Analysis of long-term results and prognostic factors among 138 patients with advanced Hodgkin's disease treated with the alternating MOPP/ABVD chemotherapy

Hodgkin lymphoma patients have an increased incidence of idiopathic acquired aplastic anemia

Idiopathic acquired aplastic anemia (AA) is a rare lymphocyte-mediated bone marrow aplasia. No specific mechanisms or triggers of AA have been identified. We recently observed several patients who developed AA after Hodgkin lymphoma (HL). We hypothesized that the co-occurrence of HL and AA is not random and may be etiologically significant. To test this hypothesis, we determined the incidence of AA in HL patients at our institution. We identified four patients with co-occurring HL and AA, with the incidence of AA in HL patients >20-fold higher compared to the general population. We identified 12 additional patients with AA and HL through a systematic literature review. Of the 16 total patients,15 (93.8%) developed AA after or concurrent with a HL diagnosis. None of the patients had marrow involvement by HL. Five of 15 patients were in complete remission from HL at the time of AA diagnosis, and six had a concurrent presentation with no prior cytotoxic therapy, with diagnostic timeframe information unavailable for four patients. The median interval between HL diagnosis and AA onset was 16 months, ranging from concurrent to 14 years after a HL diagnosis. The median survival after AA diagnosis was 14 months (range: 1 month to 20 years). Our results show that patients with HL have a higher incidence of AA compared to the general population and suggest that HL-related immune dysregulation may be a risk factor for AA. Better recognition and management of AA in HL patients is needed to improve outcomes in this population.

Do bisphosphonates inhibit direct fracture healing?

Fracture repair occurs by two broad mechanisms: direct healing, and indirect healing with callus formation. The effects of bisphosphonates on fracture repair have been assessed only in models of indirect fracture healing.

A rodent model of rigid compression plate fixation of a standardised tibial osteotomy was used. Ten skeletally mature Sprague–Dawley rats received daily subcutaneous injections of 1 µg/kg ibandronate (IBAN) and ten control rats received saline (control). Three weeks later a tibial osteotomy was rigidly fixed with compression plating. Six weeks later the animals were killed. Fracture repair was assessed with mechanical testing, radiographs and histology.

The mean stress at failure in a four-point bending test was significantly lower in the IBAN group compared with controls (8.69 Nmm-2 (sd 7.63) vs 24.65 Nmm-2 (sd 6.15); p = 0.017). On contact radiographs of the extricated tibiae the mean bone density assessment at the osteotomy site was lower in the IBAN group than in controls (3.7 mmAl (sd 0.75) vs 4.6 mmAl (sd 0.57); p = 0.01). In addition, histological analysis revealed progression to fracture union in the controls but impaired fracture healing in the IBAN group, with predominantly cartilage-like and undifferentiated mesenchymal tissue (p = 0.007).

Bisphosphonate treatment in a therapeutic dose, as used for risk reduction in fragility fractures, had an inhibitory effect on direct fracture healing. We propose that bisphosphonate therapy not be commenced until after the fracture has united if the fracture has been rigidly fixed and is undergoing direct osteonal healing.

Cite this article: Bone Joint J 2013;95-B:1263–8.

Healing of the bone with anti-fracture drugs

INTRODUCTION

Fracture healing is a complex process that leads to the restoration of tissue integrity through bone repair and represents a unique physiological characteristic of bone. Developing a better understanding of a fracture is essential to plan best noninvasive treatment for the patient. In osteoporosis, the patient who suffers of a fragility fracture is recommended to initiate a treatment with compounds active in preventing other low-energy skeletal trauma. Pharmaceutical industries are developing controlled clinical trials aiming to evaluate the capability of osteoporosis drugs to accelerate fracture healing.

AREAS COVERED

In preparing this review, a search was made with key words encompassing 'osteoporosis anti-fracture drugs and bone repair/healing', 'antiresorptives and bone repair/healing', 'bone-forming agents and bone repair/healing', and 'osteoporosis/anti-fracture drugs in fractures'. The results published in the area of the use of registered anti-fracture drugs to improve fracture repair and the efforts made to recommend measures for clinical outcomes in fracture healing acceleration are described in this report.

EXPERT OPINION

At present, the use of systemic pharmacological agents active to improve fracture healing by the clinicians is controversial and clinicians and scientists must do a better job in determining the methods of assessment for fracture healing.

