Prognostic factors in surgical resection of sacral chordoma

Comparison of clinical outcome between surgical treatment and particle beam therapy for pelvic bone sarcomas: A retrospective multicenter study in Japan

BACKGROUND

Few studies have compared the clinical outcomes of patients with pelvic bone sarcomas treated surgically and those treated with particle beam therapy. This is a multicenter retrospective cohort study which compared the clinical outcomes of patients with pelvic bone sarcoma who underwent surgical treatment and particle beam therapy in Japan.

METHODS

A total of 116 patients with pelvic bone sarcoma treated at 19 specialized sarcoma centers in Japan were included in this study. Fifty-seven patients underwent surgery (surgery group), and 59 patients underwent particle beam therapy (particle beam group; carbon-ion radiotherapy: 55 patients, proton: four patients).

RESULTS

The median age at primary tumor diagnosis was 52 years in the surgery group and 66 years in the particle beam group (P < 0.001), and the median tumor size was 9 cm in the surgery group and 8 cm in the particle beam group (P = 0.091). Overall survival (OS), local control (LC), and metastasis-free survival (MFS) rates were evaluated using the Kaplan-Meier method and compared among 116 patients with bone sarcoma (surgery group, 57 patients; particle beam group, 59 patients). After propensity score matching, the 3-year OS, LC, and MFS rates were 82.9% (95% confidence interval [CI], 60.5-93.2%), 66.0% (95% CI, 43.3-81.3%), and 78.4% (95% CI, 55.5-90.5%), respectively, in the surgery group and 64.9% (95% CI, 41.7-80.8%), 86.4% (95% CI, 63.3-95.4%), and 62.6% (95% CI, 38.5-79.4%), respectively, in the particle beam group. In chordoma patients, only surgery was significantly correlated with worse LC in the univariate analysis.

CONCLUSIONS

The groups had no significant differences in the OS, LC, and MFS rates. Among the patients with chordomas, the 3-year LC rate in the particle beam group was significantly higher than in the surgery group.

Soft Tissue Reconstruction After Sacral Neoplasm Resection: The University of California San Francisco Experience

PURPOSE

Resection of sacral neoplasms such as chordoma and chondrosarcoma with subsequent reconstruction of large soft tissue defects is a complex multidisciplinary process. Radiotherapy and prior abdominal surgery play a role in reconstructive planning; however, there is no consensus on how to maximize outcomes. In this study, we present our institution's experience with the reconstructive surgical management of this unique patient population.

METHODS

We conducted a retrospective review of patients who underwent reconstruction after resection of primary or recurrent pelvic chordoma or chondrosarcoma between 2002 and 2019. Surgical details, hospital stay, and postoperative outcomes were assessed. Patients were divided into 3 groups for comparison based on reconstruction technique: gluteal-based flaps, vertical rectus abdominus myocutaneous (VRAM) flaps, and locoregional fasciocutaneous flaps.

RESULTS

Twenty-eight patients (17 males, 11 females), with mean age of 62 years (range, 34-86 years), were reviewed. Twenty-two patients (78.6%) received gluteal-based flaps, 3 patients (10.7%) received VRAM flaps, and 3 patients (10.7%) were reconstructed with locoregional fasciocutaneous flaps. Patients in the VRAM group were significantly more likely to have undergone total sacrectomy (P < 0.01) in a 2-stage operation (P < 0.01) compared with patients in the other 2 groups. Patients in the VRAM group also had a significantly greater average number of reoperations (2 ± 3.5, P = 0.04) and length of stay (29.7 ± 20.4 days, P = 0.01) compared with the 2 other groups. The overall minor and major wound complication rates were 17.9% and 42.9%, respectively, with 17.9% of patients experiencing at least 1 infection or seroma. There was no association between prior abdominal surgery, surgical stages, or radiation therapy and an increased risk of wound complications.

CONCLUSIONS

Vertical rectus abdominus myocutaneous flaps are a more suitable option for patients with larger defects after total sacrectomy via 2-staged anteroposterior resections, whereas gluteal myocutaneous flaps are effective options for posterior-only resections. For patients with small- to moderate-sized defects, local fasciocutaneous flaps are a less invasive and effective option. Paraspinous flaps may be used in combination with other techniques to provide additional bulk and coverage for especially long postresection wounds. Furthermore, mesh is a useful adjunct for any reconstruction aimed at protecting against intra-abdominal complications.

Prognostic nomogram in middle-aged and elderly patients with chordoma: A SEER-based study

BACKGROUND

Chordoma is a bone tumor that tends to occur in middle-aged and elderly people. It grows relatively slowly but is aggressive. The prognosis of middle-aged and elderly patients with chordoma is quite different from that of young patients with chordoma.

OBJECTIVES

The purpose of the research was to construct a nomogram to predict the Individualized prognosis of middle-aged and elderly (age greater than or equal to 40 years) patients with chordoma.

METHODS

In this study, we screened 658 patients diagnosed with chordoma from 1983 to 2015 in the Surveillance, Epidemiology, and End Results (SEER) database. We determined the independently prognostic factors that affect the survival of patients by univariate and multivariate Cox proportional hazards model. Based on the independent prognostic factors, we constructed a nomogram to predict the overall survival (OS) rates of middle-aged and elderly patients with chordoma at 3 and 5 years. The validation of this nomogram was completed by evaluating the calibration curve and the C-index.

RESULTS

We screened a total of 658 patients and divided them into two cohort. Training cohort had 462 samples and validation cohort had 196 samples. The multivariate Cox proportional hazards model of the training group showed an association of age, tumor size, histology, primary site, surgery, and extent of disease with OS rates. Based on these results, we constructed the corresponding nomogram. The calibration curve and C-index showed the satisfactory ability of the nomogram in terms of predictive ability.

CONCLUSION

Nomogram can be an effective prognostic tool to assess the prognosis of middle-aged and elderly patients with chordoma and can help clinicians in medical decision-making and enable patients to receive more accurate and reasonable treatment.

A Bibliometric Analysis of the 20 Most Cited Articles on Sacrococcygeal Chordomas

This study aims to summarize sacrococcygeal chordoma literature through bibliometric analysis and to offer insights into key studies to guide clinical practices and future research. The Web of Science database was searched using the terms "sacral chordoma", "chordomas of the sacrum", "chordomas of the sacral spine", "chordomas of the sacrococcygeal region", "coccygeal chordoma", and "coccyx chordoma". Articles were analyzed for citation count, authorship, publication date, journal, research area tags, impact factor, and evidence level. The median number of citations was 75 (range: 53-306). The primary publication venue was the International Journal of Radiation Oncology, Biology, Physics. Most works, published between 1999 and 2019, featured a median journal impact factor of 3.8 (range: 2.1-7) and predominantly fell under the research area tag, radiation, nuclear medicine, and imaging. Of these articles, 19 provided clinical data with predominantly level III evidence, and one was a literature review. This review highlights the increasing volume of sacrococcygeal chordoma publications over the past two decades, indicating evolving treatment methods and interdisciplinary patient care. Advances in radiation, particularly intensity-modulated radiation therapy (IMRT) and proton beam therapy, are believed to be propelling research growth, and the lack of level I evidence underscores the need for more rigorous studies to refine treatment protocols for sacrococcygeal chordomas.

Complication Pattern of Sacral Primary Tumor Resection: A Study on the Risk Factors of Surgical Site Infection and Bowel or Bladder Dysfunction and Their Associations with Length of Hospital Stay

STUDY DESIGN

Retrospective open cohort study.

PURPOSE

The current study aimed to explore the pattern of complications after primary sacral tumor resection, to investigate the possible effect of several perioperative parameters on the development of complications, and to identify which complications are associated with the length of hospital stay (LOS).

OVERVIEW OF LITERATURE

Primary sacral tumor (pST) resection is associated with a high complication rate. However, the number of studies on these complications and their effect on LOS is limited.

METHODS

The clinical data of 140 patients with pST surgeries and 106 subsequent patients with local recurrence surgeries in four subgroups (index surgery, local recurrence surgery, malignant, and benign tumor) were prospectively collected and analyzed. The prognostic value of several perioperative factors on the development of surgical site infection (SSI), bowel and bladder dysfunction (BBD), and LOS was investigated using the logistic and linear regression models.

