A phase I study of two dosing schedules of volasertib (BI 6727), an intravenous polo-like kinase inhibitor, in patients with advanced solid malignancies

BACKGROUND

Polo-like kinase 1 (Plk1) has an important role in mitosis. Volasertib (BI 6727), a potent and selective cell cycle kinase inhibitor, induces mitotic arrest and apoptosis by targeting Plk; this phase I study sought to determine its maximum tolerated dose (MTD) in Asian patients with advanced solid tumours.

METHODS

Patients were enrolled simultaneously into two 3-week schedules of volasertib: a 2-h infusion on day 1 (schedule A) or days 1 and 8 (schedule B). Dose escalation followed a 3+3 design. The MTD was determined based on dose-limiting toxicities (DLT) in the first treatment course.

RESULTS

Among 59 treated patients, the most common first course DLTs were reversible thrombocytopenia, neutropenia and febrile neutropenia; MTDs were 300 mg for schedule A and 150 mg for schedule B. Volasertib exhibited multi-exponential pharmacokinetics (PK), a long terminal half-life of ∼135 h, a large volume of distribution (>3000 l), and a moderate clearance. Partial responses were observed in two pre-treated patients (ureteral cancer; melanoma). Volasertib was generally well tolerated, with an adverse event profile consistent with its antimitotic mode of action and a favourable PK profile.

CONCLUSIONS

These data support further development of volasertib and a harmonised dosing for Asian and Caucasian patients.

Three-year oral clodronate treatment does not impair mineralization of newly formed bone--a histomorphometric study

Bisphosphonates have been used successfully in the treatment of malignant hypercalcemia and skeletal metastases. Recently, clodronate has been studied in adjuvant settings in primary breast cancer. However, long-term effect of adjuvant clodronate on bone histology has not been reported, whereas bone mineral density studies have been published. The aim of this study was to examine the effect and safety of long-term clodronate treatment on bone quality as measured by histomorphometric techniques from bone biopsies. A total of 299 patients with early stage breast cancer were randomized to receive adjuvant oral clodronate (1.6 g/day) or to a control group for 3 years. All patients had adjuvant treatment: premenopausal women had six cycles of chemotherapy and postmenopausal women had antiestrogen for 3 years. Trabecular bone quality was examined in transiliac bone biopsy specimens by using histomorphometric techniques in 28 clodronate treated and 35 control patients who were disease-free at 3 years and who allowed the biopsy specimen to be obtained. No statistically significant differences were found in the values of osteoid, mineral apposition rate, or mineralization lag time in bone biopsies between the clodronate and the control groups. Postmenopausal women who received two antiresorptive drugs, antiestrogen and clodronate, developed features of secondary hyperparathyroidism with increased eroded surface and osteoclast number. In premenopausal, women clodronate with adjuvant chemotherapy, which induced early menopause and rapid bone loss in most of the patients, seemed to conduct slight depression in bone formation. Three-year oral clodronate treatment does not impair mineralization of newly formed bone: however, clodronate with different adjuvant breast cancer treatments has a diverse impact on bone histomorphometry depending on the type of therapy.

Comparison between TaqMan and LightCycler technologies for quantification of minimal residual disease by using immunoglobulin and T-cell receptor genes consensus probes

Quantification of residual leukemic cells at early time points during therapy can reliably predict the outcome in children with acute lymphoblastic leukemia (ALL). Recently, semiquantitative minimal residual disease (MRD) detection assays such as dot-blot hybridization have been replaced by real-time quantitative PCR. We tested the flexibility of the two most used real-time PCR machines: the SDS 7700 or 'TaqMan' (TM) (Applied Biosystems) and the LightCycler (LC) (Roche) instruments. Clonal T-cell receptor and immunoglobulin gene rearrangements were used for MRD detection with germline hydrolyzation probes and clone-specific primers. Sensitivity tests for 65 clonal gene rearrangements and MRD quantification in 90 bone marrow samples during therapy of 49 children with ALL at diagnosis or relapse were performed with both machines. Both real-time PCR systems provided specific results for MRD quantification in all follow-up samples. In conclusion, we were able to demonstrate that TM and LC real-time PCR technologies produce similar MRD quantification results and that the quantification assays can be easily transferred from one detection system to the other. Using the same detection format, both techniques can be applied in combination in multicenter MRD studies.