Prevention of strain-related osteopenia in aseptic loosening of hip prostheses using perioperative bisphosphonate

The hypothesis tested in this study was that perioperative administration of the bisphosphonate zoledronate will reduce strain protection-related calcar osteopenia and maintain functional integration of the femoral component in an ovine hemiarthroplasty model. Twelve sheep received a unilateral cemented hemiarthroplasty where six animals were given nine intravenous infusions of zoledronate (10 microg/kg) pre-, peri-, and postsurgery over 8 months. Control animals received physiological saline only. Implants remained in vivo for 9 months. Ground reaction force (GRF) was used to assess functional loading of the implanted limb, bone mineral density (BMD) was quantified using dual energy X-ray absorptiometry (DEXA). Cortical bone area, thickness, and viable osteocytes were assessed histologically. No significant differences in GRF data between groups was identified. Results demonstrated a significant drop in BMD values in the control group (9.7%) when compared with the bisphosphonate-treated group (3.2%) (p = 0.0159). Histological results showed that cortical area, thickness, and the percentage of lacunae with viable osteocytes was significantly greater in the bisphosphonate-treated group when compared with control (p = 0.002, p = 0.001, p = 0.003, respectively). The administration of zoledronate reduced cortical osteopenia in the calcar region of the proximal femur and this therapy could be used as a preventive measure to combat strain protection osteopenia and its contribution to associated aseptic loosening in total hip replacement surgery.

A single systemic dose of pamidronate improves bone mineral content and accelerates restoration of strength in a rat model of fracture repair

Complications in fracture repair that lead to a delay in union remain clinically problematic. We believe that unwanted pre-mature catabolism of the healing callus, for example, in stress shielded situations, diminishes the rate at which strength is restored in bone repair and possibly leads to delayed union. We hypothesized that a single systemic dose of a nitrogen-containing bisphosphonate (N-BP) would increase bone mineral content (BMC), volume, and mechanical strength of union in fracture repair. We also set out to investigate local delivery to assess whether systemic exposure could be eliminated, due to concerns of bisphosphonate dosing of non-target organs. After an open osteotomy fixed with a K wire, 40 12-week old Wistar male rats were divided into four groups of 10: saline control, bolus systemic subcutaneous injection of pamidronate (3 mg/kg), local low dose of pamidronate (0.1 mg), and a local high dose of pamidronate (1.0 mg). Rats were sacrificed 6 weeks post-operatively. Operated and non-operated femora underwent radiographic evaluation, quantitative computer tomography, and biomechanical testing in torsion. The growth plates and metaphyses of the tibia of the non-operated side were assessed for evidence of systemic exposure in the local groups. Significant increases in callus BMC and volume of the bolus systemic dose group were found compared to the saline control (p< or =0.05). Further, the strength of the systemic dose callus was increased by 60% from 0.35 Nm (+/-0.11) for the saline control callus to 0.56 Nm (+/-0.25) for the systemic group (p=0.05). Local treatment did not result in increased strength. The contralateral tibial growth plates of the local groups showed evidence of systemic exposure by the presence of retained primary spongiosa. This study confirms that a single perioperative systemic dose of pamidronate leads to significant increases in the BMC, volume, and strength of healing fractures in rats, making single dose N-BP therapy an appealing candidate for further examination in fracture repair.

Long-term administration of clodronate does not prevent fracture healing in rats

Clinicians have been concerned that fractures do not heal properly in individuals exposed to bisphosphonate treatment, a treatment that strongly affects bone metabolism. The current study attempted to clarify the long-term effects of clodronate (dichloromethylene bisphosphonate) treatment on fracture healing in growing rats. Clodronate was administered subcutaneously twice a week in a dose of 2 mg/kg or 10 mg/kg. Physiologic saline served as a control. After 24 weeks of treatment, the tibiae were fractured, and the treatment was continued for another 4 weeks and 8 weeks. At both end points the cross-sectional areas of the callus, measured by peripheral quantitative computed tomography, were greater in the clodronate-treated rats than in controls, but there were no significant differences in bone mineral density. There were no significant differences between treatments in radiologic healing, histomorphometry, or in mechanical failure load of the callus with the exception of increased tensile stiffness at a dose of 2 mg/kg at 4 weeks. Clodronate treatment does not seem to prolong the fracture healing process, even when administered on a long-term basis before the fracture. Clodronate increases the size of the callus, but has only a minor effect on its biomechanical properties. The current results suggest that long-term clodronate treatment does not inhibit fracture healing.