RESULTS

The overall complication rates were 61.2% after index surgeries and 50.9% after local recurrence surgeries. The most frequent complications were SSI, vegetative dysfunction, urinary tract infections, and neurological deterioration. Age >55 years, malignant tumors, and red blood cell transfusion had a predictive effect on the development of SSI in the logistic model (p<0.01, R2=0.43). Bilateral S2 or S3 resection commonly caused postoperative BBD (chi-square test=62.5, degrees of freedom=4, p<0.001). In the multiple linear regression model, wound dehiscence, BBD, systemic and urinary tract infection, cerebrospinal fluid leak, and neurologic deterioration were associated with a significantly long LOS (p<0.01, R2=0.62).

CONCLUSIONS

Surgical resection of pSTs has a high complication rate. Its common complications are SSI and BBD, both of which can have a significant influence on global therapeutic outcome. Malignant tumor diagnosis, old age, and red blood cell transfusion can remarkably increase the risk of SSI. Further, the development of BBD is significantly associated with the number of resected sacral nerve roots. By decreasing perioperative complications, LOS can decrease significantly.

Squash smear and fine needle aspiration features of conventional chordoma

Chordoma is a rare primary central nervous system tumour of notochordal origin. Proper intraoperative or preoperative diagnosis of this entity is crucial for appropriate surgical management. The most common histopathological subtype is conventional chordoma. Cytological characteristics of this subtype are quite distinctive and the diagnosis can be easily made by cytology. There are two particularly important features that are observed in both squash smear and fine needle aspiration specimens: an abundant myxochondroid stroma and cells with large vacuoles, including physaliferous cells. The main differential diagnosis is conventional chondrosarcoma, but in problematic cases immunohistochemical studies are useful to establish the correct diagnosis.

Imaging of spinal chordoma and benign notochordal cell tumor (BNCT) with radiologic pathologic correlation

Benign notochordal cell tumor (BNCT) and chordoma are neoplasms of notochordal differentiation. BNCT represents notochordal rests, commonly an incidental lesion present in the spine in 19% of cadaveric specimens. BNCTs are often radiographically occult. CT of BNCT frequently reveals patchy sclerosis between areas of maintained underlying trabeculae. BNCT demonstrates marrow replacement on T1-weighted MR images with high signal intensity on T2-weighting. BNCTs are frequently smaller than 35 mm and lack significant enhancement, bone destruction, cortical permeation, or soft tissue components. Biopsy or surgical resection of BNCT is usually not warranted, although imaging surveillance may be indicated. Chordoma is a rare low-grade locally aggressive malignancy representing 1-4% of primary malignant bone tumors. Chordoma is most frequent between the ages of 50-60 years with a male predilection. Clinical symptoms, while nonspecific and location dependent, include back pain, numbness, myelopathy, and bowel/bladder incontinence. Unfortunately, lesions are often large at presentation owing to diagnosis delay. Imaging of chordoma shows variable mixtures of bone destruction and sclerosis, calcification (50-70% at CT) and large soft tissue components. MR imaging of chordoma reveals multilobulated areas of marrow replacement on T1-weighting and high signal intensity on T2-weighting reflecting the myxoid component within the lesion and areas of hemorrhage seen histologically. Treatment of chordoma is primarily surgical with prognosis related to resection extent. Unfortunately, complete resection is often not possible (21-75%) resulting in high local recurrence incidence (19-75%) and a 5-year survival rate of 45-86%. This article reviews and illustrates the clinical characteristics, pathologic features, imaging appearance spectrum, treatment, and prognosis of BNCT and spinal chordoma.

Nomograms for predicting long-term overall survival and cancer-specific survival in chordoma: a population-based study

Background: The aim of this study was to develop two predictive models to predict overall survival (OS) and cancer-specific survival (CSS) in chordoma patients. Methods: We searched for independent prognostic factors by using univariate and multivariate Cox regression analyses. The prediction model of OS and CSS of chordoma patients was constructed by using the screened factors. Results: The study enrolled 362 chordoma patients. Cox regression analysis showed that disease stage, age, surgery, marital status and tumor size are independent influencing factors of OS and CSS in chordoma patients. After testing, the prediction model constructed in this study has good performance. Conclusion: Two predictive models were successfully constructed and validated for chordoma patients' OS and CSS.

Dysregulated Epigenetics of Chordoma: Prognostic Markers and Therapeutic Targets

Chordoma is a rare, slow-growing sarcoma that is locally aggressive, and typically resistant to conventional chemo- and radiotherapies. Despite its low incidence, chordoma remains a clinical challenge because therapeutic options for chordoma are limited, and little is known about the molecular mechanisms involved in resistance to therapies. Furthermore, there are currently no established predictive or prognostic biomarkers to follow disease progression or treatment. Whole-genome sequencing of chordoma tissues has demonstrated a low-frequency mutation rate compared to other cancers. This has generated interest in the role of epigenetic events in chordoma pathogenesis. In this review, we discuss the current understanding of the epigenetic drivers of chordoma and their potential applications in prognosis and the development of new therapies.

Management of chordoma of the sacrum and mobile spine

Chordoma is a very rare, poorly known malignancy, with slow progression, mainly located in the sacrum and spine. All age groups may be affected, with a diagnostic peak in the 5th decade of life. Clinical diagnosis is often late. Histologic diagnosis is necessary, based on percutaneous biopsy. Specific markers enable diagnosis and prediction of response to novel treatments. New radiation therapy techniques can stabilize the tumor for 5 years in inoperable patients, but en-bloc resection is the most effective treatment, and should be decided on after a multidisciplinary oncology team meeting in an expert reference center. The type of resection is determined by fine analysis of invasion. According to the level of resection, the patients should be informed and prepared for the expected vesico-genito-sphincteral neurologic sequelae. In tumors not extending above S3, isolated posterior resection is possible. Above S3, a double approach is needed. Anterior release of the sacrum is performed laparoscopically or by robot; resection uses a posterior approach. Posterior wall reconstruction is performed, with an associated flap. Spinopelvic stabilization is necessary in trans-S1 resection. Total or partial sacrectomy shows high rates of complications: intraoperative blood loss, infection or mechanical issues. Neurologic sequelae depend on the level of root sacrifice. No genital-sphincteral function survives S3 root sacrifice. Patient survival depends on initial resection quality and the center's experience. Immunotherapy is an ongoing line of research.

Impact of preoperative sarcopenia in patients undergoing sacral tumor resection

INTRODUCTION

Sacral tumor resection is known for a high rate of complications. Sarcopenia has been found to be associated with wound complications; however, there is a paucity of data examining the impact of sarcopenia on the outcome of sacral tumor resection.

METHODS

Forty-eight patients (31 primary sarcomas, 17 locally recurrent carcinomas) undergoing sacrectomy were reviewed. Central sarcopenia was assessed by measuring the psoas:lumbar vertebra index (PLVI), with the 50th percentile (0.97) used to determine which patients were high (>0.97) versus low (<0.97).

RESULTS

Twenty-four (50%) patients had a high PLVI and 24 (50%) had a low PLVI (sarcopenic). There was no difference (p > 0.05) in the demographics of patients with or without sarcopenia. There was no difference in the incidence of postoperative wound complications (odds ratio [OR] = 1.0, p = 1.0) or deep infection (OR = 0.83, p = 1.0). Sarcopenia was not associated with death due to disease (hazard ratio [HR] = 2.04, p = 0.20) or metastatic disease (HR = 2.47, p = 0.17), but was associated with local recurrence (HR = 6.60, p = 0.01).

CONCLUSIONS

Central sarcopenia was not predictive of wound complications or infection following sacral tumor resection. Sarcopenia was, however, an independent risk factor for local tumor recurrence following sacrectomy and should be considered when counseling patients on the outcome of sacrectomy.

Clinical Outcome of Sacral Chordoma Patients Treated with Pencil Beam Scanning Proton Therapy

AIMS

Sacral chordomas are locally aggressive, radio-resistant tumours. Proton therapy has the potential to deliver high radiation doses, which may improve the therapeutic ratio when compared with conventional radiotherapy. We assessed tumour control and radiation-induced toxicity in a cohort of sacral chordoma patients treated with definitive or postoperative pencil beam scanning proton therapy.

METHODS AND MATERIALS

Sixty patients with histologically proven sacral chordoma treated between November 1997 and October 2018 at the Paul Scherrer Institute with postoperative (n = 50) or definitive proton therapy (n = 10) were retrospectively analysed. Only 10 (17%) patients received combined photon radiotherapy and proton therapy. Survival rates were calculated using the Kaplan-Meier actuarial method. The Log-rank test was used to compare different functions for local control, freedom from distant recurrence and overall survival. Acute and late toxicity were assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0.

