Cortical Atrophy Related to Tumor Prosthesis in Skeletally Immature Osteosarcoma Patients.

BACKGROUND: Cortical atrophy is commonly observed after prosthetic reconstruction for bone sarcomas. However, relevant literature regarding this phenomenon in skeletally immature patients is limited. Therefore, in this study, we evaluated the incidence and patterns of cortical atrophy. We then assessed its predisposing factors. Finally, we analyzed whether cortical atrophy was associated with poor prosthesis survival. METHODS: We retrospectively reviewed 31 stems in 19 skeletally immature osteosarcoma patients who were treated with resection and tumor prosthesis surgery. We measured the cortical thickness using plain radiographs annually. The mean patient age was 11 years (range, 6 to 14 y) and the mean follow-up period was 10 years (range, 2 to 14 y). RESULTS: Cortical atrophy developed in 13 stems, all within 3 years. There were 3 gross types of cortical atrophy: hourglass in 5, sharpening in 4, and shortening atrophy in 4. On multivariate analysis, stem-cortex diameter ratio of ≥0.5 and age of less than 10 years were significantly associated with cortical atrophy (P=0.002 and P=0.019, respectively). Cortical atrophy was significantly associated with eventual prosthesis failure (9/13 in the cortical atrophy group vs. 4/18 in the nonatrophy group, P=0.035). CONCLUSIONS: Cortical atrophy is common in the skeletally immature patients with tumor prosthesis and is associated with prosthesis failure. Patients with cortical atrophy should be closely monitored for prosthesis failure and appropriately managed to prevent failures. LEVEL OF EVIDENCE: Level IV-therapeutic study.

Influence of Musculoskeletal Manifestations as the Only Presenting Symptom in B-Cell Acute Lymphoblastic Leukemia.

OBJECTIVE: To evaluate the clinical and prognostic impact of musculoskeletal manifestations as the only initial presenting symptom in childhood acute lymphoblastic leukemia (ALL). STUDY DESIGN: We retrospectively reviewed 158 children with precursor B-cell type ALL who were followed up for >2 years. The patients were assigned to the groups musculoskeletal manifestations (n = 24) or nonmusculoskeletal manifestations (n = 134) based on initial presenting symptom. The symptom duration (regarding any initial presenting symptom) and the leukemic symptom duration (regarding symptoms of systemic manifestation, such as fever, bleeding, or pallor) were assessed, along with other clinical characteristics. RESULTS: The musculoskeletal manifestations group exhibited a longer symptom duration than the nonmusculoskeletal manifestations group (43 days vs 22 days, P = .006), but overall survival did not significantly differ between the groups. Multivariate analysis indicated that a longer symptom duration did not affect prognosis but that a longer leukemic symptom duration was associated with a poorer prognosis (hazard ratio, 7.720; P = .048). CONCLUSION: Musculoskeletal manifestations are associated significantly with diagnostic delay, but this delay does not affect the prognosis. Diagnostic delay after the onset of leukemic symptoms, however, does appear to affect the prognosis. Intensive evaluations for hematologic malignancies may be unnecessary in children who complain of limb pain without any definite cause, unless they also present with accompanying leukemic symptoms.

Outcomes of Hemiepiphyseal Stapling for Genu Valgum Deformities in Patients With Multiple Hereditary Exostoses: A Comparative Study of Patients With Deformities of Idiopathic Cause.

