Doxorubicin plus the IGF-1R antibody cixutumumab in soft tissue sarcoma: a phase I study using the TITE-CRM model.

BACKGROUND: Insulin-like growth factor receptor (IGF-1R) has been studied as an oncologic target in soft tissue sarcoma (STS), but its role in sarcoma biology is unclear. Anti-IGF-1R antibody cixutumumab demonstrated acceptable toxicity but limited activity as a single agent in STS. We carried out a dose-escalation study of cixutumumab with doxorubicin to evaluate safety and dosing of the combination. PATIENTS AND METHODS: Eligible patients with advanced STS were treated with cixutumumab intravenously on days 1/8/15 at one of three dose levels (A: 1 mg/kg, B: 3 mg/kg, C: 6 mg/kg) with doxorubicin at 75 mg/m(2) as a 48 h infusion on day 1 of a 21 day cycle. After six cycles of the combination, patients could receive cixutumumab alone. The Time-to-Event Continual Reassessment Method was used to estimate the probability of dose-limiting toxicity (DLT) and to assign patients to the dose with an estimated probability of DLT≤20%. RESULTS: Between September 2008 and January 2012, 30 patients with advanced STS received a median of six cycles of therapy (range <1-22). Two DLTs were observed, grade 3 mucositis (dose level B) and grade 4 hyperglycemia (dose level C). Grade 2 and 3 reduced left ventricular ejection fraction was seen in three and two patients, respectively. Five partial responses were observed, and estimated progression-free survival was 5.3 months (95% confidence interval 3.0-6.3) in 26 response-assessable patients. Immunohistochemical staining of 11 available tumor samples for IGF-1R and phospho-IGF-1R was not significantly different among responders and non-responders, and serum analysis of select single-nucleotide polymorphisms did not predict for cardiotoxicity. CONCLUSION: The maximum tolerated dose was doxorubicin 75 mg/m(2) on day 1 and cixitumumab 6 mg/kg on days 1/8/15 of a 21 day cycle. Cardiac toxicity was observed and should be monitored in subsequent studies, which should be considered in STS only if a predictive biomarker of benefit to anti-IGF-1R therapy is identified. TRIAL REGISTRATION: ClinicalTrials.gov:NCT00720174.

An open-label, multicenter, phase II study of bevacizumab for the treatment of angiosarcoma and epithelioid hemangioendotheliomas.

BACKGROUND: To determine efficacy and safety of bevacizumab, a recombinant humanized antibody against vascular endothelial growth factor (VEGF), in the treatment of metastatic or locally advanced angiosarcoma and epithelioid hemangioendotheliomas. PATIENTS AND METHODS: In this single-arm phase II trial, 32 patients were enrolled and they received bevacizumab 15 mg/kg IV infusion in 21-day cycles. Patients had disease that was deemed not surgically resectable, Eastern Cooperative Oncology Group (ECOG) performance status of ≤1, adequate organ function and had not received any radiation treatment in the last 28 days. RESULTS: Of the 30 patients evaluated for efficacy and toxic effect, four (two angiosarcoma and two epithelioid hemangioendothelioma; 17%) had a partial response. Fifteen patients (11 angiosarcoma and 4 epithelioid hemangioendothelioma; 50%) showed stable disease with a mean time to progression of 26 weeks. Bevacizumab was well tolerated with only one grade 4 adverse event. Expected known toxic effects of the drug were manageable. CONCLUSION: Bevacizumab is an effective and well-tolerated treatment for metastatic or locally advanced angiosarcoma and epithelioid hemangioendotheliomas. Further phase III studies of bevacizumab in combination with other chemotherapeutic agents and/or radiation treatment are warranted.

Induction chemotherapy and concurrent chemoradiotherapy for locoregionally advanced head and neck cancer: a multi-institutional phase II trial investigating three radiotherapy dose levels.

