Muscle strength characteristics following megaprosthetic knee reconstruction for bone sarcoma

OBJECTIVE

To assess muscle strength characteristics in patients with resection and megaprosthetic reconstruction of the knee for bone sarcoma compared to age- and sex-matched controls.

METHODS

This was a cross-sectional, case-control study. Muscle strength characteristics for knee extension and -flexion were assessed isokinetically at three different joint velocities: 60, 120 and 180°/s, and by the rate of force development (RDFmax) in knee extension. The Toronto Extremity Salvage Score (TESS) was used in patients.

RESULTS

Eighteen patients (91.6 months postop.) and 18 controls were included. Relative to controls, patients generated maximal torques of 19%, 23% and 23% in knee extension at 60, 120 and 180°/s, respectively. For knee flexion, patients generated maximal torques of 58%, 53% and 60% at 60, 120, and 180°/s, relative to the controls. RDFmax of the operated leg was 2.75 ± 2.13 N/ms, 7.16 ± 4.78 N/ms for the non-operated leg, and 7.95 ± 4.29 N/ms for the controls. The mean TESS score was 84.0.

CONCLUSION

Patients reached approximately 20% of the maximal knee extension torque. In isometric assessments, they used double the amount of time to generate one-third of the maximal force compared to the controls despite good TESS scores.

Chondrosarcoma local recurrence in the Cancer Registry of Norway cohort (1990-2013): Patterns and impact

BACKGROUND

There appears to be an association between local recurrence (LR) and risk of metastasis and death in central conventional chondrosarcoma (CCCS) of bone, but this has not been quantified in modern cohorts at a subtype level.

METHODS

We identified nonmetastatic cases of CCCS (N = 180) from the Cancer Registry of Norway. We present prognostic analysis of LR accounting for immortal time bias by descriptive statistics and multivariable Cox models.

RESULTS

Of 40 LR, one case demonstrated upgrading while two dedifferentiation. LR was associated with increased risk of metastasis (hazard ratio [HR] = 4.1 [confidence interval, 1.5-10.7]) and death (HR = 9.3 [5.0-17.5]) overall. LR was associated with significant increased risk of metastasis for those with a soft tissue component, axial location, malignancy grade 2, but not atypical cartilaginous tumor's, appropriately treated curettage patients, intramedullary tumors, grade 1 histology, extremity location or "Oslo low risk" group status. We found an increased risk of death for all groups except for those treated by appropriate curettage or belonging to the "Oslo low risk" group. About 50% of LR CCCS were asymptomatic and revealed by routine follow-up.

CONCLUSIONS

Upgrading of LR for CCCS was a seldom event. LR was associated with significant increased risk of metastasis and death overall, but not for appropriately treated curettage patients or "Oslo low risk" status.

Risk stratification for central conventional chondrosarcoma of bone: A novel system predicting risk of metastasis and death in the Cancer Registry of Norway cohort

BACKGROUND AND OBJECTIVES

Interobserver variability in histological grading of central conventional chondrosarcoma (CCCS) limits the quality of patient information and research progression. We aim to quantify known and new prognostic variables and propose a risk stratification model.

METHOD

We selected 149 cases from the Cancer Registry of Norway. Cox proportional hazard models were estimated. Based on these results a dichotomous risk classification was proposed and presented by Kaplan-Meier estimates for rates of local recurrence, metastasis, and disease-specific survival.

RESULTS

The influence of axial skeletal location (Hazard ratio [HR] = 19.06), a soft tissue component ≥1 cm (HR = 13.45), and histological grade 3 (HR = 16.46) are all significant in predicting the rate of metastasis. The creation of a variable combining axial skeletal location and a soft tissue component ≥1 cm strongly predicts the risk of metastasis (HR = 14.02; P < .001) and death (HR = 2.74; P = .030) at multivariate analysis, making the histological grade insignificant. Together with metastasis at diagnosis (HR = 285.65; P < .001), this forms the basis of our proposed risk stratification, producing a small high-risk group (39 cases with 33% risk of metastasis) and a large low-risk group (103 cases with 2% risk of metastasis) without a histological grade.

CONCLUSION

Axial skeletal location and a soft tissue component ≥1 cm combined divides a CCCS cohort into low- and high-risk groups without a histological grade.

Chondrosarcoma in Norway 1990-2013; an epidemiological and prognostic observational study of a complete national cohort

BACKGROUND

Knowledge of chondrosarcoma (CS) of bone to date is based on institutional reports and registry publications with limits in reporting, detail and quality of data.

METHOD

We have performed a retrospective search of CS of bone in the National Cancer Registry in Norway from 1990-2013, cross checked against local tumor databases with further quality control and supplementation of all data from clinical files. The time period is defined by the routine use of axial imaging in clinical practice. A total of 311 cases are included. We performed 108 pathological reviews and 223 radiological reviews. The manuscript was prepared according to the STROBE checklist for strengthening of observational studies. We performed uni-/multivariate cox analyses to define independent prognostic variables from the main cohort of central CS of bone.

RESULTS

The incidence of CS of bone in Norway is 2.85/million/yr. for both sexes overall, rising to 3.45/million/yr. in the last 5-year period. There is an increase in the most common central CS subtype, stronger for women than for men. Central CS had, in general 10-15% local recurrence rates, all evident by 5 years while metastasis rate increases with location and grade. Exceptions are extremity grade 1 CS which displayed no metastatic events and axial grade-3 disease with high rates (50%) of both local and metastatic relapse. Peripheral CS had limited metastatic potential (2%), but rates of local relapse (13%) continue to appear towards 10 years of follow up. Malignancy grade 3 independently predicts rate of metastasis and presence of soft tissue component predicts local recurrence, metastasis and survival.

