Undifferentiated Sarcomatoid Carcinoma of the Pancreas: From Histology and Molecular Pathology to Precision Oncology.

Undifferentiated sarcomatoid carcinoma of the pancreas (SCP) is a rare and aggressive subtype of pancreatic cancer. Histologically, SCP is a poorly differentiated tumor characterized by the lack of glandular differentiation and the presence of mesenchymal-like, spindle-shaped tumor cells. Due to its rarity, only sporadic cases have been reported, while its molecular characterization has not been sufficiently described. Surgical resection with curative intent is the gold-standard of SCP management, but this strategy is possible only in a small proportion of cases due to SCP early metastasization. Although SCP is generally associated with a poor prognosis, some clinical cases amenable to surgical resection and followed by adjuvant chemotherapy have demonstrated a remarkably long survival. Preliminary molecular insights on the SCP molecular landscape have demonstrated the recurrent presence of KRAS and TP53 mutations, highlighting genetic similarities with conventional pancreatic ductal adenocarcinoma (PDAC). Although the use of immunotherapy in PDAC remains an unmet challenge, recent insights indicated a potentially significant role of the PD-L1/Notch3 axis in SCP, opening new horizons for immunotherapy in this cancer subtype. In this review, we described the most important clinic-pathologic features of SCP, with a specific focus on their molecular landscape and the potential targets for precision oncology.

Clinical Impact of Nutritional Status and Sarcopenia in Pediatric Patients with Bone and Soft Tissue Sarcomas: A Pilot Retrospective Study (SarcoPed).

BACKGROUND: We evaluated nutritional and sarcopenia status and their clinical impact in pediatric patients affected by bone and soft tissue sarcomas. METHODS: Body mass index (BMI), prognostic nutritional index (PNI), and total psoas muscle area (tPMA) at diagnosis and after 12 months were analyzed. tPMA was measured from single cross-sectional computed tomography (CT) images at L4-L5. Age-specific and sex-specific tPMA Z-scores were retrieved from an online calculator. RESULTS: A total of 21 patients were identified between February 2013 and December 2018. Twelve patients (57.1%) experienced sarcopenia at diagnosis, although not statistically associated with overall survival (OS) (p = 0.09). BMI Z-score, PNI, and tPMA Z-score significantly decreased between diagnosis and after 12 months of treatment (p < 0.05). Univariate analysis showed significant associations between poor OS and the presence of metastasis (p = 0.008), the absence of surgery (p = 0.005), PNI decrease (p = 0.027), and the reduction in tPMA > 25% (p = 0.042) over the 12 months. CONCLUSIONS: Sarcopenia affects more than half of the patients at diagnosis. Decreased PNI during 12 months of treatment has significant predictive value for OS. The role of tPMA derived from CT scan among pediatric patients with sarcoma should be investigated in further prospective and larger studies.

Surgical phocomelia or phoco-reduction as a method of limb salvage for sarcomas of the upper limb: A suitable alternative to amputation.

BACKGROUND: Reconstruction following resection of sarcomas of the upper extremity with methods described in the prevalent literature may not be possible in few selected cases. We describe surgical phocomelia or phoco-reduction as a method of limb salvage in such cases of extensive sarcomas of the upper limb with its functional and oncological outcomes. METHODS: Evaluation of functional and oncological outcomes was performed for 11 patients who underwent surgical phocomelia or phoco-reduction for extensive sarcomas of the upper limb between 2010 and 2019. RESULTS: The mean follow-up period in the study was 27.8 months. Five patients required a segmental resection including the entire humerus while six patients underwent segmental resection around the elbow with a mean resection length of 21.5 cm. Mean Musculoskeletal Tumor Society 93 score was 22 depicting a good functional outcome. Mean handgrip strength on the operated side was 62% of the contralateral side with preservation of useful hand function. Meantime to humeroulnar union was 6.7 months. Radial nerve palsy and implant failure occurred in one patient each. No patient developed local recurrence while three patients died of metastasis. CONCLUSION: Surgical phocomelia is a prudent alternative to severely incapacitating amputations in situations where other reconstruction methods are not feasible.

Expression of TLE1, INI1, ß-catenin, Claudin1, CK7, CK19, SS18 and calponin in synovial sarcoma.