Relapse of TEL-AML1--positive acute lymphoblastic leukemia in childhood: a matched-pair analysis

PURPOSE

The aim of this study was to investigate whether, in relapsed childhood acute lymphoblastic leukemia (ALL), the frequent genetic feature of TEL-AML1 fusion resulting from the cryptic chromosomal translocation t(12;21)(p13;q22) is an independent risk factor.

PATIENTS AND METHODS

A matched-pair analysis was performed within a homogeneous group of children with first relapse of BCR-ABL-negative B-cell precursor (BPC) ALL treated according to relapse trials ALL-Rezidiv (REZ) of the Berlin-Frankfurt-Münster Study Group. A total of 249 patients were eligible for this study: 53 (21%) were positive for TEL-AML1, and 196 (79%) were negative. Positive patients were matched for established most-significant prognostic determinants at relapse, time point, and site of relapse, as well as age and peripheral blast cell count at relapse.

RESULTS

Fifty pairs matching the aforementioned criteria could be determined. The probabilities with SE of event-free survival and survival at 5 years for matched TEL-AML1 positives and negatives are 0.63 +/- 0.10 versus 0.38 +/- 0.10 (P =.09) and 0.82 +/- 0.09 versus 0.42 +/- 0.19 (P =.10), respectively. These results were confirmed by multivariate analysis, revealing an independent prognostic significance of time point and site of relapse (both P <.001) but not of TEL-AML1 expression (P =.09).

CONCLUSION

TEL-AML1 expression does not constitute an independent risk factor in relapsed childhood BCP-ALL after matching for relevant prognostic parameters. It undoubtedly characterizes genetically an ALL entity associated with established favorable prognostic parameters. High-risk therapeutic procedures such as allogeneic SCT should be considered restrictively.

Unusual T-cell receptor-delta gene rearrangement patterns revealed by screening of a large series of childhood acute lymphoblastic leukaemia by multiplex polymerase chain reaction

Rearrangements of the T-cell receptor (TCR) and immunoglobulin genes are considered as useful clonal markers in lymphoproliferative disorders of B- and T-cell lineage, and are frequently used for the detection of minimal residual disease (MRD). In this paper, we report on the unexpected results of an extensive analysis of TCR-delta chain gene rearrangement frequencies and patterns in leukaemic bone marrow DNA samples collected from 438 children with initial (n = 112) or relapsed (n = 326) acute lymphoblastic leukaemia (ALL). By applying a previously described multiplex polymerase chain reaction, the overall incidence of non-deleted TCR-delta gene rearrangements in ALL was 47% (206/438), 52% in initial ALL (58/112) and 45% in relapsed ALL (148/326). As expected, the majority of B-cell precursor (BCP) ALL had incomplete Vdelta2-Ddelta3 or Ddelta2-Ddelta3 TCR-delta gene rearrangements, whereas most T-ALL showed complete rearrangements of the TCR-delta gene locus (Vdelta1-Jdelta1, Vdelta2-Jdelta1, Vdelta3-Jdelta1). However, unexpectedly, 5/206 rearranged TCR-delta alleles in BCP-ALL showed a complete Vdelta-(Ddelta)-Jdelta gene rearrangement pattern, and 3/31 T-ALL had an incomplete recombination. Theoretically, complete TCR-delta gene rearrangements should not occur in cells other than T-lymphocytes and have only been reported once previously in BCP-ALL. The data contribute to the discussion about the reliable screening for clonal markers in ALL.

Specific reverse transcription-PCR quantification of vascular endothelial growth factor (VEGF) splice variants by LightCycler technology

BACKGROUND

Overexpression of vascular endothelial growth factor (VEGF) is associated with increased angiogenesis, growth and invasion in solid tumors, and hematologic malignancies. The expression of isoforms of VEGF, which mediate different effects, can be discriminated by splice-variant-specific quantitative reverse transcription-PCR (RT-PCR), but current methods have only modest sensitivity and precision and suffer from heteroduplex formation.