BACKGROUND: Patients with multiple hereditary exostoses (MHE) frequently present with a genu valgum deformity. Temporary hemiepiphysiodesis, such as hemiepiphyseal stapling, is a relatively safe surgical method to correct angular deformities in skeletally immature patients, but its outcomes for genu valgum deformity in MHE patients have not been extensively reported. We investigated the outcomes of hemiepiphyseal stapling in MHE patients (MHE group) and compared those with the outcomes in patients with idiopathic deformities (idiopathic group) after adjusting for potential bias. METHODS: Data from 70 limbs with genu valgum deformity (15 MHE and 55 idiopathic), which had undergone hemiepiphyseal stapling, were retrospectively reviewed. The outcomes were focused on the achievement of satisfactory correction and the velocity of correction. The independent effects of each characteristic on each outcome were investigated using multivariate analyses. The outcomes between the groups were also compared after 1:2 matching using propensity score analysis. RESULTS: The mean valgus angle of the MHE group was 7.4±4.1 degrees at stapling and was corrected to 1.3±3.0 degrees at staple removal. The rate of satisfactory corrections was not different between the MHE and idiopathic groups (67% and 70%, respectively, P=0.820). However, the correction velocity was significantly lower in the MHE group than in the idiopathic group on both multivariate analysis (P=0.001) and matching comparison (4.4 vs. 7.9 degrees/y, P<0.001). The duration of correction was longer in the MHE group than in the idiopathic group by approximately half a year (1.5±0.6 vs. 0.9±0.3 y, respectively, P=0.003). CONCLUSIONS: In MHE patients with genu valgum deformity, satisfactory correction can be achieved by hemiepiphyseal stapling and is comparable with that seen in idiopathic patients. However, the MHE group showed lower correction velocity and required a longer time by about one half year for correction compared with the idiopathic group. Temporary hemiepiphysiodesis should be considered at an earlier age for patients with MHE compared with those with idiopathic deformity. LEVEL OF EVIDENCE: Level III-prognostic study.

Cross-cultural adaptation and validation of the Korean Toronto Extremity Salvage Score for extremity sarcoma.

BACKGROUND: A Korean version of Toronto Extremity Salvage Score (TESS), a widely used disease-specific patient-reported questionnaire for assessing physical function of sarcoma patients, has not been developed. OBJECTIVES: 1) to translate and cross-culturally adapt the TESS into Korean, and 2) to examine its comprehensibility, reliability and validity. METHODS: TESS was translated into Korean, then translated back into English, and reviewed by a committee to develop the consensus version of the Korean TESS. The Korean TESS was administered to 126 patients to examine its comprehensibility, reliability, and validity. RESULTS: Comprehensibility was high, as the patients rated questions as "easy" or "very easy" in 96% for the TESS lower extremity (LE) and in 97% for the TESS upper extremity (UE). Test-retest reliability with intraclass coefficient (0.874 for LE and 0.979 for UE) and internal consistency with Cronbach's alpha (0.978 for LE and 0.989 for UE) were excellent. Korean TESS correlated with the MSTS score (r = 0.772 for LE and r = 0.635 for UE), and physical functioning domain of EORTC-CLQ C30 (r = 0.840 for LE and r = 0.630 for UE). CONCLUSION: Our study suggests that Korean version of the TESS is a comprehensible, reliable, and valid instrument to measure patient-reported functional outcome in patients with extremity sarcoma.

Soft tissue sarcoma misdiagnosed as benign peripheral neurogenic tumor.

BACKGROUND: Because of the distinctive clinical and MR findings associated with benign peripheral neurogenic tumors (BPNTs), they are commonly diagnosed without histological confirmation. As such, they are one of the most frequently misdiagnosed entities among the soft tissue sarcomas (STSs) that undergo initial unplanned excision. In this study, we investigate the characteristics of STSs misdiagnosed as BPNTs. METHODS: We present a series of nine STS patients with an initial preoperative diagnosis of BPNT (BPNT-STS), and compare their clinical and MR findings to those of the 18 genuine BPNT patients, matched for site, depth, and size of tumors as well as related nerves. RESULTS: Among the nine BPNT-STS cases, the most common histological diagnosis was synovial sarcoma (n = 4). Six patients (67 %) had deep-seated tumors; four patients (44 %) had tumors 5 cm or greater in size. BPNT-STS patients were more likely to experience pain (78 % vs. 22 %) and shorter symptom duration (9 vs. 55 months) compared to BPNT patients. A target sign on MR imaging was observed only in BPNT patients (0 % vs. 50 %), whereas peritumoral edema was found only in BPNT-STS patients (33 % vs. 0 %). CONCLUSIONS: If a tumor suggestive of a BPNT is painful, with a relatively short symptom duration, and presents with peritumoral edema without a definite target sign on MR images, the possibility of an STS must be considered.