BACKGROUND: We hypothesized induction chemotherapy (IndCT) would improve distant control (DC) without compromising locoregional control (LRC) for locoregionally advanced head and neck cancer patients. Additionally, we systematically lowered radiotherapy (RT) doses attempting to maintain LRC while decreasing toxicity. PATIENTS AND METHODS: Stages III-IV (M0) locoregionally advanced head and neck cancer patients received carboplatin/paclitaxel (Taxol) IndCT followed by four or five cycles consisting of 5 days of paclitaxel, fluorouracil, hydroxyurea, and BID RT followed by a nine day break. RT dose to gross disease (high risk), intermediate, and low-risk volumes were reduced from cohort A (n = 68): 75, 60, and 45 Gy; to cohort B (n = 64): 75, 54, and 39 Gy; then cohort C (n = 90): 72, 51, and 36 Gy. RESULTS: A total of 222 patients accrued from November 1998 to September 2002. Median follow-up is 56 months. In all, 93/96/76% achieved a complete response to concurrent chemoradiotherapy (CRT) in cohort A/B/C. Three- and 5-year overall survivals (OSs) are 68% and 62%, respectively. Five-year LRC and DC are 91% and 87%, respectively. Response to IndCT predicted for OS, LRC, and time to progression (TTP). Cohort C patients had similar OS (P = 0.95), LRC, and DC, but worse (TTP) (P = 0.027). CONCLUSIONS: IndCT before CRT reduces distant progression while maintaining high LRC. The cohort B schedule provides the best therapeutic ratio. A randomized trial investigating IndCT before CRT has been initiated.

Concomitant infusional paclitaxel and fluorouracil, oral hydroxyurea, and hyperfractionated radiation for locally advanced squamous head and neck cancer.

PURPOSE: To improve local disease control and survival with organ preservation, we conducted a phase II multi-institutional trial with a concomitant taxane-based chemotherapy and hyperfractionated radiation regimen. PATIENTS AND METHODS: Sixty-four patients with locally advanced squamous cancers (stage IV, 98%; N2/3, 81%) were treated on an intensive regimen consisting of 5-day (120-hour) infusions of paclitaxel (20 mg/m(2)/d) and fluorouracil (600 mg/m(2)/d), oral hydroxyurea 500 mg every 12 hours for 11 doses, and radiation 1.5 Gy bid (T-FH2X). Chemoradiation was administered concomitantly on days 1 to 5 of each 14-day cycle. A full treatment course consisted of five cycles during a 10-week period to a total radiation dose of 72 to 75 Gy. RESULTS: The median follow-up for the group is 34 months. At 3 years, progression-free survival is 63%, locoregional control is 86%, and systemic control is 79%; overall survival is 60%. Seventeen patients died of recurrent cancer, two died of second primary cancers, and four died of other causes. Side effects observed include anemia (22% required transfusion), leucopenia (34%, grade 3 to 4), and mucositis (84%, grade 3 to 4). Organ preservation principles were maintained. At 1 year posttreatment, 61% of patients had severe xerostomia and 47% had compromised swallowing. There was little disturbance of speech quality in 97% of patients at the same follow-up point. CONCLUSION: T-FH2X is a highly active and tolerable concomitant chemotherapy and hyperfractionated radiation regimen that induces sustained local tumor control and holds promise for improved survival with organ preservation in high-risk patients. Identification of less toxic therapy and improved distant disease control are needed. T-FH2X should be tested in a randomized trial and compared with a less intensive concomitant regimen that uses once-daily radiation fractionation.

Phase I study of concomitant chemoradiotherapy with paclitaxel, fluorouracil, and hydroxyurea with granulocyte colony-stimulating factor support for patients with poor-prognosis cancer of the head and neck.

PURPOSE: We have previously demonstrated high locoregional control rates in patients with poor-prognosis head and neck cancer using fluorouracil (5-FU), hydroxyurea (HU), and concomitant radiotherapy (RT) (FHX). In the trial reported here, we added paclitaxel to the FHX base and used hyperfractionated RT to determine the maximum-tolerated dose (MTD), toxicities, and response rate in a poor-prognosis group of patients. METHODS: Fifty-five patients who had either failed to respond to prior RT (n = 25) or surgery, had a coexistent or prior second malignancy, or who had unresectable or metastatic disease and an expected 2-year survival rate less than 10%, were treated. Chemoradiotherapy consisted of 2 Gy on days 2 to 6 (once-daily RT cohorts) or 1.5 Gy twice a day (hyperfractionated cohorts). Simultaneous HU (500 or 1,000 mg twice per day for 11 doses) and infusional 5-FU (600-800 mg/m2/d for 5 days) were given along with infusional paclitaxel at escalating doses of 5 to 25 mg/m2/d for 5 days. Granulocyte colony-stimulating factor (G-CSF) was administered on days 7 through 13 at 5 microg/kg/d. Cycles were repeated every 14 days until completion of RT. Plasma paclitaxel levels were determined on day 4 of cycle 1. RESULTS: Dose-limiting toxicities (DLTs) consisted of myelosuppression, mucositis, dermatitis, and diarrhea. Plasma concentrations of paclitaxel greater than 10 nmol/L were achieved in 65% of patients at the recommended phase II dose (RPTD) level of paclitaxel. Seventy percent of assessable patients achieved a complete response (CR) to therapy. Twenty patients were treated at the RPTD of HU 500 mg orally twice daily for 11 doses, 5-FU 600 mg/m2/d by continuous infusion for 5 days; and paclitaxel 20 mg/m2/d by continuous infusion for 5 days, with twice-daily RT. CONCLUSION: The addition of infusional paclitaxel and hyperfractionated RT to FHX is feasible. Radiosensitizing levels of paclitaxel are achieved in most patients. The high locoregional control rate of this regimen justifies further investigation in previously untreated patients.

