Is Chemotherapy Associated with Improved Overall Survival in Patients with Dedifferentiated Chondrosarcoma? A SEER Database Analysis

A Systematic Review of Adjuvant Chemotherapy in Localized Dedifferentiated Chondrosarcoma

Dedifferentiated chondrosarcoma (DDCS) is a high-grade subtype of chondrosarcoma with the bimorphic histological appearance of a conventional chondrosarcoma component with abrupt transition to a high-grade, non-cartilaginous sarcoma. DDCS can be radiographically divided into central and peripheral types. Wide resection is currently the main therapeutic option for localized DDCS. Moreover, the effectiveness of adjuvant chemotherapy remains controversial. Therefore, we performed a systematic review of available evidence to evaluate the effect of adjuvant chemotherapy on localized DDCS. The purpose was to compare the 5-year survival rate among patients treated with surgery plus adjuvant chemotherapy or surgery alone for localized DDCS. The search was conducted in PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Of the 217 studies shortlisted, 11 retrospective non-randomized studies (comprising 556 patients with localized DDCS) were selected. The 5-year survival rates were similar between the two treatment groups (28.2% (51/181) vs. 24.0% (90/375), respectively). The overall pooled odds ratio was 1.25 (95% confidence interval: 0.80-1.94; p = 0.324), and heterogeneity I2 was 2%. However, when limited to peripheral DDCS, adjuvant chemotherapy was associated with prolonged survival (p = 0.03). Due to the paucity of included studies and the absence of prospective comparative studies, no conclusions can be drawn regarding the effectiveness or ineffectiveness of adjuvant chemotherapy for localized DDCS.

PRISMA-the 100 most-cited articles on chondrosarcoma recurrence: A bibliometric analysis

BACKGROUND

Chondrosarcoma (CHS) is highly prone to recurrence and has become the most common malignant bone tumor in adults. The authors aim to identify and analyze the top 100 most-cited articles in this field, enabling researchers to quickly grasp the research focus and progress in the area of chondrosarcoma recurrence.

METHODS

A search in the Web of Science database yielded a total of 305 articles related to CHS recurrence between 2013 and 2022. Filtering was done based on the titles and abstracts of the articles in the list, and the top 100 most-cited articles were selected. The following information were analyzed using bibliometric methods: article title, first author, year of publication, journal of publication, total citations, country, institution, and keywords.

RESULTS

Among the selected 100 articles, the most frequently cited one has 224 citations. The most commonly appearing journals, institutions, and countries are as follows: "Clinical Orthopaedics Related Research" (5 times); Fudan University, University of Texas System, and Royal Orthopaedic Hospital (4 times each), with China and the USA cited the most (21 times each). The year 2018 is the most productive year (17 articles). About 97 first authors contributed one article each, and 3 had 2 articles each. Among all 229 keywords, the top 3 in frequency are CHS (20%), recurrence (4%), and surgery (3%). Twenty article topics are related to surgical treatment.

CONCLUSION

Research on CHS recurrence is citation-rich but focuses more on treatments than understanding mechanisms, indicating a need for deeper mechanistic exploration for treatment breakthroughs in the future.

Dedifferentiated Chondrosarcoma from Molecular Pathology to Current Treatment and Clinical Trials

Dedifferentiated chondrosarcoma (DDCS) is a rare subtype of chondrosarcoma, a primary cartilaginous malignant neoplasm. It accounts for up to 1-2% of all chondrosarcomas and is generally associated with one of the poorest prognoses among all chondrosarcomas with the highest risk of metastasis. The 5-year survival rates range from 7% to 24%. DDCS may develop at any age, but the average presentation age is over 50. The most common locations are the femur, pelvis humerus, scapula, rib, and tibia. The standard treatment for localised disease is surgical resection. Most patients are diagnosed in unresectable and advanced stages, and chemotherapy for localised and metastatic dedifferentiated DDCS follows protocols used for osteosarcoma.

Primary dedifferentiated chondrosarcoma of the lung with a 4-year history of breast cancer: A case report

BACKGROUND

Primary dedifferentiated chondrosarcoma (DDCS) of the lung is extremely rare and has a poor prognosis, especially in patients with a history of carcinomas and related treatment. Herein, we report a case of primary DDCS of the lung in a patient with a 4-year history of breast cancer and related treatment.