Non-spine bone metastasis as an initial manifestation of cancer in Korea.

Non-spine bone metastasis accounts for approximately 20% of all skeletal metastases, but little data have been published that focused on bone metastasis to the pelvis and extremities as an initial manifestation of cancer. We determined 1) clinicopathologic characteristics of patients who presented with non-spine bone metastasis of unknown primary malignancy, and 2) process by which the diagnosis of primary cancer was made. We retrospectively reviewed 84 patients with bone metastasis of unknown primary cancer site at the time of presentation. The study population consisted of 56 men and 28 women, with a mean age of 59.1 yr (17.5-85.6 yr). The average follow-up period was 20.8 months (1-120 mo). Primary cancer site was identified in 79 patients (94.0%), and was determined to be the lung (46.4%), kidney (13.1%), liver (9.5%), thyroid (8.3%), and prostate (4.8%). Five-year overall survival rate was 28.0%. Multiple bone metastases, distant organ metastasis, and multiple bone with organ metastases were the significant prognostic factors in univariate analysis. Multiple bone metastases remained significant after multivariate analysis (P = 0.008). Lung cancer is the most common site of primary cancer, and patients with multiple bone metastases have a poor prognosis, possibly due to disseminated cancer and a greater tumor burden.

Pseudonormalization of negative T wave during stress test in asymptomatic patients without ischemic heart disease: a clue to apical hypertrophic cardiomyopathy?.

INTRODUCTION: Generally, apical hypertrophic cardiomyopathy (ApHCM) shows a negative T wave on an electrocardiogram (ECG), which waxes and wanes during the clinical course. However, some patients with ApHCM just have negative T waves and show no obvious diagnostic evidence on their echocardiography, so the diagnosis of ApHCM cannot be confirmed or is delayed for several years in many cases. CASE REPORT: In our study, 2 males in their 50s showed negative T waves on their ECG precordial leads, but no diagnosis was confirmed for over 10 years, despite all efforts. Both patients showed pseudonormalization of the negative T wave during a stress test using a treadmill and dobutamine. They were finally diagnosed with ApHCM confirmed by cardiac magnetic resonance (MR). DISCUSSION: Pseudonormalization of the negative T wave during a stress test is a quite rare phenomenon, particularly in the general population, and cardiac MR is very costly and inaccessible. Thus, when such an ECG pattern is observed without evidence of other pathology, the possibility of ApHCM should be kept in mind and the performance of cardiac MR may be considered. Furthermore, this pseudonormalization pattern could also be one possible explanation for the waxing and waning of the negative T wave during the course of ApHCM.

Asymptomatic brain lesions in pilots: a comparative study with non-flying personnel using brain MRI.

INTRODUCTION: As modern aircraft fly at higher altitudes with rapid velocity, pilots have been put in the environment with a possible increasing risk of brain injury and could sustain cumulative brain damage. However, very few studies have investigated brain lesions using MRI in asymptomatic pilots. We evaluated asymptomatic pilots for the presence of cerebral lesions using MRI. METHODS: Enrolled were 31 healthy pilots of the Republic of Korea Air Force (ROKAF) on active flight duty and 31 healthy nonflying ROKAF personnel with ages of or over 45. We checked for the presence of acute and/or chronic medical conditions, smoking habits, alcohol intake, blood pressure, blood tests including lipid panel, glucose, and liver panel, aircraft type, flight hours, flight altitude, and white matter hyperintensities (WMH) on brain MRI. RESULT: The mean age of both groups was 51.2 yr and the mean total flight hours of the pilots was 3025.0 h. There was no statistical difference between the pilots and non-flying personnel for WMH findings (54.8%/ vs. 32.3%). Of the factors related to flight, only the flying altitude (OR 1.005) was significantly related to the presence of WMH on multivariate analysis. Glucose levels and cholesterol levels were also related to WMH. DISCUSSION: Despite our negative results, there could be the possibility of cumulative brain damage in asymptomatic pilots considering the positive effect of altitude and the positive trend of pilots for the presence of WMH. Additional investigations are surely needed.