Phase I study of eniluracil, a dihydropyrimidine dehydrogenase inactivator, and oral 5-fluorouracil with radiation therapy in patients with recurrent or advanced head and neck cancer.

5-Fluorouracil (5-FU) is an effective enhancer of radiation therapy (RT) in head and neck cancers. Due to rapid, predominantly hepatic metabolism by dihydropyrimidine dehydrogenase (DPD) and suggested clinical benefit from prolonged drug exposure, 5-FU is commonly given by continuous infusion. Eniluracil is a novel DPD-inactivator designed to prolong the half-life of 5-FU and provide sustained plasma concentrations of 5-FU with oral dosing. We conducted a Phase I study of the safety and efficacy of eniluracil given with oral 5-FU in patients receiving concurrent RT for recurrent or advanced squamous cell carcinomas of the head and neck. Thirteen patients with recurrent, metastatic, or high-risk (defined as an expected 2-year survival rate of <10%) head and neck cancer were enrolled and treated with concomitant chemoradiotherapy on an every-other-week schedule. Eniluracil at a fixed dose [20 mg twice a day (BID)] was given for 7 consecutive days (days 1-7). 5-FU and RT were given on 5 consecutive days (days 2-6). One patient was treated with once-daily RT (2.0 Gy fractions). The remaining patients received hyperfractionated RT (1.5-Gy fractions BID). The initial dose of 5-FU was 2.5 mg/m2 given BID. Dose escalation in patient cohorts was scheduled at 2.5-mg/m2 increments, with intrapatient dose escalation permitted. Lymphocyte DPD activity and serum 5-FU and uracil concentrations were monitored during two cycles. DPD activity was completely or nearly completely inactivated in all patients. Sustained, presumed therapeutic concentrations of 5-FU were observed at a dose of 5.0 mg/m2 given BID. Cumulative dose-limiting myelosuppression (both neutropenia and thrombocytopenia) was observed during the fourth and fifth cycles following administration of 5.0 mg/m2 5-FU BID. One patient died of neutropenic sepsis during cycle 4. Other late cycle toxicities included diarrhea, fatigue, and mucositis. Grade 3 mucositis was observed in 4 patients, but no grade 4 mucositis or grade 3 or 4 dermatitis was observed. A second patient death occurred during cycle 1 of treatment. No specific cause of death was identified. The study was subsequently discontinued. Cumulative myelosupression was the significant dose-limiting toxicity of oral 5-FU given with the DPD-inactivator eniluracil on an every-other-week schedule. Clinical radiation sensitization was not observed, based on the absence of dose-limiting mucositis and dermatitis. Alternative dosing schedules need to be examined to determine the most appropriate use of eniluracil and 5-FU as radiation enhancers.

Phase II and pharmacodynamic studies of pyrazine diazohydroxide (NSC 361456) in patients with advanced renal and colorectal cancer.

