Chondrosarcoma of the Osseous Spine: An Analysis of Epidemiology, Patient Outcomes, and Prognostic Factors Using the SEER Registry From 1973 to 2012

Solitary Plasmacytoma of Bone of the Spine: Results From Surveillance, Epidemiology, and End Results (SEER) Registry

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To determine the prognostic indicators in patients with solitary plasmacytoma of bone (SPB) of the spine.

SUMMARY OF BACKGROUND DATA

Population-level estimates for prognosis among patients with SPB of the spine are still lacking. Sociodemographic and clinical predictors of outcome have not been well characterized.

METHODS

The Surveillance, Epidemiology, and End Results Registry was used to identify all patients with SPB of the spine from 1995 through 2014. Associated population data were used to determine annual incidence and limited-duration prevalence. Overall survival (OS) estimates were obtained using the Kaplan-Meier method and compared across groups using log-rank test. A Cox regression model was used for multivariate analysis of survival. Logistic regression was performed to identify predictors of the progression to multiple myeloma (MM).

RESULTS

The incidence and prevalence of the disease increased during the study period. Spinal SPB most commonly affected older people (>50) with a male preponderance. The median OS were 74.0 months. The 5 and 10-year survival rates for these patients were 56.1% and 36.7%, respectively. On multivariable analyses, older age, and surgery without radiotherapy were correlated with poor survival of patients with spinal SPB. The 3-year probability of progression to MM was 10.1%. Patients aged >70 years were associated with progression to MM. There was no significant association between the methods of surgical resection (radical or local/partial) and OS or progression to MM.

CONCLUSION

The findings of this study provide population-based estimates of the incidence, prevalence and prognosis for patients with SPB of the spine. This analysis indicated that the only identifiable prognostic indicators were older age and surgery without radiotherapy. Moreover, the methods of surgical resection did not influence the OS or progression to MM.

LEVEL OF EVIDENCE

4.

Development and Validation of Nomograms Predicting Overall and Cancer-Specific Survival of Spinal Chondrosarcoma Patients

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To develop and validate nomograms to predict overall survival (OS) and cancer-specific survival (CSS) of spinal chondrosarcoma patients.

SUMMARY OF BACKGROUND DATA

In this era of personalized medicine, data those are available to predict the survival of spinal chondrosarcoma patients are still limited due to the rarity of the disease. Nomogram, which has been widely used in clinical oncology, could conveniently and precisely predict survival outcome for individual patient.

METHODS

We retrospectively collected 450 spinal chondrosarcoma patients from the Surveillance, Epidemiology, and End Results (SEER) database between 1984 and 2013. Univariate log-rank and multivariate Cox analyses were used to identify independent prognostic factors. These prognostic factors were included in the nomograms, which predict 3- and 5-year OS and CSS rate. The nomograms were bootstrap validated internally and externally.

RESULTS

A total of 450 patients were collected and randomly assigned into the training (n = 225) and validation (n = 225) cohorts. Age, histologic subtype, grade, tumor size, stage, and surgery were identified as independent prognostic factors for OS and CSS (all P < 0.05) and were further incorporated to construct the nomograms. The concordance indices (C-indices) for internal validation of OS and CSS prediction were 0.807 and 0.821, while for external validation of OS and CSS prediction were 0.756 and 0.767. Internal and external calibration plots both revealed an excellent agreement between nomogram prediction and actual survival.

CONCLUSION

Nomograms were developed to predict OS and CSS for spinal chondrosarcoma patients. The nomograms could assist clinicians in making more accurate survival evaluation and identifying patients with high risk of mortality.

LEVEL OF EVIDENCE

4.

Can Machine-learning Techniques Be Used for 5-year Survival Prediction of Patients With Chondrosarcoma?

BACKGROUND

Several studies have identified prognostic factors for patients with chondrosarcoma, but there are few studies investigating the accuracy of computationally intensive methods such as machine learning. Machine learning is a type of artificial intelligence that enables computers to learn from data. Studies using machine learning are potentially appealing, because of its possibility to explore complex patterns in data and to improve its models over time.

QUESTIONS/PURPOSES

The purposes of this study were (1) to develop machine-learning algorithms for the prediction of 5-year survival in patients with chondrosarcoma; and (2) to deploy the best algorithm as an accessible web-based app for clinical use.