METHODS

We used a real-time RT-PCR assay on the LightCycler system. Applicability for detection of different VEGF mRNAs and total VEGF message was tested on seven healthy tissues (each pooled from healthy donors) and seven correlated malignant tissues. Results were normalized to beta(2)-microglobulin mRNA. Amplification of VEGF splice variants was performed exclusively with variant-specific reverse primers, whereas forward primer and fluorescent probe were common to obtain similar RT-PCR kinetics.

RESULTS

Highly specific detection of VEGF splice variants was achieved with minor intra- and interassay variation (<0.22 threshold cycle). Total VEGF expression was higher in malignant tissues. In healthy tissues, the mRNA encoding diffusible variants VEGF(121) and VEGF(165) constituted on average 78% (SD = 9.3%) of the total VEGF message, and the cell-adherent variant VEGF(189) constituted on average 22% (SD = 5.4%). In contrast, in malignant tissues VEGF(121) and VEGF(165) accounted for 94% (SD = 7.6%) and VEGF(189) only 6% (SD = 3.7%).

CONCLUSIONS

Because of the ability for quantification of VEGF splice variants with high specificity, sensitivity, and reproducibility, this new LightCycler assay is superior to conventional semiquantitative competitive RT-PCR and immunological assays and may contribute to better understanding of VEGF-mediated angiogenesis.

Molecular quantification of response to therapy and remission status in TEL-AML1-positive childhood ALL by real-time reverse transcription polymerase chain reaction

Although TEL-AML1 positivity [translocation t(12;21)(p13;q22)], detected in 20-25% of initial childhood acute lymphoblastic leukemia (ALL), has been associated with an excellent prognosis, its positive predictive value is insufficient for appropriate treatment stratification considering reported prevalence in relapsed ALL (3-28%). Molecular quantification of response to therapy by PCR-based methods has been shown to improve risk assessment. Here, we report on the sensitive quantification of leukemia-specific TEL-AML1 fusion transcript levels normalized to beta-actin expression (sensitivity threshholds, 10(-5)) by a novel real-time reverse transcription-PCR (RQ-RT-PCR) based on fluorescent TaqMan technique providing early and rapid evidence on the treatment efficacy of children with initial or relapsed TEL-AML1+ ALL enrolled in frontline or relapse trials of the Berlin-Frankfurt-Münster (BFM)-Study Group. In initial ALL, TEL-AML1/beta-actin decrease was > or =10(5)-fold in 50% of patients after induction therapy (day 33) and stayed TEL-AML1-negative throughout therapy, which suggested high sensitivity of leukemic cells to antineoplastic therapy. The remaining patients were still TEL-AML1+ before reintensification (ratios, 0.7 x 10(-2):10(-4)). In relapsed ALL, TEL-AML1/beta-actin decrease was generally less pronounced at corresponding time points, and conversion to TEL-AML1 negativity was observed in 40% of patients. Most notably, subsequent relapses occurred only among molecular poor responders, whereas all early responders remain in their second complete remission. In conclusion, real-time quantification of TEL-AML1/beta-actin kinetics distinguishes distinct molecular response groups, and provides indications capable of directing therapeutic interventions for patients with TEL-AML1+ ALL. Before considering modification of therapy, results should be interpreted cautiously taking into account the long duration of remission associated with TEL-AML1+ ALL.

Absence of mutations in the CDKN2 binding site of CDK4 in childhood acute lymphoblastic leukemia

The cell cycle regulatory circuit resulting in phosphorylation of the retinoblastoma protein (pRB) is frequently altered in human cancers. Several mechanisms of disruption are known in that pathway. In childhood acute lymphoblastic leukemia (ALL), the main disrupting mechanism is the homozygous deletion of the CDKN2 (cyclin dependent kinase inhibitor 2) genes: p16CDKN2a, p15CDKN2b, and p19ARF. Another pRB pathway disturbance is a previously described point mutation in the exon 2 of CDK4, a pRB phosphorylating enzyme, which abrogates binding of the latter to its inhibitors, p16CDKN2a and p15CDKN2b. Here we report the absence of point mutations in the CDKN2-binding site of CDK4 in 100 cases of childhood ALL, 2 cases of childhood chronic myeloid leukemia and 9 hematologic cell lines screened by PCR-SSCP (polymerase chain reaction single stranded conformational polymorphism gel electrophoresis), thereby minimizing the possibility of the existence of these specific CDK4 mutations in childhood ALL.

