Winston W. Huh

Childhood rhabdomyosarcoma: new insight on biology and treatment.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood. The two most common histologic variants are the embryonal and alveolar subtypes. Although successive collaborative group clinical trials have improved survival rates for many RMS patients, the outcome for those patients with metastatic or recurrent disease remains poor. Recent studies have pointed to a possible mesenchymal stem cell as the progenitor for alveolar RMS. Other studies have implicated several cellular mechanisms and pathways being involved in RMS pathogenesis and survival, such as the cyclin-dependent kinase inhibitors, insulin-like growth factor pathway, and the mammalian target of rapamycin pathway, thus providing potential avenues for targeted therapy. Recent clinical trials have tried to improve risk stratification and prediction of clinical outcome based upon clinical or radiographic response to initial therapy and also to determine the role of high-dose chemotherapy with stem cell rescue in high-risk RMS patients.

Novel bone cancer drugs: investigational agents and control paradigms for primary bone sarcomas (Ewing's sarcoma and osteosarcoma).

Background: New investigational agents and chemotherapy regimens including cyclophosphamide + topotecan, temozolomide + irinotecan, and anti-IGF-1R antibodies in Ewings sarcoma (ES) and liposomal muramyltripeptide phosphatidylethanolamine (L-MTP-PE), aerosol therapy, and bone-specific agents in osteosarcoma (OS) may improve survival and/or quality of life on ‘continuation’ therapy. Objective: Review of investigational approaches and control paradigms for recurrent or metastatic primary bone tumors. Methods: Analyze temozolomide + irinotecan data and review in the context of other newer approaches including antiangiogenesis, anti-IGF-1R antibodies and bisphosphonates for ES. Review some current state-of-the-art approaches for OS including L-MTP-PE, anti-IGF-1R inhibition, aerosol therapies and bone specific agents. Results/conclusion: L-MTP-PE with chemotherapy in OS has been shown to improve survival; compassionate access is available for recurrence and/or metastases. Aerosol therapy (granulocyte–macrophage colony stimulating factor, cisplatin, gemcitabine) for lung metastases is a promising approach to reduce systemic toxicity. The bone-specific agents including denosumab (anti-receptor activator of NF-κB ligand antibody) and bisphosphonates may have benefit against giant cell tumor, ES and OS. Anti-IGF-1R antibody SCH717454 has preclinical activity in OS but best effectiveness will most likely be in combination with chemotherapy earlier in therapy. Both temozolomide + irinotecan and cyclophosphamide + topotecan combinations are very active in ES and are likely to be tested with anti-IGF-1R antibodies against ES.

Psychosocial and functional outcomes in long-term survivors of osteosarcoma: a comparison of limb-salvage surgery and amputation.

Traditionally, physicians have believed that limb‐salvage surgery has functional and cosmetic advantages over amputation, yet the literature is equivocal. Therefore, we sought to compare the psychosocial and functional outcomes in osteosarcoma survivors after limb‐salvage surgery and amputation. We hypothesized there to be neither psychosocial nor functional outcome differences between groups.

Multimodality treatment of osteosarcoma: Radiation in a high-risk cohort

Chemotherapy during radiation and/or bone‐seeking radioisotope therapy (153‐samarium; 1 mCi/kg) during radiation may improve osteosarcoma cancer control.

Rhabdomyosarcoma in adolescent and young adult patients: current perspectives

Rhabdomyosarcoma (RMS), a malignant tumor of mesenchymal origin, is the third most common extracranial malignant solid tumor in children and adolescents. However, in adults, RMS represents <1% of all solid tumor malignancies. The embryonal and alveolar histologic variants are more commonly seen in pediatric patients, while the pleomorphic variant is rare in children and seen more often in adults. Advances in the research of the embryonal and alveolar variants have improved our understanding of certain genes and biologic pathways that are involved in RMS, but much less is known for the other variants. Multimodality therapy that includes surgery and chemotherapy with or without radiation therapy is the mainstay of treatment for RMS. Improvements in the risk stratification of the pediatric patients based on presurgical (primary tumor site, tumor size, regional lymph node involvement, presence of metastasis) and postsurgical parameters (completeness of resection or presence of residual disease or metastasis) has allowed for the treatment assignment of patients in different studies and therapeutic trials, leading to increases in 5-year survival from 25%–70% over the past 40 years. However, for adult patients, in great part due to rarity of the disease and the lack of consensus on optimal treatment, clinical outcome is still poor. Many factors have been implicated for the differing outcomes between pediatric RMS versus adult RMS, such as the lack of standardized treatment protocols for adult RMS patients and the increased prevalence of advanced presentations. Now that there are increased numbers of survivors, we can appreciate the sequelae from therapy in these patients, such as bone growth abnormalities, endocrinopathies, and infertility. Improvements in risk stratification have led to clinical trials using lower doses of chemotherapy or radiation therapy with the intention of decreasing the incidence of side effects without compromising survival outcome.

Functional, psychosocial and professional outcomes in long-term survivors of lower-extremity osteosarcomas: amputation versus limb salvage.