Pyrazine diazohydroxide (PZDH) is a novel antitumor agent that forms DNA adducts via the reactive pyrazine diazonium ion. In a recent Phase I study of PZDH, we identified a recommended Phase II dose of 100 mg/m2/day x 5, given as a 5-min i.v. bolus with the cycles repeated every 42 days (N. J. Vogelzang, et al, Cancer Res., 54: 114-119, 1994). There was a moderate negative correlation between serum chloride concentration and logarithm platelet nadir, suggesting the hypothesis that PZDH is activated in an acidic environment, leading to more toxicity in acidotic patients. Therefore, the University of Chicago Phase II cooperative network conducted two Phase II studies of PZDH in renal cancer (15 patients, 2 with liver metastases) and in 5-fluorouracil-refractory colorectal cancer (14 patients, 13 with liver metastases) to determine efficacy in each disease and to correlate safety and tolerance of the drug with PZDH pharmacokinetics/pharmacodynamics and with arterial blood gas measurements. There were no responses seen in either tumor type. The primary toxicity of PZDH was myelosuppression with neutropenia (absolute neutrophil count, < 1000/microl) and thrombocytopenia (<50,000 cells/microl), seen in 41 and 24% of all cycles, respectively. Other grade 3 and 4 toxicities were rare. Pharmacodynamic analysis revealed no significant correlation between plasma levels at 5, 60, and 120 min; WBCs; absolute neutrophil and platelet count nadirs; and initial serum chloride or blood pH levels. The colorectal patients experienced significantly more thrombocytopenia than did the renal cancer patients (median platelet nadir after cycle 1 was 151 x 10(3)/microl for renal patients versus 76 x 10(3)/microl for colon patients; P = 0.04), suggesting either that prior 5-fluorouracil and leucovorin reduced bone marrow reserve or that colorectal patients with liver metastases experienced more PZDH toxicity. Regression analyses revealed a possible relationship (P = 0.06) between serum pH and thrombocytopenia (i.e., for each increase of 0.03 in pH, there was a 34% increase in the platelet nadir), but there was no relationship between serum chloride and thrombocytopenia. Curiously, an increase in alkaline phosphatase was associated with an increase in the platelet nadir (P = 0.02). If PZDH continues to be developed as an antineoplastic agent, further studies of these relationships are suggested.

Paclitaxel, 5-fluorouracil, hydroxyurea, and concomitant radiation therapy for poor-prognosis head and neck cancer.

A series of phase I and phase II studies investigating multiagent concomitant chemoradiotherapy in patients with poor-prognosis head and neck cancer have been conducted at the University of Chicago. Drug combinations initially included 5-fluorouracil (5-FU) and hydroxyurea, with the more recent addition of cisplatin; in the most recent trial, paclitaxel was substituted for cisplatin. The primary end point of these trials was definition of maximum tolerated doses in combination with radiation therapy. All radiation therapy was given concomitantly with chemotherapy on an every-other-week schedule (total dose,

Oral chemotherapy in head and neck cancer.

Chemotherapy plays an important role in the palliative treatment of head and neck cancer and in the neoadjuvant setting for larynx preservation. Together with concomitant radiotherapy, chemotherapy is also important for the curative and palliative therapy of unresectable head and neck cancer. Although issues relating to anatomical and pharmacological constraints exist, new orally administered drugs, as well as oral substitutes for the currently utilised intravenous drugs, would be extremely desirable in each of these situations. Of the oral fluorinated pyrimidines, tegafur/uracil (UFT) alone produced a complete response rate of 19%, and combination therapy of tegafur/uracil or tegafur with cisplatin or carboplatin has produced response rates comparable to those seen with intravenous fluorouracil (5-FU) plus cisplatin or carboplatin. An initial dose-finding study of 5-FU plus eniluracil indicates that further studies are warranted. The ribonuclease reductase inhibitor hydroxycarbamide (hydroxyurea) has been extensively studied in combination with 5-FU and radiotherapy (the FHX regimen) in patients with head and neck cancer, with high rates of local control. Improvement in locoregional and distant control rates may occur when FHX is combined with additional systemically active agents (cisplatin then paclitaxel) and hyperfractionated radiotherapy is used. Good candidate drugs for head and neck cancer include BMS-182751, an oral platinum complex, and capecitabine and S-1, other oral fluoropyrimidines. In addition, methotrexate and cyclophosphamide both have some activity in head and neck cancer and deserve further investigation.

Cardiac and pulmonary toxicity in patients undergoing high-dose chemotherapy for lymphoma and breast cancer: prognostic factors.