RESULTS

The median follow-up was 48 months (range 4-186). Local recurrence occurred in 20 (33%) patients. The 4-year local control, freedom from distant recurrence and overall survival rates were 77%, 89% and 85%, respectively. On univariate analysis, subtotal resection/biopsy (P = 0.02), tumour extension restricted to bone (P = 0.01) and gross tumour volume >130 ml (P = 0.04) were significant predictors for local recurrence. On multivariate analysis, tumour extension restricted to bone (P = 0.004) and gross total resection (P = 0.02) remained independent favourable prognostic factors for local recurrence. Twenty-four (40%), 28 (47%) and eight (11%) patients experienced acute grade 1, 2 and 3 toxicities, respectively. The 4-year late toxicity-free survival was 91%. Two patients developed secondary malignancies to the bladder 3-7 years after proton therapy.

CONCLUSIONS

Our data indicate that pencil beam scanning proton therapy for sacral chordomas is both safe and effective. Gross total resection, tumour volume <130 ml and tumour restricted to the bone are favourable prognostic factors for local tumour control.

Partial Sacrectomy for Resection of a Sacral Chordoma: 2-Dimensional Operative Video

Sacral chordomas are infrequent tumors that arise from remnants of the notochord. They are most often found in the sacrum and skull-base.1,2 These lesions rarely metastasize and usually have an indolent and oligosymptomatic clinical course. Chordomas show low sensitivity to standard radiation therapy and chemotherapy. Operative resection with wide resection margins offers the best long-term prognosis, including longer survival and local control.1,3 However, achieving a complete resection with oncological margins may be difficult because of the anatomic complexity of the sacrococcygeal region.4 The main complications of sacral resection include infections, wound closure defects, and anorectal and urogenital dysfunction. The rate of these complications is significantly increased when the tumor involves the S2 level or above. We report the case of a 64-yr-old male who presented with progressive sacrococcygeal pain and a feeling of incomplete evacuation. A heterogeneous, osteolytic lesion was found at the sacrococcygeal region. Full body imaging tests were negative for other lesions. A computed tomography (CT) guided biopsy was made. We usually use the midline approach in case we have to include the needle path in the resection. The pathology confirmed a sacrococcygeal, low-grade chordoma. We decided to perform an en bloc resection. A posterior, partial sacrectomy was planned distal to the S4 level.

Outcomes of Surgery for Sacral Chordoma and Impact of Complications: A Report of 50 Consecutive Patients With Long-Term Follow-Up

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To determine predictive factors of overall survival (OS) and local recurrence (LR), report complications, and assess the impact of complications on survival, recurrence, and function in patients undergoing en bloc resection of sacral chordoma.

METHODS

This retrospective case series was obtained from a prospective database (1995-2016). All patients underwent en bloc resection of sacral chordoma. Demographic, perioperative, and complication data were collected. Outcomes included: overall survival(OS), local recurrence(LR), and complications. Survival analysis with multivariable cox regression was performed.

RESULTS

Among 50 patients, median follow-up was 5.3 years (range = 1.3-17.2). The majority (82%) underwent a negative margin resection. Survival: 17 patients died (34%) with a median OS of 10.0 years (range = 1.3-17.2). Multivariable cox regression revealed that a negative margin resection was not significantly associated with improved survival (HR = 3.35, 95%CI 0.87-12.80, P = .078). Recurrence: 20 patients (40%) experienced LR with a median time of 6.2 years (range = 0-16.9). Multivariable cox regression revealed that a negative margin resection was associated with a significant decreased risk of LR (HR = 4.96, 95%CI 1.84-13.34, P = 0.002,). A 62% overall complication rate was seen (42% major), with 26% reoperation rate. Of the reoperations, 54% were delayed (>6 weeks after the index surgery). Multivariable cox regression demonstrated that neither major complication nor reoperation significantly impacted OS (HR = 0.62, 95%CI 0.22-1.79, P = 0.380), LR (HR = 1.28, 95%CI 0.49-3.36, P = 0.611), or functional outcomes (OR = 2.94, 95%CI 0.25-34.8, P = 0.393).

CONCLUSIONS

Negative margin resection was associated with decreased LR. Neither major complication nor reoperation significantly impacted OS, LR, or functional outcome. Though additional studies are needed, it appears that despite the morbidity associated with sacral chordoma resection, the long-term clinical outcomes are favorable.

Team Approach: Oncologic Sacrectomy

Oncologic sacrectomy is used in the curative treatment of patients with primary sacral malignancies or select locally invasive visceral malignancies. A systematic surgical approach involves preoperative imaging, diagnosis, and multidisciplinary surgical execution. Close collaboration with pediatric, medical, and radiation oncology colleagues is often necessary to individualize treatment plans.

Carbon ion radiotherapy for sacral chordoma: A retrospective nationwide multicentre study in Japan

BACKGROUND AND PURPOSE

Usefulness of carbon ion radiotherapy (CIRT) for sacral chordoma has been reported from single institutions. We conducted a retrospective nationwide multicentre study to evaluate the clinical outcomes of CIRT for sacral chordoma in Japan.

MATERIALS AND METHODS

A total of 219 patients who underwent CIRT for sacral chordoma at institutions across Japan between December 2003 and July 2014 were included in this study.

RESULTS

Median patient age was 67 years (range, 26-87 years). Most patients had no history of surgical resection (96%). The most frequent planning target volume (PTV) range was 100-500 mL (65%). The most frequently used dose-fractionation was 67.2 Gy (relative biological effectiveness) in 16 fractions (65%). The median follow-up was 56 months (range, 7-132 months). The 5-year overall survival (OS), progression-free survival, and local control rates were 84%, 48%, and 72%, respectively. Frequent sites of out-of-field recurrence included bone (9%) and lung (9%) metastases. The Cox proportional hazards model revealed that both younger age (P = 0.004) and smaller PTV (P = 0.001) were associated with significantly better OS. Acute toxicities of ≥Grade 3 occurred in eight patients (4%). Late toxicities of ≥Grade 3 occurred in 13 patients (6%): skin disorders in six patients (3%), pain in three (1%), myositis in three (1%), etc. CONCLUSION: Our retrospective nationwide multicentre study showed that CIRT for sacral chordoma was effective and safe, and replicated the previously reported data from a representative CIRT institution in Japan demonstrating high local control and low toxicity rates.

Hip Arthroplasty Following Subtotal Sacrectomy for Chordoma

BACKGROUND/AIM

Chordomas often affect the sacrum with a high predilection for local-regional recurrence. Patients typically retain their ability to ambulate, and the development of metastatic disease in the periacetabular region can have significant morbidity and pain with ambulation. The purpose of the study was to describe the outcome of patients undergoing a hip arthroplasty following resection of a sacral chordoma.

PATIENTS AND METHODS

From 1990 to 2015, 84 patients underwent sacrectomy for chordoma, while four of these (5%) patients underwent hip arthroplasty. The most common level of nerve root sacrifice was S2-5 (n=2). The mean time between sacrectomy and hip arthroplasty was 7 years. Indications for arthroplasty included metastatic disease (n=3) and coxarthrosis (n=1).

RESULTS

Postoperatively two patients ambulated with a gait aid, and no patient had a Trendelenburg gait. The mean Harris Hip Score significantly improved from 49 to 80 postoperatively (p=0.02).

CONCLUSION

The results of this study indicate that hip arthroplasty is a durable treatment option for patients with metastatic disease or coxarthrosis following subtotal sacrectomy for chordoma.

High-dose carbon-ion based radiotherapy of primary and recurrent sacrococcygeal chordomas: long-term clinical results of a single particle therapy center

BACKGROUND

This study aimed to analyze the oncological long-term results and late toxicity of carbon ion-based radiotherapy (RT) of patients with sacral chordoma and to identify potential prognostic factors for local control (LC) and overall survival (OS).

METHODS

A total of 68 patients with sacral chordoma treated at the Heidelberg Ion Beam Therapy Center were included in this study. Of these 52 patients (77%) received a primary RT and 16 patients (23%) received a RT in a recurrent situation. All patients were treated with carbon ion RT (CIRT), either in combination with photons (n = 22; 32%) or as a monotherapy (n = 46; 68%), with a median radiation dose of 66 Gy RBE (range 60-74 Gy). In 40 patients (59%), RT was performed in the postoperative situation. Postoperative care included regular MRI scans. Local progression was defined as an enlargement of the maximum tumor diameter by 10% or a new tumor growth within the planning target volume (PTV). LC and OS were determined using the Kaplan-Meier method. Furthermore, the relevance of various prognostic factors for LC and OS was assessed by univariate and multivariate analysis.