Bisphosphonates in renal osteodystrophy

The present review considers the role that bisphosphonates might have in patients with renal failure. Although bisphosphonates are widely used to reduce fracture risk in patients with osteoporosis, few studies have documented their effect in patients with renal osteodystrophy. The pathogenesis of bone loss after renal transplantation and the role of the recently identified osteoprotegerin/receptor activating nuclear factor-kappaB system is described. Inhibition of bone resorption may prove beneficial when high bone turnover is present, but there are potential drawbacks to widespread use of bisphosphonates. These issues are discussed, with emphasis placed on reports published within the past 18 months.

Normal osteoconduction and repair in and around submerged highly bisphosphonate-complexed hydroxyapatite implants in rat tibiae

BACKGROUND

Ceramic hydroxyapatite implants have been used in dentistry for their unique compatibility with alveolar bone. Recently it was reported that bisphosphonates may be beneficial in preventing alveolar bone destruction associated with natural and experimental periodontal disease. Furthermore, bisphosphonate does prevent resorption of alveolar bone following mucoperiosteal flap surgery. We undertook a preliminary study evaluating the effects of highly bisphosphonate-complexed hydroxyapatite implants on osteoconduction and repair in rat tibiae.

METHODS

Porous hydroxyapatite implants were pre-incubated in 10(-2)M bisphosphonate solutions at pH 3.49 and pH 7.32. The implants had a diameter of 2.1 mm and a height of 2 mm and adsorbed 115 microg bisphosphonate in vitro. Bisphosphonate/hydroxyapatite implants and plain hydroxyapatite implants were inserted in opposite tibial metaphyses of 35 rats. The measurement errors for the mineral density (MD) of the implants and the proximal trabecular mineral bone density (TD) were estimated by peripheral computed tomography and the bone mineral density (BMD) measurement error by dual x-ray absorptiometry.

RESULTS

The measurement errors for the MD of the implants and the TD by peripheral computed tomography were 0.81% and 1.96%, respectively ex vivo. The BMD measurement error estimated by dual x-ray absorptiometry was 0.51% ex vivo. TD and BMD for bisphosphonate/hydroxyapatite implants were insignificantly higher compared to plain hydroxyapatite implants. Bisphosphonate/hydroxyapatite pre-incubated at pH 7.32 were found to be nondegradable implants, while bisphosphonate/hydroxyapatite (pH 3.49) implants were slowly degradable and lost a significant 5% of their density. Histologically, all bisphosphonate/hydroxyapatite implants appeared to be fully integrated and effective as bone replacement material in rat tibial bone. They exhibited vascularization and osteoconduction of tibial bone growth along and inside their porous structure.

CONCLUSIONS

Our study suggests that normal osteoconduction and repair occurred in and around the highly bisphosphonate-complexed hydroxyapatite implants in rat tibiae.

Treatment of relapsed Hodgkin's disease: strategies and prognostic factors

The major points in salvage therapy of patients in relapse following combination chemotherapy for advanced disease are: (1) success of any second-line approach is determined by prognostic factors which include age, duration of the initial remission, and quantity of disease at relapse; (2) induction failures (progression without remission or incomplete remission and short initial remission) require innovative therapy which currently entails high-dose chemotherapy with peripheral or bone marrow autologous support; (3) late relapse still retains an order to sensitivity to chemotherapy and can be treated with conventional dose combination with complementary radiation therapy to previously unirradiated bulky sites. The choice of regimen is empiric and can include a repeat of the regimen used for the original remission or induction. The relative advantage of HDC in this favorable group is uncertain.

A prognostic score for advanced Hodgkin's disease. International Prognostic Factors Project on Advanced Hodgkin's Disease

BACKGROUND

Two thirds of patients with advanced Hodgkin's disease are cured with current approaches to treatment. Prediction of the outcome is important to avoid overtreating some patients and to identify others in whom standard treatment is likely to fail.

METHODS

Data were collected from 25 centers and study groups on a total of 5141 patients treated with combination chemotherapy for advanced Hodgkin's disease, with or without radiotherapy. The data included the outcome and 19 demographic and clinical characteristics at diagnosis. The end point was freedom from progression of disease. Complete data were available for 1618 patients; the final Cox model was fitted to these data. Data from an additional 2643 patients were used for partial validation.

