seen for patients who had an M-protein decrease of at least 30% after the first MP cycle, which became significant when an M-protein decrease of 40% or more was reached. As established prognostic parameters (Salmon & Durie stage, serum creatinine, and haemoglobin) also remained prognostically significant, we concluded that early response to MP predicts for survival in MM.

Effects of IL-6 variants in multiple myeloma: growth inhibition and induction of apoptosis in primary cells

Interleukin-6 (IL-6) plays a pathogenetic role in B-cell malignancies and is a growth factor for multiple myeloma (MM) cells. Elevated serum IL-6 levels and a higher proliferative activity of bone marrow plasma cells are poor prognostic factors in MM patients. In addition to clinical trials with anti-IL-6 monoclonal antibodies, an alternative therapeutic approach based on the use of IL-6 receptor (R) super-antagonists (Sants) has been proposed. Sants are variants of the native cytokine characterized by a wild type affinity for the ligand-specific receptor chain IL-6R alpha and by a reduced ability to bind and/or dimerize the signaling chain gp-130. We report the in vitro effects of four different Sants on cell kinetic modulation and induction of apoptosis of primary cells from MM patients. Ten MM samples were cultured in the presence of four different Sants and heterogeneous effects in terms of reduction of proliferation and induction of apoptosis could be observed. A decrease of the S phase cells (> or = 25%) coupled with the induction of apoptosis was obtained in 4/10 samples: three of these samples had a diploid DNA stem line and an inferior initial percentage of S phase cells. Serum IL-6 concentrations did not correlate with the anti-proliferative activities of the Sants. Cell growth inhibition was observed especially in samples with soluble IL-6R serum concentrations > 200 ng/ml. We conclude that Sants can exert antiproliferative effects on selected MM samples. Such effects may depend on the availability of large amounts of soluble IL-6R. Further studies should aim at defining the conditions necessary for optimal antiproliferative activity.

Magnetic resonance imaging as a supplement for the clinical staging system of Durie and Salmon?

BACKGROUND

This study evaluated the prognostic value of a three-grade staging system of spinal involvement using magnetic resonance imaging (MRI) in patients with multiple myeloma and determined its usefulness as an independent parameter in the staging system of Durie and Salmon.

METHODS

Seventy-seven previously untreated patients with multiple myeloma underwent MRI of the thoracic and lumbar spine with unenhanced T1-weighted spin echo and short-tau inversion time inversion recovery sequences. The patients were evaluated according to their infiltration patterns and the extent of bone marrow involvement was staged using a three-grade scale: Stage I, no focal or diffuse infiltration; Stage II, 1-10 foci or mild diffuse infiltration; Stage III, more than 10 foci or strong diffuse infiltration.

RESULTS

The infiltration patterns had no significant effect on survival. Of 77 patients, 25 would have been understaged using the standard staging system of Durie and Salmon without the findings of MRI and 8 patients would have been understaged if the staging was based only on MRI. The combination of the staging system of Durie and Salmon and MRI was highly significant with respect to survival (P < 0.0001, log rank analysis). MRI staging I-III was independent of the staging system of Durie and Salmon (Cox regression model).

CONCLUSIONS

A three-grade staging of spinal MRI provides a significant prognostic tool for patients with multiple myeloma. The authors propose including it in the staging system of Durie and Salmon.

Impact of early response to sequential high-dose chemotherapy on outcome of patients with advanced myeloma and poor prognostic features

We report the results of a dose-intense chemotherapy regimen designed to rapidly induce remissions in patients with advanced multiple myeloma (MM). Patients received VAD for 3-6 cycles depending on response kinetics. This was followed by three sequential cycles of cyclophosphamide (CTX) at 3 g/m2 every 15 days with G-CSF support. 71% of these patients had stage IIIa, 23% had renal failure. The median age was 58, median beta-2 microglobulin 4.6 and median albumin was 3.5, indicating poor prognosis. Of 35 patients, 66% achieved a complete response (CR) (SWOG). Six patients (18%) had a partial response. Fifty percent of the patients with renal failure recovered their kidney function. High-dose CTX contributed to tumor-mass reduction particularly in patients presenting with high-tumor burden. Tumor-mass reduction following three pulses of dexamethasone (4 days each) is significantly higher than with one pulse (p < 0.005). While high beta-2 microglobulin and LDH levels (p < 0.05) were associated with poor outcome, patients who responded faster to chemotherapy had a longer survival (p = 0.005). We conclude that this regimen is safe and effective. A rapid response may be useful in selecting patients who may benefit from further high dose chemotherapy and stem cell support.

