The Indications for and the Prognostic Significance of Amputation as the Primary Surgical Procedure for Localized Soft Tissue Sarcoma of the Extremity

BACKGROUND

The indications for primary amputation of a localized soft tissue sarcoma (STS) of the extremity are not well defined in the literature. However, it has been suggested that patients who require an amputation to treat an STS are at increased risk for developing metastases. We categorized the main indications for primary amputation in our patient population and compared their oncological outcome with the outcome of patients who underwent limb-sparing surgery.

METHODS

413 consecutive patients treated surgically at a single center for primary, nonmetastatic, deep, intermediate-, or high-grade STS of the extremity were reviewed. Indications for primary amputation were identified. Demographics and outcomes were compared between the amputation and limb-salvage groups. Multivariate Cox model analysis was used to identify independent risk factors for systemic relapse.

RESULTS

Twenty-five (6%) of 413 patients with STS underwent primary amputation: they were older (P = .05), had larger tumors (P = .001), and had a significantly greater risk of developing metastatic disease than patients who underwent limb-sparing procedures (P = .008). However, multivariate analysis demonstrated that the only independent predictors of systemic relapse were tumor size (P = .0001) and tumor grade (P = .0001). Primary amputation was not an independent risk factor for metastatic disease.

CONCLUSIONS

The decision to perform a primary amputation for an STS of the extremity is based on the location and local extent of the tumor, and the expected function of the extremity after tumor resection. The higher risk of metastases for patients who require primary amputation is accounted for by independent risk factors associated with their tumors--predominantly large tumor size.

Radiation response: an additional unique signature of myxoid liposarcoma

PURPOSE

Historically, myxoid liposarcoma (MLS) has been reported to show a marked clinical response to radiotherapy (RT), but objective data to support that contention have been lacking. We performed a retrospective analysis of the response of a group of MLS tumors to preoperative RT using tumor dimensions calculated from pretreatment imaging and the subsequent surgical specimen obtained approximately 1 month after RT.

METHODS AND MATERIALS

Data were abstracted from the Princess Margaret Hospital prospective database on a series of patients with MLS who had undergone preoperative RT between 1991 and 1999. A group of malignant fibrous histiocytoma (MFH) patients treated on the same protocol served as controls. Pretreatment and posttreatment three-dimensional measurements were obtained; comparison tumor volume measurements were estimated using the ellipsoid formula, and the analysis was also repeated using the maximal tumor dimension. Identical measurement procedures were used for the MLS (experimental) and MFH (control) cases.

RESULTS

A total of 16 MLS tumor specimens were available for analysis, and 16 MFH cases were randomly chosen for comparison. The mean pretreatment and posttreatment volume of the MLS tumors was 415 and 199 cm(3), respectively (P = <0.0001). The mean pretreatment and posttreatment volume of the MFH tumors was 264 and 273 cm(3), respectively (p = 0.804). The proportional reduction in the median tumor volume was 59% and -7% for MLS and MFH tumors, respectively. Both the absolute and the proportional reduction in volume for MLS tumors vs. MFH tumors was statistically significant (p = 0.006 and p = 0.002, respectively).

CONCLUSION

These results provide the first objective data to support the idea that MLS tumors show a statistically significant reduction in size when treated with RT and that this response is greater than that of MFH tumors given the same RT. These results may be relevant to the management of MLS with combined RT and surgery in difficult anatomic situations in which adequate surgical excision is not feasible. They also confirm another unique characteristic of this unusual subtype of soft tissue sarcoma.