RESULTS

The median follow-up period was 60 months (range 1.3-97.4 months). The 5-year rates for LC, progression-free survival, metastasis-free survival and OS were 53, 53, 52 and 74%, respectively. Local recurrence was observed in 31 patients (46%), occurring after a median follow-up time of 25 months (range 2.5-73.1 months). Only 10% of local recurrences occurred later than 5 years after RT. Statistical analysis showed that RT in the relapse situation corresponded to inferior LC rates compared to the primary situation, while other factors such as the GTV, radiation dose (EQD2) and treatment approach (CIRT alone vs. CIRT combined with photons) were insignificant. For OS after RT, patient age and PTV size proved to be significant predictors. The incidence of late toxicity ≥ III° according to CTCAE v5.0 was 21%. Sacral insufficiency fractures occurred in 49% of patients (maximum III°: 16%) and were thus by far the most frequent late side effect in our analysis. Radiogenic damage to the peripheral nerves, intestinal tract and skin was observed in only 9% (≥ III°: 5%), 3% (all II°) and 9% (all I°) of patients.

CONCLUSION

Our analysis showed only moderate long-term LC rates after carbon ion-based RT, with sacral chordomas having a particularly poor prognosis in the recurrent situation. Therefore, future studies should evaluate the safety and effectiveness of further dose escalation and hypofractionation of RT in sacral chordoma and weight potential benefits of dose escalation against side effects.

"Sandwich" wound dressing to reduce surgical site infections during sacrococcygeal surgery: A retrospective analysis

OBJECTIVE

To explore whether the "sandwich" wound dressing method with a hydrocolloid dressing can effectively reduce surgical site infection rates in sacrococcygeal aseptic operations.

METHODS

A retrospective cohort of patients with sacrococcygeal aseptic operations (class I incision category) from January 2017 to March 2018 were divided into intervention (sandwich dressing) and control groups (conventional dressing). The surgical site infections (SSI) rate, wound healing course, hospitalization time, and medical costs in the two groups were determined. To exclude the influence of other factors, operation time, blood loss, age, sex ratio, the distance of the incision from the distal edge to the anus, and initial defecation times were compared between the groups.

RESULTS

The SSI rates and medical costs in the interventional group were significantly lower than the control group (0% vs 78.57%, P < 0.0001; 3.27 ± 0.98 vs 5.83 ± 1.66 ¥10,000, p < 0.0001). Hospitalization times were also lower in the intervention compared to the control group (17.05 ± 4.77 vs 34.50 ± 15.47 day, P = 0.001).

CONCLUSIONS

The sandwich wound dressing method with a hydrocolloid dressing can effectively prevent SSI during sacrococcygeal aseptic surgery.

The sacral chordoma margin

OBJECTIVE

Aim of the manuscript is to discuss how to improve margins in sacral chordoma.

BACKGROUND

Chordoma is a rare neoplasm, arising in half cases from the sacrum, with reported local failure in >50% after surgery.

METHODS

A multidisciplinary meeting of the "Chordoma Global Consensus Group" was held in Milan in 2017, focusing on challenges in defining and achieving optimal margins in chordoma with respect to surgery, definitive particle radiation therapy (RT) and medical therapies. This review aims to report on the outcome of the consensus meeting and to provide a summary of the most recent evidence in this field. Possible new ways forward, including on-going international clinical studies, are discussed.

RESULTS

En-bloc tumor-sacrum resection is the cornerstone of treatment of primary sacral chordoma, aiming to achieve negative microscopic margins. Radical definitive particle therapy seems to offer a similar outcome compared to surgery, although confirmation in comparative trials is lacking; besides there is still a certain degree of technical variability across institutions, corresponding to different fields of treatment and different tumor coverage. To address some of these questions, a prospective, randomized international study comparing surgery versus definitive high-dose RT is ongoing. Available data do not support the routine use of any medical therapy as (neo)adjuvant/cytoreductive treatment.

CONCLUSION

Given the significant influence of margins status on local control in patients with primary localized sacral chordoma, the clear definition of adequate margins and a standard local approach across institutions for both surgery and particle RT is vital for improving the management of these patients.

The Relationship Between Tumor-Stroma Ratio, the Immune Microenvironment, and Survival in Patients With Spinal Chordoma

BACKGROUND

Currently, little is known about the clinical relevance of tumor-stroma ratio (TSR) in chordoma and data discussing the relationship between TSR and immune status of chordoma are lacking.

OBJECTIVE

To characterize TSR distribution in spinal chordoma, and investigated its correlation with clinicopathologic or immunological features of patients and outcome.

METHODS

TSR was assessed visually on hematoxylin and eosin-stained sections from 54 tumor specimens by 2 independent pathologists. Multiplex immunofluorescence was used to quantify the expression levels of microvessel density, Ki-67, Brachyury, and tumor as well as stromal PD-L1. Tumor immunity status including the Immunoscore and densities of tumor-infiltrating lymphocytes (TILs) subtypes were obtained from our published data and reanalyzed.

RESULTS

Bland-Altman plot showed no difference between mean TSR derived from the two observers. TSR was positively associated with stromal PD-L1 expression, the Immunoscore and CD3+ as well as CD4+ TILs density, but negatively correlated with tumor microvessel density, Ki-67 index, surrounding muscle invasion by tumor and number of Foxp3+ and PD-1+ TILs. Low TSR independently predicted poor local recurrence-free survival and overall survival. Moreover, patients with low TSR and low Immunoscore chordoma phenotype were associated with the worst survival. More importantly, combined TSR and Immunoscore accurately reflected prognosis and enhanced the ability of TSR or Immunoscore alone for outcome prediction.

CONCLUSION

These data reveal the significant impact of TSR on tumor progression and immunological response of patients. Subsequent use of agents targeting the stroma compartment may be an effective strategy to treat chordoma especially in combination with immune-based drugs.

Natural History of a Patient with Sacral Chordoma: Case Report and Literature Review

BACKGROUND

Chordomas are rare, slow-growing, locally aggressive, malignant tumors of the spine. Chordomas are conventionally treated with surgical resection with or without radiation. There is an absence of literature documenting the natural history of a primary sacral chordoma.

CASE DESCRIPTION

A 65-year-old man presented with rectal pain, constipation, urinary and fecal incontinence, S1 radiculopathy, and a palpable rectal mass. A needle biopsy confirmed the pathologic diagnosis of sacral chordoma. The patient declined to have surgery because of the surgical risks involved. He was managed conservatively with supportive care only. The patient was routinely followed in clinic and had a subjective and objective excellent quality of life with adequate pain management. Meanwhile, his neurologic status did not deteriorate. During follow-up, some posterolateral aspects of the chordoma regressed. However, the bulk of the lesion continued to slowly progress. The patient survived for 7.5 years. He eventually succumbed to urosepsis and new-onset peritoneal metastasis.

CONCLUSIONS

To our knowledge, the patient is the only documented case in the literature of an untreated biopsy-proven sacral chordoma. The patient's tumor was intended for resection, and therefore comparable with data from treated chordomas. The patient's survival is similar to the median survival in treated chordomas. The patient's survival was despite negative prognosticators, such as advanced age of the patient and high sacral location above S2.

Can the ACS-NSQIP surgical risk calculator predict postoperative complications in patients undergoing sacral tumor resection for chordoma?

BACKGROUND AND OBJECTIVES

The ACS-NSQIP surgical risk calculator is an online tool that estimates the risk of postoperative complications. Sacrectomies for chordoma are associated with a high rate of complications. This study was to determine if the ACS-NSQIP calculator can predict postoperative complications following sacrectomy.

METHODS

Sixty-five (42 male, 23 female) patients who underwent sacrectomy were analyzed using the Current Procedural Terminology (CPT) codes: 49215 (excision of presacral/sacral tumor), 63001 (laminectomy of sacral vertebrae), 63728 (laminectomy for biopsy/excision of sacral neoplasm) and 63307 (sacral vertebral corpectomy for intraspinal lesion). The predicted rates of complications were compared to the observed rates.

RESULTS

Complications were noted in 44 (68%) patients. Of the risk factors available to input to the ACS-NSQIP calculator, tobacco use (OR, 20.4; P < .001) was predictive of complications. The predicted risk of complications based off the CPT codes were: 49215 (16%); 63011 (6%); 63278 (11%) and 63307 (15%). Based on ROC curves, the use of the ACS-NSQIP score were poor predictors of complications (49215, AUC 0.65); (63011, AUC 0.66); (63307, AUC 0.67); (63278, AUC 0.64).