Expression analysis and characterization of alternatively spliced transcripts of human IL-7Ralpha chain encoding two truncated receptor proteins in relapsed childhood all

In the family of cytokines and cytokine receptors, alternative splicing of pre-mRNA is a frequently observed process that generates different protein isoforms from a single genetic locus. The splicing-derived cytokine receptor protein isoforms are mostly soluble receptors or show alterations in their cytoplasmic domain. It is possible that receptor abnormalities or a pathological ratio of different isoforms may contribute to leukaemia by circumventing normal growth factor control or altering the balance of proliferation and differentiation. IL-7 plays a critical role in early stages of both B and T cell maturation. Moreover, it stimulates the expansion of mature T cells including anti-tumour reactive cells as well as a number of T and B cell malignancies underlining its potential importance for deregulated lymphoid proliferation and leukaemogenesis. Here, we present detailed data on the expression of the interleukin 7 receptor alpha chain (IL-7Ralpha) in leukaemic cells from 210 children with acute lymphoblastic leukaemia (ALL) and describe two novel alternatively spliced transcripts of human IL-7Ralpha coding for truncated receptor proteins which are still capable of binding IL-7. IL-7Ralpha mRNA expression was more frequent in more mature pre-B ALL [91% (30/33)] than in common [81% (81/100)] or pro-B ALL [64% (18/28)], or even in T ALL [64% (29/45)]. These results are in concordance with flow cytometric analyses on the proportion of IL-7Ralpha bearing cells among total blast cell population. Our results lead us to assume that splicing derived IL-7Ralpha isoforms play a potential role in modulating IL-7 signal transduction and might be important for the pathogenesis of leukaemia.

Potential of LightCycler technology for quantification of minimal residual disease in childhood acute lymphoblastic leukemia

A certain quantity of residual leukemic cells at several time points during chemotherapy of childhood acute lymphoblastic leukemia (ALL) was proved to predict outcome. Future childhood ALL treatment will take minimal residual disease (MRD) into consideration for stratification aiming at an individualization of chemotherapeutic regimens. Recently, the first quantitative real-time PCR assay for MRD detection was described using T cell receptor and immunoglobulin gene rearrangements as clonal markers. Quantitative real-time PCR was performed with TaqMan technology. Here, we present for the first time the potential of LightCycler real-time PCR technology to quantify MRD. We compare and assess different approaches for real-time PCR quantification of leukemic cells, based either on clone-specific primers and general fluorescence detection with SYBR Green, TaqMan probe or hybridization probes, or based on general PCR amplification and clone-specific detection with hybridization probes. MRD quantification with LightCycler real-time PCR technology is a sensitive, specific and incomparably rapid method that needs no post-PCR handling, hence eliminating contamination risk and saving time. Working towards the establishment of MRD quantification in routine diagnostics and towards treatment strategies based on these results, LightCycler quantitative PCR seems to be a promising new technique that makes results immediately available for treatment decisions.

Metacarpal morphometry using a semi-automated technique in the assessment of osteoporosis and vertebral fracture risk

