Perioperative chemotherapy with and without high-dose methotrexate in adult osteosarcoma

Thymoquinone Augments Methotrexate-Induced Apoptosis on Osteosarcoma Cells

BACKGROUND

Osteosarcoma (OS) as the most frequent primary bone malignancy in children and adolescents has a short survival rate in advanced stages. Alternative herbal medicines with fewer side effects or the potency to protect common therapy's side effects can be helpful in combinational therapies. Herein, we aim to explore the effects of Thymoquinone (TQ) combined with Methotrexate (MTX) on Saos-2 cells apoptosis.

METHODS

The effects of TQ and MTX alone or in combination on Saos-2 cell viability were measured by MTT assay. Real-time PCR was applied for the measurement of Bax, BCL-2, and caspase-9 mRNA expression. Apoptosis evaluation was conducted by flow cytometry.

RESULTS

TQ improves the cytotoxic effects of MTX on Saos-2 cells proliferation at lower doses. Indeed, the IC50 of MTX decreased from 26 μM to 15 μM when it combined with TQ. TQ and MTX can induce the expression level of pro-apoptotic factors, Bax and caspase-9 while inhibiting anti-apoptotic protein BCL-2. Moreover, the combination of TQ and MTX potentiates apoptosis to 73%, compared to either TQ (48%) or MTX (53%) treated cells.

CONCLUSION

The co-treatment of TQ and MTX is associated with the up-regulation of apoptotic factors and down-regulation of anti-apoptotic factors, conducting apoptosis aggravation and OS cell death.

Targeting Molecular Mechanisms Underlying Treatment Efficacy and Resistance in Osteosarcoma: A Review of Current and Future Strategies

Osteosarcoma is the most common primary malignant bone tumour in children and adolescents. Due to micrometastatic spread, radical surgery alone rarely results in cure. Introduction of combination chemotherapy in the 1970s, however, dramatically increased overall survival rates from 20% to approximately 70%. Unfortunately, large clinical trials aiming to intensify treatment in the past decades have failed to achieve higher cure rates. In this review, we revisit how the heterogenous nature of osteosarcoma as well as acquired and intrinsic resistance to chemotherapy can account for stagnation in therapy improvement. We summarise current osteosarcoma treatment strategies focusing on molecular determinants of treatment susceptibility and resistance. Understanding therapy susceptibility and resistance provides a basis for rational therapy betterment for both identifying patients that might be cured with less toxic interventions and targeting resistance mechanisms to sensitise resistant osteosarcoma to conventional therapies.

Circular RNA hsa_circ_0000073 contributes to osteosarcoma cell proliferation, migration, invasion and methotrexate resistance by sponging miR-145-5p and miR-151-3p and upregulating NRAS

An increasing number of studies have demonstrated that circular RNAs (circRNAs), as promising therapeutic targets, are essential for diverse human diseases, especially cancer. However, the potential functions and complex mechanisms of most circRNAs in osteosarcoma (OS) are still not fully elucidated. In the present study, we obtained the expression profile of circRNAs from a GEO database (GSE96964) and identified hsa_circ_0000073 as a highly expressed candidate in OS. Overexpression of hsa_circ_0000073 accelerated the proliferation, migration, invasion and MTX resistance of OS cells, and knockdown of hsa_circ_0000073 resulted in the opposite effects. Mechanistically, hsa_circ_0000073 upregulated NRAS expression by targeting miR-145-5p and miR-151-3p in OS cells. In addition, the promotion of OS progression by hsa_circ_000007 was blocked by miR-145-5p and miR-151-3p-mediated NRAS inhibition. In conclusion, hsa_circ_0000073 facilitated the proliferation, migration, invasion and MTX resistance of OS cells through the inhibition of miR-145-5p and miR-151-3p-mediated downregulation of NRAS.