RESULTS

The prognostic score was defined as the number of adverse prognostic factors present at diagnosis. Seven factors had similar independent prognostic effects: a serum albumin level of less than 4 g per deciliter, a hemoglobin level of less than 10.5 g per deciliter, male sex, an age of 45 years or older, stage IV disease (according to the Ann Arbor classification), leukocytosis (a white-cell count of at least 15,000 per cubic millimeter), and lymphocytopenia (a lymphocyte count of less than 600 per cubic millimeter, a count that was less than 8 percent of the white-cell count, or both). The score predicted the rate of freedom from progression of disease as follows: 0, or no factors (7 percent of the patients), 84 percent; 1 (22 percent of the patients), 77 percent; 2 (29 percent of the patients), 67 percent; 3 (23 percent of the patients), 60 percent; 4 (12 percent of the patients), 51 percent; and 5 or higher (7 percent of the patients), 42 percent.

CONCLUSIONS

The prognostic score we developed may be useful in designing clinical trials for the treatment of advanced Hodgkin's disease and in making individual therapeutic decisions, but a distinct group of patients at very high risk could not be identified on the basis of routinely documented demographic and clinical characteristics.

Hodgkin's disease: the next decade

Although treatment of Hodgkin's disease has been extensively studied in the past, fewer clinical studies are being reported, despite the fact that the optimal therapy for each stage has not yet been established. The pathologic subtypes have not been officially changed for years, although lymphocyte-predominant disease may be unrelated to the other subtypes, lymphocyte depleted histology may really be a T-cell large-cell lymphoma, mixed cellularity represents a spectrum of disease, and some cases remain unclassifiable. Staging has also still not been completely standardized, mainly because of reliance on the lymphangiogram and the staging laparotomy, which are being less commonly performed for treatment planning. Investigators still question the value of the gallium scan, magnetic resonance imaging, and abdominal ultrasound for treatment planning, and the role of these tests in the era of managed care is not defined. Finally, because treatment for the disease is so effective, the merit of each treatment plan may eventually be weighed in terms of emotional, social, and financial costs to the patient. For patients with early-stage (I-II) disease, only limited toxicity is acceptable; for patients with bulky stage II or stage III disease, combined modality therapy must be considered standard therapy, but investigators must find ways to lessen toxicity of radiotherapy and intensive chemotherapy. Finally, for patients with stage IV disease, ongoing studies of patients at high risk of relapse may reveal which will benefit from bone marrow or peripheral stem-cell transplantation as initial therapy.

Results of CAV regimen (CCNU, melphalan, and VP-16) as third-line salvage therapy for Hodgkin's disease

BACKGROUND

A prospective study was conducted to assess the efficacy and toxicity of a salvage regimen consisting of CCNU, Melphalan, and VP-16 (CAV) given at 28-day intervals in patients with Hodgkin's disease (HD) relapsing after primary therapy or refractory to the alternating MOPP/ABVD regimen.

PATIENTS AND METHODS

This study included 58 patients (median age: 34 years), with resistant or relapsing HD. Primary therapy had consisted of alternating MOPP/ABVD (81%) or MOPP alone (19%); 38% of patients were relapsing from prior complete remission (CR) while 62% had resistant disease. Extranodal disease was present in 55% and B-symptoms in 72% of patients; one-fifth had bulky disease and/or bone marrow involvement. The CAV was used as first salvage in half of the patients.

RESULTS

Complete remission was obtained in 17 patients (29%); unfavorable factors for CR in univariate analysis were the presence of bulky disease and the failure to achieve CR with prior therapy. Nine patients (53% of remitters) have subsequently relapsed with a 10-month median duration of CR. The 3-year overall survival after CAV was 25% with an 18-month median survival; significant differences in survival were found according to the extent of disease, the presence of B-symptoms and the HD status (prior sensitive or resistant disease, first or subsequent relapse). Seven patients are long-term remitters (12%), and one of them has been given high-dose chemotherapy and autologous bone marrow transplantation at relapse after CAV. The CAV toxicity was mostly hematological; severe pancytopenia occurred in six cases with two cases of fatal infections and one of fatal hemorrhage.

CONCLUSION

CAV therapy was moderately effective as third-line salvage in patients with HD resistant to alternating MOPP/ABVD or previously given two different regimens for relapse; the toxicity was mostly hematological and supportive therapy was needed in one-third of the patients.