Metacarpal morphometry represents a potentially cheap and widely available non-invasive assessment of skeletal status. In two cross-sectional studies, we compared the performance characteristics of a semiautomated technique (the Teijin Bonalyzer) with an in-house manual measurement, and with measures of skeletal strength at other sites. The metacarpal cortical index (mCI) was measured on hand radiographs of 178 osteoporotic women using both the Teijin Bonalyzer and a digitizing tablet. Measurements on the latter were consistently lower than with the Bonalyzer except for mCI (0.443+/-0.080 vs 0.364+/-0.060, p<0.001), although correlation coefficients between these two methods were highly significant (r = 0.62-0.83, p<0.001). The reproducibility errors of metacarpal bone mineral density (mBMD) were constant (1.1-1.2%) whilst those for mCI showed a marked operator-dependency (2.0-7.9%). In 379 elderly community-dwelling women, Bonalyzer mCI and mBMD showed a significant decline with age (r = -0.30 and -0.27 respectively, p<0.05). Both mCI and mBMD correlated significantly with forearm BMD (r = 0.50 and 0.57 respectively, p<0.001) and hip BMD (r = 0.48 and 0.53 respectively, p<0.001). After adjustment for age and weight, hip BMD demonstrated the best discrimination for prevalent vertebral fractures as judged by the gradient of risk for a 1 SD decrease in measurement (odds ratio (OR) 2.17, 95% CI 1.56-3.01). Similar but smaller gradients of risk were shown by Bonalyzer mCI (OR 1.32, 95% CI 1.00-1.75), mBMD (OR 1.35, 95% CI 1.02-1.78) and forearm BMD (OR 1.39, 95% CI 1.08-1.80). MCI, and in particular mBMD, may be useful assessments of bone mass and fracture risk. In our study, it is comparable to peripheral assessment of skeletal status by forearm densitometry.

Extensive alternative splicing of interleukin-7 in malignant hematopoietic cells: implication of distinct isoforms in modulating IL-7 activity

Interleukin-7 (IL-7) plays a pivotal role in early stages of normal B and T cell development. In addition, IL-7 stimulates the proliferation of both antitumor reactive cells and a number of T and B cell malignancies, underlining its significance for leukemogenesis. However, its exact role in the process of pathologic maturation of lymphocytes and regulation of the immune response is not completely understood. As alternative splicing of pre-mRNA has been shown to be involved in the control of gene expression, and splicing-derived protein isoforms with antagonistic activity have been found, we assessed the mRNA-expression of IL-7 and its previously described alternative splice variant lacking exon 4, IL-7delta4, in leukemic cells from children with acute lymphoblastic leukemia (ALL). PCR of full-length IL-7 cDNA enabling the competitive amplification of both variants led to the amplification of diverse unexpected PCR products. The sequence data demonstrated the existence of three additional in-frame splice variants resulting from exon skipping of exon 3 or exon 5 or both in combination with exon 4. We named these IL-7delta3/4, IL-7delta4/5, and IL-7delta3/4/5. Furthermore, three out-of-frame splice variants were identified, IL-7(-56bpExon2), IL-7delta4(-56bpExon2), and IL-7delta3/4/5(-56bpExon2), in which, in addition to the aforementioned exon skipping, 56 bp of the 3' end of exon 2 are omitted. Our results led us to assume that splicing-derived IL-7 isoforms play a potential role in modulating IL-7-mediated biologic effects. Further studies are required to clarify the significance of the diverse IL-7 protein isoforms for the regulation of IL-7 function and the pathogenesis of leukemia.

Clodronate as a cause of aminotransferase elevation

Adverse events (AEs) associated with bisphosphonates are usually gastrointestinal, but elevation of aminotransferases (alanine and aspartate aminotransferase) has also been described in many cases. The frequency of such elevation is, however, poorly investigated. The Probone study is a continuing phase II trial of 610 osteopenic women randomized for 3 years to receive placebo or clodronate at the following clodronate doses: 65 mg, 400 mg and 800 mg daily, and 400 mg for 15 days out of 90 (intermittent group). During the first study year, gastrointestinal AEs were reported by 20-26% of the patients in the five study groups, but no differences appeared between groups. The high-dose clodronate groups (400 mg and 800 mg daily) had no more hepatic side-effects than the low-dose groups, and no serious AE due to liver disease was reported. These higher doses of clodronate caused, however, a mean alanine aminotransferase (ALT) elevation of 5.4-5.8 U (25-24%) which differed significantly from the change in the placebo group (p = 0.002 and p<0.0001, respectively). In those volunteers with initially normal aminotransferase values the risk ratio for an aminotransferase increase to an above-normal value (compared with the placebo group) during the study year was up to 1.8 in the clodronate 400 mg group and up to 2.5 in the clodronate 800 mg group. Among these groups an elevation above the normal limits occurred in up to 11.7% of the volunteers for aspartate aminotransferase (AST) and up to 17.7% for ALT. The respective percentages in the placebo group were 6.2% and 7. 2%. All analyzed bilirubin values were normal. We conclude that oral clodronate use may elevate serum aminotransferase levels, and that these enzymes most likely come from the liver. This elevation has also been described for several other bisphosphonates. However, clinically significant liver injury is unlikely.