As the number of osteosarcoma survivors increases, the impact of quality of life and function needs to be addressed. Limb salvage is the preferred treatment when patients have treatment options; yet, the questionable long-term durability and complications of prostheses, combined with ambiguous function, leave some doubt regarding the best clinical and surgical options. Comparisons between limb salvage patients, amputees and controls also require further investigation. Amputation would leave the patients with a lifelong requirement for an external prosthetic leg associated with an overall limited walking distance. While artificial limbs are much more sophisticated than those used in the past, phantom limb sensations remain a substantial and unpredictable problem in the amputee. Complications such as stump overgrowth, bleeding, and infection, also require further elucidation. Limb salvage surgery using endoprosthesis, allografts or reconstruction is performed in approximately 85% of patients affected by osteosarcoma located in the middle and/or distal femur. One drawback in limb-salvage surgery in the long-term survivor is that endoprostheses have a limited life span with long-term prosthetic failure. The inherent high rate of reoperation remains a serious problem. Replacing a damaged, infected or severely worn-out arthroplastic joint or its intramedullary stem is difficult, especially in the long-stem cemented endoprostheses used in the 1980s. Limb lengthening procedures in patients who have not reached maturity must also be addressed. Periprosthetic infections, compared to other indications for joint reconstruction, were found to be more frequent in patients treated for neoplastic conditions and their outcome can be devastating, resulting in total loss of joint function, amputation, and systemic complications. Quality of life in terms of function, psychological outcome and endpoint achievements such as marriage and employment apparently do not differ significantly between amputee and nonamputee osteosarcoma survivors. Amputee patients nonetheless appear to have made satisfactory adjustments to their deficits with or without a functional external prosthesis. It also appeared that amputee patients had a similar psychological and quality of life outcome as limb salvage patients. There was no evidence of excessive anxiety or depression or deficits in self-esteem compared with the normal population or matched controls. A number of long-term survivors also achieved high ranking in the professional and commercial work place. These positive aspects should be recognized and emphasized to patients and their parents when discussing the outcome.

Recurrent osteosarcoma with a single pulmonary metastasis: a multi-institutional review

Background:Late relapse and solitary lesion are positive prognostic factors in recurrent osteosarcoma.Methods:We reviewed the records of 39 patients treated at three major centres for recurrent osteosarcoma with a single pulmonary metastasis more than 1 year after diagnosis. We analysed their outcomes with respect to clinical factors and treatment with chemotherapy.Results:Median age at diagnosis was 14.6 years. Relapse occurred at a median of 2.5 years (range, 1.2–8.2 years) after initial diagnosis. At relapse, all patients were treated by metastasectomy; 12 (31%) patients also received chemotherapy. There was no difference in time to recurrence or nodule size between the patients who received or did not receive chemotherapy at relapse. Sixteen patients had no subsequent recurrence, 13 of whom survive without evidence of disease. The 5-year and 10-year estimates of post-relapse event-free survival (PREFS) were 33.0±7.5% and 33.0±9.6%, respectively, and of post-relapse survival (PRS) 56.8±8.6% and 53.0±11.0%, respectively. There was a trend for nodules <1.5 cm to correlate positively with PREFS (P=0.070) but not PRS (P=0.49). Chemotherapy at first relapse was not associated with PREFS or PRS.Conclusion:Approximately half of the patients with recurrent osteosarcoma presenting as a single pulmonary metastasis more than 1 year after diagnosis were long-term survivors. Metastasectomy was the primary treatment; chemotherapy did not add benefit.

Can anthracycline therapy for pediatric malignancies be less cardiotoxic

Anthracyclines have a central role in the treatment of cancer in pediatric patients but confer an increased risk of cardiac dysfunction. Several strategies have been employed to help reduce anthracycline-induced cardiotoxicity, including pretreating the patient with the iron chelator dexrazoxane and infusing the dose of anthracycline over a longer period. Much focus has also been placed on the development of methods that decrease the toxicity of parent compounds, specifically through the use of drug carriers such as liposomes, and on the development of new, potentially less toxic anthracycline derivatives, such as amrubicin and pixantrone. We provide a review of these strategies, focusing on studies in pediatric patients when available, and support the idea that anthracycline therapy can be less cardiotoxic in pediatric patients.

Mifamurtide in Metastatic and Recurrent Osteosarcoma: A Patient Access Study with Pharmacokinetic, Pharmacodynamic, and Safety Assessments

This non‐randomized, patient‐access protocol, assessed both safety and efficacy outcomes following liposomal muramyl‐tripeptide‐phosphatidylethanolamine (L‐MTP‐PE; mifamurtide) in patients with high‐risk, recurrent and/or metastatic osteosarcoma.

COMPARISON OF DOXORUBICIN CARDIOTOXICITY IN PEDIATRIC SARCOMA PATIENTS WHEN GIVEN WITH DEXRAZOXANE VERSUS AS CONTINUOUS INFUSION

Doxorubicin is an effective agent for many malignancies. To limit cardiotoxicity, doxorubicin can be given as prolonged infusion (PIDX) or bolus infusion following dexrazoxane (DZX). The authors report their institutional experience comparing PIDX and DZX in a sarcoma cohort. Retrospective record review for newly diagnosed sarcoma patients at the University of Texas M.D. Anderson Cancer Center from June 1998 to June 2006. There were 23 Ewings sarcoma (EWS) patients treated with DZX and 40 osteosarcoma (OS) patients treated with PIDX. The DZX group had higher mean cumulative anthracycline dose (510 mg/m2 [SD 120 mg/m2] versus 414 mg/m2 [SD 99 mg/m2], P = .002), however mean lowest left ventricular ejection fraction (EF) values were higher for DZX (52.5% [SD 5.6%] versus 47.2% [SD 10.9%], P = .014). Fifteen of 19 patients with cardiac dysfunction were PIDX patients (P = .15). Five PIDX patients required cardiac medication, and 1 patient died of congestive heart failure (CHF). Sixteen patients with cardiac dysfunction had improvement, demonstrated by EF ≥ 50% at last echocardiogram. Although not statistically significant, there were 4 DZX patients with cardiac dysfunction. Prospective studies are required to determine which strategy has long-term advantages and if certain patients are at increased risk for cardiac dysfunction.