BACKGROUND AND OBJECTIVES: Synovial sarcomas (SS) are enigmatic soft tissue tumors, which are yet to have a defined cell of origin. SS have a variety of differential diagnosis depending upon the age of the patient and the site of presentation. This makes diagnosis cumbersome unless the specific fusion SS18:SSX is identified by reverse transcription-polymerase chain reaction (RT-PCR) or fluorescence in situ hybridization (FISH). Immunohistochemistry is a useful tool in resource-poor settings in helping to narrow the differentials and help diagnose this tumor. This study set about assessing possible candidate immunohistochemical markers in their utility to recognize SS. METHODS: Forty cases of SS, proven by FISH were included. A tissue microarray (TMA) was constructed, and immunohistochemistry was done using antibodies - TLE1 (OTI1F5), ß-catenin (14), INI1 (MRQ-27), CK7 (OV-TL), CK19 (polyclonal), SS18 (polyclonal), calponin (CALP), and claudin1 (Polyclonal). The expression was analyzed to arrive at sensitivity and specificity. RESULTS: TLE1 had a sensitivity of 92.5% and a specificity of 100%; ß-Catenin had a sensitivity of 17.5% and specificity of 100%; Calponin had a sensitivity of 97.5% and a specificity of 81.25%; SS18 had a sensitivity of 95% and specificity of 100%; INI1 had a sensitivity of 95% and specificity of 100%; CK7 had a sensitivity of 90% and specificity of 87.5%; CK19 had a sensitivity of 90% and a specificity of 59.38%; and Claudin had a sensitivity of 85% and a specificity of 78.12%. INTERPRETATION AND CONCLUSIONS: The study showed both TLE1 and SS18 are robust diagnostic markers of synovial sarcoma with a sensitivity of 92% and 95%, respectively. INI1 can be used to discriminate SS from nonepithelioid and nonrhabdoid differentials. Calponin expression is helpful to differentiate poorly differentiated SS from its mimics. CK7 is a better marker than CK19 and can be used as a replacement for EMA in the initial screening panel. The use of claudin1 was restricted to delineating the epithelial component. ß-Catenin had poor sensitivity, restricting its utility in SS.

Surgical Stabilization for Patients with Mechanical Back Pain Secondary to Metastatic Spinal Disease is Associated with Improved Objective Mobility Metrics: Preliminary Analysis in a Cohort of 26 Patients.

OBJECTIVES: To investigate the effect of surgical stabilization for patients with metastatic spinal disease on objective mobility metrics. METHODS: A retrospective chart review identified patients who had mechanical back pain from metastatic spinal disease and underwent spinal stabilization during 2017. Mobility metrics, the Activity Measure for Post-Acute Care (AM-PAC) inpatient mobility short form (IMSF) and the Johns Hopkins Highest Level of Mobility (JH-HLM), were reviewed. RESULTS: A total of 26 patients were included in the analysis with median hospital stay of 8 days. Preoperative JH-HLM scores were available for 17 patients with a mean score of 5.4, increasing to mean score of 6.6 at last follow-up (P = 0.036). Preoperative AM-PAC IMSF scores were available for 14 patients with a mean score of 19.4, decreasing slightly to a mean score of 18.7 at last follow-up (P = 0.367). Last follow-up with mobility metrics occurred a median of 6.5 days postoperatively (range: 3-66 days). Multivariable analysis showed that American Spinal Injury Association and Karnofsky Performance Status scores were significantly associated with both JH-HLM and AM-PAC mobility scores at last follow-up. A higher JH-HLM or AM-PAC score was significantly associated with direct home discharge and a higher AM-PAC score was associated with shorter hospital stay. CONCLUSIONS: Surgical stabilization for patients with mechanical back pain secondary to metastatic spinal disease might lead to an objective improvement in JH-HLM score. JH-HLM and AM-PAC scores may be correlated with length of hospital stay and discharge disposition. Future studies are encouraged to further characterize the role of these mobility metrics in the management plan of these patients.

Tumor morphology and location associate with immune cell composition in pleomorphic sarcoma.