We sought to define risk factors predisposing breast cancer and lymphoma patients to cardiac and pulmonary toxicity when undergoing high-dose chemotherapy (HDC) and autologous stem cell rescue (ASCR). Additionally, we evaluated in depth the predictive value of the ejection fraction measured prior to HDC in determining cardiac toxicity. In this retrospective analysis, 24 variables were examined in 138 patients undergoing HDC and ASCR from 1990 until 1995. Logistic regression models were used to model the probability of experiencing cardiac and pulmonary toxicity as a function of the 24 prognostic covariates. Cardiac toxicity occurred in 12% of patients and pulmonary toxicity in 24% of patients. Bivariate analyses showed that patients with lymphoma (as opposed to breast cancer) and those with a higher cardiac risk factor score were more likely to experience cardiac toxicity. Multivariate logistic regression models predicted lymphoma and older age to be risk factors for cardiac toxicity. History of an abnormal ejection fraction and higher doses of anthracyclines prior to HDC may also contribute to cardiac toxicity. Pulmonary toxicity occurred more commonly in lymphoma than breast cancer patients, likely due to the busulfan used in the HDC regimen. No other risk factors for pulmonary toxicity were identified. We conclude that older patients with lymphoma should be carefully evaluated prior to being accepted for HDC programs. Older patients with breast cancer may tolerate this procedure well. There is a trend towards cardiac toxicity in patients with a past history of low ejection fraction, although seemingly poor cardiac risk patients may fare well with HDC if carefully selected with the aid of a thorough cardiac evaluation.

The spectrum of vascular lesions in the mammary skin, including angiosarcoma, after breast conservation treatment for breast cancer.

BACKGROUND: With the general acceptance of lumpectomy, axillary staging, and radiotherapy as local treatment for infiltrating breast cancer, an appreciation is evolving for the spectrum of vascular lesions that occur in the mammary skin after this treatment. Most of these lesions develop within the prior radiation field after breast conservation treatment. STUDY DESIGN: A retrospective chart and slide review was conducted, consisting of five patients with cutaneous vascular lesions after breast conservation treatment for infiltrating breast cancer. RESULTS: The latent time interval from definitive treatment of breast cancer to the clinical recognition of vascular lesions ranged from 5 to 11 years. Two patients did not have either arm or breast edema, two patients had breast edema, and the fifth patient had arm edema. Lesions arising in the irradiated mammary skin included extensive lymphangiectasia (one), atypical vascular lesions (two), and cutaneous angiosarcoma (four). CONCLUSIONS: Atypical vascular lesions at the skin margins of mastectomy may be predictive of recurrence after resection of angiosarcoma. Excision of skin from the entire radiation field may be necessary to secure local control of the chest wall in patients with cutaneous angiosarcoma after therapeutic breast radiotherapy.

Oral 5-FU alternatives for the treatment of head and neck cancer.

The common clinical presentations of head and neck cancer include early (stage I or II) disease, locally or regionally advanced (stage III or IV, M0) disease, and recurrent or metastatic disease (< 5% of patients). Patients with stage I-II disease are usually cured following surgery or radiotherapy; those with more advanced disease, however, will benefit from chemotherapy--either as induction treatment to avoid surgery and preserve the larynx, or as simultaneous chemoradiotherapy for patients with locoregionally advanced disease; patients presenting with metastatic disease and those with recurrent disease receive chemotherapy as the primary treatment modality. The clinical experience with oral chemotherapy in head and neck cancer patients is limited, partly because of the anatomic location of the disease and complications of local treatment. At the University of Chicago, several regimens that include oral chemotherapy have been studied, including infusional 5-fluorouracil/oral hydroxyurea/radiotherapy, and eniluracil/oral 5-FU/radiotherapy. These trials and others assessing oral agents in the treatment of patients with head and neck cancer will be discussed.

Swallowing function in patients with head and neck cancer prior to treatment.

OBJECTIVE: To define the site-specific swallowing dysfunctions of patients with head and neck cancer with respect to tumor site and stage by, videofluoroscopic oropharyngeal motility (OPM) study prior to initiation of treatment. DESIGN: Retrospective survey. SETTING: Academic university institution. PATIENTS: A consecutive sample of 79 patients with stage III or IV head and neck cancer without prior treatment or tracheotomy. Patients were divided into groups according to tumor site: oral cavity (n = 7), oropharynx (n = 27), larynx (n = 24), and hypopharynx (n = 10). Patients with sinonasal, nasopharyngeal, and unknown primary carcinomas served as the comparison group (n = 11). INTERVENTION: All patients underwent OPM study prior to treatment. MAIN OUTCOME MEASURES: Parameters of swallowing function, including oral impairment, pharyngeal impairment, cervical esophageal impairment, aspiration, and Swallowing Performance Status Scale (SPSS) score (a global measure of swallowing function) were extracted from the pretreatment OPM study and analyzed with reference to tumor site, T stage, and overall stage. The relations between tumor site and area or degree of dysfunction, and between stage of disease and area or degree of dysfunction were analyzed using chi2 and Fisher exact tests. RESULTS: Aspiration status, cervical esophageal impairment, and pharyngeal impairment examined as a function of disease site showed statistically significant differences between groups, with laryngeal and hypopharyngeal sites revealing the most severe dysfunctions. The SPSS score did not correlate with tumor site, T stage, or overall stage. Other OPM parameters analyzed as a function of T stage and overall stage revealed no consistent patterns. CONCLUSIONS: Hypopharyngeal and laryngeal disease sites have a high degree of pretreatment functional impairment. The SPSS score is a good global measure of swallowing dysfunction. In addition, significant site-specific dysfunctions are found when the OPM study is analyzed via its separate parameters. It is therefore critical that posttreatment function is compared with baseline pretreatment dysfunction.