Thiotepa, busulfan, cyclophosphamide (TBC) and autologous hematopoietic transplantation: an intensive regimen for the treatment of multiple myeloma

The study was designed to evaluate the efficacy and safety of an intensive, tri-alkylator conditioning regimen, consisting of thiotepa, busulfan and cyclophosphamide (TBC), prior to autologous hematopoietic cell transplantation in patients with multiple myeloma (MM) and to analyze factors associated with outcome. One hundred and twenty patients with MM received high-dose chemotherapy with TBC followed by autologous bone marrow (n = 24) or peripheral blood stem cell (PBSC) transplantation (n = 96). Fifty-four patients had chemosensitive disease and 66 had refractory disease at the time of transplantation. The overall response rate was 81% and the complete remission (CR) rate was 26%. Patients with chemosensitive disease had a CR rate of 52% vs 5% for patients with refractory disease. Multivariable analysis determined disease status at transplant as the factor most likely associated with long survival. Estimated median survival was 48, 35 and 9 months for patients with chemosensitive, primary refractory or disease in refractory relapse, respectively. Short interval from diagnosis to transplant among patients with primary refractory disease and younger age were also favorable prognostic factors for survival. Patients with refractory disease pre-transplant who achieved remission criteria rapidly after treatment had a worse outcome than the slow responders. Treatment-related mortality with the introduction of PBSC and better supportive care was 4.8%. In conclusion, TBC is an effective and relatively well-tolerated intensive conditioning regimen in patients with MM. A more favorable outcome was observed in patients with chemosensitive disease and with early treatment for primary refractory disease. TBC merits further study in these subgroups and comparison with alternative regimens in prospective studies is warranted.

The bone marrow plasma cell labeling index by flow cytometry

The bone marrow plasma cell labeling index is the most important prognostic indicator for patients with multiple myeloma. Traditionally, this test has been performed as a two color immunofluorescent microscope technique which is time consuming and requires a degree of subjectivity in its interpretation. We have assessed various adaptations of this method to flow cytometry. A bromodeoxyuridine method has been compared with a propidium iodide DNA method to detect cells in S phase and CD38-FITC has been compared with CD38-FITC + CD138-FITC and CD38-biotin + streptavidin FITC to identify plasma cells. The mean channel fluorescent intensity of the plasma cell peaks for each of these markers was 12. 7, 17.4 and 35.3 respectively demonstrating the superiority of CD38-biotin + streptavidin FITC. Analysis after propidium iodide staining provided a good correlation with the slide technique (r = 0. 71; P < 0.0001) but the bromodeoxyuridine method did not correlate with the slide method (r = 0.09; P = NS). The labeling index values obtained from either of the flow methods were greater than the microscopic method. Thus a labeling index of >4% will replace the traditional >1% threshold for identifying patients with a significantly increased labeling index. The advantages of the new method are that it takes less time to perform, is more objective and provides additional data on ploidy and cell cycle status.

Prognostic factors in multiple myeloma

There is significant variation in the survival of patients with myeloma. This article reviews the major prognostic factors in myeloma and the evidence supporting their usefulness in clinical practice and research. The factors reviewed include serum beta 2-microglobulin, bone marrow plasma cell labeling index, cytogenetics, plasmablastic morphology, and other standard clinical laboratory variables. Novel factors such as bone marrow angiogenesis are also discussed. A combination of independent factors provides greater prognostic information than any one factor alone, and survival data using various combinations of prognostic factors are presented.