Measuring the cumulative effect of G force on aviator neck pain.

INTRODUCTION: In many studies, high G force is thought to be the most important causal factor of aviator neck pain. However, most of the studies performed to date have compared neck pain of aviators exposed to high G force with that of aviators not so exposed or with that of the general population. As a result, neck pain for aviators exposed to high G force as it relates to G level is not yet well-known. METHODS: The subjects were 1003 male aviators who were sent an anonymous questionnaire. Subject variables were information on physical characteristics, lifestyle, and flight characteristics, including information about exposed maximum G (Gmax). There were three dependent variables: whether the aviator had experienced neck pain, frequency of neck pain, and subjective severity of neck pain. RESULT: With the multivariate analysis, amount of Gmax exposure (frequency or monthly duration of Gmax exposure) had a statistically significant positive relationship with all three dependent variable. BMI, flight hours in current aircraft, and posterior seat type had a meaningful positive relationship with experience of neck pain and subjective severity of neck pain. Other characteristics, including Gmax level, were not significantly related with any dependent variables. DISCUSSION: These results suggest that G level could have a ceiling effect; in other words, above a certain G level, aviator neck pain risk does not increase. This means that amount of Gmax exposure becomes more influential on aviator neck pain than the level of Gmax.

Physical Condition Does Not Affect Gravity-Induced Loss of Consciousness during Human Centrifuge Training in Well-Experienced Young Aviators.

BACKGROUND: Consensus on whether physical condition affects the risk of gravity-induced loss of consciousness (G-LOC) has not been reached, and most previous studies about the issue did not include well-experienced aviators. We compared the physical conditions of well-experienced young aviators according to the occurrence of G-LOC during human centrifuge training. METHODS: Among 361 young male aviators on active flight duty with experience in high performance aircrafts for at least 2 years, 350 had full data available and were reviewed in this study. We divided the aviators into the G-LOC group and the non-G-LOC group according to their human centrifuge training results. We then compared their basic characteristics, body composition, physical fitness level, and pulmonary function. RESULTS: Twenty nine aviators (8.3%) who experienced G-LOC during human centrifuge training in their first trials were classified into the G-LOC group. There was no difference in physical condition of aviators between the two groups. CONCLUSIONS: Young aviators with experience in G-LOC showed no difference in physical condition such as muscle mass, strength, and general endurance from the aviators with no such experience. Although more studies are needed, physical condition does not seem to be a significant determinant of G-LOC among the experienced aviators.

Lateral Tibiocalcaneal Angle As a Determinant for Percutaneous Achilles Tenotomy for Idiopathic Clubfeet.