BACKGROUND: Soft-tissue sarcomas (STS) are a rare group of mesenchymal malignancies that account for approximately 1% of adult human cancer. Undifferentiated pleomorphic sarcoma (UPS) is one of the most common subtypes of adult STS. Clinical stratification of UPS patients has not evolved for decades and continues to rely on tumor-centric metrics including tumor size and depth. Our understanding of how the tumor microenvironment correlates to these clinicopathologic parameters remains limited. METHODS: Here, we performed single-cell flow cytometric immune-based profiling of 15 freshly resected UPS tumors and integrated this analysis with clinical, histopathologic, and outcomes data using both a prospective and retrospective cohort of UPS patients. RESULTS: We uncovered a correlation between physiologic and anatomic properties of UPS tumors and the composition of immune cells in the tumor microenvironment. Specifically, we identified an inverse correlation between tumor-infiltrating CD8 + T cells and UPS tumor size; and a positive correlation between tumor-infiltrating CD8 + T cells and overall survival. Moreover, we demonstrate an association between anatomical location (deep or superficial) and frequency of CD4 + PD1hi infiltrating T cells in UPS tumors. CONCLUSIONS: Our study provides an immune-based analysis of the tumor microenvironment in UPS patients and describes the different composition of tumor infiltrating lymphocytes based on size and tumor depth.

Soft-Tissue Sarcoma as a Potential Differential Diagnosis of an Exophytic Soft-Tissue Mass: A Case Report.

The detection of a soft-tissue mass requires a detailed and conscientious examination to make a definitive diagnosis and propose appropriate treatment strategies. Benign mesenchymal tumors occur more frequently than malignant tumors. However, because of their aggressive growth and poor prognosis, sarcomas must always be considered as a potential differential diagnosis. To make a formal diagnosis and plan appropriate surgical treatment, the surgeon should obtain cross-sectional imaging studies and biopsies.

Paratesticular liposarcoma: a rare cause of scrotal lump.

Paratesticular tumours are tumours arising from within the scrotum not of testicular origin. They may originate from the epididymis, spermatic cord, tunica vaginalis and other supporting structures. Preoperative diagnosis can be difficult as benign and malignant cases are often indistinguishable and may be confused with other benign or malignant pathology (testicular tumours or hernias).We describe the presentation and management of a patient managed at our centre (a tertiary referral teaching hospital).A high index of suspicion for malignancy should be considered when managing atypical scrotal lumps to ensure optimal management. This is particularly important when managing sarcomas due to the risk of local recurrence and spread.

Undifferentiated pleomorphic sarcoma of skin in unusual locations: Report of two cases.

Undifferentiated pleomorphic sarcoma (UPS) of the skin is a rare soft tissue sarcoma subtype with a high risk of metastasis and local recurrence. Ultraviolet exposure plays a prominent role in its etiology. Herein, we present two rare cases of UPS of the skin with an occurrence in non-ultraviolet exposed locations and discuss the need of wide resection and the identification of the depth of the tumor. Due to the resection of the skin, resulting defect was undertaken with skin grafting. One case was extending to the fascia and, after the resection, vacuum-assisted closure therapy was used for the formation of granulation tissue. No recurrence was seen after three and four years for either cases. In conclusion, UPS is a rare, aggressive malignant tumor with a high local recurrence and metastasis rate. Suspicion of malignancy in a plaque-like or nodular lesion in the skin is crucial, and local recurrence and metastasis risk is significantly correlated to the success of wide excision.

Effectiveness of Salvage Knee Rotationplasty on Sarcoma Around the Knee in Adolescents and Young Adults.

BACKGROUND/AIM: This study aimed to investigate the effectiveness of knee rotationplasty (KRP) as salvage surgery for uncontrolled infection and implant failure of total knee arthroplasty (TKA) for sarcoma around the knee in adolescents and young adults (AYA). PATIENTS AND METHODS: This retrospective cohort study included 33 patients who underwent KRP and were grouped based on the treatment received: initial surgery for sarcoma around the knee (n=18) or as salvage surgery (n=15). Musculoskeletal Tumor Society (MSTS) score, range of motion (ROM) and postoperative results were analyzed. RESULTS: All 15 patients who underwent salvage KRP had TKA as an initial surgery. Although there were five infections in salvage KRP, which originated from the initial TKA, all cases were controllable, no implant failure occurred. MSTS score and ROM were deemed acceptable in both groups. CONCLUSION: Salvage KRP is an effective option for uncontrolled complications of initial TKA for sarcoma around the knee.

Prognostic factors in patients undergoing pulmonary resection for sarcomatoid carcinomas of the lung.