Risk groups of myeloma patients by histologic pattern and proliferative activity

We investigated the histologic pattern and the cell proliferative activity of myeloma cells by the analysis of the nucleolar organizer regions (AgNORs) in bone marrow biopsy specimens from 150 multiple myelomas at diagnosis. The objective was an attempt to define risk groups of myeloma patients. On univariate analysis, the percentage of bone marrow plasma cells (BMPC%), the pattern of infiltration, the degree of plasma cell (PC) atypia, the marrow fibrosis, and the number of AgNOR/PC were correlated with survival time. On multivariate analysis, only AgNOR counts and pattern of infiltration retained independent prognostic significance. At 4-year followup, all patients with BMPC% < or = 20, interstitial pattern of invasion, and well-differentiated (G1) PC plus AgNOR/cell < or = 3.32 were alive, while no patient with BMPC% >50, diffuse pattern of infiltration, and poorly differentiated (G3) PC plus AgNOR/cell >5.15 survived (p < 0.0001). In conclusion, the histologic pattern and proliferative activity of myeloma cells, evaluated by AgNOR counts, are reliable predictors of survival in myeloma. Both parameters can be easily assessed in the same biopsy specimen, are reproducible, and permit identification of a group of patients with favourable outcome at 4-year followup. Thus, bone marrow biopsy should always be included in the diagnostic procedures for myeloma patients.

Diagnosis, prognosis, and standard treatment of multiple myeloma

The diagnosis of multiple myeloma (MM) is often difficult; most patients present with asymptomatic gammopathy. The only findings that confirm a diagnosis of MM are an elevation in the M-component or extension of the lytic bone lesions that are the hallmark of the disease. Tests that delineate plasma cell biology, such as plasma cell proliferation rate, are helpful; magnetic resonance imaging can disclose bone marrow lesions leading to subsequent osteolytic disease. After the diagnosis of MM has been established and prognostic factors identified, the appropriate therapy can be determined. Melphalan and prednisone are no longer considered to be the "gold standard" of therapy. In fact, this approach is suitable for less than half of patients with myeloma. This article presents guidelines for standard treatment options and examines the efficacy of new high-dose chemotherapy approaches.

Prognostic variable in patients with advanced colorectal cancer treated with fluorouracil and leucovorin-based chemotherapy

Possible prognostic variables for tumor response, time to progression (TTP), and survival in 141 patients with advanced colorectal cancer treated with fluorouracil and leucovorin-based chemotherapy were analyzed. None of the variables examined for their possible influence on tumor response attained significance in the stepwise logistic regression. In the univariate analysis, variables found to be strongly associated with TTP were performance status (PS) (P = 0.0301), liver involvement (P = 0.030), and the initial values of WBC (P = 0.0319), lactic dehydrogenase (LDH; P = 0.0053), gamma-glutamyl-transpeptidase (gamma-GT; P = 0.0013), alkaline phosphatase (ALP; P = 0.0186), albumin (P = 0.0004), and carcinoembryonic antigen (CEA; P = 0.0014). In the Cox analysis, liver involvement (P = 0.0553), albumin (P = 0.0181), PS (P = 0.484), and ALP (P = 0.0553) were retained as independently significant variables. When only patients with liver metastases were included in the analysis, then only albumin (P < 0.001) demonstrated a prognostic significance. Also, in the univariate analysis, variables predicting survival were PS (P = 0.0230), grade (P = 0.00600), liver involvement (P = 0.0002), LDH (P = 0.0001), gamma-GT (P < 0.001), ALP (P = 0.0006), albumin (P = 0.0309), and CEA (P = 0.005). With the multivariate analysis, gamma-GT (P = 0.0004), albumin (P = 0.0634), and CEA (P = 0.0804) were selected as significant. In those patients who presented with liver involvement, variables predicted survival were gamma-GT (P = 0.0041), albumin (P = 0.0442), and the percentage of involved liver parenchyma (P = 0.0690). These results could be helpful for the stratification of future trials in advanced colorectal cancer.

Correlation between argyrophilic nucleolar organizer region counts and labelling index in multiple myeloma

The correlation between the bromodeoxiuridine (BrdU)-labelling index (LI) of plasma cells and a new proliferation marker, the Argyrophilic Nucleolar Organizer Regions (AgNORs), was investigated in 44 myeloma patients at diagnosis. A preliminary analysis was made to verify the reproducibility of the assessment of plasma cell infiltration (PC%) in bone marrow aspirates, used to collect cells for LI determination, and in bone marrow biopsies, used for AgNORs evaluation. Although an overall good correlation was observed between PC% in biopsies and aspirates (r=0.58, p=0.001), the ratio between PC% in biopsies and in aspirates ranged form 0.35 to 7.5. Only 17 patients (38.6%) were within the 0.5-1.5 range. A positive correlation between LI and AgNORs was observed in these patients (r=0.68, p=0.003), whereas the correlation was lost in patients with higher ratio between PC% in biopsies and in aspirates (r=0.08, p=0.69). The prognostic significance of AgNORs was confirmed by survival analysis, showing a reduced survival for patients with high (>4.4) AgNOR counts (14 months vs 35 months, p=0.004). The AgNORs analysis therefore allows the simultaneous evaluation of myeloma cell infiltration, degree of differentiation and kinetics of growth in bone marrow biopsies. AgNOR counts deserve to be included in the procedures for diagnosis and prognostic evaluation of myeloma patients.