BACKGROUND: The aim of the present study was to evaluate the clinical value of using the lateral tibiocalcaneal (LTiC) angle, measured on a lateral radiograph made with the foot and ankle in maximal dorsiflexion, instead of the ankle dorsiflexion (ADF) angle, measured on physical examination, as a determining indicator of the need for percutaneous Achilles tenotomy after Ponseti serial cast treatment of idiopathic clubfoot. METHODS: We identified patients with idiopathic clubfoot who had been treated at our institution between March 2006 and June 2012. After exclusion of patients with Diméglio grade-I clubfoot and those followed for less than two years, 125 idiopathic clubfeet were evaluated. The clubfeet were grouped according to their LTiC and ADF angles, after which we evaluated the clinical outcomes of each group and investigated the prognostic effects of each angle-based decision regarding whether to perform percutaneous Achilles tenotomy. RESULTS: Patients with a favorable LTiC angle (≤80°) showed no sagittal relapse even though none underwent percutaneous Achilles tenotomy. In contrast, patients with an unfavorable LTiC angle (>80°) had a high chance of sagittal relapse if percutaneous Achilles tenotomy had not been performed, even when they had a favorable ADF angle (≥15°). The LTiC-angle-based decision showed the most significant prognostic value in multivariate analyses of relapse-free and surgery-free survival rates. CONCLUSIONS: The LTiC angle measured on simple radiographs is a more objective and prognostic indicator of the need for percutaneous Achilles tenotomy, as compared with the ADF angle measured on physical examination, in patients with idiopathic clubfoot. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Predisposing Effect of Elbow Alignment on the Elbow Fracture Type in Children.

OBJECTIVES: Under the hypothesis that the elbow alignment, namely the carrying angle, could predispose individuals to a specific type of pediatric elbow fracture after a fall onto an outstretched arm, we investigated the relationship between radiographic carrying angle and elbow fracture type in children. DESIGN: Retrospective case-control study. SETTING: Level I pediatric trauma center. PATIENTS/PARTICIPANTS: We reviewed 374 children who were diagnosed with supracondylar fracture (SCF, n = 208), lateral condylar fracture (LCF, n = 132), and radial neck fracture (RNF, n = 34). INTERVENTION: The association between the radiographic carrying angle and the fracture type was investigated. MAIN OUTCOME MEASUREMENTS: To adjust for bias, 2 statistical methods were used: multivariate analysis using a baseline-category logistic model and a case-matching method using propensity score analysis. RESULTS: In the multivariate analysis, with SCF patients set as the baseline category, a more valgus-deviated elbow (increased carrying angle, P = 0.011) predisposed individuals to RNF, whereas a more varus-deviated elbow (decreased carrying angle, P < 0.001) predisposed them to LCF. In the case-matched analysis, there were also significant differences in carrying angles between RNF and case-matched SCF patients (14.3 vs. 11.4 degrees, P = 0.013) and between LCF and case-matched SCF patients (7.7 vs. 11.7 degrees, P < 0.001). CONCLUSIONS: Elbow alignment, which may influence the transmission of traumatic force during a fall onto an outstretched elbow, could be a predisposing factor for specific types of pediatric elbow fracture. The results provide the additional information about the injury mechanisms of pediatric elbow fracture and may deepen our understanding of the fractures. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Unplanned Excision of Extremity Soft Tissue Sarcoma in Korea: A Nationwide Study Based on a Claims Registry.

Unplanned excision of extremity soft tissue sarcoma (STS) is common and has detrimental effects not only on patients' oncologic outcomes but also on functional and economic issues. However, no study has analyzed a nationwide population-based database. To estimate the incidence and treatment pattern of unplanned excision in extremity STS in the Korean population, a nationwide epidemiologic study was performed using the Korean Health Insurance Review and Assessment Service database, a centralized nationwide healthcare claims registry of Korea that covers the entire Korean population. Among 1,517 patients with extremity STS in the 4-year study period, 553 (36.5%) underwent unplanned excision (unplanned group). About 80% of unplanned excisions were performed in tertiary or general hospitals. Of the unplanned group, 240 (43.4%) underwent re-excision with or without radiation therapy and/or chemotherapy, and 51 (9.2%) did not undergo re-excision but were treated with radiation therapy and/or chemotherapy; whereas, 262 (47.4%) did not undergo any further treatment following unplanned excision. This study is the first nationwide population-based study on the unplanned excision of extremity STS. The results may have implications in establishing preventive or therapeutic measures to reduce the burden of unplanned excision of extremity STS.

Acute spinal injury after centrifuge training in asymptomatic fighter pilots.