CONCLUSION

The ACS-NSQIP calculator was a poor predictor of complications and was marginally better than a coin flip in its ability to predict complications following sacrectomy for chordoma.

Association between patient age and the risk of mortality following local recurrence of a sacral chordoma

BACKGROUND

Local recurrence (LR) of sacral chordoma is a difficult problem and the mortality risk associated with LR remains poorly described. The purpose of this study was to evaluate the risk of mortality in patients with LR and determine if patient age is associated with mortality.

METHODS

A total of 218 patients (144 male, 69 female; mean age 59 ± 15 years) with sacrococcygeal chordomas were reviewed. Cumulative incidence functions and competing risks for death due to disease and nondisease mortality were employed to analyze mortality trends following LR.

RESULTS

The 10-year overall survival (OS) was 55%. Patients with LR had 44% 10-year OS, similar to patients without (59%; P = .38). The 10-year OS between those less than 55 compared with ≥55 years were similar (69% vs 48%; P = .52). The 10-year death due to disease was worse in patients with LR compared with those without (44% vs 84%; P < .001). In patients without LR, patients ≥55 years were 1.6-fold more likely to experience death due to other causes.

CONCLUSIONS

Patients with an LR are more likely to die due to disease. Advanced patient age was associated with higher all-cause mortality following resection of sacral chordoma. LR of chordoma was associated with increased disease-specific mortality, regardless of age.

A four-factor immune risk score signature predicts the clinical outcome of patients with spinal chordoma

BACKGROUND

Currently, the measurement of immune cells in previous studies is usually subjective, and no immune-based prognostic model has been established for chordoma. In this study, we sought to simultaneously measure tumor-infiltrating lymphocyte (TIL) subtypes in chordoma samples using an objective method and develop an immune risk score (IRS) model for survival prediction.

METHODS

Multiplexed quantitative immunofluorescence staining was used to determine the TIL levels in the tumoral and stromal subareas of 114 spinal chordoma specimens (54 in the training and 60 in the validation cohort) for programmed death-1 (PD-1), CD3, CD8, CD20 (where CD is cluster of differentiation), and FOXP3. Flow cytometry was performed to validate the immunofluorescence assay for lymphocyte measurement on an additional five fresh chordoma specimens. Subsequently, the IRS model was built using the least absolute shrinkage and selection operator (LASSO) Cox regression method.

RESULTS

Flow cytometry and quantitative immunofluorescence showed similar lymphocytic percentages and TIL subpopulation proportions in the fresh tumor specimens. With the training data, the LASSO model identified four immune features for IRS construction: tumoral FOXP3, tumoral PD-1, stromal FOXP3, and stromal CD8. In both cohorts, a high IRS was significantly associated with tumoral programmed cell death-1 ligand 1 expression, Enneking inappropriate tumor resection, and surrounding muscle invasion by tumor. Multivariate Cox regression and stratified analysis in the two cohorts revealed that the IRS was an independent predictor and could effectively separate patients with similar Enneking staging into different risk subgroups, with significantly different survival rates. Further receiver operating characteristic analysis found that the IRS classifier had a better prognostic value than the traditional clinicopathological factors and compensated for the deficiency of Enneking staging for outcome prediction. More importantly, a nomogram based on the IRS and clinical predictors showed adequate performance in estimating disease recurrence and survival of patients.

CONCLUSIONS

These data support the use of the IRS signature as a reliable prognostic tool in spinal chordoma and may facilitate individualized therapy decision making for patients.

Sacral chordoma: do the width of surgical margin and the use of photon/proton radiotherapy affect local disease control?

PURPOSE

Chordoma is a rare but highly aggressive primary bone sarcoma that arises commonly from the sacrum. While en bloc resection has been the mainstay of the treatment, the role of resection margin in millimetres with/without adjuvant radiotherapy (RT) has been unknown. We investigated the prognostic impact of surgical margin width, adjuvant RT, and their combined factor for sacral chordoma.

METHODS

Forty-eight patients who underwent surgical treatment between 1996 and 2016 were studied. Of these, 11 patients (23%) received adjuvant RT; photon RT in 7 (15%) and proton RT in 4 (8%). Margins were microscopically measured in millimetres from the resection surface to the closest tumour on histologic slides.

RESULTS

The five year and ten year disease-specific survival was 88% and 58%, respectively, and the local recurrence (LR) rate was 48%. The LR rate with 0-mm, < 1.5-mm, and ≥ 1.5-mm margin was 50% (group 1), 50% (group 2: RT-, 61%; group 3: RT+, 14%), and 0% (group 4), respectively. We observed a significantly lower LR rate in patients with adjuvant photon/proton RT (18%) than without it (57%; p = 0.026), and no LR was observed after post-operative proton RT. The combined factor of margin with RT clearly stratified the LR risk: patients of group 1 (positive margin) and 2 (< 1.5-mm margin, RT-) had approximately 7.5× LR risk (p = 0.049) compared with those of group 3 (< 1.5-mm margin, RT+) and 4 (≥ 1.5-mm margin).

CONCLUSION

This study identified the lowest risk of local failure in tumour resection with ≥ 1.5-mm margin or negative but < 1.5-mm margin with the use of adjuvant photon/proton radiotherapy for sacral chordoma. Early results of adjuvant proton RT demonstrated excellent local control.

Recurrence or neurological loss? Resection mode selection for patients with large sacral chordoma: an analysis of prognostic factors and quality of life

BACKGROUND

Surgical resection represents the main therapeutic method for sacral chordoma, but plans for resection mode must weigh neurological loss against complete tumor excision, a difficult balance to strike. The purpose of this study was to provide useful information contributing to surgical decision making in sacral chordoma.

METHODS

A retrospective review was performed on 47 patients with large sacral chordoma. Prognostic factors affecting recurrence-free survival (RFS) and overall survival (OS) were analyzed using the Kaplan-Meier method and Cox proportional hazards model. Quality of life was assessed by the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire and compared using Student's t test.

RESULTS

Resection mode was the independent prognostic factor affecting RFS, while independent prognostic factors affecting OS were resection mode and postoperative recurrence. As for quality of life, the en bloc resection group showed a higher score in emotional well-being, while the piecemeal resection group scored better in function well-being. No significant difference was identified in total the FACT-G score between two groups.

CONCLUSIONS

On the one hand, en bloc resection showed huge advantages in disease control for sacral chordoma. On the other hand, despite the unsatisfaction in functional well-being, en bloc resection did not sacrifice quality of life significantly in terms of the total FACT-G score.

Conditional survival and changing risk profile in patients with chordoma: a population-based longitudinal cohort study

Objective

To evaluate the conditional survival of patients with chordoma to potentially help physician planning of optimal cancer surveillance and guide better clinical decisions.

Methods

In total, 1942 patients with chordoma were identified and extracted from Surveillance, Epidemiology, and End Results (SEER) databases (1973–2015). The cumulative survival estimates were used to calculate the conditional survival rate, and the Greenwood formula was used to estimate the 95% CI. In addition, multivariable Cox regression analyses were used to calculate hazard ratios, according to the duration of survival.

Results

The conditional 5-year disease-specific survival in patients with regional or localized chordoma was relatively stable over time, whereas in patients with distant chordoma, there was a gradual improvement. The conditional 5-year disease-specific survival (DSS) of patients older than 60 years old and patients with a tumor size between 5 and 10 cm improved. Interestingly, for patients with a tumor larger than 10 cm, the conditional 5-year DSS decreased over time. After surviving 5 years, the hazard ratio (HR) of patients older than 60 years old decreased from 1.33 to 1.24, that of patients with a tumor size between 5 and 10 cm decreased from 1.61 to 1.52 and that of patients with distant metastasis decreased from 3.30 to 1.09. However, after surviving 5 years, the HR of patients with a tumor size larger than 10 cm increased from 2.33 to 3.77, that of patients who underwent surgical resection increased from 0.37 to 0.58 and that of patients who received radiation therapy increased from 0.81 to 1.04.

Conclusion

Age at diagnosis, tumor size and disease stage can influence conditional survival for patients with chordoma. The HR of different factors will change over the survival time. Therefore, understanding the changing risk profile and conditional 5-year DSS of chordoma is critical for accurate clinical treatment guidance.

