Postrelapse Prognostic Factors in Nonmetastatic Osteosarcoma: A Single-institution Experience

Solitary pulmonary metastases at first recurrence of osteosarcoma: Presentation, treatment, and survival of 219 patients of the Cooperative Osteosarcoma Study Group

BACKGROUND

To evaluate patient and tumour characteristics, treatment and their impact on survival in patients with a solitary pulmonary metastasis at first relapse of high-grade osteosarcoma.

PROCEDURE

Two-hundred and nineteen consecutive patients who had achieved a complete surgical remission and then developed a solitary pulmonary metastasis at first recurrence of high-grade osteosarcoma were retrospectively reviewed.

RESULTS

Two hundred and three (94.9%) of 214 patients achieved a second complete remission. After a median time from initial diagnosis of osteosarcoma to first relapse of 2.3 years (range, 0.3-18.8 years), actuarial post-relapse overall survival after 2 and 5 years was 72.0% and 51.2%. Post-relapse event-free survival was 39.1% and 31.1%. Median follow-up time was 3.2 years (range, 0.1-29.4 years). A longer time until first relapse and diagnosis due to imaging were positive prognostic factors in uni- and multivariate analyses, as were a second complete surgical remission and, in regard to death, the absence of a subsequent relapse. The use of salvage chemotherapy and radiotherapy were not associated with patient outcomes, nor was the surgical approach (thoracoscopy vs. thoracotomy) nor the exploration (uni- vs. bilateral).

CONCLUSION

Approximately half of the patients who experience a solitary pulmonary relapse at first recurrence of osteosarcoma remain alive 5 years after this first relapse. Only one third will remain disease-free. A complete surgical resection of the lesion is essential for long-term survival while relapse chemotherapy does not seem to improve survival. Innovative therapies are required to improve outcomes.

Establishment of a Survival Risk Prediction Model for Adolescent and Adult Osteosarcoma Patients

To build a nomogram model for predicting the survival risk of teens and adults with osteosarcoma based on the TARGET database, patients with osteosarcoma were collected via the TARGET database, and the survival curves of the patients were plotted using the Kaplan-Meier method in SPSS 24.0. Least absolute shrinkage and selection operator (LASSO) univariate regression analysis was performed to identify risk factors that influence osteosarcoma survival. A model (nomogram) for predicting the survival risk of adolescent and adult patients with osteosarcoma was built or plotted using the rms26 package as implemented in R (ver. 3.5.3). The predictive accuracy and discriminating power of the nomogram were determined by the C-index and calibration curves. A total of 94 patients with osteosarcoma were included. Classification of cases based on the tumor site revealed 59 cases involving the femur (62.8%), 5 involving the fibula (5.3%), 6 humerus (6.4%), 2 radius (2.1%), 19 tibia (20.2%), and 3 ulna (3.2%). Classification of cases based on surgical method showed 81 cases involving limb sparing (86.2%), 9 cases of amputation (9.6%), and 4 without surgery (4.2%). Among the 94 cases, bone metastasis occurred in 3 cases (3.2%) and lung metastasis in 14 cases (14.9%). Among all survivors, the median rate of survival is 8.6 years (95% CI: 8.0210.92); the three-year and five-year survival rates are 64.6% and 52.6%, respectively. The LASSO regression analysis showed that metastasis site, definitive surgery, and histologic response were potential risk predictors. The C-index of the nomogram plotted was 0.729, and the C-index of the validated sample was 0.742. The nomogram used in this study allows physicians to objectively and accurately predict the prognosis and survival of osteosarcoma patients. In order to determine whether the method is applicable to other groups of patients, additional studies need to be conducted.