METHODS

All patients with a microscopically confirmed diagnosis of conventional or dedifferentiated chondrosarcoma were extracted from the Surveillance, Epidemiology, and End Results (SEER) Registry from 2000 to 2010. SEER covers approximately 30% of the US population and consists of demographic, tumor characteristic, treatment, and outcome data. In total, 1554 patients met the inclusion criteria. Mean age at diagnosis was 52 years (SD 17), ranging from 7 to 102 years; 813 of the 1554 patients were men (55%); and mean tumor size was 8 cm (SD 6), ranging from 0.1 cm to 50 cm. Exact size was missing in 340 of 1544 patients (22%), grade in 88 of 1544 (6%), tumor extension in 41 of 1544 (3%), and race in 16 of 1544 (1%). Data for 1-, 3-, 5-, and 10-year overall survival were available for 1533 (99%), 1512 (98%), 1487 (96%), and 977 (63%) patients, respectively. One-year survival was 92%, 3-year survival was 82%, 5-year survival was 76%, and 10-year survival was 54%. Missing data were imputed using the nonparametric missForest method. Boosted decision tree, support vector machine, Bayes point machine, and neural network models were developed for 5-year survival. These models were chosen as a result of their capability of predicting two outcomes based on prior work on machine-learning models for binary classification. The models were assessed by discrimination, calibration, and overall performance. The c-statistic is a measure of discrimination. It ranges from 0.5 to 1.0 with 1.0 being perfect discrimination and 0.5 that the model is no better than chance at making a prediction. The Brier score measures the squared difference between the predicted probability and the actual outcome. A Brier score of 0 indicates perfect prediction, whereas a Brier score of 1 indicates the poorest prediction. The Brier scores of the models are compared with the null model, which is calculated by assigning each patient a probability equal to the prevalence of the outcome.

RESULTS

Four models for 5-year survival were developed with c-statistics ranging from 0.846 to 0.868 and Brier scores ranging from 0.117 to 0.135 with a null model Brier score of 0.182. The Bayes point machine was incorporated into a freely available web-based application. This application can be accessed through https://sorg-apps.shinyapps.io/chondrosarcoma/.

CONCLUSIONS

Although caution is warranted, because the prediction model has not been validated yet, healthcare providers could use the online prediction tool in daily practice when survival prediction of patients with chondrosarcoma is desired. Future studies should seek to validate the developed prediction model.

LEVEL OF EVIDENCE

Level III, prognostic study.

Marital Status and Survival of Patients with Chondrosarcoma: A Population-Based Analysis

Background

Previous studies have shown that differences in marital status contribute to different prognoses for certain cancers, but the relationship between marital status and the prognosis of chondrosarcoma has not been reported previously.

Material/Methods

In this study, we selected 4502 eligible cases through the Surveillance, Epidemiology, and End Results (SEER) database from 1977 to 2014 to analyze the impact of marital status on chondrosarcoma cancer-specific survival (CSS) by Kaplan-Meier method and Cox regression model.

Results

The sex, age, histotype, pathological grade, tumor location, tumor size, SEER stage, socioeconomic status, marital status, and treatment were identified as independent prognostic factors for chondrosarcoma CSS. Widowed patients presented the worst CSS compared with their married, divorced, and single counterparts (P<0.001). Subgroup analyses showed widowed patients also had a significantly higher risk of cancer-specific mortality compared with married patients in localized stage (HR: 1.971, 95% CI: 1.298–2.994, P=0.001), regional stage (HR: 1.535, 95% CI: 1.094–2.154, P=0.013), low pathological grade (HR: 1.866, 95% CI: 1.332–2.613, P<0.001), and high pathological grade (HR: 1.662, 95% CI: 1.139–2.426, P=0.008).

Conclusions

Marital status was first identified as an independent prognostic factor for chondrosarcoma CSS, and widowhood was always associated with a high risk of cancer-specific mortality. It is necessary to provide timely psychological treatment for widowed patients in clinical practice, which can improve the survival of chondrosarcoma patients.

Surgical Techniques and Associated Outcomes of Primary Chondrosarcoma of the Spine

BACKGROUND

Only a few case reports and case series exist reporting on primary chondrosarcomas of the spine. The objective of this study was to gain a better understanding of this patient population and surgical techniques used for treatment.

METHODS

A systematic literature search was performed in January 2018 querying several scientific databases, per PRISMA guidelines. Surgery type was categorized into en bloc, piecemeal excision, or non-en bloc or piecemeal excision.

RESULTS

In total, 34 records and 3 patients were included in the systematic review, yielding 87 patients with primary chondrosarcoma of the spine. The mean age was 41.5 years, with the tumor most commonly arising in adult patients (90.8%, 79/87); most were male (66.7%, 58/87). Those who underwent piecemeal excision had the highest death rate (56.7%, P ≤ 0.001) and highest rate of recurrence (63.3%, P ≤ 0.001) compared with en bloc and non-en bloc or piecemeal excision. The calculated reduced relative risk (RR) comparing en bloc with the other surgical techniques for recurrence and mortality was 78.8% (RR, 0.21; P ≤ 0.001) and 80.7% (RR, 0.19; P≤ 0.001), respectively. Survival analysis showed patients with a piecemeal excision had 9.4 times hazards ratio for death compared with en bloc (P = 0.001).