Sacral chordoma: a clinical review of 101 cases with 30-year experience in a single institution

BACKGROUND

Local recurrence rates are high in sacral chordoma patients. Adjuvant radiotherapy may play a role in increasing local control. Patients with locally recurrent tumors continue to comprise a significant proportion of the sacral chordoma population and appear to have worse prognosis than those with primary tumors. High-quality studies comparing presentation and treatments for primary and first local recurrent sacral chordoma tumors are sparse.

PURPOSE

To determine: whether there is a difference in how primary and tumors at first recurrence present; the overall survival, local relapse-free survival, and distant relapse-free survival rates and prognostic factors for patients presenting with a primary tumor; overall survival, local relapse-free survival, and distant relapse-free survival rates and prognostic factors for patients presenting with a first local relapse; if there any differences in overall survival, local relapse-free survival, and distant relapse-free survival rates between patients presenting with a primary tumor and those with a first local relapse.

STUDY DESIGN

Retrospective case series.

PATIENT SAMPLE

One hundred one sacral chordoma cases.

OUTCOME MEASURE

Overall survival, local relapse-free survival, and distant relapse-free survival rates.

METHODS

Between 1978 and 2013, 131 patients with sacral chordoma were seen. Of them, 17 patients (13%) presented with a history of more than one local recurrence. One patient (1%) presented with multiple distant metastases. Ten patients (8%) had less than 36 months of follow-up and had no event (eg, death, local recurrence, or distant metastasis). A total of 102 patients met our inclusion criteria: patients with primary or first recurrent tumors, without metastatic disease, who underwent surgery and with at least 36 months of follow-up. One patient (1%) died intraoperatively; therefore, 101 patients were included in the present analysis. Cox proportional hazards regression analysis was performed for primary and local recurrent tumor separately and to compare primary and local recurrent tumors.

RESULTS

We analyzed 73 primary and 28 first time recurrent sacral chordomas. Tumor size at presentation was different for primary and recurrent tumors (primary median size: 158 cm³, interquartile range [IQR]: 46-634; recurrent median size: 39 cm³, IQR: 14-175; p=.001). Overall survival at 5 and 10years for the primary tumors was 79% and 59%, respectively. Local relapse-free survival at 5years was 86%. For primary tumors, not receiving radiation was an independent predictor for worse local relapse-free survival (hazard ratio [HR]: 0.20; 95% confidence interval [CI]: 0.0043-0.90; p=.004) and increased tumor size was an independent predictor for both worse overall survival (HR: 1.68; 95% CI: 1.38-2.42; p=.004) and worse distant relapse-free survival (HR: 2.25; 95% CI: 1.47-3.44; p<.001). For recurrent tumors, the 5- and 10-year overall survival was 65% and 40%, respectively. Local relapse-free survival at 5years was 79% for recurrent tumors. On bivariate analysis, increased tumor size was a significant predictor for worse survival (LR median: 338 mL; IQR: 218-503 mL; no LR median: 26 mL; IQR: 9-71 mL). A trend was seen toward better distant relapse survival for tumors presenting as a primary tumor (HR: 0.51; 95% CI: 0.25-1.06; p=.072).

CONCLUSION

Using a combination of surgical resection and adjuvant radiotherapy allowed us to obtain a good overall survival, local relapse-free survival, and distant relapse-free survival in patients presenting with either a primary tumor or with a first time local recurrent tumor.

Local and Distant Recurrence in Resected Sacral Chordomas: A Systematic Review and Pooled Cohort Analysis

STUDY DESIGN

Systematic review.

OBJECTIVES

Sacral chordomas are rare, primary tumors of the spine, best treated with en bloc resection. The purpose of this study was to assess the literature for resected sacral chordoma and to quantify the prevalence of, risk factors for, and treatment outcomes of local and distant recurrence therein.

METHODS

We searched 5 online databases from January 1980 to May 2016 to find articles that report survival, recurrence outcomes, and/or prognostic factors for the resected sacral chordoma patient population. Characteristics and clinical outcomes of the pooled cohort are reported. Fisher exact tests, unpaired t tests, and one-way analysis of variance were used to investigate patient- and treatment-associated prognostic factors for local and distant recurrence. Survival analyses were performed for time to local recurrence and death. The protocol's PROSPERO ID is CRD42015024384.

RESULTS

Fifty-seven studies, with 1235 unique sacral chordoma patients, were included in this review. Local and distant recurrence occurred in 42.6% and 22.4% of patients with adequate follow-up, respectively. Kaplan-Meier overall median survival for patients with and without recurrence were 98 and 209 months after surgery, respectively. Wide surgical margin was associated with a lower rate of local recurrence; and wide surgical margin, female sex, and patient age ≥65 years were associated with lower rates of distant recurrence.

CONCLUSIONS

While surgical margin remains the most significant prognostic factor for local and distant recurrence, combined surgical approach may be associated with local recurrence. Male sex and age <65 years may be associated with distant recurrence. Patients with risk factors for recurrence should undergo close monitoring to maximize survival.

Low dose radiotherapy is associated with local complications but not disease control in sacral chordoma

BACKGROUND

We reviewed the disease control and complications of the treatment of sacrococcygeal chordoma from four tertiary cancer centers with emphasis on the effects of radiotherapy in surgically treated patients.

METHODS

A total of 193 patients with primary sacrococcygeal chordoma from 1990 to 2015 were reviewed. There were 124 males, with a mean age of 59 ± 15 years and a mean follow-up of 7 ± 4 years. Eighty-nine patients received radiotherapy with a mean total dose of 61.8 ± 10.9 Gy.

RESULTS

The 10-year disease-free and disease-specific survival was 58% and 72%, respectively. Radiation was not associated with local recurrence (hazard ratio [HR], 1.13; 95% confidence interval [CI], 0.59-2.17; P = 0.71), metastases (HR, 0.93; 95% CI, 0.45-1.91; P = 0.85) or disease-specific survival (HR, 0.96; 95% CI, 0.46-2.00; P = 0.91). Higher doses (≥70 Gy; HR, 0.52; 95% CI, 0.20-1.32; P = 0.17) may be associated with reduced local recurrence. Radiotherapy was associated with wound complications (HR, 2.76; 95% CI, 1.64-4.82;, P < 0.001) and sacral stress fractures (HR, 4.73; 95% CI, 1.88-14.38; P < 0.001).

CONCLUSIONS

In this multicenter review, radiotherapy was not associated with tumor outcome but associated with complications. The routine use of radiotherapy with en-bloc resection of sacrococcygeal chordomas should be reconsidered in favor of a selective, individualized approach with a radiation dose of ≥70 Gy.

Predictive Value of Preoperative Magnetic Resonance Imaging Findings for Survival and Local Recurrence in Patients Undergoing En Bloc Resection of Sacral Chordomas

BACKGROUND

Few studies have assessed the prognostic importance of preoperative magnetic resonance imaging (MRI) scan findings in patients undergoing en bloc resection of sacral chordomas.

OBJECTIVE

To (1) report in-depth imaging characteristics of sacral chordomas, (2) describe the patterns of local and distant recurrence, and (3) determine imaging predictors of overall survival (OS) and local recurrence (LR).

METHODS

This retrospective case series was obtained from a prospectively maintained spine database from 1995 to 2016. All patients underwent en bloc resection of sacral chordomas. Detailed demographic, outcome, and MRI data were collected. A survival analysis was completed with multivariable cox regression to assess the impact of MRI findings on OS and LR.

RESULTS

A total of 41 patients underwent en bloc resection of sacral chordoma with preoperative MRI scans. Tumor characteristics included lobulated: (93%) and soft tissue tail (54%). The following areas had tumor invasion lobulated: sacroiliac (SI) joint (15%), ilium (5%), piriformis (61%), gluteus (46%), subcutaneous fat (32%), and lumbosacral venous plexus (22%). After multivariable analysis, only subcutaneous fat extension was an independent predictor of decreased OS (hazard ratio 5.30, 95% confidence interval 1.47-19.19, P = .011). Though not significant after multivariable analysis, the following factors were significant predictors of LR after univariate logrank testing: above the L5/S1 disc space (P = .004), SI joint invasion (P = .036), and piriformis extension (P = .022).

CONCLUSION

The presence of subcutaneous fat extension was an independent predictor of decreased OS. Other MRI findings with potential for future evaluation include size, presence of soft tissue tail, extension above L5/S1, and SI joint and piriformis invasion.