INTRODUCTION: Many countries have hypergravity training centers using centrifuges for pilots to cope with a high gravity (G) environment. The high G training carries potential risk for the development of spinal injury. However, no studies evaluated the influence of centrifuge training on the spines of asymptomatic fighter pilots on a large scale. METHODS: Study subjects were 991 male fighter pilots with high G training at one institution. Subject variables included information about physical characteristics, flight hours of pilots prior to the training, and G force exposure related factors during training. The two dependent variables were whether the pilots developed acute spinal injury after training and the severity of the injury (major/minor). RESULTS: The incidence of acute spinal injury after high G training was 2.3% (23 of 991 subjects). There were 19 subjects who developed minor injury and 4 subjects who developed a herniated intervertebral disc, which is considered a major injury. In multivariate analysis, only the magnitude of G force during training was significantly related to the development of acute spinal injury. However, there was no significant factor related to the severity of the injury. DISCUSSION: These results suggest that high G training could cause negative effects on fighter pilots' spines. The magnitude of G force during training seemed to be the most significant factor affecting the occurrence of acute spinal injury.

Incidence and Treatment Pattern of Extremity Soft Tissue Sarcoma in Korea, 2009-2011: A Nationwide Study Based on the Health Insurance Review and Assessment Service Database.

PURPOSE: We conducted a nationwide study to assess the incidence and treatment patterns of extremity soft tissue sarcoma (STS) in South Korea. MATERIALS AND METHODS: The nationwide incidence and treatment patterns of extremity STS were assessed using two nationwide databases, the Korea National Cancer Incidence (KNCI) database and the Health Insurance Review and Assessment Service (HIRA) database. RESULTS: A total of 1,236 patients were newly diagnosed with extremity STS during the 3-year study period, from 2009 to 2011. The annual incidence of extremity STS in the Korean population was approximately 0.9 per 100,000 people with a male bias that increased with age and was especially pronounced amongst individuals aged > 80 years. Approximately 7% of patients did not receive any treatment, and surgical excision was performed for 85% of those who were treated. CONCLUSION: This is the first nationwide study of the incidence and treatment patterns of extremity STS in Korea using two national databases (KNCI and HIRA), which include the entire Korean population. The results of this study may be useful for future planning and management of STS, at the national level.

Outcomes of curettage and anhydrous alcohol adjuvant for low-grade chondrosarcoma of long bone.

BACKGROUND: Low-grade chondrosarcoma of long bones can be treated successfully with extended intralesional curettage using adjuvants. However, there is no study reporting the use of anhydrous alcohol as an adjuvant in the treatment of low-grade chondrosarcoma. We asked (1) whether intralesional curettage and anhydrous alcohol adjuvant for low-grade chondrosarcoma is associated with good oncologic outcomes; and we report (2) the complications of the procedure. METHODS: Thirty-six patients (13 men, 23 women) with a mean age of 46 years (range, 18-67 years) were treated for low-grade chondrosarcoma and followed up for a median of 62 months (range, 24-169 months). After intralesional curettage, and additional burring, anhydrous alcohol was used as an adjuvant therapy. RESULTS: At the time of last follow-up, there were no local recurrences or distant metastases. Six patients developed complications: 4 postoperative fractures (11%), 1 intra-articular loose body (3%) and 1 postoperative joint stiffness (3%). CONCLUSION: Anhydrous alcohol is a reasonable adjuvant for the curettage of low-grade chondrosarcoma of long bones. A long-term follow-up study is necessary, considering the slow biological progression of low-grade chondrosarcoma.

Comorbidity is independently associated with poor outcome in extremity soft tissue sarcoma.