BACKGROUND: Pulmonary sarcomatoid carcinomas are very rare lung neoplasms, and no consensus exists regarding their optimal treatment. The prognosis of sarcomatoid carcinomas has been reported to be unfavorable compared with non-small-cell lung cancers; however, prognostic factors in patients undergoing surgery for sarcomatoid carcinomas remain unclear. AIMS: To analyze clinicopathologic prognostic factors and survival outcomes in patients who underwent surgery for pulmonary sarcomatoid carcinoma. STUDY DESIGN: Retrospective cross-sectional study. METHODS: We designed a retrospective cross-sectional study in patients who underwent surgery for pulmonary sarcomatoid carcinomas and statistically analyzed the prognostic factors regarding clinicopathologic features with respect to survival outcomes. RESULTS: We had a total of 44 patients with sarcomatoid carcinoma who had pulmonary resection. Sex distribution was 34 (77%) males and 10 (22.7%) females, which was determined by declaration. The mean age of patients was 57.3 ± 16 years with a median of 60 years. The 5-year progression-free survival and overall survival rates were 59% and 58%, respectively. The 5-year survival rates were significantly different for tumors > 5 cm (P = 0.044), tumorstatus (T) (P=0.016), lymph node status (N) (P=0.005), and pathologic tumor-node-metastasis (TNM) stage (P = 0.0001 ). However, histologic subtype (P = 0.628) and adjuvant treatment (P = 0.804) did not have any significant effect on survival. Similarly, the significant prognostic factors in univariate analysis were tumor size (P = 0.085), T status (P = 0.005), N status (P = 0.028), and pathologic TNM stage (P = 0.0001). Multivariate analysis showed only T status (P = 0.058), N status (P = 0.018), and pathologic TNM stage (P = 0.019) as independent prognostic factors, with statistical power of 87%, 43.1% and 21.2%. CONCLUSION: Surgery appears to be an optimal treatment with favorable outcomes for patients with pulmonary sarcomatoid carcinoma. Patients with small tumors at earlier stages are very likely to benefit from surgery, regardless of histologic subtype.

Lgr5 Marks Adult Progenitor Cells Contributing to Skeletal Muscle Regeneration and Sarcoma Formation.

Regeneration of adult skeletal muscle is driven largely by resident satellite cells, a stem cell population increasingly considered to display a high degree of molecular heterogeneity. In this study, we find that Lgr5, a receptor for Rspo and a potent mediator of Wnt/ß-catenin signaling, marks a subset of activated satellite cells that contribute to muscle regeneration. Lgr5 is found to be rapidly upregulated in purified myogenic progenitors following acute cardiotoxin-induced injury. In vivo lineage tracing using our Lgr5-2ACreERT2R26tdTomatoLSL reporter mouse model shows that Lgr5+ cells can reconstitute damaged muscle fibers following muscle injury, as well as replenish the quiescent satellite cell pool. Moreover, conditional mutation in Lgr52ACreERT2;KrasG12D;Trp53flox/flox mice drives undifferentiated pleomorphic sarcoma formation in adult mice, thereby substantiating Lgr5+ cells as a cell of origin of sarcomas. Our findings provide the groundwork for developing Rspo/Wnt-signaling-based therapeutics to potentially enhance regenerative outcomes of skeletal muscles in degenerative muscle diseases.

Cancer Stem Cells in Soft-Tissue Sarcomas.

Soft tissue sarcomas (STS) are a rare group of mesenchymal solid tumors with heterogeneous genetic profiles and clinical features. Systemic chemotherapy is the backbone treatment for advanced STS; however, STS frequently acquire resistance to standard therapies, which highlights the need to improve treatments and identify novel therapeutic targets. Increases in the knowledge of the molecular pathways that drive sarcomas have brought to light different molecular alterations that cause tumor initiation and progression. These findings have triggered a breakthrough of targeted therapies that are being assessed in clinical trials. Cancer stem cells (CSCs) exhibit mesenchymal stem cell (MSC) features and represent a subpopulation of tumor cells that play an important role in tumor progression, chemotherapy resistance, recurrence and metastasis. In fact, CSCs phenotypes have been identified in sarcomas, allied to drug resistance and tumorigenesis. Herein, we will review the published evidence of CSCs in STS, discussing the molecular characteristic of CSCs, the commonly used isolation techniques and the new possibilities of targeting CSCs as a way to improve STS treatment and consequently patient outcome.

Unusual cause of filling defect in pulmonary artery: pulmonary artery sarcoma.

Pulmonary artery (PA) sarcoma is an extremely rare malignant tumor of pulmonary artery. It is often misdiagnosed as pulmonary thromboembolism (PTE) because of its clinical and imaging features which are quite similar to PTE. Multimodality diagnostic imaging and recognition of specific imaging characteristics with appropriate clinical suspicion are required to make correct diagnosis. In this report, we present a case of PA sarcoma with imaging and clinical features as well as emphasize significance of using multimodality imaging.