Functional outcome of endoprosthetic proximal femoral replacement

Endoprosthetic proximal femur replacement is a well-accepted method for treatment of primary bone tumors; however the functional results of treatment are not well documented. To evaluate functional outcomes, we recorded the Toronto Extremity Salvage Score and Musculoskeletal Tumor Society 1987 and 1993 scores in 29 patients, and also recorded Musculoskeletal Tumor Society scores alone in four more patients treated with endoprosthetic proximal femur replacement. The mean followup was 3 years. Twelve patients had a total hip endoprosthetic proximal femur replacement, and 21 had a bipolar hip endoprosthetic proximal femur replacement. In nine patients, the greater trochanter was attached to the femoral prosthesis. Sixteen patients had an abductor soft tissue repair, and in eight patients, no abductor repair was possible. The mean Musculoskeletal Tumor Society 1987 score was 23.2 +/- 4.1 points of 35 points. The mean Musculoskeletal Tumor Society 1993 score was 67.7 +/- 12.0%. The Toronto Extremity Salvage Score mean was 76.2 +/- 16.2 points of 100 points. Functional scores did not differ significantly between abductor repair types. There was a trend toward less disability in patients with abductor soft tissue repair compared with patients with no abductor repair. Functional results were similar in patients receiving bipolar and total hip replacements.

Lymph node metastasis in soft tissue sarcoma in an extremity

For patients with soft tissue sarcoma in an extremity, the outcome is thought to be poor if lymph node metastasis develops. The purpose of this study was to examine the impact of lymphatic involvement from soft tissue sarcoma on patient survival. Thirty-nine (3.7%) of 1066 patients who had surgery for soft tissue sarcoma in an extremity had lymph node metastases develop. Three (20%) of 15 patients with epithelioid sarcoma, four (19%) of 21 patients with rhabdomyosarcoma, two (11.1%) of 18 patients with clear cell sarcoma, and two (11.1%) of 18 patients with angiosarcoma had lymphatic involvement. Thirty patients who had resection of involved lymph nodes had an estimated 5-year survival of 57%, whereas nine patients treated without surgery all died within 30 months. An estimated 4-year survival of 71% for patients with isolated lymph node metastases was significantly better than 21% for patients with synchronous systemic and lymph node involvement. There was no difference in outcome for patients with isolated lymphatic involvement compared with patients with American Joint Committee on Cancer Stage III extremity sarcomas. These results suggest that long-term survival is possible after surgical resection of lymphatic metastases from soft tissue sarcoma. The American Joint Committee on Cancer should consider separating isolated nodal metastases from systemic involvement in patients with Stage IV sarcoma.

Action of hypoxanthine and meiosis-activating sterol on oocyte maturation in the mouse is strain specific

Follicular fluid meiosis-activating sterol (FF-MAS) is regarded as an important compound relevant to meiotic resumption in mammalian oocytes. The objective of this study was to investigate the influence of FF-MAS on germinal vesicle breakdown (GVBD) and first polar body (PBI) extrusion with regard to culture conditions, state of the oocyte and mouse strain. Denuded oocytes (DO) and cumulus-enclosed oocytes (CEO) were retrieved from PMSG-primed Quackenbush or C57BL/6J x DBA/2 (C57) mice and cultured for 20 h in alpha-MEM medium under the following conditions: (i) 250 micromol/l dibutyryl cAMP (dbcAMP) +/- EGF, 1 ng/ml or FF-MAS, 20 micromol/l; (ii) 4 mmol/l hypoxanthine (HX) +/- EGF or FF-MAS; (iii) HX + EGF + FF-MAS; and (iv) HX + FF-MAS 5 h priming and subsequent culture with HX + EGF. Oocyte GVBD and PBI emission were recorded and stained with Hoechst 33342. Very limited meiotic inhibition was observed in Quackenbush mice in comparison with C57 mice. FF-MAS promoted maturation in C57 DO and CEO and Quackenbush DO. In Quackenbush DO and CEO and C57 DO a significant increase in atypical PBI extrusion occurred, but not in C57 CEO as well as in EGF-treated Quackenbush CEO primed or co-cultured with FF-MAS. These results support a meiosis resumption function for FF-MAS and suggest that in its presence, the quality of the MII oocytes retrieved appears to be influenced by the strain of the mice, the state of the oocyte and the presence or absence of growth factors in the culture medium.

The influence of anatomic location on functional outcome in lower-extremity soft-tissue sarcoma

BACKGROUND

The purpose of this study was to explore the relationship between the anatomical location of lower-extremity soft-tissue sarcoma and functional outcome.

