Leiomyosarcomas of Vascular Origin in the Extremity

Between 1996 and 2006 a total of 278 patients with soft tissue Leiomyosarcoma were treated at our centre. We identified 16 patients (5.8%) where the tumour directly arose from the blood vessels. These tumours were studied to determine their prognosis and behaviour. All tumors were in the lower limbs: 11 from the femoral vein, 3 popliteal vein, and 2 from the posterior tibial vein. Mean tumour size was 10.4 cm (3 to 33). Histological grade was high in all patients. Surgical treatment was amputation in one, excision with or without vascular reconstruction in 12 followed by radiotherapy, and 3 patients had no surgery because of advanced disease at diagnosis. Seven out of the 16 patients (44%) had metastasis at diagnosis, and five patients without metastasis at diagnosis rapidly developed metastases at a median time of 5 months from diagnosis (2–30 months). The overall survival of the patients at 5 years was 25% which was considerably worse than those with nonvascular leiomyosarcoma. We conclude that patients with leiomyosarcoma of vascular origin have a very high risk of metastases and poor prognosis when treated in the conventional way

‘‘Two-Week Waits”—Are They Leading to Earlier Diagnosis of Soft-Tissue Sarcomas?

Introduction. The ‘‘two-week wait” was established as a potential means of diagnosing malignant tumours earlier. This paper investigated whether these clinics are leading to earlier diagnosis of malignant soft-tissue lumps. Method. We identified all referrals to our centre from a database over a 4-year period. Results. 2225 patients were referred to our unit for investigation of a soft-tissue mass. 576 (26%) were referred under the ‘‘two-week wait” criteria. 153 (27%) of which were found to have a malignant or borderline malignant diagnosis. 1649 patients were referred nonurgently. 855 (52%) of which were diagnosed with a malignant or borderline lesion. The average size at diagnosis was 9.4 cm with no difference in size between the different referral routes. Conclusion. There is little evidence that the two-week wait clinic is leading to earlier diagnosis of soft-tissue sarcomas with the majority still being referred nonurgently

Primary Leiomyosarcoma of Bone: Analysis of Prognosis

Leiomyosarcoma of bone is just one of the variants of spindle cell sarcoma of bone characterised by the expression of desmin and other markers indicating a significant element of smooth muscle in the tumour, without osteoid production we have investigated the management and outcome of this rare type of primary malignant bone tumour. Method. Retrospective review of data stored on a prospective database. Results. In a database of 3364 patients with primary malignant bone sarcomas, 31 patients were identified with a primary leiomyosarcoma of bone. There were 12 males and 19 females with a mean age of 46 and tumour size of 8 cm. The most common site was the distal femur followed by the proximal tibia. Treatment was with chemotherapy and surgical resection. Seven of the patients had metastases at diagnosis. Surgery was carried out in 28 patients, 8 having amputation and 20 limb salvage. Three patients developed local recurrence, but half developed metastases. All patient disease-specific survival was 57% at five years and 44% at 10 yrs but for those without metastases was 82% and 60%, respectively. The only prognostic factors were metastases at diagnosis. Conclusion. Leiomyosarcoma of bone is a very rare primary malignant bone tumour affecting a predominantly older population. Despite the high incidence of metastases, survival is better than for other bone sarcomas for those without metastases at diagnosis

Chondroblastoma of bone in extremities. - A single centre study of 177 cases

Introduction Chondroblastoma is a rare benign bone tumour that usually occurs in children and young adults. They are cartilaginous tumours arising in the epiphysis or apophysis of a long bone. The tumour is classified as benign, although rare cases of pulmonary metastases have been reported. The aims of this study were to describe clinical, radiographic characteristics of chondroblastoma; to analyse the local recurrence rate and complications associated with surgery. Material and methods This retrospective study included 177 patients, who had been diagnosed with a chondroblastoma in extremity between 1990 and 2015. Results The most common site was proximal tibia 20%, followed by proximal humerus 19%, proximal femur 18%, distal femur 16% and foot 15%. One patient has died of the disease and one patient is alive after being operated for lung metastases. There was local recurrence in 25/177 (14%) patients. The median time to local recurrence was 10 months (range 3-158 months). The most common site for local recurrence was proximal tibia (22.2%). The proximal femur was the location in 32/178 (18%) of the cases. 18/32 (56%) were in the greater trochanter and 14/32 (44%) in the femoral head. The mean age was lower in tumours located in femoral head when compared to the greater trochanter; 19.5 years and 13.9 years respectively (p=0.004). Tumours located in greater trochanter were all curetted without further complications. Local recurrence was seen more often in femoral head tumours, though without statistical significance; 3/14 (21%) and none, respectively (p=0.073). Conclusions Chondroblastoma is a rare benign to intermediate grade bone tumour with a potential to metastasise. Femoral head chondroblastoma is rare, presenting 4.5% of all chondroblastoma cases. Around 50% of the chondroblastoma in femoral head. occur in patients with open growth plates.Peer reviewe

The effect of investment and financing optimization policies for developing photovoltaic power generation in Cameroon; a dynamic CGE model assessment