Plasma cell dyscrasias: classification, clinical and laboratory characteristics, and differential diagnosis

Plasma cell dyscrasias form a heterogeneous group of diseases characterized by the expansion of the number of monoclonal bone marrow plasma cells that produce monoclonal immunoglobulins. Sensitive electrophoretic methods have shown that the incidence of these diseases is as high as 5% in adult individuals. Thus, the majority of cases should be considered to be a normal phenomenon. A few transform into neoplastic diseases, plasma cells becoming responsible for lytic bone lesions, the hallmark of MM. The distinction of benign and malignant forms is frequently difficult at presentation. We can easily recognize solitary myeloma, overt myeloma and plasma cell leukaemia, which require immediate chemotherapy. Therapy could be safely withheld in all the remaining forms, which require only follow-up. Thus, we suggest that plasma cell dyscrasias should be classified simply into two main groups according to the need of immediate chemotherapy. The appearance of new bone lesions and the increase of the M-component level remain the only two criteria that define malignant transformation. Several clinical and laboratory prognostic parameters indicate the risk of transformation, and hence how close the follow-up of the patient should be. Parameters related to the expansion of the plasma cell clone (percentage of bone marrow plasma cells, M-component level, lytic bone lesions and beta 2-microglobulin) are not always very low and very high in the benign and malignant forms, respectively, and frequently overlap in patients with intermediate plasma cell expansions. On the contrary, all parameters related to the intrinsic malignancy of the plasma cells (plasma cell LI, Karyotypic abnormalities and molecular alterations) have, by definition, to be normal in the benign forms. MRI is a new tool that may, early on, reveal lytic bone lesions undetectable by conventional radiography.

Angiogenesis in B cell lymphoproliferative diseases. Biological and clinical studies

Angiogenesis is a necessary step in solid tumor progression (growth, invasion and metastasis) with which it correlates and is indicative of an unfavourable prognosis. We observed bone marrow angiogenesis in patients with active multiple myeloma (MM), though not in patients with non-active MM nor with monoclonal gammopathies of undetermined significance (MGUS). Microvessel density increased in parallel with the labeling index (LI%)--an indicator of plasma cell proliferating activity that correlates with prognosis--and defined a risk of MM progression in much the same way as LI% itself. Consequently, bone marrow angiogenesis could be an indication for unfavourable prognosis in MGUS and MM. Angiogenesis has also been demonstrated in lymph nodes involved by B cell non Hodgkin's lymphoma (B-NHL) belonging to the Working Formulation intermediate-grade (diffuse subtypes), and high-grade categories, but not in the low-grade and intermediate-grade (follicular subtype) categories. It correlated with the B-NHL cell proliferating activity, since large increments in this activity have already been demonstrated in intermediate- and high-grade vs low-grade tumors. Active MM, intermediate-grade, diffuse subtypes, and high-grade B-NHLs correspond to the vascular phases of B cell lymphoproliferative diseases, and could thus be assimilated to locally invasive and metastatic solid tumors. Similarly to solid tumors during these stages of progression, tumor B cells are also capable of inducing angiogenesis, both directly and indirectly by activating the inflammation infiltrate--a possibility that was first demonstrated by means of B-NHL implants onto the chick embryo chorioallantoic membrane. Anti-angiogenic therapy can be envisaged as a possible future development.

