Osteonecrosis of the jaw: Long-term follow-up shows variable rate of healing

9061

Background: Osteonecrosis of the jaw (ONJ) is a rare but clinically significant disorder recently reviewed in a large retrospective study (Hoff et al, 42nd ASCO Annual Meeting 2006, Abstract #8528). A subset of the ONJ patients from that study with breast cancer or multiple myeloma (MM) was followed at the University of Texas M.D. Anderson Cancer Center (UTMDACC) dental clinic. This analysis describes the natural history of ONJ in this subset. Methods: Thirteen of 29 ONJ patients treated with intravenous bisphosphonates (IVBP) at UTMDACC and 1 treated elsewhere were evaluated in the dental clinic for > 6 months (MM, n=7; breast cancer, n=7). The maximum length of exposed bone was measured at each visit. Patients received a standard regimen of conservative dental care with debridement when indicated. Results: All 14 patients received zoledronic acid (median cumulative dose 72 mg; range 24–152) and 10 also received pamidronate (median cumulative dose 1,710 mg; range 90–2,700). They were followed for a median duration of 17.1 months (range: 7.1–67.3). The mean length of exposed bone at initial evaluation was 11 mm (SD: 8.4). Each patient demonstrated fluctuating clinical courses. The lesion from baseline to the last visit progressed in 7 patients (median increase of 13 mm), remained stable in 2, regressed in 2 and resolved in 3. Persistent ONJ was seen if IVBP was stopped (n=8), decreased in frequency (n=1) or continued at the same dose/frequency (n=2). Complete resolution occurred in 3 MM patients, where IVBP was discontinued, decreased in frequency or replaced by weekly oral alendronate. Conclusions: Our experience shows that ONJ resolved in 21% but persisted in the majority of patients with a duration of up to 5 years with conservative dental care. Further studies are needed to evaluate the pathogenesis and healing process of ONJ.

No significant financial relationships to disclose.

Osteopenia and osteoporosis in untreated non-Hodgkin's lymphoma patients: An important and potentially treatable survivorship issue in lymphoma

9055

Background: Alkylating agents and steroids can cause premature osteoporosis, increasing the risk of vertebral and hip fracture. The bisphosphonate pamidronate every 3 months can reduce bone loss and the risk of new vertebral fractures in lymphoma patients receiving chemotherapy.(Kim et al., 2004 Am J Med) We are conducting a randomized study of the more potent bisphosphonate zoledronic acid in untreated non-Hodgkin's lymphoma (NHL) patients to study chemotherapy induced bone loss. Methods: During the accrual period, we report the baseline bone mineral density (BMD) characteristics for screened untreated NHL patients. Exclusion criteria included bone fractures, BMD T-scores worse than -2.0, CrCl < 60 mL/min, dental problems, prior bisphosphonate or significant steroid use. Patients accrued to the study were randomized to receive either: 1) oral calcium and vitamin D (Ca+D) or 2) Ca+D and 4 mg zoledronic acid IV at baseline and at 6 months. Results: Patient characteristics: 59 males and 55 females with median age 63 (range: 18–87). Lymphoma types: B-cell n=111, T-cell 3; follicular (FL) 56, diffuse large B-cell (DLBCL) 33, mantle cell 8, and others, totaling 114 patients. Of untreated NHL individuals screened for baseline BMD to date 11/114 (10%) had osteoporosis and 62/114 (54%) had osteopenia or osteoporosis. The lowest BMD was a T-score of -4.4. Other bone, dental, and endocrine abnormalities excluded some patients from treatment randomization. Patients with T scores < -2.0 were considered for off-study treatment with bisphosphonates. Osteopenia and osteoporosis were common across lymphoma subtypes: FL 25/56 (45%), DLBCL 20/33 (61%), mantle cell 6/8 (75%), and marginal zone 5/6 (83%). The low rate of osteopenia/osteoporosis of 25% for Burkitt/Burkitt-like lymphoma may reflect fast lymphoma kinetics without associated increase in bone loss. Conclusions: Baseline testing of BMD revealed osteopenia or osteoporosis in the majority of untreated NHL patients. This widely available and non-invasive test should be considered in untreated NHL patients. Our ongoing clinical trial will address the potential role of zoledronic acid in preserving bone density for survivors of NHL. ClinicalTrials.gov Identifier: NCT00352846

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Osteonecrosis of the jaw in patients receiving intravenous bisphosphonate therapy

