Benjamin D. Elder, Wataru Ishida, C. Rory Goodwin, Ali Bydon, Ziya L. Gokaslan, Daniel M. Sciubba, Jean-Paul Wolinsky, and Timothy F. Witham
With the advent of new adjunctive therapy, the overall survival of patients harboring spinal column tumors has improved. However, there is limited knowledge regarding the optimal bone graft options following resection of spinal column tumors, due to their relative rarity and because fusion outcomes in this cohort are affected by various factors, such as radiation therapy (RT) and chemotherapy. Furthermore, bone graft options are often limited following tumor resection because the use of local bone grafts and bone morphogenetic proteins (BMPs) are usually avoided in light of microscopic infiltration of tumors into local bone and potential carcinogenicity of BMP. The objective of this study was to review and meta-analyze the relevant clinical literature to provide further clinical insight regarding bone graft options.
A web-based MEDLINE search was conducted in accordance with preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines, which yielded 27 articles with 383 patients. Information on baseline characteristics, tumor histology, adjunctive treatments, reconstruction methods, bone graft options, fusion rates, and time to fusion were collected. Pooled fusion rates (PFRs) and I2 values were calculated in meta-analysis. Meta-regression analyses were also performed if each variable appeared to affect fusion outcomes. Furthermore, data on 272 individual patients were available, which were additionally reviewed and statistically analyzed.
Overall, fusion rates varied widely from 36.0% to 100.0% due to both inter- and intrastudy heterogeneity, with a PFR of 85.7% (I2 = 36.4). The studies in which cages were filled with morselized iliac crest autogenic bone graft (ICABG) and/or other bone graft options were used for anterior fusion showed a significantly higher PFR of 92.8, compared with the other studies (83.3%, p = 0.04). In per-patient analysis, anterior plus posterior fusion resulted in a higher fusion rate than anterior fusion only (98.8% vs 86.4%, p < 0.001). Although unmodifiable, RT (90.3% vs 98.6%, p = 0.03) and lumbosacral tumors (74.6% vs 97.9%, p < 0.001) were associated with lower fusion rates in univariate analysis. The mean time to fusion was 5.4 ± 1.4 months (range 3–9 months), whereas 16 of 272 patients died before the confirmation of solid fusion with a mean survival of 3.1 ± 2.1 months (range 0.5–6 months). The average time to fusion of patients who received RT and chemotherapy were significantly longer than those who did not receive these adjunctive treatments (RT: 6.1 months vs 4.3 months, p < 0.001; chemotherapy: 6.0 months vs 4.3 months, p = 0.02).
Due to inter- and intrastudy heterogeneity in patient, disease, fusion criteria, and treatment characteristics, the optimal surgical techniques and factors predictive of fusion remain unclear. Clearly, future prospective, randomized studies will be necessary to better understand the issues surrounding bone graft selection following resection of spinal column tumors.
Camilo Molina, C. Rory Goodwin, Nancy Abu-Bonsrah, Benjamin D. Elder, Rafael De la Garza Ramos, and Daniel M. Sciubba
Surgical interventions for spinal metastasis are commonly performed for mechanical stabilization, pain relief, preservation of neurological function, and local tumor reduction. Although multiple surgical approaches can be used for the treatment of metastatic spinal lesions, posterior approaches are commonly performed. In this study, the role of posterior surgical procedures in the treatment of spinal metastases was reviewed, including posterior laminectomy with and without instrumentation for stabilization, transpedicular corpectomy, and costotransversectomy. A review of the literature from 1980 to 2015 was performed using Medline, as was a review of the bibliographies of articles meeting preset inclusion criteria, to identify studies on the role of these posterior approaches among adults with spinal metastasis. Thirty-four articles were ultimately analyzed, including 1 randomized controlled trial, 6 prospective cohort studies, and 27 retrospective case reports and/or series. Some of the reviewed articles had Level II evidence indicating that laminectomy with stabilization can be recommended for improvement in neurological outcome and reduction of pain in selected patients. However, the use of laminectomy alone should be carefully considered. Additionally, transpedicular corpectomy and costotransversectomy can be recommended with the expectation of improving neurological outcomes and reducing pain in properly selected patients with spinal metastases. With improvements in the treatment paradigms for patients with spinal metastasis, as well as survival, surgical therapy will continue to play an important role in the management of spinal metastasis. While this review presents a window into determining the utility of posterior approaches, future prospective studies will provide essential data to better define the roles of the various options now available to surgeons in treating spinal metastases.