Multiplex PCR for simultaneous detection of the most frequent T cell receptor-delta gene rearrangements in childhood ALL

A rapid and simple multiplex polymerase chain reaction (PCR) is described that is capable of identifying the six most frequent rearrangements of the T cell receptor (TCR)-delta gene segments in childhood acute lymphoblastic leukemia (ALL). The PCR products amplified in a single reaction are of different size for each TCR-delta gene rearrangement. Therefore, they are readily and unambiguously distinguished after agarose gel electrophoresis and assigned to a specific V-D-J gene rearrangement. There is no need for labor-intensive and time-consuming Southern blot hybridization or nested PCR. To evaluate the multiplex assay we chose 45 DNA samples of childhood ALL analyzed beforehand for TCR-delta gene rearrangements by Southern blot and single PCR of which 30 showed TCR-delta gene rearrangements. The multiplex PCR results corresponded to the Southern blot and single PCR analyses. The described multiplex PCR enables the detection of clonal markers in about 50% of patients in order to monitor minimal residual disease (MRD) in prospective studies with a high turnover of samples.

Concomitant i.v. and oral clodronate in the relief of bone pain--a double-blind placebo-controlled study in patients with prostate cancer

Fifty-seven patients with advanced prostate cancer resistant to first-line hormonal therapy were treated with estramustine and additionally randomized for treatment with clodronate or placebo. Clodronate treatment was started with 5 days intravenous administration (300 mg day[-1]) and followed by oral treatment (1.6 g day[-1]) for 12 months. Skeletal pain relief was only about 10% better in the clodronate than in the placebo group. The results do not support the superiority of combined intravenous and oral treatment with clodronate compared with oral administration only.

Histomorphometric evidence for osteoclast-mediated bone resorption in metastatic breast cancer

We studied bone biopsies from 65 normocalcaemic women with breast cancer and predominantly osteolytic bone metastases in order to examine the pathophysiology of bone destruction in metastatic bone disease. Quantitative histomorphometric measurements were made at sites of tumour involvement, at sites adjacent to tumour tissue and at sites distant from tumour tissue. There were no significant differences in bone volume or in indices of bone resorption or formation between biopsies taken from sites distant from tumour and the controls. Bone resorption, as judged by eroded surface, increased progressively from bone distant from tumour to tumour-laden bone. The number of osteoclasts was significantly increased in bone immediately adjacent to tumour and within metastases. There was no decrease in the ratio of osteoclast to eroded surface in breast cancer compared to controls suggesting that increased resorption in breast cancer was mainly osteoclast mediated and locally activated by the tumour. Two thirds of the biopsies taken from tumour involved regions showed osteosclerosis with woven bone formation. The volume of the pre-existing lamellar trabecular bone was lower than normal in 75% of these biopsies, suggesting that bone resorption must have been increased before the onset of woven bone formation. Since all patients were receiving hormonal treatment or chemotherapy, it is likely that osteosclerosis at sites of previous resorption mainly resulted from the basic cancer treatment as a sign of response to treatment. Osteoclastic bone resorption was, however, not completely inhibited by the active cancer treatment.

The effect of clodronate on bone in metastatic prostate cancer. Histomorphometric report of a double-blind randomised placebo-controlled study