CONCLUSION

Rates of local recurrence, metastasis and disease specific survival follow clear patterns depending on subtype, location and grade allowing better tailoring of follow-up regimes. Malignancy grade 3 and the presence of a soft tissue component independently predict behavior for central CS of bone.

Best practices for the management of local-regional recurrent chordoma: a position paper by the Chordoma Global Consensus Group

Chordomas are rare, malignant bone tumors of the skull-base and axial skeleton. Until recently, there was no consensus among experts regarding appropriate clinical management of chordoma, resulting in inconsistent care and suboptimal outcomes for many patients. To address this shortcoming, the European Society of Medical Oncology (ESMO) and the Chordoma Foundation, the global chordoma patient advocacy group, convened a multi-disciplinary group of chordoma specialists to define by consensus evidence-based best practices for the optimal approach to chordoma. In January 2015, the first recommendations of this group were published, covering the management of primary and metastatic chordomas. Additional evidence and further discussion were needed to develop recommendations about the management of local-regional failures. Thus, ESMO and CF convened a second consensus group meeting in November 2015 to address the treatment of locally relapsed chordoma. This meeting involved over 60 specialists from Europe, the United States and Japan with expertise in treatment of patients with chordoma. The consensus achieved during that meeting is the subject of the present publication and complements the recommendations of the first position paper.

Photochemical delivery of bleomycin induces T-cell activation of importance for curative effect and systemic anti-tumor immunity

Photochemical internalization (PCI) is a technology to enhance intracellular drug delivery by light-induced translocation of endocytosed therapeutics into the cytosol. The aim of this study was to explore the efficacy of PCI-based delivery of bleomycin and the impact on systemic anti-tumor immunity. Mouse colon carcinoma cells (CT26.CL25), stably expressing the bacterial β-galactosidase, were inoculated into the legs of athymic or immuno-competent BALB/c mice strains. The mice were injected with the photosensitizer AlPcS_2a and bleomycin (BLM) prior to tumor light exposure from a 670nm diode laser. Photochemical activation of BLM was found to induce synergistic inhibition of tumor growth as compared to the sum of the individual treatments. However, a curative effect was not observed in the athymic mice exposed to 30J/cm² of light while >90% of the thymic mice were cured after exposure to only 15J/cm² light. Cured thymic mice, re-challenged with CT26.CL25 tumor cells on the contralateral leg, rejected 57-100% of the tumor cells inoculated immediately and up to 2months after the photochemical treatment. T-cells from the spleen of PCI-treated mice were found to inhibit the growth of CT26.CL25 cells in naïve thymic mice with a 60% rejection rate. The results show that treatment of CT26.CL25 tumors in thymic mice by PCI of BLM induces a systemic anti-tumor immunity.

Photochemical internalization (PCI) in cancer therapy: from bench towards bedside medicine

PDT in cancer therapy has been reviewed several times recently and many published reports have been showing promising results. The clinical approvals for PDT include curative treatment of early or superficial cancers and palliative treatment of more advanced disease. Still PDT has yet to become a widely used cancer treatment. This may partly be due to limitations in current PDT regimens and partly due to effective alternative treatment modalities. If the specificity and selectivity of PDT could be improved, PDT would probably make substantial progress and comprise an even more competitive alternative in cancer treatment. The PCI technology is based on the same principles as PDT, the activation of a photosensitizer by light and subsequently followed by formation of reactive oxygen species. Unlike PDT, the photosensitizer used in PCI has to be located in the endocytic vesicles of the targeted cells and will, upon activation of light, induce a release of endocytosed therapeutic agents after a photochemically induced rupture of the endocytic vesicles. The endocytosed therapeutic agent will then be released and may reach their intracellular target of action before being degraded in lysosomes. This site-specific drug delivery induced by PCI will take place in addition to the well described cytotoxic, vascular and immunostimulatory effects of PDT. PCI has been shown to facilitate intracellular delivery of a large variety of macromolecules that do not otherwise readily penetrate the plasma membrane, including type I ribosome-inactivating proteins (RIPs), RIP-based immunotoxins, genes and some chemotherapeutic agents. Several animal models have been used for in vivo documentation of the PCI principle and more animal models of clinical relevance have recently been utilized for addressing clinical issues. This review will focus on the possibilities and limitations offered by PCI to overcome some of the challenges recognized in current PDT regimens in cancer treatment.

Interprosthetic dislocations of the Charnley/Hastings hemiarthroplasty--report of 11 cases in 350 consecutive patients

We report 11 cases of interprosthetic dislocation of the Charnley/Hastings hemiarthroplasty in a retrospective study of 350 consecutive patients treated for an acute femoral neck fracture. We found a total of 14 dislocations (4.0%), 11 were interprosthetic. The median age of the 350 patients was 79 (36-99) years and the median age of the 11 patients with an interprosthetic dislocation was 85 years (82-94). The median time from surgery to radiologically acknowledged dislocation was 18 (4-64) days. These interprosthetic dislocations may be caused by either an assembly mistake perioperatively, by maximum angulation and impingement between the components, or by trauma.