C. Rory Goodwin, Eric W. Sankey, Ann Liu, Benjamin D. Elder, Thomas Kosztowski, Sheng-Fu L. Lo, Charles G. Fisher, Michelle J. Clarke, Ziya L. Gokaslan, and Daniel M. Sciubba
Surgical procedures and/or adjuvant therapies are effective modalities for the treatment of symptomatic spinal metastases. However, clinical results specific to the skin cancer spinal metastasis cohort are generally lacking. The purpose of this study was to systematically review the literature for treatments, clinical outcomes, and survival following the diagnosis of a skin cancer spinal metastasis and evaluate prognostic factors in the context of spinal skin cancer metastases stratified by tumor subtype.
The authors performed a literature review using PubMed, Embase, CINAHL, and Web of Science to identify articles since 1950 that reported survival, clinical outcomes, and/or prognostic factors for the skin cancer patient population with spinal metastases. The methodological quality of reviews was assessed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) tool.
Sixty-five studies met the preset criteria and were included in the analysis. Of these studies, a total of 25, 40, 25, and 12 studies included patients who underwent some form of surgery, radiotherapy, chemotherapy, or observation alone, respectively. Sixty-three of the 65 included studies were retrospective in nature (Class of Evidence [CoE] IV), and the 2 prospective studies were CoE II. Based on the studies analyzed, the median overall survival for a patient with a spinal metastasis from a primary skin malignancy is 4.0 months; survival by tumor subtype is 12.5 months for patients with basal cell carcinoma (BCC), 4.0 months for those with melanoma, 4.0 months for those with squamous cell carcinoma, 3.0 months for those with pilomatrix carcinoma, and 1.5 months for those with Merkel cell carcinoma (p < 0.0001). The overall percentage of known continued disease progression after spine metastasis diagnosis was 40.1% (n = 244/608, range 25.0%–88.9%), the rate of known recurrence of the primary skin cancer lesion was 3.5% (n = 21/608, range 0.2%–100.0%), and the rate of known spine metastasis recurrence despite treatment for all skin malignancies was 2.8% (n = 17/608, range 0.0%–33.3%). Age greater than 65 years, sacral spinal involvement, presence of a neurological deficit, and nonambulatory status were associated with decreased survival in patients diagnosed with a primary skin cancer spinal metastasis. All other clinical or prognostic parameters were of low or insufficient strength.
Patients diagnosed with a primary skin cancer metastasis to the spine have poor overall survival with the exception of those with BCC. The median duration of survival for patients who received surgical intervention alone, medical management (chemotherapy and/or radiation) alone, or the combination of therapies was similar across interventions. Age, spinal region, and neurological status may be associated with poor survival following surgery.
Ann Liu, Eric W. Sankey, C. Rory Goodwin, Thomas A. Kosztowski, Benjamin D. Elder, Ali Bydon, Timothy F. Witham, Jean-Paul Wolinsky, Ziya L. Gokaslan, and Daniel M. Sciubba
Spinal metastases from gynecological cancers are rare, with few cases reported in the literature. In this study, the authors examine a series of patients with spinal metastases from gynecological cancer and review the literature.
The cases of 6 consecutive patients who underwent spine surgery for metastatic gynecological cancer between 2007 and 2012 at a single institution were retrospectively reviewed. The recorded demographic, operative, and postoperative factors were reviewed, and the functional outcomes were determined by change in Karnofsky Performance Scale and the American Spine Injury Association (ASIA) score during follow-up. A systematic review of the literature was also performed to evaluate outcomes for patients with similar gynecological metastases to the spine.