Pulmonary Artery Sarcoma Diagnosed Using an Endovascular Catheter Forceps Biopsy.

We herein report a case of pulmonary artery sarcoma (PAS) in a 64-year-old woman. She was admitted to our hospital because of massive genital bleeding from endometrial cancer. Contrast-enhanced computed tomography (CT) revealed a left pulmonary artery mass and deep vein thrombosis. She underwent anticoagulant therapy for one year. However, the mass lesion gradually expanded. 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT showed a positive uptake of FDG by the mass. An endovascular catheter biopsy was performed for the differentiation of endometrial cancer metastasis or primary sarcoma. The biopsy specimen tissue comprised spindle-shaped cells. Thus, the patient was diagnosed with PAS.

Psychological functioning, coping styles and their relationship to appraisal of physical limitations following invasive surgical procedures for soft-tissue sarcoma: A qualitative study.

BACKGROUND AND OBJECTIVES: This study explored psychological functioning and coping styles in adult patients with soft-tissue sarcoma who underwent surgical procedures in a single expert sarcoma medical center in Canada. METHODS: This is a qualitative study with three formats of data collection. The interview guide was based on theoretical health-related quality of life model. We began the investigation with 2 online and 2 in-person focus groups. Four individual semistructured interviews were added to further explore emerging themes. Data were analyzed using inductive thematic networks approach. RESULTS: Twenty-eight adults (13 female, 24-75 years of age) participated. In the domain of psychological functioning we identified three main themes; changes in mood, worry, and body image concerns. In the domain of coping styles, we identified four adaptive coping styles; positive reframing and optimism, finding a purpose, being proactive, and using humor. Among the maladaptive coping styles, we found passive acceptance, and avoidance and denial. CONCLUSIONS: Psychological well-being can be contingent on physical functioning and coping styles in adults with soft-tissue sarcoma. Both psychological and physical function impact quality of life. Patients with more physical limitations, psychological distress and maladaptive coping styles should be monitored for their well-being.

Sarcopenia is associated with increased mortality but not complications following resection and reconstruction of sarcoma of the extremities.

BACKGROUND AND OBJECTIVES: Evidence regarding the impact of sarcopenia on operative outcomes in patients with sarcoma is lacking. We evaluated the relationship between sarcopenia and postoperative complications or mortality among patients undergoing tumor excision and reconstruction. ​ METHODS: We retrospectively reviewed 145 patients treated with tumor excision and limb reconstruction for sarcoma of the extremities. Sarcopenia was defined as psoas index (PI) < 5.45 cm2 /m2 for men and <3.85 cm2 /m2 for women from preoperative axial CT. Regression analyses were used to assess the association between postoperative complications or mortality with PI, age, gender, race, body mass index, tumor histology, grade, depth, location, size, and neoadjuvant/adjuvant therapy. RESULTS: There were 101 soft tissue tumors and 44 primary bone tumors. Sarcopenia was present in 38 patients (26%). Sarcopenic patients were older (median age: 72 vs 59 years, P = .0010) and had larger tumors (86.5%, >5 cm vs 77.7%, P = .023). Seventy-three patients experienced complications (51%) and 18 patients died within 1 year. Sarcopenia and metastatic disease were associated with increased 12-month mortality (hazard ratio [HR] = 6.68, P < .001; HR: 8.51, P < .001, respectively) but not complications (HR 1.45, P = .155, odds ratio, 1.32, P = .426, respectively). CONCLUSIONS: Sarcopenia and metastatic disease were independently associated with postoperative mortality but no complications following surgery.

Quality of Life and Pain Experienced by Children and Adolescents With Cancer at Home Following Discharge From the Hospital.

An exploratory study was conducted to examine the quality of life and pain experienced by patients with pediatric cancer at home after discharge. Physical, cognitive, social, and emotional aspects of quality of life were measured and how these may be affected by age, sex, diagnosis, and pain status. The authors also characterized intensity, location, and quality of pain experienced. A sample of 33 patients participating in a larger study was selected on the basis of having pain on the day of discharge and having completed the Pediatric Quality of Life Inventory Generic, Cancer Module, Multidimensional Fatigue Scale, and the Adolescent Pediatric Pain Tool at home. Cancer diagnoses were leukemias/lymphomas (42.4%), brain/central nervous system tumors (27.3%), sarcomas (24.2%), or other (6.1%). More than half of patients reported pain (n=17; 51.5%). Patients with pain had more fatigue affecting the quality of life (P=0.01), and lower physical and emotional functioning, leading to lower overall health-related quality of life scores (P=0.011). Female individuals and adolescents reported worse emotional functioning (P=0.02 and P=0.05, respectively). Physical, cognitive, and social functioning were lowest among patients diagnosed with sarcomas (P=0.00, P=0.01, and P=0.04, respectively). It is important to understand the symptom experience of patients at home as a first step in moving towards optimal discharge teaching and treatment.