57 patients with advanced prostate cancer and a failure of prior hormonal treatment were selected for a double-blind placebo-controlled trial, in which they were randomly allocated to receive either clodronate (C) or placebo concomitantly with the basic cancer treatment, estramustine phosphate (E) (560 mg daily). The treatment was started intravenously with 300 mg of C or placebo in 5 consecutive days, and thereafter maintained orally with 1600 mg of C or identical placebo daily for 3 months. Bone biopsies were taken at admission and at 3 months. Measurements of serum calcium, phosphate, alkaline phosphatase, prostate-specific antigen and creatinine were made at the time of both bone biopsies and at 1 month. Serum intact parathyroid hormone and vitamin D metabolites were measured at admission and at 3 months. Because of several discontinuations, the study groups at final analysis comprised 20 patients taking E + C and 19 patients taking E and placebo. Bone resorption, as judged by eroded surface and osteoclast number, was markedly increased especially in biopsies taken from tumour-involved bone. Treatments with E + C or E both induced a significant decrease in bone resorption, but were associated with the development of hypocalcaemia, secondary hypoparathyroidism, hypophosphataemia and severe impairment of mineralisation of newly formed bone, i.e. osteomalacia. Since the patients were not vitamin D deficient, we conclude that osteomalacia resulted from a relative deficiency of calcium and phosphate. The transiency of pain relief achieved with anti-resorptive agents in the treatment of bone metastases from prostate cancer may be due to the development of osteomalacia.

Distinction between focally accelerated bone formation and osteomalacia in carcinoma of prostate metastasised to bone

We studied the histological indices of skeletal turnover in 40 patients with carcinoma of the prostate and skeletal metastases in order to determine the prevalence of osteomalacia. In 20 patients biopsied through uninvolved bone, the histological indices of bone turnover were normal. In particular, osteoid seam width and bone formation rates were consistently normal, indicating the absence of osteomalacia. In biopsies from tumour-laden bone, hyperosteoidosis was present, usually associated with increased amounts of woven collagen and consistently associated with high rates of bone formation and mineralisation. It was concluded that hyperosteoidosis in prostatic cancer is rarely due to osteomalacia.

Comparative effects of clodronate and calcitonin on bone in metastatic breast cancer: a histomorphometric study

We studied the effects of long-term treatment with clodronate, calcitonin or placebo on bone in 36 normocalcaemic women with osteolytic metastases due to breast cancer. Clodronate (1.6 g daily given to 12 patients) induced a significant decrease in osteoclast surface and osteoclast number, and a significant fall in serum calcium and urinary excretion of calcium and hydroxyproline, an effect not noted after treatment with calcitonin (100 U in 12 patients) or in 12 placebo-treated patients. Treatment with clodronate did not abnormally suppress bone turnover nor impair mineralisation, as measured by bone formation and mineral apposition rates.

Evaluation of the effect of oral clodronate on skeletal metastases with type 1 collagen metabolites. A controlled trial of the Finnish Prostate Cancer Group

Clodronate relieves bone pain in patients with skeletal metastases. Since the pain relieving mechanism of clodronate may be associated with the antiosteoclastic activity, we have investigated whether the drug has simultaneous actions on bone resorption and pain. Although osteosclerotic metastases are characteristic of prostate carcinoma, bone resorption is also accelerated. The resorbing process can be investigated using a specific immunoassay for ICTP (cross-linked carboxyterminal telopeptide region of type I collagen) which allows the measurement of the degradation of type I collagen in serum samples. We have also determined serum concentration of PICP (carboxyterminal propeptide of type I procollagen) which reflects the synthesis of type I collagen (osteoid). Patients who have relapsed after first-line hormonal therapy, were randomised to receive estramustine phosphate (E) with or without clodronate (C) (E + C, n = 50; E, n = 49). The dose of E was 560 mg and that of C 3.2 g for the first month, thereafter 1.6 g. We saw elevated ICTP and PICP levels in the majority of the patients. A transient decrease in ICTP values occurred simultaneously with pain relief. The changes were more accentuated in the E + C than in the E group but the difference was not significant. In each group serum phosphate concentration decreased markedly (P = 0.001) whereas the activity of alkaline phosphatase remained increased, both indicating a development of osteomalacia during E therapy. The short-term antiosteoclastic effect of C may be explained by the dose reduction, hyperosteoidosis and osteomalacia which inhibit the binding of C on the crystal surfaces and by the late phase of disease.

