Race is an independent predictor of survival in patients with soft tissue sarcoma of the extremities

Socioeconomic disparities in reception of limb-sparing surgery versus amputation for lower extremity sarcoma

BACKGROUND

In lower extremity sarcoma treatment, limb salvage approaches present superior alternatives to amputation due to reduced postoperative morbidity and improved quality of life. This study provides a novel analysis of socioeconomic disparities that may affect reception of limb-sparing surgery.

METHODS

Patients with lower extremity bone or soft tissue sarcoma who received either limb-sparing surgery or amputation from 2007 to 2021 were identified in the Surveillance, Epidemiology and End Results (SEER) database. Demographic, socioeconomic, and oncologic variables were collected for each patient. Multivariate binary logistic regression was conducted to assess preoperative demographic and oncologic risk factors for amputation (p < 0.05).

RESULTS

A total of 6465 patients were identified in the final cohort, 586 (9.1%) of whom received amputation. After controlling for tumor size, stage, and neoadjuvant therapy administration, non-Hispanic American Indian/Alaskan Native race/ethnicity predicted the highest odds of amputation (OR: 1.78, 95% CI: 1.12-2.85, p = 0.015). Nonmetropolitan residence (OR: 1.69, 95% CI: 1.43-2.00, p < 0.001) also conferred higher risk of amputation compared with residence in a large metropolitan area. Overall, amputation was associated with a higher risk of ten-year cancer-specific mortality (p < 0.001) even when controlled by sociodemographic and clinical characteristics.

CONCLUSIONS

There are significant disparities in limb-sparing surgery and amputation rates in lower extremity sarcoma management, even when accounting for differences in baseline oncologic characteristics. Further study into socioeconomic drivers of these trends will allow the development of initiatives that improve disparities in reconstructive outcomes.

Trends in the use of immunotherapy to treat soft tissue sarcoma

BACKGROUND

The role of immune-oncology (IO) therapy in soft tissue sarcoma (STS) is underexplored. This study characterized IO use in STS.

METHODS

This is a retrospective analysis of patients with a soft tissue mass in the National Cancer Database, 2011-2021. Patients were categorized by IO receipt status. Groupwise testing and proportional trend tests were performed with Chi-squared tests. Multivariate logistic regression was performed to assess factors associated with IO receipt.

RESULTS

Of the 103,092 patients with STS, 1935 (1.9 ​%) received or were recommended IO therapy. IO use increased 10-fold (0.24 ​%-2.5 ​% from 2011 to 2021; p ​< ​0.0001). Patients had higher odds of receiving IO when having higher grade tumors and metastatic disease, and when treated at an academic research center (all p ​< ​0.001).

CONCLUSIONS

IO use in STS is low but increasing and primarily used in the metastatic setting. Future studies should identify biomarkers of IO response and facilitators for treatment receipt.

Development and external validation of a machine learning model for prediction of survival in undifferentiated pleomorphic sarcoma

PURPOSE

Machine learning (ML) algorithms to predict cancer survival have recently been reported for a number of sarcoma subtypes, but none have investigated undifferentiated pleomorphic sarcoma (UPS). ML is a powerful tool that has the potential to better prognosticate UPS.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for cases of histologically confirmed undifferentiated pleomorphic sarcoma (UPS) (n = 665). Patient, tumor, and treatment characteristics were recorded, and ML models were developed to predict 1-, 3-, and 5-year survival. The best performing ML model was externally validated using an institutional cohort of UPS patients (n = 151).

RESULTS

All ML models performed best at the 1-year time point and worst at the 5-year time point. On internal validation within the SEER cohort, the best models had c-statistics of 0.67-0.69 at the 5-year time point. The Multi-Layer Perceptron Neural Network (MLP) model was the best performing model and used for external validation. Similarly, the MLP model performed best at 1-year and worst at 5-year on external validation with c-statistics of 0.85 and 0.81, respectively. The MLP model was well calibrated on external validation. The MLP model has been made publicly available at https://rachar.shinyapps.io/ups_app/ .

CONCLUSION

Machine learning models perform well for survival prediction in UPS, though this sarcoma subtype may be more difficult to prognosticate than other subtypes. Future studies are needed to further validate the machine learning approach for UPS prognostication.

Amputation in patients with extremity soft tissue sarcoma: the experience of an East Asian referral center

BACKGROUND

This study aimed to investigate the characteristics and clinical outcomes in a series of patients with extremity soft tissue sarcoma (STS) who underwent amputation at a large East Asian referral center.

PATIENTS AND METHODS

Of the 652 patients who underwent surgery for extremity STS, data of 37 consecutive patients who underwent amputation were reviewed retrospectively. The median follow-up period was 96.0 months (range, 15-216). The patients were classified in to three cohorts. The primary localized (PL) group included patients who underwent amputation as a primary surgical procedure with curative intent. The recurrent localized (RL) group included patients who underwent amputation as a revision procedure after failure of previous limb sparing surgeries. The metastatic group included patients who underwent amputation as a palliative procedure.