In this series, details regarding metastatic gynecological cancers to the spine are as follows: 2 patients with cervical cancer (both presented at age 46 years, mean postoperative survival of 32 months), 2 patients with endometrial cancer (mean age of 40 years, mean postoperative survival of 26 months), and 2 patients with leiomyosarcoma (mean age of 44 years, mean postoperative survival of 20 months). All patients presented with pain, and no complications were noted following surgery. All patients with known follow-up had stable or improved neurological outcomes, performance status, and improved pain, without local recurrence of tumor. Overall median survival after diagnosis of metastatic spine lesions for all cases in the literature as well as those treated by the authors was 15 months. When categorized by type, median survival of patients with cervical cancer (n = 2), endometrial cancer (n = 26), and leiomyosarcoma (n = 16) was 32, 10, and 22.5 months, respectively.
Gynecological cancers metastasizing to the spine are rare. In this series, overall survival following diagnosis of spinal metastasis and surgery was 27 months, with cervical cancer, endometrial cancer, and leiomyosarcoma survival being 32, 26, and 20 months, respectively. Combined with literature cases, survival differs depending on primary histology, with decreasing survival from cervical cancer (32 months) to leiomyosarcoma (22.5 months) to endometrial cancer (10 months). Integrating such information with other patient factors may more accurately guide decision making regarding management of such spinal lesions.
Varun Puvanesarajah, Sheng-fu Larry Lo, Nafi Aygun, Jason A. Liauw, Ignacio Jusué-Torres, Ioan A. Lina, Uri Hadelsberg, Benjamin D. Elder, Ali Bydon, Chetan Bettegowda, Daniel M. Sciubba, Jean-Paul Wolinsky, Daniele Rigamonti, Lawrence R. Kleinberg, Ziya L. Gokaslan, Timothy F. Witham, Kristin J. Redmond, and Michael Lim
The number of patients with spinal tumors is rapidly increasing; spinal metastases develop in more than 30% of cancer patients during the course of their illness. Such lesions can significantly decrease quality of life, often necessitating treatment. Stereotactic radiosurgery has effectively achieved local control and symptomatic relief for these patients. The authors determined prognostic factors that predicted pain palliation and report overall institutional outcomes after spine stereotactic body radiation therapy (SBRT).
Records of patients who had undergone treatment with SBRT for either primary spinal tumors or spinal metastases from June 2008 through June 2013 were retrospectively reviewed. Data were collected at the initial visit just before treatment and at 1-, 3-, 6-, and 12-month follow-up visits. Collected clinical data included Karnofsky Performance Scale scores, pain status, presence of neurological deficits, and prior radiation exposure at the level of interest. Radiation treatment plan parameters (dose, fractionation, and target coverage) were recorded. To determine the initial extent of epidural spinal cord compression (ESCC), the authors retrospectively reviewed MR images, assessed spinal instability according to the Bilsky scale, and evaluated lesion progression after treatment.
The study included 99 patients (mean age 60.4 years). The median survival time was 9.1 months (95% CI 6.9–17.2 months). Significant decreases in the proportion of patients reporting pain were observed at 3 months (p < 0.0001), 6 months (p = 0.0002), and 12 months (p = 0.0019) after treatment. Significant decreases in the number of patients reporting pain were also observed at the last follow-up visit (p = 0.00020) (median follow-up time 6.1 months, range 1.0–56.6 months). Univariate analyses revealed that significant predictors of persistent pain after intervention were initial ESCC grade, stratified by a Bilsky grade of 1c (p = 0.0058); initial American Spinal Injury Association grade of D (p = 0.011); initial Karnofsky Performance Scale score, stratified by a score of 80 (p = 0.002); the presence of multiple treated lesions (p = 0.044); and prior radiation at the site of interest (p < 0.0001). However, when multivariate analyses were performed on all variables with p values less than 0.05, the only predictor of pain at last follow-up visit was a prior history of radiation at the site of interest (p = 0.0038), although initial ESCC grade trended toward significance (p = 0.073). Using pain outcomes at 3 months, at this follow-up time point, pain could be predicted by receipt of radiation above a threshold biologically effective dose of 66.7 Gy.
Pain palliation occurs as early as 3 months after treatment; significant differences in pain reporting are also observed at 6 and 12 months. Pain palliation is limited for patients with spinal tumors with epidural extension that deforms the cord and for patients who have previously received radiation to the same site. Further investigation into the optimal dose and fractionation schedule are needed, but improved outcomes were observed in patients who received radiation at a biologically effective dose (with an a/b of 3.0) of 66.7 Gy or higher.