BACKGROUND: Comorbidity has not been examined as an independent prognostic factor in soft tissue sarcoma (STS). We examined the prognostic impact of comorbidity on oncologic outcome in STS with an adjustment for possible confounding factors. METHODS: A retrospective review was performed on 349 patients who had undergone surgery for high-grade localized STS of extremity at our institute. Conditions known to alter the risk of mortality, as defined in the Charlson comorbidity index, were classified as comorbidities and 43 patients (12%) had at least one comorbidity at the time of surgery. The association of comorbidity and oncologic outcomes of local recurrence-free survival (LRFS) and disease-specific survival (DSS) were tested with adjustment for confounding factors. RESULTS: Comorbidity was associated with old age, high tumor grade, and large tumor size. The presence of comorbidity was independently associated with poor LRFS and DSS, even after adjusting for confounding factors including age and treatment variables. CONCLUSIONS: Our data suggest that the presence of comorbidity is an independent prognostic factor for extremity STS.

Preoperative embolization for bone metastasis from hepatocellular carcinoma.

Preoperative transcatheter arterial embolization for hypervascular bone tumors is now widely accepted as a safe and effective procedure for reducing intraoperative blood loss and surgical morbidity. However, few studies have reported the use of preoperative transcatheter arterial embolization for nonspine bone metastases from hepatocellular carcinoma. The goal of this study was to assess the effect of preoperative embolization on blood loss and clinical outcomes in surgery for nonspine bone metastasis from hepatocellular carcinoma. Seventy-five patients with metastases from hepatocellular carcinoma to the pelvis and extremities were reviewed retrospectively. The study population consisted of 62 men and 13 women, with a mean age of 64.6 years (range, 40.0-80.1). The average follow-up period was 8.2 months (range, 0.3-66.1). Twenty-two patients underwent transcatheter arterial embolization for preoperative devascularization (group A), and 53 patients underwent operative treatment only (group B). The proportion of pelvis metastases was significantly higher (P<.001) and operative time was longer (P=.006) in group A than in group B. However, a significantly smaller decrease in hemoglobin level before and after surgery was seen in group A (P=.017). No significant differences were seen in intraoperative estimated blood loss, perioperative hemoglobin level, number of allogeneic transfusions, or length of hospitalization between the 2 groups. Preoperative transcatheter arterial embolization is an effective means to reduce bleeding during surgery for nonspine metastases from hepatocellular carcinoma. In general, surgical procedures that included transcatheter arterial embolization took longer and were more extensive.

Post-metastasis survival in extremity soft tissue sarcoma: a recursive partitioning analysis of prognostic factors.

BACKGROUND: Recursive partitioning analysis (RPA) enables grouping of patients into homogeneous prognostic groups in a visually intuitive form and has the capacity to account for complex interactions among prognostic variables. In this study, we employed RPA to generate a prognostic model for extremity soft tissue sarcoma (STS) patients with metastatic disease. METHODS: A retrospective review was conducted on 135 patients with metastatic STS who had undergone surgical removal of their primary tumours. Patient and tumour variables along with the performance of metastasectomy were analysed for possible prognostic effect on post-metastatic survival. Significant prognostic factors on multivariate analysis were incorporated into RPA to build regression trees for the prediction of post-metastatic survival. RESULTS: RPA identified six terminal nodes based on histological grade, performance of metastasectomy and disease-free interval (DFI). Based on the median survival time of the terminal nodes, four prognostic groups with significantly different post-metastatic survival were generated: (1) group A: low grade/metastasectomy; (2) group B: low grade/no metastasectomy/DFI ⩾ 12 months or high grade/metastasectomy; (3) group C: low grade/no metastasectomy/DFI < 12 months or high grade/no metastasectomy/DFI ⩾ 12 months; and (4) group D: high grade/no metastasectomy/DFI < 12 months. The 3-year survival rates for each group were: group A, 76.1 ± 9.6%; group B, 42.3 ± 10.3%; group C, 18.8 ± 8.0%; and group D, 0.0 ± 0.0%. CONCLUSION: Our prognostic model using RPA successfully divides STS patients with metastasis into groups that can be easily implemented using standard clinical parameters.