Prognostic factors of sacral chordoma after surgical therapy: a study of 36 patients

The unresolved case of sacral chordoma: from misdiagnosis to challenging surgery and medical therapy resistance

PURPOSE

A sacral chordoma is a rare, slow-growing, primary bone tumor, arising from embryonic notochordal remnants. Radical surgery is the only hope for cure. The aim of our present study is to analyse our experience with the challenging treatment of this rare tumor, to review current treatment modalities and to assess the outcome based on R status.

METHODS

Eight patients were treated in our institution between 2001 and 2011. All patients were discussed by a multidisciplinary tumor board, and an en bloc surgical resection by posterior perineal access only or by combined anterior/posterior accesses was planned based on tumor extension.

RESULTS

Seven patients underwent radical surgery, and one was treated by using local cryotherapy alone due to low performance status. Three misdiagnosed patients had primary surgery at another hospital with R1 margins. Reresection margins in our institution were R1 in two and R0 in one, and all three recurred. Four patients were primarily operated on at our institution and had en bloc surgery with R0 resection margins. One had local recurrence after 18 months. The overall morbidity rate was 86% (6/7 patients) and was mostly related to the perineal wound. Overall, 3 out of 7 resected patients were disease-free at a median follow-up of 2.9 years (range, 1.6-8.0 years).

CONCLUSION

Our experience confirms the importance of early correct diagnosis and of an R0 resection for a sacral chordoma invading pelvic structures. It is a rare disease that requires a challenging multidisciplinary treatment, which should ideally be performed in a tertiary referral center.

Prognostic Factors in the Operative Management of Dedifferentiated Sacral Chordomas

BACKGROUND:

Dedifferentiated chordomas are rare high-grade malignant spinal tumors for which there is minimal information to help guide treatment.

OBJECTIVE:

To identify prognostic factors associated with increased risk of local recurrence, metastases, and reduced survival in a cohort of patients undergoing sacrectomy for de novo dedifferentiated sacral chordoma.

METHODS:

Ten patients undergoing sacrectomy for histologically confirmed dedifferentiated chordoma at a specialist center were reviewed. There were 6 male and 4 female patients with a mean age of 66.7 years (range, 57-80 years) and mean follow-up of 36.7 months (range, 3-98 months). Data on prognostic factors were collected.

RESULTS:

The commonest presenting symptom was lumbar/gluteal pain. Mean duration of preoperative symptoms was 3.6 months (range, 2-7 months). Local recurrence was seen in 7 patients; metastases occurred in 5 patients. After sacrectomy, 7 patients died at a mean of 41 months (range, 3-98 months). Tumor size >10 cm in diameter, amount of dedifferentiation within the conventional chordoma, sacroiliac joint infiltration, and inadequate resection margins were associated with increased risk of recurrence and reduced survival. Surgical approach, cephalad extent of primary tumor, and adjuvant radiotherapy did not affect oncological outcomes.

CONCLUSION:

Dedifferentiated chordomas are aggressive malignant tumors with a higher risk of local recurrence, metastases, and early mortality than conventional chordomas. Tumor diameter >10 cm, marginal resection, and sacroiliac joint infiltration may be associated with increased risk of local recurrence and mortality. Those with a smaller burden of dedifferentiated disease (<1 cm2) within the primary chordoma have a better prognosis. Patients should be counseled about these risks before surgery and should have regular follow-up for the detection of local recurrence and metastases.

Randomized phase II trial of hypofractionated proton versus carbon ion radiation therapy in patients with sacrococcygeal chordoma-the ISAC trial protocol

Background

Chordomas are relatively rare lesions of the bones. About 30% occur in the sacrococcygeal region. Surgical resection is still the standard treatment. Due to the size, proximity to neurovascular structures and the complex anatomy of the pelvis, a complete resection with adequate safety margin is difficult to perform. A radical resection with safety margins often leads to the loss of bladder and rectal function as well as motoric/sensoric dysfunction. The recurrence rate after surgery alone is comparatively high, such that adjuvant radiation therapy is very important for improving local control rates. Proton therapy is still the international standard in the treatment of chordomas. High-LET beams such as carbon ions theoretically offer biologic advantages in slow-growing tumors. Data of a Japanese study of patients with unresectable sacral chordoma showed comparable high control rates after hypofractionated carbon ion therapy only.