Methotrexate-Etoposide-Ifosfamide Compared with Doxorubicin-Cisplatin-Ifosfamide Chemotherapy in Osteosarcoma Treatment, Patients Aged 18-25 Years

Purpose: The French standard chemotherapy for osteosarcoma combines high-dose methotrexate (HDM) and etoposide-ifosfamide (EI) in children and adolescents, and API-AI (doxorubicin-cisplatin-ifosfamide) in adults. We herein present the results of M-EI and API-AI in 18- to 25-year-old patients. Methods: Patients, 18-25 years old, received either M-EI or API-AI regimens. M-EI comprised seven M and two EI doses preoperatively then M-EI in standard-risk patients (good histological response without metastasis) and five M-AP (methotrexate-doxorubicin-cisplatin) in high-risk patients (poor histological response, metastasis, and/or unresectable primary), postoperatively. API-AI comprised three API and two AI doses preoperatively, then two AI and two PI in standard-risk patients and five EI in high-risk patients, postoperatively. Results: We analyzed 95 patients 18-25 years of age: 55 received M-EI and 40 API-AI. The groups had similar baseline characteristics. Eighty-nine patients (94%) had surgery. Twenty-nine of 55 M-EI patients (60%) and 16/40 API-AI patients (41%) had good histological responses to preoperative chemotherapy. At 5 years, event-free survival was 50% (95% confidence interval [CI]: 39-60) and overall survival was 65% (95% CI: 54-74). Acute toxicity was similar, without treatment-related deaths. Conclusions: Survival outcomes with M-EI and API-AI were not significantly different. Tolerance was acceptable with both regimens. HDM is thus feasible for young adults. However, our study limitations preclude any definitive conclusions.

Safety and efficacy of high-dose methotrexate for osteosarcoma in adolescents compared with young adults

Background

Doxorubicin, cisplatin, and high‐dose methotrexate (HDMTX) are the backbone of pediatric osteosarcoma treatment. However, due to toxicity concerns and the lack of data regarding efficacy in adults, high‐dose methotrexate is rarely used in the adult population.

Methods

This single‐center retrospective study examined 33 patients who received HDMTX (12 g/m², maximum 20 g) for the treatment of osteosarcoma at Oregon Health and Science University (OHSU) from 2011 to 2017. Time to serum methotrexate level ≤0.1 µmol/L was the primary outcome. Secondary outcomes included number of HDMTX doses received, methotrexate‐related toxicities, and disease outcomes including histologic response at resection and metastasis‐free survival.

Results

Median age was 20 years [range 7‐38]; 14 patients ≤18 years old and 19 patients >18 years old. Median time to clearance for patients ≤18 years was 79 hours (range 63‐116) compared to 120 hours (range 77‐315) for patients >18 years (P < 0.001). No correlation between age and histologic response at resection was observed (P = 0.50), but there was a significant positive correlation between the number of HDMTX doses received before resection and histologic response (r = 0.49, P = 0.006). There was no significant difference in metastasis‐free survival between age groups, although a trend toward improved survival was noted for patients who received at least seven doses of HDMTX.

Conclusion

Age over 18 years correlates with delayed methotrexate clearance and fewer administered doses of methotrexate, without increased toxicity. The potential benefit of HDMTX in young adults with osteosarcoma may outweigh toxicity risks.

Relationship of peak serum methotrexate concentration to prognosis and drug tolerance in non-metastatic extremity osteosarcomas

PURPOSE

This study aimed to explore whether peak serum methotrexate concentration (C_max) correlated with adverse events, overall survival (OS) and event-free survival (EFS) in patients with primary extremity osteosarcoma.

METHODS

Patients with extremity osteosarcoma who were treated at our center between 2005 and 2015 were retrospectively studied. All the patients were Enneking stage II and had received standard perioperative chemotherapy composed of high-dose methotrexate, doxorubicin, cisplatin and ifosfamide. C_max and treatment-associated toxicities of each cycle were recorded. OS and EFS were estimated and compared by Kaplan-Meier survival analysis, and Cox regression models were performed for univariate comparisons.

RESULTS

In total, 567 patients were followed for an average of 53 months (24-104 months). The estimated 3- and 5-year EFS were 71.7 and 63.1%, and the 3- and 5-year OS were 78.2 and 72.9%, respectively. C_max ranged from 527 to 2495 µmol/L with a mean value of 931 ± 106 µmol/L. No significant differences in EFS and OS (p = 0.18 and p = 0.28) were observed among patients with a mean C_max > 1500, > 1000, > 700 and < 700 µmol/L. However, patients with a mean C_max > 1500 µmol/L had significantly increased rates of grade 3-5 toxicity. In the univariate analysis, C_max was not a prognostic factor for EFS (p = 0.08) or OS (p = 0.16).

CONCLUSIONS

C_max did not correlate significantly with the oncologic prognosis of non-metastatic extremity osteosarcoma patients treated by multi-agent chemotherapy; however, C_max correlated closely with toxicities and complications. The persistent inclusion of methotrexate in classical multidisciplinary chemotherapy was questioned and should be examined in future trials.