CASE SUMMARY

A 49-year-old woman was admitted to our hospital with complaints of headache, dizziness, slurred speech, and dyskinesia in May 2021. Computed tomography (CT) examinations showed multiple nodules in the brain, vertebral body, and both lungs with multiple enlarged lymph nodes in the right hilum and mediastinum, which were considered metastases of breast cancer. No obvious mass was discovered in the right hilum. After several months of related administration, the patient's headache disappeared, and her condition improved. However, new problems of asthma, dyspnea, cough, and restricted activity appeared in late November 2021. Although the CT scan indicated that the lesions in the brain, lung, and vertebral body had shrunk or disappeared, a soft tissue density lesion appeared in her right hilum and blocked the bronchial lumen. To relieve her dyspnea, part of the mass was resected, and a stent was placed via fiberoptic bronchoscopy. Following a complete pathological examination of the tumor, it was confirmed to be a primary DDCS of the lung. The patient then received two rounds of systemic chemotherapy with a regimen of cisplatin + ifosfamide + doxorubicin hydrochloride liposome, palliative radiotherapy for the tumor in her right lung, and four cycles of systemic chemotherapy and targeted therapy with a regimen of temozolomide combined with bevacizumab successively. She was in stable condition after the completion of the systemic chemotherapy and targeted therapy but underwent rapid progression after lung radiotherapy. The CT examinations showed multiple nodules in the brain and in both lungs, and the tumor in the right hilum was increased in size.

CONCLUSION

This case revealed a rare primary DDCS of the lung with a medical history of breast cancer, meaning a worse prognosis and making it more difficult to treat.

A Retrospective Multi-Institutional Cohort Analysis of Clinical Characteristics and Outcomes in Dedifferentiated Chondrosarcoma

BACKGROUND

Dedifferentiated chondrosarcoma (DDCS) is a rare subset of chondrosarcoma. It is an aggressive neoplasm characterized by a high rate of recurrent and metastatic disease with overall poor outcomes. Systemic therapy is often used to treat DDCS; however, the optimal regimen and timing are not well defined, with current guidelines recommending following osteosarcoma protocols.

METHODS

We conducted a multi-institutional retrospective analysis of clinical characteristics and outcomes of patients with DDCS. Between 1 January 2004 and 1 January 2022, the databases from five academic sarcoma centers were reviewed. Patient and tumor factors, including age, sex, tumor size, site, location, the treatments rendered, and survival outcomes, were collected.

RESULTS

Seventy-four patients were identified and included in the analysis. Most patients presented with localized disease. Surgical resection was the mainstay of therapy. Chemotherapy was used predominantly in the metastatic setting. Partial responses were low (n = 4; 9%) and occurred upon treatment with doxorubicin with cisplatin or ifosfamide and single-agent pembrolizumab. For all other regimens, stable disease was the best response. Prolonged stable disease occurred with the use of pazopanib and immune checkpoint inhibitors.

CONCLUSIONS

DDCS has poor outcomes and conventional chemotherapy has limited benefit. Future studies should focus on defining the possible role of molecularly targeted therapies and immunotherapy in the treatment of DDCS.

Prognostic Significance of Percentage and Size of Dedifferentiation in Dedifferentiated Chondrosarcoma

Dedifferentiated chondrosarcoma is rare, aggressive, and microscopically bimorphic. How pathologic features such as the amounts of dedifferentiation affect prognosis remains unclear. We evaluated the percentages and sizes of dedifferentiation in a consecutive institutional series of dedifferentiated chondrosarcomas from 1999 to 2021. The statistical analysis included cox proportional hazard models and log-rank tests. Of the 67 patients (26 women, 41 men; age, 39 to >89 [median 61] years; 2 with Ollier disease), 58 presented de novo; 9 were identified with conventional chondrosarcomas 0.6-13.2 years (median, 5.5 years) prior. Pathologic fracture and distant metastases were noted in 27 and 7 patients at presentation. The tumors involved the femur (n = 27), pelvis (n = 22), humerus (n = 7), tibia (n = 4), scapula/ribs (n = 4), spine (n = 2), and clivus (n = 1). In the 56 resections, the tumors ranged in size from 3.5 to 46.0 cm (median, 11.5 cm) and contained 1%-99.5% (median, 70%) dedifferentiated components that ranged in size from 0.6 to 24.0 cm (median, 7.3 cm). No correlation was noted between total size and percentage of dedifferentiation. The dedifferentiated components were typically fibrosarcomatous or osteosarcomatous, whereas the associated cartilaginous components were predominantly grade 1-2, rarely enchondromas or grade 3. The entire cohort's median overall survival and progression-free survival were 11.8 and 5.4 months, respectively. In the resected cohort, although the total size was not prognostic, the percentage of dedifferentiation ≥20% and size of dedifferentiation >3.0 cm each predicted worse overall survival (9.9 vs 72.5 months; HR, 3.76; 95% CI, 1.27-11.14; P = .02; 8.7 vs 58.9 months; HR, 3.03; 95% CI, 1.21-7.57; P = .02, respectively) and progression-free survival (5.3 vs 62.1 months; HR, 3.05; 95% CI, 1.13-8.28; P = .03; 5.3 vs 56.6 months; HR, 2.50; 95% CI, 1.06-5.88; P = .04, respectively). In conclusion, both the percentages and sizes of dedifferentiation were better prognostic predictors than total tumor sizes in dedifferentiated chondrosarcomas, highlighting the utility of their pathologic evaluations.

