Staging investigations in chondrosarcoma: Is evaluation for skeletal metastases justified? Analysis from an epidemiological study at a tertiary cancer care center and review of literature

Japanese orthopaedic association (JOA) clinical practice guidelines on the management of malignant bone tumors - Secondary publication

BACKGROUND

In Japan, there are currently no general guidelines for the treatment of primary malignant bone tumors. Therefore, the Japanese Orthopaedic Association established a committee to develop guidelines for the appropriate diagnosis and treatment of primary malignant bone tumors for medical professionals in clinical practice.

METHODS

The guidelines were developed in accordance with "Minds Clinical Practice Guideline Development Handbook 2014″ and "Minds Clinical Practice Guideline Development Manual 2017". The Japanese Orthopaedic Association's Bone and Soft Tissue Tumor Committee established guideline development and systematic review committees, drawing members from orthopedic specialists leading the diagnosis and treatment of bone and soft tissue tumors. Pediatricians, radiologists, and diagnostic pathologists were added to both committees because of the importance of multidisciplinary treatment. Based on the diagnosis and treatment algorithm for primary malignant bone tumors, important decision-making points were selected, and clinical questions (CQ) were determined. The strength of recommendation was rated on two levels and the strength of evidence was rated on four levels. The recommendations published were selected based on agreement by 70% or more of the voters.

RESULTS

The guideline development committee examined the important clinical issues in the clinical algorithm and selected 22 CQs. The systematic review committee reviewed the evidence concerning each CQ and a clinical value judgment was added by experts. Eventually, 25 questions were published and the text of each recommendation was determined.

CONCLUSION

Since primary malignant bone tumors are rare, there is a dearth of strong evidence based on randomized controlled trials, and recommendations cannot be applied to all the patients. In clinical practice, appropriate treatment of patients with primary malignant bone tumors should be based on the histopathological diagnosis and degree of progression of each case, using these guidelines as a reference.

The value of chest and skeletal staging studies in conventional chondrosarcoma

OBJECTIVE

To determine the value of chest and skeletal staging in patients presenting with conventional chondrosarcoma (CS).

MATERIALS AND METHODS

Retrospective review of patients with CS diagnosed between January 2007 and December 2019. Data collected included age, sex, skeletal location and results of chest CT and whole-body bone scintigraphy (WB-BSc) obtained at initial diagnosis. The histological tumour grade based on surgical resection or needle biopsy was classified as low-grade (LGCT), high-grade (HGCT) and dedifferentiated (DD-CS). Findings of chest CT and WB-BSc were correlated with tumour grade.

RESULTS

Four hundred twenty patients were included (234 males and 186 females with mean age 54.5 years, range 9-91 years). The major long bones were involved in 205 cases, the flat bones in 166 cases, the mobile spine in 14 cases and the small bones of the hands and feet in 35 cases. Three hundred fifty tumours were central in location, 39 peripheral and 31 on the surface of the bone. There were 151 LGCTs, 196 HGCTs and 73 DD-CSs. Of patients with LGCT, 41.7% underwent chest CT and 25.2% WB-BSc. Of patients with HGCT, 95.4% underwent chest CT and 76.5% WB-BSc. Of patients with DD-CS, 98.6% underwent chest CT and 86.3% WB-BSc. Metastases were diagnosed in 2 (3.3%) chest CT studies and 0 WB-BSc in LGCT, in 8 (4.3%) chest CT studies and 0 WB-BSc in HGCT and in 21 (30%) chest CT studies and 6 (21%) WB-BSc in DD-CS.

DISCUSSION

Staging chest CT and WB-BSc is of little or no value except in DD-CS.

Importance of Skeletal Staging in Chondrosarcoma of Bone: Results of Survey on Current Practices Among Musculoskeletal Oncologists

PURPOSE

There are no clear guidelines for staging of conventional chondrosarcoma. We conducted an online survey to determine the current practices for skeletal staging for conventional chondrosarcoma among practicing oncologists and to assess any discrepancy in practices and with the published literature.

METHODOLOGY

A simple ten-question online survey (e-mails and WhatsApp) was conducted among practicing oncologists over a period of 3 weeks using online portal (surveymonkey.com). It was followed by analysis based on each question to find current practices.

