The prognostic value of the central location of pulmonary nodules in osteosarcoma patients

BACKGROUND

Most metastatic osteosarcoma pulmonary nodules exist in the periphery of the lung, while other lesions are close to the airway and vascular branches in the center. Central lesions require anatomical resection. However, there is a scarcity of data on the prognostic value of the central location of pulmonary metastasis in osteosarcoma.

METHODS

We reviewed the medical records of osteosarcoma patients with metastasectomy between January 2009 and June 2022. The central lesions were identified as lesions requiring lobectomy or segmentectomy. We divided our cohort into Group A (peripheral lesion) and Group B (central lesion). The primary outcome measures were overall survival (OS) and postmetastasectomy event-free survival (PMEFS).

RESULTS

We identified a total of 204 osteosarcoma patients with pulmonary metastases. Among them, 162 patients underwent metastasectomy: Group A (n = 128, 80.6%) and Group B (n = 34, 19.4%). Group A had a 5-year overall survival rate (OS) of 36.6% ± 5.7%, whereas Group B had a 5-year overall survival rate of 17.5% ± 8.5%, with (p = 0.048). The 3-year PMEFS for peripheral and central lesions was 25.7 ± 5.1 and 11.8 ± 7.1, respectively, with (p = 0.034).

CONCLUSION

In Osteosarcoma patients who underwent metastasectomy, central pulmonary nodules are associated with lower OS and PMEFS. We recommend, however, to keep offering these patients the option of metastasectomy as a predictor of survival until a more effective treatment is approved.

An improved experimental model of osteosarcoma lung metastases to investigate innovative therapeutic interventions and sex as a biological variable

Osteosarcoma (OS) is the most common primary bone malignancy, with OS lung metastasis (OSLM) being the leading cause of death in OS patients. No curative pharmacotherapies for OSLM are available, highlighting the clinical need for new therapies. Improved and rigorous preclinical models of OSLM are key in supporting advancements in this field. We aimed to develop an immunocompetent mouse model of OSLM that allows monitoring pharmacotherapies' effect on the lung metastatic burden over time and assessing the impact of sex as a biological variable in tumor growth and response to therapy. We transformed K7M2 cells to express bioluminescence and fluorescence, enabling real-time tracking of OSLM in BALB/c mice following tail vein injection. Metastasis was confined to the lungs and exhibited exponential growth with typical downregulated Fas receptor expression. In vivo bioluminescence correlated strongly with ex vivo, suggesting its reliability for evaluating metastatic progression and therapy response. Fluorescence from tdT was stable upon tissue processing, providing unique opportunities to probe the tumor characteristics ex vivo. We also assessed the effect of local lung-delivered gemcitabine, which was well-tolerated and significantly reduced OSLM burden without causing pulmonary toxicity. However, treatment did not resolve metastatic disease. We also explored the effect of sex on tumor growth and response to therapy; while no difference was observed in tumor growth between male and female mice, females showed a better response to local gemcitabine administration. In sum, we established a robust and rigorous immunocompetent mouse model of OSLM that will facilitate exploring new pharmacotherapies for OSLM.

The management of osteosarcoma in children and adolescents in a resource-limited setting: quality improvement considerations to improve treatment outcomes

BACKGROUND

The survival rates for children and adolescents with osteosarcoma in low-income countries are poor. Insufficient data regarding the challenges of managing osteosarcoma in resource-limited settings has been published. We evaluated the treatment of osteosarcoma in children and adolescents with the aim of improving the health system and management outcomes.

METHODS

We sourced data on children under 18 years treated for osteosarcoma at the Uganda Cancer Institute between January 2016 and December 2020. Descriptive statistics and Kaplan-Meier survival analysis were used.