Analysis of prognostic factors for survival in patients with primary spinal chordoma using the SEER Registry from 1973 to 2014

BACKGROUND

Spinal chordomas are rare primary osseous tumors that arise from the remnants of the notochord. They are commonly considered slow-growing, locally invasive neoplasms with little tendency to metastasize, but the high recurrent rate of spinal chordomas may seriously affect the survival rate and quality of life of patients. The aim of the study is to describe the epidemiological data and determine the prognostic factors for decreased survival in patients with primary spinal chordoma.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) Registry database, a US population-based cancer registry database, was used to identify all patients diagnosed with primary spinal chordoma from 1973 to 2014. We utilized Kaplan-Meier method and Cox proportional hazards regression analysis to evaluate the association between patients overall survival and relevant characteristics, including age, gender, race, disease stage, treatment methods, primary tumor site, marital status, and urban county background.

RESULTS

In the data set between 1973 and 2014, a total of 808 patients were identified with primary spinal chordoma. The overall rate of distant metastatic cases in our cohort was only 7.7%. Spinal chordoma was more common occurred in men (62.6%) than women (37.3%). Majority of neoplasms were found in the White (87.9%), while the incidence of the Black is relatively infrequent (3.3%). Three hundred fifty-seven spinal chordomas (44.2%) were located in the vertebral column, while 451 patients' tumor (55.8%) was located in the sacrum or pelvis. Age ≥ 60 years (HR = 2.72; 95%CI, 1.71 to 2.89), distant metastasis (HR = 2.16; 95%CI, 1.54 to 3.02), and non-surgical therapy (HR = 2.14; 95%CI, 1.72 to 2.69) were independent risk factors for survival reduction in analysis. Survival did not significantly differ as a factor of tumor site (vertebrae vs sacrum/pelvis) for primary spinal chordoma (HR = 0.93, P = 0.16). Race (P = 0.52), gender (P = 0.11), marital status (P = 0.94), and urban background (P = 0.72) were not main factors which affected overall survival rate.

CONCLUSION

There was no significant difference in overall survival rate between chordomas located in the sacrum and vertebral column. Spinal chordoma patients with an elderly age (age ≥ 60), performing non-surgical therapy, and distant metastasis were associated with worse overall survival. Performing surgery was an effective and reliable treatment method for patients with spinal chordoma, and public health efforts should pay more attention to the elderly patients with spinal chordoma prior to distant metastasis.

U-CH17P, -M and -S, a new cell culture system for tumor diversity and progression in chordoma

Chordoma is a rare bone tumor with a known intrinsic heterogeneity. Here, we address this tumor heterogeneity in a new cell culture model for tumor diversity and progression in chordoma. The three cell lines U-CH17P, U-CH17M, and U-CH17S were established from a primary sacral chordoma and its derived metastases, a soft tissue and a skin metastasis, respectively. The lesions had divergent differentiation patterns which are conserved in the derived cell lines making them a suitable in vitro model for the analysis of tumorigenesis in chordoma. A common feature of the three cell lines is the expression of typical chordoma markers, such as Brachyury, vimentin, cytokeratins, EMA and S100 protein. A comparison of the genomic aberrations by array comparative genomic hybridization of the cell lines and the corresponding parental tumor tissues revealed that the precursor cells of U-CH17P, U-CH17M and U-CH17S were already present in the primary tumor. Therefore, we show that clonal diversity of this chordoma exists in the primary tumor and that not all of these subclones tend to metastasize. All cell lines had a CDKN2A loss. A comparison of the gene expression profiles of the cell lines revealed significant differences in the expression of several genes like MAGEC2 and SEMA6A known to be associated with the tendency to metastasize or proliferation and migration. Since the underlying mechanisms of tumor progression in chordoma are still largely unclear, the three U-CH17 cell lines are a suitable in vitro model for elucidating chordoma oncobiology.

HOXA7, HOXA9, and HOXA10 are differentially expressed in clival and sacral chordomas

Chordomas are rare tumours of the bone arising along the spine from clivus to sacrum. We compared three chordoma cell lines of the clivus region including the newly established clivus chordoma cell line, U-CH14, with nine chordoma cell lines originating from sacral primaries by morphology, on genomic and expression levels and with patient samples from our chordoma tissue bank. Clinically, chordomas of the clivus were generally smaller in size at presentation and patients with sacral chordomas had more metastases and more often recurrent disease. All chordoma cell lines had a typical physaliphorous morphology and expressed brachyury, S100-protein and cytokeratin. By expression analyses we detected differentially expressed genes in the clivus derived cell lines as compared to the sacral cell lines. Among these were HOXA7, HOXA9, and HOXA10 known to be important for the development of the anterior-posterior body axis. These results were confirmed by qPCR. Immunohistologically, clivus chordomas had no or very low levels of HOXA10 protein while sacral chordomas showed a strong nuclear positivity in all samples analysed. This differential expression of HOX genes in chordomas of the clivus and sacrum suggests an oncofetal mechanism in gene regulation linked to the anatomic site.

Prognostic Factors and Survival Outcome in Patients with Chordoma in the United States: A Population-Based Analysis

OBJECTIVE

To evaluate prognostic factors of patients with chordoma through a population-based analysis.

METHODS

Surveillance, Epidemiology, and End Results (SEER) database was queried for patients with chordoma from 1973 to 2013. Kaplan-Meier univariate analysis and Cox regression multivariate analysis were performed to examine prognostic factors in overall survival (OS) and disease-specific survival (DSS).

RESULTS

One thousand five hundred ninety-eight patients with chordoma are identified. Kaplan-Meier analysis showed that OS and DSS were 61% and 71% at 5 years and 41% and 57% at 10 years. Multivariate Cox regression analysis demonstrated that independent predictors of OS and DSS are age at diagnosis (hazard ratio [HR]= 2.80 [95% confidence interval {CI}, 2.12-3.70], P < 0.001; HR = 1.60 [95% CI, 1.18-2.16], P = 0.002), surgical treatment (HR = 0.62 [95% CI, 0.52-0.73], P < 0.001; HR = 0.64 [95% CI, 0.52-0.79], P < 0.001), radiation therapy (HR = 1.23 [95% CI, 1.07-1.42], P = 0.004; HR = 1.29 [95% CI, 1.09-1.54], P = 0.004), tumor size (HR = 1.53 [95% CI, 1.32-1.78], P < 0.001; HR = 1.62 [95% CI, 1.35-1.94], P < 0.001) and distant metastasis (HR = 3.40 [95% CI, 2.45-4.71], P < 0.001; HR = 3.77 [95% CI, 2.61-5.45], P < 0.001).

CONCLUSION

We report the largest study to date to evaluate prognostic factors of patients with chordoma. Multivariate analysis demonstrated that older age, greater tumor size, and distant metastasis were correlated with decreased survival, whereas surgical resection was correlated with increased survival. Patients receiving radiation therapy also showed decreased survival, likely an indication of the patients' advanced stage of disease, making them poor surgical candidates.

Aggressive Chordomas: Clinical Outcome of 13 Patients

The authors reviewed the files of all patients with chordomas who were admitted and treated at their institutions from 1975 to 2012. Patients were categorized by early local recurrence and metastasis. Aggressive clinical behavior was defined as local recurrence and metastasis within 24 months of diagnosis and adequate treatment (wide en bloc resection with microscopically negative tumor margins). According to these criteria, 13 patients (14.3%) had aggressive chordomas, including 7 men and 6 women, with mean age of 54 years (range, 37-65 years) at diagnosis and treatment. All patients had preoperative tumor biopsy, followed by resection with partial (7 patients) or total sacrectomy (6 patients). In all cases, biopsy and histologic analysis of resected tumor specimens showed conventional chordomas. Resection margins were wide (grossly negative) in 6 patients and wide contaminated in 7 patients. Mean maximum tumor diameter was 11.8 cm (range, 5-21 cm). Mean follow-up was 43 months (range, 8-131 months). Rates of local recurrence, metastasis, and death were evaluated. At the last follow-up, all patients had local recurrence at a mean of 13 months (range, 5-22 months). Histologic examination of recurrent tumors showed a dedifferentiated chordoma with a fibrosarcoma component in 2 patients and no histologic change in the remaining patients. In addition, 8 patients had metastases at a mean of 13 months (range, 4-24 months) and died of their disease. All histologic findings of metastatic lesions were similar to those of primary tumors. Early diagnosis of aggressive tumors requires close follow-up of patients with chordomas. Metastasis is common, with resultant poor survival. [Orthopedics. 2017; 40(2):e248-e254.].

What Are the Conditional Survival and Functional Outcomes After Surgical Treatment of 115 Patients With Sacral Chordoma?