RESULTS

139 members participated in the survey (84% surgeons, 9% radiologists, 3% medical and 3% radiation oncologists and 1% nuclear medicine). 65% have been treating chondrosarcoma for more than 5 years. 88% opined that biopsy is mandatory even if the radiology is suggestive of a chondrosarcoma. 66% said that solitary skeletal metastasis is seen in less than 2% of the cases but 84% of participants were in favour of performing an investigation (bone scan/PET scan) for skeletal survey. While 43% opined skeletal metastasis is more common in recurrent chondrosarcoma, 26% said that performing a bone scan was likely to impact management, 28% said it will not impact management and 46% were unsure. Of the group who thought that a bone scan would impact management or were unsure, the majority (56%) opined that this was relevant only in grade 2 and grade 3 chondrosarcoma.

CONCLUSION

There was lack of consensus regarding staging for chondrosarcoma. Only 26% of respondents were convinced that performing a bone scan was likely to impact management of chondrosarcoma. There is a need to analyze large data sets (retrospective/prospective) to arrive at an evidence-based staging algorithm for chondrosarcoma.

Chondrosarcomas in children and adolescents

Chondrosarcomas in children and adolescents are uncommon and constitute < 5% of all chondrosarcomas. There are very few studies discussing extremity chondrosarcomas in young patients.

The pelvis is the most common site, followed by the proximal femur.

As cartilaginous tumours can be quite challenging to diagnose, it is best for these lesions to be discussed in a multidisciplinary meeting which includes a radiologist and a pathologist specializing in bone tumours.

Treatment principles are similar to those in adults, with adequate surgical excision respecting oncologic principles being the mainstay of treatment. Select extremity Grade I chondrosarcomas may be managed with extended intralesional curettage without increasing the risk for local recurrence or metastatic disease, but case selection is critical and should be based on clinical, imaging and histological characteristics.

Chondrosarcomas are resistant to chemotherapy and relatively radioresistant. For mesenchymal chondrosarcomas, there may be a role for chemotherapy, though data on this is limited.

Prognosis and rate of recurrence correlate directly to the adequacy of the surgical resection.

Chondrosarcomas in younger patients behave in a similar fashion to those in adults, and outcomes in the young are no different from those in adults.

Cite this article: EFORT Open Rev 2020;5:90-95. DOI: 10.1302/2058-5241.5.190052

The diagnostic significance of pulmonary nodules on CT thorax in chondrosarcoma of bone

AIM

To provide a diagnostic approach to pulmonary nodules in patients with chondrosarcoma.

MATERIALS AND METHODS

A search of the oncology database at a specialist orthopaedic oncology referral centre was performed to identify all patients who were treated surgically for chondrosarcoma between January 2007 and December 2018. Reports from the computed tomography (CT) examinations of the thorax of these patients were reviewed. In patients who had pulmonary nodules/metastases identified on CT, data on the primary chondrosarcoma and pulmonary nodule characteristics were collected.

RESULTS

Twenty point two percent of patients had a pulmonary nodule identified on either initial or follow-up staging CT of the thorax, of which 8.1% were pulmonary metastases. Patients with grade 3 and dedifferentiated chondrosarcoma were more likely to have pulmonary metastases than patients with grade 1/2 chondrosarcoma. The time interval to developing metastases was shorter in patients with grade 2/3 and dedifferentiated chondrosarcoma versus patients with grade 1 chondrosarcoma. A low proportion of patients with grade 1 chondrosarcoma developed metastases (12.5%), all of which were identified at the time of a local recurrence. Nodules ≥10mm, nodules with lobulate margins, nodules containing irregular or subtle calcification, and nodules seen bilaterally or both centrally and peripherally were more likely to represent pulmonary metastases than benign nodules.

CONCLUSION

The diagnostic significance of pulmonary nodules (i.e., whether they represent pulmonary metastases or not) can be predicted by taking into account a number of factors, in particular, the histological grade of the patient's chondrosarcoma, the size and margins of the nodules, and the presence of subtle/irregular calcification.