RESULTS

Seventy-four osteosarcoma cases were identified, with a median age of 13 years (IQR 9.8-15). Referrals were made after a median of 28 days (range 1-147). Before appropriate referral, more than a quarter (26%) had undergone invasive procedures that could compromise tumour integrity and outcome. Half (50%) of the patients had metastatic disease at diagnosis, primarily to the lungs (n = 43; 92%). Only 14 (33%) patients received neoadjuvant chemotherapy. Forty-three (58.1%) patients underwent limb amputation surgery, including 25 localized tumours and 18 patients with distant metastatic disease. No metastatectomies were performed. Adjuvant chemotherapy was delayed for longer than 21 days in 26 (61%) patients. No pathology reports described the status of resection margins or the degree of chemotherapy-induced necrosis. Twenty-six (35%) patients abandoned treatment, mainly due to pending radical surgery (n = 18/26; 69%). Only 18% (n = 13) were still alive; 46% (n = 34) had died; and 37% (n = 27) had an unknown status. The median overall survival was 1.1 years, and was significantly negatively affected by disease metastasis, timing of adjuvant therapy, and treatment abandonment.

CONCLUSIONS

Osteosarcoma outcomes for children and adolescents at the Uganda Cancer Institute are extremely poor. The quality of care can be improved by addressing delayed referrals, high rates of prior manipulative therapy, metastatic disease, treatment abandonment, surgical challenges, and delayed resumption of adjuvant chemotherapy.

Effectiveness of Learning Systems from Common Image File Types to Detect Osteosarcoma Based on Convolutional Neural Networks (CNNs) Models

Osteosarcoma is a rare bone cancer which is more common in children than in adults and has a high chance of metastasizing to the patient’s lungs. Due to initiated cases, it is difficult to diagnose and hard to detect the nodule in a lung at the early state. Convolutional Neural Networks (CNNs) are effectively applied for early state detection by considering CT-scanned images. Transferring patients from small hospitals to the cancer specialized hospital, Lerdsin Hospital, poses difficulties in information sharing because of the privacy and safety regulations. CD-ROM media was allowed for transferring patients’ data to Lerdsin Hospital. Digital Imaging and Communications in Medicine (DICOM) files cannot be stored on a CD-ROM. DICOM must be converted into other common image formats, such as BMP, JPG and PNG formats. Quality of images can affect the accuracy of the CNN models. In this research, the effect of different image formats is studied and experimented. Three popular medical CNN models, VGG-16, ResNet-50 and MobileNet-V2, are considered and used for osteosarcoma detection. The positive and negative class images are corrected from Lerdsin Hospital, and 80% of all images are used as a training dataset, while the rest are used to validate the trained models. Limited training images are simulated by reducing images in the training dataset. Each model is trained and validated by three different image formats, resulting in 54 testing cases. F1-Score and accuracy are calculated and compared for the models’ performance. VGG-16 is the most robust of all the formats. PNG format is the most preferred image format, followed by BMP and JPG formats, respectively.

Mesenchymal stromal cells mediated delivery of photoactive nanoparticles inhibits osteosarcoma growth in vitro and in a murine in vivo ectopic model

Background

Osteosarcoma (OS) is an aggressive malignant neoplasm that still suffers from poor prognosis in the case of distal metastases or occurrence of multi-drug resistance. It is therefore crucial to find novel therapeutic options able to go beyond these limitations and improve patients’ survival. The objective of this study is to exploit the intrinsic properties of mesenchymal stromal cells (MSCs) to migrate and infiltrate the tumor stroma to specifically deliver therapeutic agents directly to cancer cells. In particular, we aimed to test the efficacy of the photoactivation of MSCs loaded with nanoparticles in vitro and in a murine in vivo ectopic osteosarcoma model.