BACKGROUND

Conditional survival is a measure of prognosis for patients who have already survived for a specific period of time; however, data on conditional survival after sacrectomy in patients with sacral chordoma are lacking. In addition, because sacral tumors are rare and heterogeneous, classifying them in a way that allows physicians to predict functional outcomes after sacrectomy remains a challenge.

QUESTIONS/PURPOSES

(1) What is the overall survival and disease-free survival in patients treated by sacrectomy for chordoma? (2) What is the conditional survival probability and how do prognostic factors change over time in patients undergoing surgical resection for sacral chordoma? (3) What is the local recurrence rate after surgery, how was it treated, and what factors impact on local recurrence? (4) What is the postoperative motor, sensory, bowel, and bladder function by level of resection as determined by using a newly designed scoring method?

METHODS

Between 2003 and 2012, our center treated 122 patients surgically for sacral chordoma. Of those, two died and five were lost before a minimum followup of 1 year was achieved, leaving 115 patients available for analysis in this retrospective study at a mean of 4.9 years (range, 1.3-10.8 years). Basically, single posterior or combined approaches were chosen based on the most cephalad extent of the tumor and resection level was normally at half or one sacral vertebrae above the tumor. The 5-year conditional survival rate was calculated based on Kaplan-Meier survival analysis. The effect of prognostic factors on conditional survival was also explored. A newly designed score method was proposed and adopted in the current study to critically evaluate the functional outcome after resection of the sacrum. Inter- and intraobserver reliability was tested by a preliminary study using kappa statistics and Spearman rank correlation coefficients. Significant interobserver (p < 0.01) and intraobserver agreement (κ > 0.75) were found in nine items between each observer.

RESULTS

The estimated 5-year overall survival rate was 81% (95% confidence interval [CI], 72%-90%) at diagnosis. The 5-year disease-free survival rate was 52% (95% CI, 43%-63%). The 5-year conditional overall survival decreased with each additional year in the first 4 years (81% at diagnosis versus 60% at the fourth year, p < 0.0001) and increased slightly in the fifth year. Patients with adequate surgical margins displayed a higher 5-year survival than those with an inadequate margin (86% [95% CI, 76%-95%] versus 67% [95% CI, 48%-85%], p = 0.01) at diagnosis. Conditional survival estimates for patients who received operations elsewhere were lower than that of newly diagnosed patients treated by us at diagnosis (64% [95% CI, 46%-83%] versus 90% [95% CI, 82%-99%], p = 0.012), but with the numbers we had, we could not detect a difference in conditional survival between those treated elsewhere first compared with those initially treated by us at 5 years. The proposed score system for function evaluation was able to distinguish different levels of resection. The overall functional results for the preservation of bilateral S1, S2, and S3 were 40 ± 8%, 60 ± 12%, and 82 ± 11%, respectively. Patients who had preservation of only one S3 nerve root had more severe incontinence (1.99 ± 0.79 versus 2.60 ± 0.63, p = 0.01) and more sensory loss (1.88 ± 0.82 versus 2.31 ± 0.59, p = 0.02) than those patients with preservation of bilateral S3 nerve roots.

CONCLUSIONS

The 5-year conditional survival for sacral chordoma decreased with each additional year and began to improve after the fourth year. In addition, the effect of the surgical margin and influence of previous surgery on conditional survival were not linear over time. The level of nerve root resections corresponded with the overall function scores according to the proposed scoring method. This information and scoring system should be valuable in discussing outcomes of sacrectomy in patients with chordoma who are considering this operation and serve as the basis for further study.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Carbon Ion Radiation Therapy for Unresectable Sacral Chordoma: An Analysis of 188 Cases

PURPOSE

To evaluate the results of carbon ion radiation therapy administered to 188 patients with unresectable primary sacral chordomas.

PATIENTS AND METHODS

One hundred eighty-eight patients were treated with carbon ion radiation therapy at a single institute between 1996 and 2013 and retrospectively analyzed. The median age was 66 years. The highest proximal invasion reached past S2 level in 137 patients. The median clinical target volume was 345 cm(3). One hundred six patients received 67.2 gray equivalents (GyE)/16 fractions (fr), 74 patients received 70.4 GyE/16 fr, 7 patients received 73.6 GyE/16 fr, and 1 patient received 64.0 GyE/16 fr.

RESULTS

The median follow-up period was 62 months (range, 6.8-147.5 months). Seventy percent of patients were followed for 5 years or until death. The 5-year local control, overall survival, and disease-free survival rates were 77.2%, 81.1%, and 50.3%, respectively. Forty-one patients had a local recurrence. Sex, tumor volume, level of proximal invasion, and irradiated dose were unrelated to local control. There was grade 3 toxicity of the peripheral nerves in 6 patients and grade 4 toxicity of the skin in 2 patients. Ambulation remained in 97% of patients.

CONCLUSIONS

Carbon ion radiation therapy was safe and effective for unresectable chordoma and provided good local control and survival while preserving ambulation.

Upregulated human telomerase reverse transcriptase (hTERT) expression is associated with spinal chordoma growth, invasion and poor prognosis

Altered expression or activity of human telomerase reverse transcriptase (hTERT) has been associated with human carcinogenesis. This study detected hTERT expression in spinal chordoma tissues and associated the level of hTERT expression with clinicopathological data and patient survival. Tissue samples from 54 patients and 20 controls were subjected to immunohistochemical analysis of hTERT protein levels. hTERT expression levels were then analyzed for associations with patient survival rates and clinicopathological parameters (such as age, gender, tumor size, location, tumor grade, tumor stage, muscle invasion, recurrence or not, type of resection, tumor hemorrhage, tumor necrosis, levels of tumor-infiltrating lymphocytes (TILs) and Ki-67 expression). hTERT expression was detected in all 54 spinal chordomas. Expression levels were weak in 7, moderate in 17 and strong in 30 spinal chordoma tissue samples. In contrast, hTERT was rarely expressed in nucleus pulposus tissues (20 samples). hTERT expression was significantly associated with the Ki-67-staining index (t = -6.616, p < 0.001), TIL levels (F = 5.27, p = 0.008) and tumor invasion of the surrounding muscle tissue (t = -4.49, p < 0.001). Kaplan-Meier curves indicated that high hTERT expression was significantly associated with poor local recurrence-free survival of patients (χ(2) = 19.07, p < 0.001 via the log-rank test), but not associated with overall patient survival. Multivariate analysis of local recurrence-free survival demonstrated that hTERT expression was an independent prognostic factor among spinal chordoma patients (HR = 1.013, 95% CI: 1.002-1.024, p = 0.016). High hTERT expression was associated with spinal chordoma growth, invasion and poor patient prognosis. Future studies will investigate the use of hTERT as a biomarker to predict patient prognosis and disease progression or as a potential spinal chordoma therapy target.

Surgical treatment of sacral chordoma: survival and prognostic factors

INTRODUCTION

Sacral chordoma is a rare low-to-intermediate grade malignant tumour. The mainstay of treatment is still surgery with en bloc and wide resection margins, which can grant the best chances of a long-term control or cure of this disease. The first aim of this paper is to collect data about survival, time to local recurrence and metastasis among patients affected by sacral chordoma and primarily treated with surgery. The second aim is to analyze the influence of level resection, tumor volume and surgical margins on local recurrence.

MATERIALS AND METHODS

The study population was composed of 14 patients treated with sacral chordoma resection at the National Tumour Institute of Naples-Pascale (Italy) from January 2000 to June 2013. The median follow-up was 84 months (range 24-132 months). The follow-up was characterized by: standard radiographs, MRI, and a CT scan of the chest annually. Time to recurrence or metastasis was calculated from the date of resection to the date of diagnosis of first recurrence or metastasis.

RESULTS

Out of all the patients, six died (42.86 %) during the follow-up; 6 (42.86 %) had local recurrence; 4 (28.57 %) had metastasis. At univariate analysis wide surgical margins (R0) were associated with increased survival up to a local recurrence (OR = 0.0286; 95 % CI = 0.0014-0.5739; P = 0.026); the level of resection (OR = 3.33; 95 % CI = 0.3619-30.7025; P = 0.592) and tumour volume (P = 1) did not show a statistically significant correlation.

DISCUSSION

Based on our experience, we hope all patients to be treated by surgery, the only good standard treatment of this disease. The resection should result in margins as wide as possible. For these reasons, it is essential for this disease to be treated in highly specialized centres because only a complete surgery can offer a chance to care for these patients.

CONCLUSIONS

Solid survival at long-term follow-up can be achieved by a surgical resection performed with wide margins.