Methods and design

This clinical study is a prospective randomized, monocentric phase II trial. Patients with histologically confirmed sacrococcygeal chordoma will be randomized to either proton or carbon ion radiation therapy stratified regarding the clinical target volume. Target volume delineation will be carried out based on CT and MRI data. In each arm the PTV will receive 64 GyE in 16 fractions. The primary objective of this trial is safety and feasibility of hypofractionated irradiation in patients with sacrococygeal chordoma using protons or carbon ions in raster scan technique for primary or additive treatment after R2 resection. The evaluation is therefore based on the proportion of treatments without Grade 3–5 toxicity (CTCAE, version 4.0) up to 12 months after treatment and/or discontinuation of the treatment for any reason as primary endpoint. Local-progression free survival, overall survival and quality of life will be analyzed as secondary end points.

Discussion

The aim of this study is to confirm the toxicity results of the Japanese data in raster scan technique and to compare it with the toxicity analysis of proton therapy given in the same fractionation. Using this data, a further randomized phase III trial is planned, comparing hypofractionated proton and carbon ion irradiation.

Trial registration

ClinicalTrials.gov Identifier: NCT01811394.

A review of the surgical management of sacral chordoma

BACKGROUND

Sacral chordomas are rare low-to-intermediate grade malignant tumours, which arise from remnants of the embryonic notochord. This review explores prognostic factors in the management of sacral chordomas and provides guidance on the optimal treatment regimens based on the current literature.

PATIENTS AND METHODS

Electronic searches were performed using MEDLINE, Embase and the Cochrane library to identify studies on prognostic factors in the management of sacral chordomas published between January 1970 and December 2013. The literature search and review process identified 100 articles that were included in the review article. This included both surgical and non-surgical studies on the management of sacral chordomas.

RESULTS

Sacrectomy with wide resection margins forms the mainstay of treatment but is associated with high risk of disease recurrence and reduced long-term survival. Adequate resection margins may require sacrifice of adjacent nerve roots, musculature and ligaments leading to functional compromise and mechanical instability. Large tumour size (greater than 5-10 cm in diameter), dedifferentiation and greater cephalad tumour extension are associated with increased risk of disease recurrence and reduced survival. Chordomas are poorly responsive to conventional radiotherapy and chemotherapy.

CONCLUSION

Operative resection with wide resection margins offers the best long-term prognosis. Inadequate resection margins, large tumour size, dedifferentiation, and greater cephalad chordoma extension are associated with poor oncological outcomes. Routine long-term follow-up is essential to enable early detection and treatment of recurrent disease.

Expression of PTEN and mTOR in sacral chordoma and association with poor prognosis

Sacral chordoma is an aggressive, locally invasive neoplasm, and has a poor prognosis. However, the molecular basis for the clinical behavior remains unknown. The purpose of this study was to investigate the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and mammalian target of rapamycin (mTOR) in sacral chordoma, and explore their roles in the prognosis. PTEN and mTOR were detected immunohistochemically in 40 sacral chordoma tissues and 10 adjacent normal tissues. Correlations between PTEN and mTOR expression and clinicopathological factors were analyzed. Kaplan-Meier survival curves and log-rank test were used to analyze the continuous disease-free survival time (CDFS). The expression of PTEN in sacral chordoma was significantly lower than that in adjacent normal tissues, while the levels of mTOR expression in sacral chordoma were significantly higher than that in adjacent normal tissues (P = 0.000, P = 0.030). The positive expression of mTOR appears to correlate with the negative expression of PTEN in sacral chordoma (P = 0.021). PTEN-negative expression and mTOR-positive expression were associated with tumor invasion into the surrounding muscles (P = 0.038, P = 0.014). Log-rank test showed that PTEN-negative and mTOR-positive expressions had an important impact on the patients' CDFS (P = 0.011, P = 0.015). Our results suggest that PTEN and mTOR might play an important role in the local invasiveness of sacral chordoma. PTEN and mTOR might be recognized as important prognostic predictors of recurrence and could be used as potential therapeutic targets for the treatment for sacral chordoma.

En bloc resection of sacral chordomas aided by frameless stereotactic image guidance: a technical note

BACKGROUND

The most important predictor of survival for patients with sacral chordomas is an initial en bloc resection with negative margins. However, obtaining negative margins can be technically challenging. Intraoperative navigation may be helpful in attempting an excision with negative margins.