CONCLUSIONS

CS is a rare lesion that most commonly presents in adult male patients. En bloc surgical resection was associated with a significant decrease in recurrence, mortality, and increased survival compared with the other surgical techniques. In addition, any surgical technique that involved entering the tumor capsule showed a significantly greater risk for recurrence and death.

Chondrosarcoma of the Osseous Spine Treated by Surgery With or Without Radiotherapy: A Propensity Score Matched and Grade/Stage-stratified Study

STUDY DESIGN

This was a longitudinal cohort study.

OBJECTIVE

The main objective of this study was to investigate the outcomes of surgery with or without radiotherapy during treatment of patients with chondrosarcoma of the osseous spine.

SUMMARY OF BACKGROUND DATA

Chondrosarcoma is a primary spinal malignant tumor; chemotherapy and radiotherapy (RT) are generally unsuccessful, and thus, the main treatment of choice is complete en bloc resection. However, even with complete resection, these patients still have a significant rate of recurrence, morbidity, and mortality. Although there have been reports that the addition of RT to surgery may lead to increased survival and better cancer control, the evidence of the efficacy of RT remains controversial.

MATERIALS AND METHODS

Patients diagnosed with chondrosarcoma who are then treated by surgery alone or surgery+RT were identified and extracted from the SEER (Surveillance, Epidemiology, and End Results) database (1973-2013). Propensity score matched (PSM) analysis was performed to balance patient characteristics between surgery alone and surgery+RT groups. Patients with a different grade and stage were stratified and analyzed.

RESULTS

A total of 778 patients with chondrosarcoma of the osseous spine treated by surgery alone or surgery+RT were extracted from the SEER database. Before PSM, the unadjusted Kaplan-Meier curve and bivariable Cox proportional hazard regression models showed that the surgery alone group had higher chondrosarcoma cancer-specific survival and overall survival than the surgery+RT group (both P<0.001), while the difference was attenuated after PSM. Stratified analysis found that RT was worse for low-grade chondrosarcoma patients and had a better trend for high-grade chondrosarcoma patients.

CONCLUSIONS

The results of our present study suggest that low-grade chondrosarcoma of the osseous spine is resistant to RT, while high-grade chondrosarcoma patients had a better trend with RT.

LEVEL OF EVIDENCE

Level III.

Prognostic factors for survival among patients with primary bone sarcomas of small bones

Background

Primary bone sarcomas of the hands or feet are rare lesions and poorly documented. Moreover, the prognostic determinants of bone sarcomas of the hands or feet have not been reported.

Materials and methods

The Surveillance, Epidemiology, and End Results (SEER) program database was used to screen patients with bone sarcomas of the hands or feet from 1973 to 2013, with attention paid to chondrosarcoma, Ewing sarcoma, and osteosarcoma. The prognostic values of overall survival (OS) and cancer-specific survival (CSS) were assessed using Cox proportional hazards regression model with univariate and multivariate analyses. The Kaplan–Meier method was used to obtain OS and CSS curves.

Results

A total of 457 cases were selected from the SEER database. Chondrosarcoma was the most common form of lesion in hands or feet or both, followed by Ewing sarcoma and osteosarcoma. The 5- and 10-year OS rates of the entire group were 75.7% and 66.1%, respectively. The 5- and 10-year CSS rates were 78.7% and 73.7%, respectively. Multivariate analysis revealed that age under 40 years, localized stage, low grade, surgical treatment, and first primary tumor were associated with improved OS, and decade of diagnosis, stage, grade, and surgery were independent predictors of CSS. However, no significant differences were observed in OS and CSS among patients with different primary tumor locations and tumor subtypes. Additionally, the most significant prognostic factor was whether metastasis had occurred at the time of initial diagnosis.

Conclusion

Among patients with primary bone sarcomas of the hands or feet, younger age (<40 years), localized stage, low grade, surgical treatment, and first primary tumor are favorable factors for prolonging survival.

Excision of thoracic vertebral chondrosarcoma after spinal decompression

A 44-year-old man presented with an abnormal chest shadow. Computed tomography-guided biopsy showed a chondral tumor of the thoracic vertebrae. Five years later, he developed a walking disorder, left leg numbness, and a vesicorectal disorder. Emergency orthopedic spinal decompression was performed. Eight months later, the residual tumor had become larger and was adjacent to the aorta. Prior to thoracotomy, an intraaortic stent was inserted. The 4th and 5th ribs were invaded by the tumor. The entire tumor and chest wall were excised with the aortic adventitia. The tumor was diagnosed as a low-grade chondrosarcoma of the thoracic vertebrae.