METHODS

Function was evaluated with the Musculoskeletal Tumor Society (MSTS 1993) score and Toronto Extremity Salvage Score (TESS); 207 patients (median age, 54 years) were eligible. The median maximum tumor diameter was 8.0 cm; 58 tumors were superficial and 149 were deep. Nine locations based on anatomical compartments were defined: 6 tumors were in the groin/femoral triangle; 8, the buttock; 52, the anterior thigh; 22, the medial thigh; 20, the posterior thigh; 10, the popliteal fossa; 13, the posterior calf; 11, the anterolateral leg; and 7, the foot or ankle.

RESULTS

Treatment of superficial tumors did not lead to significant changes in MSTS score (mean, 90.6% preoperatively vs. 93.0% postoperatively; P =.566) or TESS (mean, 86.4% preoperatively vs. 90.9% postoperatively; P =.059). Treatment of deep tumors lead to significant reductions in MSTS score and TESS (mean MSTS, 86.9% preoperatively vs. 83.0% postoperatively; P =.001; and mean TESS, 83.0% preoperatively vs. 79.4% postoperatively; P =.015). Anatomical location was not a significant predictor of aggregated MSTS and TESS evaluations. Exploratory analysis showed variation in MSTS pain and gait handicap or limp items and TESS dressing, sitting, bending, and bathing items by anatomical location.

CONCLUSIONS

The treatment of superficial tumors does not lead to significant changes in MSTS score or TESS. Anatomical location is not a significant predictor of aggregated MSTS and TESS evaluations. However, there is variation in MSTS and TESS item scores across anatomical locations.

Large segment allograft survival is improved with intramedullary cement

BACKGROUND AND OBJECTIVES

The most common cause of failure in large segment bone allografts used for oncologic reconstruction is allograft fracture. Reinforcement with pressurized intramedullary cement may improve the mechanical properties of allografts.

METHODS

We reviewed the prospectively collected records of 45 patients who underwent en bloc resection of an extremity bone tumor and reconstruction using an allograft with intramedullary cement.

RESULTS

Seven allografts were used for arthrodesis, 20 were intercalary, and 18 were osteochondral. Twenty eight of 45 patients were alive at a mean 5.8 years (SD 1.9; range 3-11.2) with 24 allografts in situ. In these 45 patients, there were four allograft fractures and four infections. Six of these complications resulted in allograft removal. The estimated 5-year allograft survival rate was 86% (95% confidence interval 74-98%). Seven patients required secondary autogenous bone grafting for non-unions. Function measured by the Toronto Extremity Salvage Score and the 1987 and 1993 Musculoskeletal Tumor Society Rating Scales demonstrated a consistent pattern with worse function in patients with osteochondral allografts and best function with intercalary allografts.

CONCLUSIONS

These results suggest the addition of intramedullary cement to large segment bone allografts improves their survival by decreasing the fracture risk, particularly for allografts used for arthrodesis and intercalary reconstructions.

Acetabular metastases: planning for reconstruction and review of results

The treatment of acetabular bone metastases presents numerous clinical challenges including the necessity for careful patient selection for surgery, determination of the extent of bone destruction, and providing the patient with stable surgical reconstruction of the pelvis. There are relatively few patient series reported in the literature to inform treatment planning, surgical reconstruction techniques, and patient outcomes. We describe a rationale for assessment of patients with acetabular metastases and options for reconstruction. The three general principles for surgical treatment of metastatic bone disease (tumor removal, filling of the resultant bone defect, and bypass of the defect) are defined for acetabular metastases. The results of surgical treatment are described with reference to recent articles in the literature. The reconstruction of acetabular metastatic disease is a major surgical procedure with a significant risk of complications. The surgeon must be certain that the patient's longevity and potential improvement in quality of life justify the risk of the operation.