Are Accelerometer-based Functional Outcome Assessments Feasible and Valid After Treatment for Lower Extremity Sarcomas?

BACKGROUND: Aspects of physical functioning, including balance and gait, are affected after surgery for lower limb musculoskeletal tumors. These are not routinely measured but likely are related to how well patients function after resection or amputation for a bone or soft tissue sarcoma. Small, inexpensive portable accelerometers are available that might be clinically useful to assess balance and gait in these patients, but they have not been well studied. QUESTIONS/PURPOSES: In patients treated for lower extremity musculoskeletal tumors, we asked: (1) Are accelerometer-based body-worn monitor assessments of balance, gait, and timed up-and-go tests (TUG) feasible and acceptable? (2) Do these accelerometer-based body-worn monitor assessments produce clinically useful data (face validity), distinguish between patients and controls (discriminant validity), reflect findings obtained using existing clinical measures (convergent validity) and standard manual techniques in clinic (concurrent validity)? METHODS: This was a prospective cross-sectional study. Out of 97 patients approached, 34 adult patients treated for tumors in the femur/thigh (19), pelvis/hip (3), tibia/leg (9), or ankle/foot (3) were included in this study. Twenty-seven had limb-sparing surgery and seven underwent amputation. Patients performed standard activities while wearing a body-worn monitor on the lower back, including standing, walking, and TUG tests. Summary measures of balance (area [ellipsis], magnitude [root mean square {RMS}], jerkiness [jerk], frequency of postural sway below which 95% of power of acceleration power spectrum is observed [f95 of postural sway]), gait [temporal outcomes, step length and velocity], and TUG time were derived. Body-worn monitor assessments were evaluated for feasibility by investigating data loss and patient-reported acceptability and comfort. In addition, outcomes in patients were compared with datasets of healthy participants collected in parallel studies using identical methods as in this study to assess discriminant validity. Body-worn monitor assessments were also investigated for their relationships with routine clinical scales (the Musculoskeletal Tumour Society Scoring system [MSTS], the Toronto Extremity Salvage Score [TESS], and the Quality of life-Cancer survivors [QoL-CS)] to assess convergent validity and their agreement with standard manual techniques (video and stopwatch) to assess concurrent validity. RESULTS: Although this was a small patient group, there were initial indications that body-worn monitor assessments were well-tolerated, feasible to perform, acceptable to patients who responded (95% [19 of 20] of patients found the body-worn monitor acceptable and comfortable and 85% [17 of 20] found it user-friendly), and produced clinically useful data comparable with the evidence. Balance and gait measures distinguished patients and controls (discriminant validity), for instance balance outcome (ellipsis) in patients (0.0475 m/s [95% confidence interval 0.0251 to 0.0810]) was affected compared with controls (0.0007 m/s [95% CI 0.0003 to 0.0502]; p = 0.001). Similarly gait outcome (step time) was affected in patients (0.483 seconds [95% CI 0.451 to 0.512]) compared with controls (0.541 seconds [95% CI 0.496 to 0.573]; p < 0.001). Moreover, body-worn monitor assessments showed relationships with existing clinical scales (convergent validity), for instance ellipsis with MSTS (r = -0.393; p = 0.024). Similarly, manual techniques showed excellent agreement with body-worn monitor assessments (concurrent validity), for instance stopwatch time 22.28 +/- 6.93 seconds with iTUG time 21.18 +/- 6.23 seconds (intraclass correlation coefficient agreement = 0.933; p < 0.001). P < 0.05 was considered statistically significant. CONCLUSIONS: Although we had a small, heterogeneous patient population, this pilot study suggests that body-worn monitors might be useful clinically to quantify physical functioning in patients treated for lower extremity tumors. Balance and gait relate to disability and quality of life. These measurements could provide clinicians with useful novel information on balance and gait, which in turn could guide rehabilitation strategies. LEVEL OF EVIDENCE: Level III, diagnostic study.