8528

There have been reports of osteonecrosis of the jaw (ONJ) in patients (pts) with metastatic bone disease (MBD) treated with IV bisphosphonates (IVBP). To estimate the frequency and identify risk factors for ONJ we performed a retrospective analysis of pts treated with IVBP. The cohort included 4019 patients identified through the MDACC pharmacy database (PD) treated with IVBP from 9/1996 to 2/2004, and 6 patients diagnosed with ONJ at the MDACC Dental Clinic. ONJ was defined as exposed non-healing bone of at least 3 months duration. Preliminary statistical analysis included 4000 patients. The most common diagnoses were breast cancer [BRCA] (1340), MM (550) and lung cancer (380).The indications for IVBP therapy included MBD (60%), hypercalcemia (25%), MM (14%) and osteoporosis (7%). We identified 34 patients with ONJ: 18 BRCA, 14 MM, 1 prostate cancer and 1 thyroid cancer. The frequency of ONJ was calculated by including patients from the PD only: 16/1338 (1.2 %) in BRCA and 14/448 (3.1%) in MM. Patients with ONJ received pamidronate [P] (6), zoledronate [Z] (10), combination of P and Z (15). The mean cumulative dose (MCD) of P was 2182 mg (720–4410) in MM and 2745mg (1980–3510) in BRCA. MCD of Z was 61 mg (24–152) in MM and 62 mg (28–110) in BRCA. The total doses of P and Z were significantly higher in the ONJ group VS NON-ONJ group (P<0.0001). Pts with ONJ had longer duration of disease and longer follow-up than NON-ONJ cases (P<0.0001). Univariate and multivariate logistic regression analyses (MLRA) revealed dental extractions (DE), ER positive tumors, and treatments with P and Z as significant factors associated with ONJ in BRCA pts. In MM, DE, periodontal disease and osteoporosis were significant factors. Further statistical analysis, including Cox regression analysis, is under way. ONJ pts were treated with aggressive oral hygiene, oral rinses, debridement of necrotic bone and antibiotics. 15 pts were followed at the dental clinic longer than 6 months. ONJ healed in 1, improved in 1, stable in 4 and progressed in 9 pts. In conclusion, ONJ is a significant but uncommon event. Higher doses of IVBP, longer treatment duration, DE, and periodontal disease are associated with a greater risk to develop ONJ. Good dental care and avoidance of dental interventions should be recommended to all patients treated with IVBP.

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Phase I/II trial of capecitabine (C), dacarbazine (D) and imatinib (I) (CDI) for patients (pts) metastatic medullary thyroid carcinomas (MTC)

13048

Background: MTC is a rare tumor that responds poorly to conventional chemotherapy. 5-FU and D are frequently used, with an expected response rate of around 15%. MTC is often associated with multiple endocrine neoplasia type 2, an autosomal dominant syndrome caused by a mutation in the RET proto-oncogene which encodes RET, a tyrosine kinase receptor. I is a tyrosine kinase inhibitor with activity against c-Kit, PDGF and possibly RET, and we postulated that its addition to chemotherapy would increase its efficacy against this disease. Methods: We designed a phase I/II trial combining escalating doses of oral C, IV D and oral I. Pts with any advanced solid tumors were eligible for the phase I part of the trial. Results: 13 pts were entered and 12 were eligible (7 MTC, 2 adrenocortical, 1 islet-cell, 1 insular thyroid and 1 small cell). 4 pts did not complete one cycle (1 pt withdrew after 5 days and 2 pts progressed in less than 10 days and were replaced for toxicity analysis, 1 had a DLT and is included). 3 patients were entered in dose level 1, without DLT. 2 out of 6 pts developed DLT at the second dose level (1 G 3 fatigue and 1 G3 hypokalemia). Three additional pts are being entered on dose level 1. The first one had PD after 7 days and is being replaced. For the 11 pts who were evaluable, best response was 3 SD (range 3 to 9 + months) and 8 PD. Conclusions: The combination of CDI is feasible but has resulted in an unexpected pattern of toxicity in this patient population, with fatigue and hypokalemia as the DLT. No significant diarrhea or hand-foot syndrome was seen. Only G1 and 2 fluid retention and neutropenia have been encountered. Only minor reduction in tumor size has been seen among these heavily pretreated pts. Once the phase I is complete, the trial will continue in a phase II setting for untreated MTC pts.

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Arthritic calcitonin/alpha calcitonin gene-related peptide knockout mice have reduced nociceptive hypersensitivity