Preoperative radiotherapy is effective in the treatment of fibromatosis

The use of preoperative radiation is well-established for soft tissue sarcoma, but its use in fibromatosis is not well-characterized. The purpose of this study was to examine the impact of preoperative radiotherapy on the local control of fibromatosis and to assess treatment-related morbidity in this setting. In particular we assessed complication rates in comparison with soft tissue sarcoma treatment. All patients with fibromatosis referred to this unit who received preoperative radiotherapy (50 Gy in 25 fractions) from 1988 to 2000 and who had at least 2 years of followup were included in this study. The rate of recurrence in this group was ascertained. Similarly constructed datasets from all patients with soft tissue sarcomas of the extremities who received preoperative radiation from 1986 to 1997 also were analyzed. The rates of complications in the two groups were compared. Fifty-eight patients were treated with preoperative radiation for fibromatosis and the median followup was 69 months. There were 11 local recurrences (19%). Major wound complications manifested in two patients (3.4%). Wound-related complications arose in 89 of 265 patients with soft tissue sarcomas (33.5%). There was a significant difference in the rate of major wound complications observed in the two groups. The use of radiotherapy before surgery is effective in the combined treatment of fibromatosis.

The influence of anatomic location on outcome in patients with soft tissue sarcoma of the extremity

BACKGROUND

The anatomic location of an extremity soft tissue sarcoma may influence the patient's presentation, management, and local and systemic recurrence rates. The objective of this study was to compare the presentation, management, and outcome of patients with soft tissue sarcomas of the upper extremity and the lower extremity.

METHODS

Prospectively collected data from patients who underwent limb-sparing surgery for extremity soft tissue sarcoma between January, 1986 and April, 1997 were analyzed. Local recurrence free rates and metastasis free rates were calculated using the method of Kaplan and Meier. Univariate and multivariate analyses of potential predictive factors were evaluated with the log-rank test and the Cox proportional hazards model.

RESULTS

Of 480 eligible patients, 48 patients (10.0%) had a local recurrence, and 131 patients (27.3%) developed distant metastasis. The median follow-up of survivors was 4.8 years (range, 0.1-12.9 years). Patients with upper extremity tumors had smaller lesions (6.0 cm vs. 9.3 cm; P < 0.001), more often underwent unplanned excision before referral (89 patients [64.0%] vs. 160 patients [46.9%]; P < 0.001), and less often received radiotherapy (98 patients [70.5%] vs. 289 patients [84.8%]; P < 0.001). The 5-year local recurrence free rate was 82% for patients with sarcomas of the upper extremity and 93% for patients with sarcomas of the lower extremity (P = 0.002). The 5-year metastasis free rate was 82% for patients with sarcomas of the upper extremity and 69% for patients with sarcomas of the lower extremity (P = 0.013).

CONCLUSIONS

Local recurrence was more frequent in patients who had sarcomas of the upper extremity compared with patients who had sarcomas of the lower extremity. Factors that contributed to this difference included histologic type, the use of radiotherapy, and local anatomy. Metastasis was more frequent among patients with sarcomas of the lower extremity, because those tumors tended to be large and deeper compared with upper extremity tumors.

Classification of positive margins after resection of soft-tissue sarcoma of the limb predicts the risk of local recurrence

We considered whether a positive margin occurring after resection of a soft-tissue sarcoma of a limb would affect the incidence of local recurrence. Patients with low-grade liposarcomas were expected to be a low-risk group as were those who had positive margins planned before surgery to preserve critical structures. Two groups, however, were expected to be at a higher risk, namely, patients who had undergone unplanned excision elsewhere with a positive margin on re-excision and those with unplanned positive margins occurring during primary resection. Of 566 patients in a prospective database, 87 with positive margins after limb-sparing surgery and adjuvant radiotherapy were grouped according to the clinical scenario by an observer blinded to the outcome. The rate of local recurrence differed significantly between the two low- (4.2% and 3.6%) and the two high-risk groups (31.6% and 37.5%). This classification therefore provides useful information about the incidence of local recurrence after positive-margin resection.

Instability after major tumor resection: prevention and treatment

Instability is a significant problem after resection of musculoskeletal tumors. In this article, the authors discuss the issue of instability after resections of the pelvis, the femur, and the proximal tibia. The options for reconstruction in each area are discussed along with a review of the literature and a description of the authors' preferred approach.