OBJECTIVE

This is the first report of partial sacrectomy guided by frameless stereotactic navigation.

METHODS

Three patients with a mean age of 58.7 years underwent en bloc resection of sacral chordomas aided by image guidance. Intraoperatively, the reference arc was clamped to the spinous process of L5 and the bony landmarks of S1 were used for registration. Subsequently, the drill was registered, allowing the osteotomy trajectory to be visualized in real time with reference to the patients' anatomy and tumor location.

RESULTS

None of the patients had any intraoperative or postoperative complications. Two patients with smaller tumors (5 cm) had negative margins, whereas the third patient with an 11.5 cm tumor had marginal margins. With an average follow-up of 44 months, none of the patients have had a recurrence of the tumor.

CONCLUSION

The use of frameless stereotaxy during the en bloc resection of sacral tumors is safe and feasible. Frameless stereotactic navigation was a useful adjunct to preoperative imaging and to the surgeon's anatomic knowledge. Image guidance was used during the osteotomies to decrease the likelihood of injury to vital adjacent structures or violation of the tumor capsule and to increase the likelihood that the appropriate surrounding tissue was resected to attempt a wide or marginal resection.

Analysis of prognostic factors for patients with chordoma with use of the California Cancer Registry

BACKGROUND

Chordoma is the most common primary malignant tumor of the spine. It is extremely rare and has been studied primarily in single-institution case series. Using data from a large, population-based cancer registry, we designed the present study to examine the outcome for patients with chordoma and to determine relevant prognostic factors.

METHODS

A retrospective analysis of the California Cancer Registry database was performed to identify patients with a diagnosis of chordoma in the years 1989 to 2007. Comparisons examined differences in demographics, disease characteristics, treatment, and survival. Survival analyses were performed with use of the Kaplan-Meier method with log-rank tests and Cox proportional hazards models.

RESULTS

Four hundred and nine patients with chordoma were identified; 257 (62.8%) were male and 152 (37.2%) were female. With regard to racial or ethnic distribution, 266 patients (65%) were white; ninety-three (22.7%), Hispanic; forty-three (10.5%), Asian or other; and seven (1.7%), black. The site of presentation was the head in 202 patients (49.4%), spine in 106 patients (25.9%), and pelvis and/or sacrum in 101 patients (24.7%). Hispanic race (p = 0.0002), younger age (less than forty years; p < 0.0001), and female sex (p = 0.009) were associated with cranial presentation, whereas older age (forty years or older; p < 0.0001) was associated with pelvic presentation. After adjustment for clinically relevant factors, a significantly decreased risk of death for chordoma-specific survival was seen for Hispanic race (hazard ratio = 0.51, 95% confidence interval [95% CI], 0.28 to 0.93; p = 0.03), high socioeconomic status (hazard ratio = 0.8, 95% CI, 0.67 to 0.95; p = 0.01), and local excision and/or debulking (hazard ratio = 0.38, 95% CI, 0.18 to 0.81; p = 0.01). Large tumor size was independently associated with an increased risk of death (hazard ratio = 2.05, 95% CI, 1.01 to 4.20; p = 0.048).

CONCLUSIONS

In this study, the survival of patients with chordoma was significantly better for those who were Hispanic and had a small tumor, high socioeconomic status, and surgical intervention.

Wide resection of sacral chordoma via a posterior approach

PURPOSE

The study was carried out to report the results of wide resection in sacral chordoma using a posterior approach and gauze packing technique.

MATERIALS AND METHODS

The study was carried out between 1990 and 2002; there were 21 patients who underwent the operation. Fourteen patients were male and seven were female. Their ages ranged between 29 and 75 years. Most of the patients presented with sacral mass, pain and neurological deficit. Total sacrectomy and bone reconstruction were carried out in 12 patients. Subtotal sacrectomy was carried out in the remaining nine patients. All patients were followed up for at least seven years.

RESULTS

All survived after the operation. Operative time ranged between five and ten hours. All patients needed blood transfusion which ranged between four and 11 units. After the operation, all patients had a certain degree of bowel and bladder dysfunction. Five patients had local complications including infection in three patients with wound disruption and two patients with a seroma. During the follow-up, three patients (14%) had tumour recurrence and one of the patients expired. The remaining 18 patients were still tumour-free at the seven-year follow-up.

CONCLUSION

Wide resection via the posterior approach and gauze packing technique could be used for management of sacral chordoma with acceptable results.