Peripheral inflammation induced with a knee joint injection of a mixture of kaolin/carrageenan (k/c) produces primary and secondary hyperalgesia. Inflammatory pain is thought to involve a variety of transmitters released from nerve terminals, including amino acids, substance P (SP) and calcitonin gene-related peptide (CGRP). In the present study, mice deficient in the calcitonin/alpha CGRP gene (CGRP(-/-)) displayed normal responses to noxious stimuli. However, the CGRP knockout mice failed to demonstrate development of secondary hyperalgesia after induction of knee joint inflammation in two tests that assess central sensitization, through testing at sites remote from the primary insult. Nociceptive behavioral responses were assessed using the hot-plate test and paw withdrawal latency (PWL) to radiant heat applied to the hindpaw. The CGRP(-/-) mice showed no signs of secondary hyperalgesia after development of knee joint inflammation, while the expected significant decrease in the PWL was observed in the CGRP(+/+) mice as control. The CGRP(-/-) mice also had a prolonged rather than a shortened response latency in the hot-plate test 4 h after knee joint injection of k/c. Immunohistological study showed that CGRP-like immunoreactivity (CGRP-LI) was absent in the spinal cord and dorsal root ganglia taken from the CGRP(-/-) mice. These results indicate that endogenous CGRP plays an important role in the plastic neurogenic changes occurring in response to peripheral inflammatory events including the development of nociceptive behaviors.

Multiple endocrine neoplasias

The multiple endocrine neoplasia syndromes form a distinct group of genetic tumor syndromes. They include multiple endocrine neoplasia types 1 and 2, von Hippel Lindau syndrome, neurofibromatosis, and Carney complex. Research over the past decade has identified a molecular basis for each of these syndromes. This knowledge has revolutionized not only the clinical management but also has illuminated the field of human cancer research by the identification of new and important genes critical for regulation of cell growth, differentiation, and death. This review focuses on the structure, physiologic function, and molecular abnormalities of the genes involved in these syndromes.

Calcium-induced activation of a mutant G-protein-coupled receptor causes in vitro transformation of NIH/3T3 cells

The calcium-sensing receptor (CaR) is a G-protein-coupled receptor that is widely expressed, has tissue-specific functions, and regulates cell growth. Activating mutations of this receptor cause autosomal dominant hypocalcemia, a syndrome characterized by hypocalcemia and hypercalciuria. The identification of a family with an activating mutation of the CaR (Thr151Met) in which hypocalcemia cosegregates with several unusual neoplasms led us to examine the transforming effects of this mutant receptor. Transfection of NIH/3T3 cells with the mutant but not the normal receptor supported colony formation in soft agar at subphysiologic calcium concentrations. The mutant CaR causes a calcium-dependent activation of the extracellular signal-regulated protein kinase (ERK) 1/2 and Jun-N-terminal kinase/stress-activated (JNK/ SAPK) pathways, but not P38 MAP kinase. These findings contribute to a growing body of information suggesting that this receptor plays a role in the regulation of cellular proliferation, and that aberrant activation of the mutant receptor in this family may play a role in the unusual neoplastic manifestations.

The role of glucagon administration in the diagnosis and treatment of patients with tumor hypoglycemia

BACKGROUND

Tumor hypoglycemia can be recurrent and severe enough to interfere with definitive antineoplastic treatment. Therefore, rapid commencement of effective therapy is essential. This is best accomplished by identifying which of the hypoglycemic processes is involved, as treatments differ. Some patients present with hypoglycemia and liver metastases; among them, only a few develop hypoglycemia as a result of a failure of hepatic glucose production. Most develop hypoglycemia as a result of an insulin-mediated process--either the secretion of insulin by an islet-cell tumor or the secretion of insulin-like growth factor-II by an extrapancreatic tumor. Administration of glucagon can rapidly make the two groups distinguishable, thus allowing institution of therapy and prompt symptomatic control of hypoglycemia.

METHODS

The charts of seven patients with tumor hypoglycemia and liver metastases who had a glucagon stimulation test (serial glucose measurements after a 1 mg infusion of glucagon) as part of the workup for hypoglycemia were retrospectively reviewed. Those patients whose test revealed a rise in serum glucose of >30 mg/ dL were subsequently treated as outpatients, with a continuous glucagon infusion delivered by a portable pump.

RESULTS

Three patients had an insulinoma and four had non-islet cell tumor hypoglycemia (NICTH) due to hepatocellular carcinoma, colon carcinoma, meningeal sarcoma, and hemangiopericytoma, respectively. All of the patients had liver metastases. Evaluation of these patients included a glucagon stimulation test (1 mg intravenous push), which quickly provided information about the mechanism of tumor hypoglycemia and the direction towards therapy. All patients with insulinoma responded to glucagon with a rise in blood serum glucose levels, indicating adequate glycogen stores. The four patients with NICTH had mixed responses: in two patients, the response suggested that hypoglycemia was due to an insulin-like tumor product; glucose levels did not rise in the other two cases, indicating that hypoglycemia was due to poor hepatic glycogen reserve/liver failure. In all cases, a glycemic response to glucagon predicted good response to long term treatment with glucagon (0.06-0.3 mg/hour, via intravenous infusion pump).

CONCLUSIONS

The glucagon stimulation test is a simple and fast approach that serves to clarify the etiology of hypoglycemia (diagnostic use) and guide effective long term strategies for its control (therapeutic use) in patients with neoplastic diseases and liver metastases.