Integration of taxanes into primary chemotherapy for squamous cell carcinoma of the head and neck: promise fulfilled?

Chemotherapy has become integrated into the treatment of head and neck cancer in not only the palliative but now also the primary setting. Organ preservation is possible using induction chemotherapy, and improved survival results have been confirmed for concomitant chemoradiotherapy. The taxanes, paclitaxel and docetaxel, appear to be as active as any other drugs in head and neck cancer. When used in combination in the induction, recurrent, or metastatic settings, response rates rival those of the standard cisplatin/5-fluorouracil regimen. At least one ongoing study will help to establish superiority of cisplatin/paclitaxel versus cisplatin/5-fluorouracil in the recurrent or metastatic setting, and another between cisplatin/5-fluorouracil and doctaxel/cisplatin/5-fluorouracil in the induction setting. Both paclitaxel and docetaxel are being extensively studied as radiosensitizers. They are relatively well tolerated and have good efficacy but have not yet been adequately studied in comparison with other regimens. In conclusion, the taxanes have significantly expanded our effective treatment options in both the primary and recurrent or metastatic settings.

High-dose chemotherapy with autologous stem cell rescue for breast cancer: yesterday, today and tomorrow.

Metastatic breast cancer remains incurable by conventional means and is the second leading cause of all cancer deaths in women in the United States. Laboratory and clinical studies have shown chemotherapy dose intensity may be important in breast cancer therapy, and therefore clinical trials have been investigating high-dose chemotherapy (HDC) with autologous stem cell rescue (ASCR) for the past decade. Initial Phase I trials in heavily pretreated patients demonstrated good response rates but short survival times. The next generation of trials used HDC as initial treatment for metastatic breast cancer and showed improved results. Most recently, patients receive HDC after "induction" chemotherapy to minimize tumor burden prior to HDC. Results from these most recent trials are encouraging, with complete remissions (CR) achievable in at least half of patients and long-term survivors noted. An ongoing randomized trial of HDC versus conventional chemotherapy should answer whether HDC is superior to conventional chemotherapy for metastatic breast cancer. Based on encouraging data from a preliminary trial, two ongoing randomized trials are comparing HDC versus conventional chemotherapy in high-risk primary breast cancer. Technological improvements, better supportive care and experience have all contributed to decrease the morbidity and mortality of this procedure. Additionally, hospitalizations have become shorter and costs may be decreasing. This review will discuss the issues pertinent to this modality in the past and present, including chemotherapy regimens, stem cell technology and related issues, outcomes, ongoing trials and future directions for consideration.

Blood supply to the spinal cord: anatomic and physiologic correlations.

Although the subject has been studied for many years, the clinician's understanding of the blood supply to the spinal cord is complicated by both confusing nomenclature and conflicting data. This review attempts to clarify prevailing thoughts on the arterial and venous structures in this clinically important area.

Oncogenic osteomalacia as a harbinger of recurrent osteosarcoma.

Discussion. Oncogenic osteomalacia is a rare paraneoplastic syndrome of skeletal demineralization from renal phosphate loss. Patients with this disorder have the characteristic clinical, laboratory, and radiographic findings of hyperphosphaturic osteomalacia. Although the pathophysiology has not yet been clearly delineated, a humoral factor produced by the tumor is suspected to be the cause.Purpose. We report the first case of oncogenic osteomalacia that improved with chemotherapy, discuss this paraneoplastic syndrome, and review the medical literature regarding its etiology.