S-phase cells of the lymphoplasmocytic compartment in hyperdiploid multiple myeloma are diploid cells

In vivo S-phase cell labeling with iododexoyuridine (IdUrd) was performed in six multiple myeloma (MM) patients. Myeloma cells from four patients were hyperploid. In three out of four patients, DNA/IdUrd flow cytometry revealed that most of the labeled cells, which had divided during the period, elapsed between flash labeling and sampling, had returned to the diploid G0/G1 compartment and not to the hyperdiploid peak. To eliminate contaminating cells belonging to the normal hematopoiesis, plasmocytic and lymphocytic cells were fractionated and analyzed separately. Cell enrichment was performed with use of murine monoclonal antibodies (MoAbs) against plasmocytic and lymphocytic cell markers and subsequent magnetic activated cell sorting with immunobeads, i.e., polysterene magnetic particles coated with sheep anti-mouse IgG. The purified plasmocytic cells were mainly hyperdiploid and largely unlabeled. The lymphocytic cells appeared to belong chiefly to the diploid cell population. The IdUrd-labeled cells were predominantly lymphocytic cells, returning after mitosis to the diploid G0/G1 peak. Although this pattern of S-phase cells in hyperdiploid MM, belonging to the diploid cell compartment, was observed in three out of four hyperploid cases and although the number of observations is small, S-phase cells may demonstrate an aspect of tumor cell kinetics in hyperploid MM, which has been debated for many years and which indicates the existence of a non-plasmocytic stem cell compartment that feeds the plasmocytoma. The behavior of the labeled cells as observed in a few cases of MM provides another, hitherto undescribed, argument that, at least in some MM patients, a part of the proliferating tumor cells may be diploid lymphocytic (precursor) cells. These findings should be considered when targeting and monitoring treatment of MM and also in purging procedures of bone marrow in patients to be treated by ablative cytotoxic therapy and autologous bone marrow transplantation.

Retinoic acid inhibits the growth of human myeloma cells in vitro

Retinoic acid has been shown to induce growth inhibition in a variety of cell types including human myeloma cell lines. Bone marrow plasma cells from 31 multiple myeloma (MM) patients were cultured to investigate the activity of 13-cis-retinoic acid (cRA), all-trans-retinoic acid (tRA), interferon-alpha (IFN-alpha), interferon-gamma (IFN-gamma), and dexamethasone (DEX), alone or in combination, on in vitro proliferation and immunoglobulin (Ig) secretion. Both cRA and tRA inhibited proliferation: the labelling index (LI) of treated cultures/controls, was 0.47 +/- 0.05 (mean +/- standard error mean, M +/- SEM) P < 0.0001, and 0.67 +/- 0.04 (M +/- SEM), P < 0.0001, respectively. The inhibitory effect of cRA was significantly superior to tRA (P = 0.0129) and IFN-alpha, similar to IFN-gamma and DEX. The combinations of cRA + IFN alpha, tRA + IFN-gamma, tRA + DEX did not show any synergistic effect on myeloma proliferation. In contrast, the combination cRA + DEX (0.29 +/- 0.04, M +/- SEM) markedly increased the effect of both cRA and DEX used as single agents. Ig synthesis was not significantly affected by CRA, tRA, IFN-gamma and the combination tRA + IFN-gamma. As expected, only IFN-alpha (P = 0.002) and DEX (P < 0.001) inhibited Ig production. The combinations cRA + IFN-alpha, cRA + DEX and tRA + DEX decreased Ig secretion to the same extent as IFN-alpha and DEX alone respectively. In conclusion, our data indicate that tRA and especially cRA strongly inhibited plasma cell proliferation but had no effect on Ig synthesis. The combination of cRA + DEX showed the highest degree of inhibitory activity of all cytokines, alone or in combination.

Prognostic factors in myeloma: what they tell us about the pathophysiology of the disease

Prognostic factors in myeloma are not only important for allowing comparisons to be made between therapeutic protocols but they also provide us with an insight into the pathophysiology of the disease and important mechanisms which result in disease progression. Prognostic factors in myeloma relate to the inherent proliferative capacity of the malignant clone, tumor bulk, renal function and other factors which reflect tumor host and host tumor interactions. The highly significant effect of the labelling index (LI) suggests that the clonogenic cell is ontologically very close to the malignant plasma cell on which the labelling index is derived. The explanation for the important role of the beta 2-microglobulin (beta 2M) level over and above its reflection of renal function is as yet unclear. Other factors involved in prognosis such as serum cytokines (IL-2 and IL-6) and soluble IL-6 receptor levels reflect host tumor interactions. An understanding of these interactions may allow us to control the disease and prevent escape from plateau phase by biological means. This may become a viable alternative to high dose aggressive chemotherapy which up till now appears unable to eradicate the malignant clone.

Prognosis in myeloma

OBJECTIVE

To review biologic factors that may be useful in determining prognosis in patients with myeloma.