Methods

AlPcS₄@FNPs were produced by adding tetra-sulfonated aluminum phthalocyanine (AlPcS₄) to an aqueous solution of positively charged poly-methyl methacrylate core-shell fluorescent nanoparticles (FNPs). The photodynamic therapy (PDT) effect is achieved by activation of the photosensitizer AlPcS₄ in the near-infrared light with an LED source. Human MSCs were isolated from the bone marrow of five donors to account for inter-patients variability and used in this study after being evaluated for their clonogenicity, multipotency and immunophenotypic profile. MSC lines were then tested for the ability to internalize and retain the nanoparticles, along with their migratory properties in vitro. Photoactivation effect was evaluated both in a monolayer (2D) co-culture of AlPcS₄@FNPs loaded MSCs with human OS cells (SaOS-2) and in tridimensional (3D) multicellular spheroids (AlPcS₄@FNPs loaded MSCs with human OS cells, MG-63). Cell death was assessed by AnnexinV/PI and Live&Dead CalceinAM/EthD staining in 2D, while in the 3D co-culture, the cell killing effect was measured through ATP content, CalceinAM/EthD staining and TEM imaging. We also evaluated the effectiveness of AlPcS₄@FNPs loaded MSCs as delivery systems and the ability of the photodynamic treatment to kill cancer cells in a subcutaneous mouse model of OS by bioluminescence imaging (BLI) and histology.

Results

MSCs internalized AlPcS₄@FNPs without losing or altering their motility and viability in vitro. Photoactivation of AlPcS₄@FNPs loaded MSCs induced high level of OS cells death in the 2D co-culture. Similarly, in the 3D co-culture (MSCs:OS ratios 1:1 or 1:3), a substantial decrease of both MSCs and OS cells viability was observed. Notably, when increasing the MSCs:OS ratio to 1:7, photoactivation still caused more than 40% cells death. When tested in an in vivo ectopic OS model, AlPcS4@FNPs loaded MSCs were able to decrease OS growth by 68% after two cycles of photoactivation.

Conclusions

Our findings demonstrate that MSCs can deliver functional photosensitizer-decorated nanoparticles in vitro and in vivo and inhibit OS tumor growth. MSCs may be an effective platform for the targeted delivery of therapeutic nanodrugs in a clinical scenario, alone or in combination with other osteosarcoma treatment modalities.

Effect of timing of pulmonary metastasis occurrence on the outcome of metastasectomy in osteosarcoma patients

BACKGROUND

Complete metastasectomy is the best predictor of survival in patients with osteosarcoma pulmonary metastases. There has been some controversy in the literature regarding the prognostic significance of the timing of occurrence of lung metastasis.

METHODS

We reviewed the clinical course of all osteosarcoma patients with pulmonary metastases treated by metastasectomy in our hospital from January 2008 through December 2016. Each patient who underwent metastasectomy was placed into one of three groups based on whether lung metastases were present at initial presentation (Group 1), developed during chemotherapy (Group 2), or appeared after completion of chemotherapy (Group 3). Data were obtained retrospectively and follow-up was obtained until the end of June 2017.

RESULTS

We identified 170 patients with pulmonary nodules of whom 99 (58.2%) underwent at least one metastasectomy (149 thoracotomies). Eleven patients had benign pulmonary nodules and were excluded. The other 88 patients were classified as Group 1 (37), Group 2 (18) or Group 3 (33). The median follow-up was 35 months (range 8 to 99). Postmetastasis 5-year overall survival (OS) was 38.1 ± 6.4%; event-free survival (EFS) was 25 ± 5.3%. By group, postmetastasis 5-year OS and EFS were 34.3 ± 13% and 18 ± 9.3% in Group 1, 8 ± 6.5% and 6.5 ± 5% in Group 2, and 52 ± 11.4% and 25 ± 9% in Group 3 (P < 0.001). In univariate analysis, the only significant factors associated with survival were timing of occurrence of lung metastasis and the number of lung nodules found.

CONCLUSION

The timing of occurrence of lung metastasis is an important prognostic factor among osteosarcoma patients eligible for metastasectomy. Patients whose metastases occurred during chemotherapy had the worst survival.

LEVEL OF EVIDENCE

Level II.