Cancers of unknown primary: Survival by histologic type, demographic features, and treatment in the U.S. Military Health System

BACKGROUND

Cancers of unknown primary (CUP), a group of heterogenous metastatic cancers lacking a known primary site, have poor prognosis. This study compared survival of CUP by histologic type, patient characteristics, and treatment in the U.S. Military Health System (MHS), which provides universal care to its members.

METHODS

Patients histologically diagnosed with CUP were identified from the U.S. Department of Defense (DoD)'s Automated Central Tumor Registry. Median survival with 95 % confidence intervals was calculated for demographic and treatment variables by histologic type. A multivariable accelerated failure time model estimated time ratios and 95 % confidence intervals.

RESULTS

The study included 3358 CUP patients. The most prevalent CUP in this study was well- and moderately-differentiated adenocarcinomas. Median survival varied by histologic type with squamous cell carcinoma having the longest at 25.1 months and poorly-differentiated carcinomas having the shortest at 3.0 months. For each histologic type, survival was generally similar by sex and active-duty status although women with well- and moderately-differentiated adenocarcinoma had longer survival than their male counterparts. Younger patients tended to have longer survival than those aged 65 years or older. Generally, there were no racial differences in survival except poorer survival for Black patients than White patients in the group of other histologic types. Patients with chemotherapy and radiation treatment generally had improved survival whereas patients with squamous cell carcinoma who received chemotherapy had shorter survival than those without.

CONCLUSION

Survival generally did not differ between racial groups, which may be related to equal healthcare access despite racial background. Further studies are warranted to better understand how survival in the MHS compares with that in the general U.S.

POPULATION

The clinicopathological characteristics and prognosis of young patients with chondrosarcoma of bone

Purpose

Clinicopathologic characteristics and treatment outcomes for young patients (less than 40 years) with chondrosarcoma of bone are rarely documented. The purpose of this study is to determine the clinicopathological characteristics and identify the survival predictors for this rare population.

Patients and Methods

We used the Surveillance, Epidemiology, and End Results (SEER) database to identify young patients with chondrosarcoma of bone between 1973 and 2016. Univariate and multivariate Cox regression analyses were conducted to determine the independent risk factors. Kaplan-Meier method was used to intuitively show the survival difference stratified by different treatments.

Results

A total of 1312 eligible young patients with chondrosarcoma of bone were analyzed this study. The mean age at diagnosis was 28.5 ± 0.2 years old (ranging from 1 to 40 years). 51.1% of cases were located in the extremity. More than two-thirds of patients (71.4%) were high grade. The majority of the patients (92.0%) received surgery, only 11.8% of patients received radiotherapy, and only 10.4% of patients received chemotherapy. The 5-year overall survival (OS) and cancer-specific survival (CSS) rates of this cohort were 88.5% and 89.1%, respectively. According to the results of multivariate analysis, nine variables were significantly correlated with OS and CSS, including gender, year of diagnosis, tumor site, tumor grade, tumor subtype, distant metastasis, tumor size, surgery, and chemotherapy.

Conclusion

Young patients with chondrosarcoma of bone experienced better prognosis. Surgery was significantly correlated with increased survival, while chemotherapy was significantly correlated with decreased survival. Radiotherapy was not a meaningful survival predictor of young patients with chondrosarcoma of bone. Prospective clinical trials are needed in the future to determine the effect of radiotherapy and chemotherapy on prognosis of those patients.