DESIGN

The currently available clinical variables and staging systems were assessed for their predictive value in myeloma, and newly proposed prognostic factors were summarized.

RESULTS

Because some patients with myeloma may potentially benefit by new, more intensive therapies such as stem cell transplantation or may have prolonged survival with standard therapy, determining factors that would distinguish such patients is important. Independent prognostic factors such as the plasma cell labeling index and beta 2-microglobulin have repeatedly outperformed other prognostic clinical variables and can be combined into a system that identifies poor, intermediate, and good prognostic groups of patients with myeloma. New factors are needed to improve on the predictive value of these two variables. Studies of the biologic features of myelomas have led to the discovery of soluble interleukin 6 receptor (sIL 6R) in the serum. sIL 6R enhances the myeloma cell response to interleukin 6, a central growth factor that affects myeloma cell proliferation. Preliminary studies by the Eastern Cooperative Oncology Group show that sIL 6R predicts survival independent of the plasma cell labeling index and beta 2-microglobulin. Other proposed independent prognostic factors include cytokines and their soluble receptors, regulatory T cells, circulating myeloma cells, myeloma cell precursors, and markers of proliferation, apoptosis, and drug resistance.

CONCLUSION

Because of wide variation in duration of survival, the prognosis of patients with myeloma, a fatal bone marrow plasma cell neoplasm, cannot yet be adequately predicted. Better prognostic factors are needed for stratification in clinical trials, counseling of patients, and designing of new therapeutic trials.

N- and K-ras oncogenes in plasma cell dyscrasias

N- and K-ras oncogene mutations represent the most frequent molecular lesions in plasma cell dyscrasias. They are not randomly distributed since they are detectable in multiple myeloma (MM) (9-31%) and plasma cell leukemia (PCL) (30%), and not in monoclonal gammopathy of undetermined significance (MGUS) and solitary plasmacytoma (SP). Codons 12, 13 and 61 of N- and K-ras genes have been found mutated. Mutations affecting codon 61 of N-ras gene are the most frequent finding. A heterogeneous pattern of mutations is described with a prevalence of purine-pyrimidine transversions. Ras gene mutations have been predominantly detected in myelomas characterized by an advanced stage disease, and adverse prognostic parameters. These findings suggest that ras mutations represent a late molecular lesion and may be implicated in tumor progression rather than tumor initiation.

Impact of response to treatment on survival in multiple myeloma: results in a series of 243 patients

Two hundred and forty-three patients diagnosed with multiple myeloma (MM) in a single institution over a 22-year period and treated with standard chemotherapy were analysed in an attempt to determine the impact of response to therapy on survival. The overall response rate in 229 evaluable patients was 50.1% (34.9% objective response plus 15.2% partial response). Median survivals of patients with objective and partial response were 43.4 and 42.8 months, respectively, versus 19 months for nonresponders. Median survival of 14 patients who achieved a complete remission was 42 months, whereas in 21 rapid responders (< or = 2 months) median survival was 43.3 months. A significant correlation between response and survival was observed with the landmark (P = 0.0169), the Mantel & Byar (P = 0.0001) and the Cox regression model (P < 0.0001) methods. These results indicate that, in responding patients, neither the degree of response nor the response kinetics has a significant influence on survival. However, the response to therapy is associated with a significantly longer survival in MM patients.

Recombinant interferon-gamma inhibits the in vitro proliferation of human myeloma cells

Interferon-alpha (IFN-alpha), interferon-gamma (IFN-gamma) and dexamethasone (DEX) have shown anti-tumour effects in multiple myeloma (MM) cells. Bone marrow plasma cells from 39 MM patients were cultured to clarify the intensity and specific activity of each compound on bromo-deoxyuridine (BrdUrd) uptake and immunoglobulin (Ig) secretion. BrdUrd uptake was inhibited by recombinant human IFN-gamma (100 U/ml) and by DEX (10(-6) M). The stimulation index (StI), i.e. labelling index (LI) of treated samples/controls, was 0.49 +/- 0.09 (mean +/- standard error of the mean, M +/- SEM), P = 0.0003, and 0.52 +/- 0.07 (M +/- SEM), P < 0.0001, respectively. Ig secretion was reduced by IFN-alpha (100 U/ml) and DEX. The secretion index (SI), i.e. Ig quantitation of treated samples/controls, was 0.04 (M +/- SEM), P < 0.0001, and 0.52 +/- 0.04 (M +/- SEM), P < 0.0001, respectively. Finally, IFN-gamma inhibits BrdUrd uptake only and IFN-alpha secretion only. In 18 patients the simultaneous addition of IFN-alpha plus IFN-gamma mainly parallel the effect of IFN-gamma on BrdUrd uptake and IFN-alpha on secretion, but not result in any additive or synergistic effect, though both BrdUrd uptake and Ig secretion were decreased to about the same extent as with DEX. These data indicate that the combination of IFN-alpha plus IFN-gamma and DEX are the strongest inhibitors of both BrdUrd uptake and secretion. Since IFN-alpha and IFN-gamma appear to have a different mechanism of action, their combined use could be considered as a possible new treatment strategy.