With less than a decade remaining until 2030, global investment in clean energy access falls short of the anticipated levels required to achieve the sustainable development goals. Notably, nations with the greatest gaps in electricity access, particularly those in Sub-Saharan Africa, have been largely excluded from energy access funding. Interestingly, the energy sector policy documents of these countries have neglected to incorporate financing strategies or plans for photovoltaic (PV) power generation. This discrepancy in the literature underscores the need to assess the economic impact of finance and investment policies that align with long-term PV power generation targets. To address this gap, our study employs a dynamic Computable General Equilibrium model to evaluate the macroeconomic consequences of achieving Cameroon’s Nationally Determined Contributions for PV power generation through optimized PV investment and finance. The model examines three policy scenarios: the Business-as-Usual, SC1 scenario involving a stable 100% increase in PV investment, and SC2 scenario featuring a stepwise 5%–100% increase in PV investment. By simulating these scenarios, we aim to shed light on their effects. The results reveal that SC1 and SC2 exhibit a 50% higher final demand for PV investment compared to the BAU scenario. Optimizing PV finance and investment in both scenarios leads to a slowdown in Cameroon’s economic growth, with SC1 showing a more pronounced impact. Additionally, SC2 encourages rapid decarbonization in energy-intensive sectors such as crude oil production and electricity generation industries. However, the SC1 policy scenario results in a rapid reduction in total investment expenditure for PV power generation. By 2035, PV power generation is projected to be three times higher in both SC1 and SC2 compared to the BAU scenario. The SC2 policy scenario also predicts relatively high levels of consumption among rural affluent and urban impoverished households. In conclusion, our study highlights the pressing need for enhanced investment and finance strategies to propel PV power generation, particularly in underserved regions. By leveraging the findings of this research, policymakers can make informed decisions and implement policies that promote sustainable and inclusive energy access, driving progress towards the fulfillment of SDGs

Preoperative surgical risk stratification in osteosarcoma based on the proximity to the major vessels

Aims The aim of this study was to determine the risk of local recurrence and survival in patients with osteosarcoma based on the proximity of the tumour to the major vessels. Patients and Methods A total of 226 patients with high-grade non-metastatic osteosarcoma in the limbs were investigated. Median age at diagnosis was 15 years (4 to 67) with the ratio of male to female patients being 1.5:1. The most common site of the tumour was the femur (n = 103) followed by tibia (n = 66). The vascular proximity was categorized based on the preoperative MRI after neoadjuvant chemotherapy into four types: type 1 > 5 mm; type 2 ≤ 5 mm, > 0 mm; type 3 attached; type 4 surrounded. Results Limb salvage rate based on the proximity type was 92%, 88%, 51%, and 0% for types 1 to 4, respectively, and the overall survival at five years was 82%, 77%, 57%, and 67%, respectively (p Conclusion The proximity of osteosarcoma to major blood vessels is a poor prognostic factor for local control and survival. Amputation offers better local control for tumours attached to the blood vessels but does not improve survival. Limb salvage surgery offers similar local control if the tumour attachment to blood vessels is limited

Mammalian Atg8 proteins regulate lysosome and autolysosome biogenesis through SNAREs

Mammalian homologs of the yeast Atg8 protein (mAtg8s) are important in autophagy, but their exact mode of action remains to be defined. Recently, syntaxin 17 (Stx17), a SNARE with major roles in autophagy, was shown to bind mAtg8s. Here we broadened the analysis of potential mAtg8-SNARE interactions and identified LC3-interacting regions (LIRs) in several SNAREs. Syntaxin 16 (Stx16), and its cognate SNARE partners all have LIR motifs and bind mAtg8s. A knockout in STX16 caused defects in lysosome biogenesis whereas a double STX16 and STX17 knockout completely blocked autophagic flux and decreased mitophagy, pexophagy, xenophagy, and ribophagy. Mechanistic analyses revealed that mAtg8s and Stx16 maintained several aspects of lysosomal compartments including their functionality as platforms for active mTOR. These findings reveal a broad direct interaction of mAtg8s with SNAREs with impact on membrane remodeling in eukaryotic cells and expand the roles of mAtg8s to lysosome biogenesis.</p

Clinical and functional outcomes of the saddle prosthesis

BACKGROUND:The implantation of a saddle prosthesis after resection of a pelvic tumor has been proposed as a simple method of reconstruction that provides good stability and reduces the surgical time, thus limits the onset of intraoperative complications. There are no studies in the literature of patients evaluated using gait analysis after being implanted with a saddle prosthesis. The present study is a retrospective case review aimed at illustrating long-term clinical and functional findings in tumor patients reconstructed with a saddle prosthesis. MATERIALS AND METHODS:A series of 15 patients who received pelvic reconstruction with a saddle prosthesis were retrospectively reviewed in terms of clinical, radiographic, and functional evaluations. Two patients were additionally assessed by gait analysis. RESULTS:Long-term functional follow-up was achieved in only 6 patients, and ranged from 97 to 167 months. Function was found to be rather impaired, as a mean of only 57 % of normal activity was restored. Gait analysis demonstrated that the implant had poor biomechanics, as characterized by very limited hip motion. CONCLUSIONS: Though the saddle prosthesis was proposed as advance in tumor-related pelvic surgery, the present study indicates that it yields unsatisfactory clinical and functional results due to both clinical complications and the poor biomechanics of the device. The use of a saddle prosthesis in tumor surgery did not provide satisfactory results in long-term follow-up. It is no longer implanted at our institute, and is currently considered a "salvage technique.