Pentyl-4-yn-valproic acid enhances both spatial and avoidance learning, and attenuates age-related NCAM-mediated neuroplastic decline within the rat medial temporal lobe

2-N-Pentyl-4-pentynoic acid [pentyl-4-yn-valproic acid (VPA)] is an analogue of valproic acid that induces neuritogenesis and increases neural cell adhesion molecule (NCAM) prevalence in cultured neural cells. As memory consolidation involves synapse growth, aided by cell adhesion molecule function, we determined whether or not pentyl-4-yn-VPA had cognition-enhancing properties. Pentyl-4-yn-VPA (16-85 mg/kg) significantly improved water maze learning and task retention when given prior to each training session. Acute administration of pentyl-4-yn-VPA also influenced memory consolidation processes as, when given at 3 h post-passive avoidance training, the amnesia induced by scopolamine given 6 h post-training was prevented in a dose-dependent manner. Chronic administration of pentyl-4-yn-VPA (16.8 or 50.4 mg/kg) also significantly reduced escape latencies in the water maze task, 24 h following the last drug administration. This improved spatial learning was accompanied by enhanced neuroplasticity as the expression of NCAM polysialylated neurons in the infragranular zone of the dentate gyrus and in layer II of the perirhinal and piriform cortex was increased significantly following chronic drug treatment. The cognition-enhancing qualities of pentyl-4-yn-VPA, combined with its ability to attenuate the age-related loss of the NCAM polysialylation state, suggest that it may effectively slow the onset of cognitive decline.

Comparison of two methods of reconstruction for primary malignant tumors at the knee: a sequential cohort study

BACKGROUND AND OBJECTIVES

The purpose of this study was to compare the complications and functional outcome associated with the use of an irradiated allograft-implant composite or a bone-ingrowth modular tumor prosthesis for replacement of the knee joint after resection of a bone sarcoma from the distal femur or proximal tibia.

METHODS

Eleven patients initially received an allograft reconstruction, followed by 64 treated with a tumor prosthesis. The primary analysis concerned reconstructive failure, defined by the requirement for removal of the original construct. Functional outcome was assessed by using the 1987 Musculoskeletal Tumor Society rating system.

RESULTS

Reconstructive failure occurred in 6 of 11 (55%) allograft constructs compared with 10 of 64 (16%) tumor prostheses (P = 0.009). Failures were due to infection (2 of 11 allografts versus 4 of 64 prostheses; P = 0.2) or mechanical complications (4 of 11 allograft fractures versus 5 of 64 broken prosthetic stems and 1 aseptically loose prosthesis; P = 0.03). The limb salvage rate was 95% (61 of 64) for patients with a tumor prosthesis compared with 64% (7 of 11) for those with an allograft (P = 0.007). Patients with a tumor prosthesis had a better functional outcome with a mean score of 75% compared with 57% for those with an allograft reconstruction (P = 0.006).

CONCLUSIONS

This comparative study suggests that limb salvage surgery at the knee has a better and more predictable outcome with a tumor prosthesis than with an allograft-implant reconstruction.

Structure and conformation of a novel genetically engineered polysaccharide P2

A new exocellular polysaccharide (P2) has been produced by the manipulation of a glycosyl transferase gene (aceP) involved in the biosynthesis of the polysaccharide acetan by the bacterium Acetobacter xylinum strain CKE5. The P2 polysaccharide has been studied by methylation analysis, reductive cleavage, and 1H and 13C NMR spectroscopy. The data are consistent with the structure predicted when the aceP gene is deactivated: [Molecular structure: see text]. The effect of cooling on proton NMR line width indicates a coil-helix transition in P2 at about 70 degrees C.

Asymmetric synthesis of functionalized carbocycles and heterocycles

Anions of 1-halo-4-hexenyl phosphonamides derived from chiral, enantiopure C2 symmetrical 1,2-diamino cyclohexane react at the gamma-position in conjugate addition reactions with alpha, beta-unsaturated carbonyl compounds such as cyclopentenone, 4-(H)-furanone, pyrroline-2-one, and cinnamates to give functionalized adducts. Addition to imines is also possible. The adducts can be transformed into enantiopure or enriched carbocyclic and heterocyclic compounds bearing useable functionality.