AgNORs and myeloma prognosis

The argyrophilic nucleolar organizer regions (AgNORs) were analysed in bone marrow biopsies from 80 patients with multiple myeloma (MM) at presentation. The mean AgNOR number per MM cell (AgNOR counts) and their distribution within the nucleus (configuration) were assessed. AgNOR counts were significantly associated with several recognized prognostic factors: Durie and Salmon clinical staging system (p = 0.02), percentage of plasma cells (PCs) in aspirates (p = 0.01) and in bone marrow biopsies (p = 0.0000), pattern of bone marrow involvement (p = 0.0003), calcaemia (p = 0.0005) and creatininaemia (p = 0.0003). AgNOR counts were also associated with the degree of PC differentiation (p = 0.0000). A single central cluster of 2-3 large-sized AgNORs (configuration A) was evident in most G1 MM; one cluster of 4-5 medium-sized dots or two clusters of 2-4 dots (configuration B) were seen in most G2 MM; many small-sized, scattered dots were present in G3 MM (configuration C). AgNOR counts and configuration were related to the prognosis: in the univariate analysis, the 5 year survival rate was 7% for cases with > 4.5 AgNORs/cell and 46% for cases with < or = 4.5 AgNORs/cell (p = 0.01), 53% for configuration A, 12% for configuration B and 0% for configuration C (p = 0.0000). AgNOR counts (p = 0.02) and configuration (p = 0.000) were independent prognostic variables in the multivariate analysis. The AgNOR counts were significantly higher in "fulminant myeloma" than in less aggressive cases (p = 0.002). The plasma cell labelling index (LI%), evaluated in 44 MM patients, showed significant correlation with prognosis: the 5 year survival rate was 51% for LI% < or = 1 and 17% for LI% > 1 (p = 0.02). More than 70% of patients with low LI% had low AgNOR counts and more than 70% of patients with high LI% had high AgNOR counts (p = 0.007). AgNOR counts and configuration reflect the myeloma cell mass, the degree of differentiation and the kinetics of the myeloma cells. They offer an exact evaluation of the tumour characteristics and can be useful additional parameters for MM prognosis.

Multiple myeloma: 'early' plasma cell phenotype identifies patients with aggressive biological and clinical characteristics

The immunological phenotype of bone marrow myeloma cells and peripheral blood lymphocytes was evaluated in 38 untreated myeloma patients. A striking increase of monotypic cells expressing the same light chain as the M component was observed in bone marrow from 18/38 (47%) patients. A two-colour analysis clarified that the majority of myeloma cells co-expressed plasma cell and B lymphocyte markers (cyIg, CD38, CD56 and sIg), and were regarded as early-plasma cells (early-PC). In the remaining patients, myeloma cells expressed plasma cell markers only (late-PC). Phenotype corresponded to a distinct morphological pattern: early-PC showed a lympho-plasmocytoid feature with significantly lower diameters than late-PC (12.1 v 14.8 microns, P < 0.007). Moreover, the plasma cell labelling index was significantly increased in early-PC patients (1.2 v 0.5%, P < 0.04). In peripheral blood from patients with early-PC, monotypic cells co-expressing sIg and CD38, CD56, but not CD19, were also detected. These data suggest a recirculation of early-PC. Myeloma cells maintained their phenotypic pattern during the course of the disease. This observation suggests that the degree of maturation is an intrinsic characteristic of the myeloma cell population in individual patients. The evaluation of prognostic factors, such as beta 2-microglobulin, C-reactive protein and neopterin, showed a statistically significant increase in the early-PC patients, suggesting a poor outcome. In conclusion, myeloma cell phenotype allows identification of a myeloma variant with aggressive biological and clinical characteristics.