Abnormal bone remodelling in patients with myelomatosis and normal biochemical indices of bone resorption

We studied bone biopsies from 26 patients with myelomatosis with apparently normal skeletal metabolism. Quantitative histomorphometric measurements suggested that skeletal disease was progressive despite normocalcaemia and normal urinary excretion rates of calcium and hydroxyproline. When biopsies were divided according to the involvement of marrow by plasma cells, bone resorption--as judged by the eroded surface--increased significantly the greater plasma cell burden. Osteoclasts were frequent with moderate tumour burdens, but there was no further increase in the number of osteoclasts when plasma cell infiltration increased by more than 50% of bone marrow. Contrary to expectation, the numbers of osteoblasts and bone formation rates were increased with bone biopsies with moderate tumour burden, but were markedly lower when plasma cell infiltration occupied more than 50% of bone marrow, due to a decreased functional capacity of osteoblasts. We conclude that skeletal bone disease in myeloma is commonly progressive despite apparently stable bone disease as judged by biochemical measurements. The major mechanism of bone loss in myelomatosis is increased osteoclastic resorption but decreased bone formation contributes to bone loss with heavy plasma cell burdens. Urinary excretion of calcium and hydroxyproline provide insensitive indices of bone resorption in myelomatosis.

Monitoring of multiple myeloma and bone marrow fibrosis with aminoterminal propeptide of type III collagen (PIIINP)

Bone marrow fibrosis is known in myelomatosis and depends on the extent of plasma cell infiltration. The serum concentration of the aminoterminal propeptide of type III procollagen (PIIINP) has previously been reported to reflect fibrogenesis in the marrow in myelofibrosis. Here we followed 15 consecutive patients with newly diagnosed multiple myeloma with repeated PIIINP measurements during treatment with intermittent courses of melphalan and prednisolone. PIIINP was found to change with clinical behaviour of the disease, nonresponders and patients with recurrent disease having elevated values and the values in responders decreasing to the normal level or remaining there. Collagen fibres in plasma cell infiltrates of biopsies from bone marrow or skeletal tumours of these patients stained heavily with antibodies against PIIINP. Our results suggest that PIIINP works as a noninvasive indicator of bone marrow fibrogenesis. In multiple myeloma PIIINP is a sensitive, but not specific marker of disease course.

Rationale for the use of bisphosphonates in bone metastases

Neoplasia affecting the skeleton is an important cause of morbidity, which includes hypercalcaemia, bone pain and fracture. In most instances these events are mediated by an increase in the resorption of bone which decreases bone density and disrupts skeletal architecture, either at focal sites or generally throughout the skeleton. Neoplastic activation of bone resorption in heterogeneous, but there is now good evidence that this is due to the increased activation of osteoclasts, the cells which mediate bone resorption in health. Bisphosphonates are specific inhibitors of osteoclast-mediated bone resorption and are capable of inhibiting osteoclastic activation independent of the mechanism of its stimulation. This provides the rationale for the use of bisphosphonates in the hypercalcaemia of malignancy. Despite refinements in the use of endocrine therapy, chemotherapy and radiotherapy these interventions have had relatively little impact on the skeletal morbidity or mortality of common malignancies affecting the skeleton, particularly breast cancer and myelomatosis. In addition, there is good evidence that skeletal disease is progressive in many patients despite the use of chemotherapy and radiotherapy. Since accelerated bone resorption can be inhibited by long-term treatment with bisphosphonates, their use is likely to decrease skeletal complications such as bone pain and fracture. The bisphosphonates, therefore, hold great promise as agents to improve the quality of life of such patients.

Aminoglutethimide for advanced prostatic cancer resistant to conventional hormonal therapy

Aminoglutethimide (AG) and hydrocortisone (HC) were given to 20 patients with advanced prostatic cancer resistant to conventional hormonal therapy. Most patients had painful bone metastases and were heavily pretreated. 12 of 16 patients required narcotic analgetics. 8 of 20 were bedridden. AG + HC produced relief of bone pain in 12 patients (75%) and only 4 required narcotics after treatment. The performance status improved in 8 of 20 patients (40%). However, the number of bone metastases seen in bone scans decreased in only 4 patients (22%). The level of serum alkaline phosphatase decreased in 11 of 18 patients and that of acid phosphatase in 8 of 16 patients. The reduction of bone pain lasted approximately 4 months (range 1-15 months). The median lifespan between the start of AG treatment and death was 8 months (range 2-22 months). There was no difference in survival between responders and nonresponders. 3 patients had skin rash, 1 lethargy and 1 thrombocytopenia.