Deep learning models for predicting the survival of patients with chondrosarcoma based on a surveillance, epidemiology, and end results analysis

Background

Accurate prediction of prognosis is critical for therapeutic decisions in chondrosarcoma patients. Several prognostic models have been created utilizing multivariate Cox regression or binary classification-based machine learning approaches to predict the 3- and 5-year survival of patients with chondrosarcoma, but few studies have investigated the results of combining deep learning with time-to-event prediction. Compared with simplifying the prediction as a binary classification problem, modeling the probability of an event as a function of time by combining it with deep learning can provide better accuracy and flexibility.

Materials and methods

Patients with the diagnosis of chondrosarcoma between 2000 and 2018 were extracted from the Surveillance, Epidemiology, and End Results (SEER) registry. Three algorithms—two based on neural networks (DeepSurv, neural multi-task logistic regression [NMTLR]) and one on ensemble learning (random survival forest [RSF])—were selected for training. Meanwhile, a multivariate Cox proportional hazards (CoxPH) model was also constructed for comparison. The dataset was randomly divided into training and testing datasets at a ratio of 7:3. Hyperparameter tuning was conducted through a 1000-repeated random search with 5-fold cross-validation on the training dataset. The model performance was assessed using the concordance index (C-index), Brier score, and Integrated Brier Score (IBS). The accuracy of predicting 1-, 3-, 5- and 10-year survival was evaluated using receiver operating characteristic curves (ROC), calibration curves, and the area under the ROC curves (AUC).

Results

A total of 3145 patients were finally enrolled in our study. The mean age at diagnosis was 52 ± 18 years, 1662 of the 3145 patients were male (53%), and mean survival time was 83 ± 67 months. Two deep learning models outperformed the RSF and classical CoxPH models, with the C-index on test datasets achieving values of 0.832 (DeepSurv) and 0.821 (NMTLR). The DeepSurv model produced better accuracy and calibrated survival estimates in predicting 1-, 3- 5- and 10-year survival (AUC:0.895-0.937). We deployed the DeepSurv model as a web application for use in clinical practice; it can be accessed through https://share.streamlit.io/whuh-ml/chondrosarcoma/Predict/app.py.

Conclusions

Time-to-event prediction models based on deep learning algorithms are successful in predicting chondrosarcoma prognosis, with DeepSurv producing the best discriminative performance and calibration.

Surgical Treatment of Bone Sarcoma

Bone sarcomas are rare primary malignant mesenchymal bone tumors. The three main entities are osteosarcoma, chondrosarcoma, and Ewing sarcoma. While prognosis has improved for affected patients over the past decades, bone sarcomas are still critical conditions that require an interdisciplinary diagnostic and therapeutic approach. While radiotherapy plays a role especially in Ewing sarcoma and chemotherapy in Ewing sarcoma and osteosarcoma, surgery remains the main pillar of treatment in all three entities. After complete tumor resection, the created bone defects need to be reconstructed. Possible strategies are implantation of allografts or autografts including vascularized bone grafts (e.g., of the fibula). Around the knee joint, rotationplasty can be performed or, as an alternative, the implantation of (expandable) megaprostheses can be performed. Challenges still associated with the implantation of foreign materials are aseptic loosening and infection. Future improvements may come with advances in 3D printing of individualized resection blades/implants, thus also securing safe tumor resection margins while at the same time shortening the required surgical time. Faster osseointegration and lower infection rates may possibly be achieved through more elaborate implant surface structures.

Challenges of Systemic Therapy Investigations for Bone Sarcomas

Bone sarcoma is a rare component of malignant solid tumors that accounts for only ~0.2% of malignancies. Bone sarcomas present various histological types, and genomic mutations differ markedly by the histological types. Although there are vast mutations in various bone sarcomas, most of them are non-actionable, and even potential targetable mutations that are actionable targets in other malignancies have not shown the appropriate responses in clinical trials for bone sarcomas. Investigations of new systemic therapy, including molecular targeted therapies for bone sarcomas, have thus not progressed like those for other solid tumors. Another problem is that high rates of pediatric/adolescent and young adult patients have bone sarcomas such as osteosarcoma, and patient recruitment for clinical trials (especially randomized trials) is challenging. For pediatric patients, evaluations of tolerability and appropriate dose modifications of new drugs are needed, as their findings could provide the threshold for investigating new drugs for bone sarcomas. To solve these problems, improvements in registry systems, real world data, and pediatric extrapolation have been attempted. We review the issues regarding targeted drug investigations for bone sarcomas, focusing on the current clinical evidence and efforts to resolve these issues.