The biological and clinical significance of the KI-67 growth fraction in multiple myeloma

We tested the significance of the Ki-67 plasma cell growth fraction in 49 bone marrow samples from 42 patients with multiple myeloma (MM). As a new approach to study myeloma cell proliferation, strong positivity of the CD38 antigen as plasma cell related feature was simultaneously evaluated with nuclear Ki-67 expression in a flow cytometric double immunofluorescence assay. Mean Ki-67 values were significantly higher in MM at relapse (22.4 per cent +/- 10.4) as compared with MM at diagnosis (11.9 per cent +/- 8.4, p less than 0.005) and plateau-phase (10.0 per cent +/- 5.5, p less than 0.001), respectively. Serial observations in six patients confirmed this change in cell kinetic behaviour during the course of the disease. Elevated Ki-67 values correlated significantly with stage III (versus stage I, p less than 0.05), beta-2-microglobulin serum levels greater than 6 (p less than 0.001), plasmablastic morphology (p less than 0.001), and diploid myeloma cell DNA-content (p less than 0.005). No correlation was found between Ki-67 and immunoglobulin isotypes as well as immunophenotypic features (expression of CD10, CD33, and CD56) of myeloma cells. Clinically, six of seven patients with Ki-67 greater than 14 per cent at diagnosis had an unfavourable course (primary resistant disease or early relapse), and three of four patients with elevated Ki-67 values at plateau-phase relapsed within 3 months. Our results demonstrate the usefulness of Ki-67 in determining proliferative activity in MM and emphasize its value in the evaluation of the risk profile of MM patients.

No correlation between response and survival in patients with multiple myeloma treated with vincristine, melphalan, cyclophosphamide, and prednisone

A vincristine, melphalan, cyclophosphamide, and prednisone (VMCP) multi-drug regimen was used in 85 previously untreated patients with multiple myeloma (MM) (symptomatic Durie Stages II and III) until they became refractory. The prognostic significance of various pretreatment characteristics was evaluated in terms of therapeutic response (according to Southwest Oncology Group [SWOG] and Chronic Leukemia-Myeloma Task Force [TF] criteria) and survival. Therapeutic responses, obtained in 31.2% (SWOG) and 68.7% (TF) of patients, had a significant inverse correlation with myeloma cell mass, serum calcium, and bone status. Median survival time of Stage II and Stage III patients was 39 and 34 months, respectively. Serum B2 microglobulin greater than or equal to 6 micrograms/ml was the only variable correlating unfavorably with survival duration after multi-variate analysis (increased risk = 2.79), although therapeutic response as a time-dependent variable had no effect on survival. These data suggest no correlation between response and survival, partially because of inadequate response assessment criteria and partially because no existing treatment is curative (although current therapeutic approaches may prevent death from complications).

Lack of correlation between objective response and death rate in multiple myeloma patients treated with oral melphalan and prednisone

An analysis of survival by response category was performed on 76 patients with stage II and III multiple myeloma, who were treated with oral melphalan and prednisone. The analysis demonstrated a survival advantage for responders over non-responders only in stage III patients (32.3 months for responders vs. 15.6 months for non-responders, p = 0.03). However, two possible sources of error must be considered: a) the poor prognosis of early responders that may adversely affect the survival of all responders, and b) the bias introduced by the 'guarantee time' of responders (i.e., the time on-study required to detect the response). Exclusion from the analysis of the unfavourable subgroup of 'early' responders (median survival 14.7 mos.) provided an improvement of the difference in survival between the remaining 'slow' responders and non-responders in stage III (p = 0.005) as well as in the series as a whole (p = 0.025). Because of the consistent 'guarantee time' of slow responders, the Mantel-Byar test (which credits survival to responders only after the response has been obtained) was then applied. The survival advantage of slow responders over non-responders, previously observed in all patients, particularly those with stage III, was not confirmed by the Mantel-Byar test (chi-square 0.831 and 1.457, respectively), thus supporting the hypothesis of an equal death rate over time in each response category. It therefore appears that the usual response criteria (which require at least a 50% reduction of the myeloma protein) should perhaps be reassessed, as they seem to be an inadequate parameter for evaluation of treatment effectiveness in multiple myeloma.