RESULTS

There were 22 cases of amputation in 596 STS patients and the amputation rate was 3.6% (22/596). Further, 1.8% (9/490) of patients with primary localized STS underwent amputation. Patients with localized STS who underwent amputation had a 5-year disease-specific survival (DSS) rate of 89.9% (95% Confidence Interval (CI), 87.1-92.7%), a local-recurrence-free survival (LRFS) of 84.1% (95% CI, 80.5-87.6%), and a metastasis-free survival (MFS) of 84.6%. (95% CI, 81.1-88.0%) Compared with previous studies, our results showed higher DSS and MFS rates with similar LRFS.

CONCLUSIONS

The amputation rate of extremity STS in our institute in East Asia was similar but slightly lower than that reported in Western studies. The oncologic outcome of amputation reported in this study was higher than that indicated in Western studies and oncologic outcome of amputation was not statistically different from those of limb salvage surgery. However, considering the small cohort in single institute study, there is a possibility of selection bias and future multi-center study is necessary. From our results, amputation is still a feasible option for appropriately selected patients unsuitable for limb-conserving surgery.

Emerging innovations and advancements in the treatment of extremity and truncal soft tissue sarcomas

In this special edition update on soft tissue sarcomas (STS), we cover classifications, emerging technologies, prognostic tools, radiation schemas, and treatment disparities in extremity and truncal STS. We discuss the importance of enhancing local control and reducing complications, including the role of innovative imaging, surgical guidance, and hypofractionated radiation. We review advancements in systemic and immunotherapeutic treatments and introduce disparities seen in this vulnerable population that must be considered to improve overall patient care.

Racial and ethnic variation in presentation and outcomes of high-grade soft tissue sarcoma at a Southeastern United States comprehensive cancer center

BACKGROUND

High-grade soft tissue sarcoma is rare and associated with poor prognosis. This study examines racial and ethnic variation in presentation and outcomes at a Southeastern US cancer center.

METHODS

Among an institutional cohort of patients seen between January 2016-December 2021, racial and ethnic differences were evaluated using chi-squared tests, Kaplan Meier curves, and Cox proportional hazards models.

RESULTS

There were 295 patients (71 ​% Non-Hispanic White, 24 ​% Black, 3 ​% Hispanic White, 2 ​% Other). Black representation was greater than national cohorts (24 ​% vs. 12 ​%). Histological subtype varied by race/ethnicity (p ​= ​0.007). Adjusting for histology and stage, survival was worse for Black vs. White patients (HR 1.71, 95 ​% CI 1.07-2.76) and those with metastatic disease (5.47, 3.54-8.44). In non-metastatic patients, survival differences for Black vs. White patients were attenuated by receipt of multi-modal treatment (1.53, 0.82-2.88).

CONCLUSION

Observed racial disparities in survival of high-grade sarcoma may be addressed by early, multidisciplinary management.

The Landscape of Alterations from 1407 Ultra-Rare Sarcomas from the AACR GENIE Database: Clinical Implications

PURPOSE

Ultra-rare sarcomas (URS) comprise a group of orphan diseases with an incidence of ≤1/1,000,000 people per year. We aimed to assess clinically actionable genomic alterations in URS.

EXPERIMENTAL DESIGN

Data were extracted from the GENIE database using cBioPortal. OncoKB was used to assess for clinical actionability of mutations. Tumor mutational burden (TMB) was inferred from clinical sequencing data.

RESULTS

Soft tissue (ST) URS made up 23.5% of ST sarcoma cases, and bone URS made up 16.5% of bone sarcoma cases. The most commonly mutated gene in all four groups was TP53. The most common fusions involved EWSR1. The most common copy-number variations included deletions of CDKN2A and CDKN2B and amplifications of MDM2 and CDK4. TMB was generally low across all four categories of sarcoma, though there was considerable heterogeneity, with 3.8% of ST URS and 0.55% of bone URS having high TMB. We find Level 1 alterations (FDA-recognized biomarker predictive of response to an FDA-approved drug) in 10.0% of ST URS compared with 7.1% of ST non-URS, 1.1% of bone URS, and 4.5% of bone non-URS. Level 1-3 alterations (also include alterations for which there are standard-of-care drugs or clinical evidence supporting a drug) were seen in 27.8% of ST URS, 25.2% of ST non-URS, 20.9% of bone URS, and 17.4% of bone non-URS.

CONCLUSIONS

Clinically actionable genomic alterations are seen in a substantial fraction of URS. Clinical sequencing in advanced URS has the potential to guide the treatment of a significant portion of patients with URS.

A web-based nomogram to predict overall survival for postresection leiomyosarcoma patients with lung metastasis

To investigate the overall survival of post-resection leiomyosarcoma (LMS) patients with lung metastasis, data of post-resection LMS patients with lung metastasis between 2010 and 2016 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The clinical characteristics and survival data for post-resection LMS patients with lung metastasis at Tianjin Medical University Cancer Hospital & Institute (TJMUCH) between October 2010 and July 2018 were collected. Patients derived from the SEER database and TJMUCH were divided into training and validation cohorts, respectively. Univariate and multivariate Cox regression analyses were performed and a nomogram was established. The area under the curve (AUC) and the calibration curve were used to evaluate the nomogram. A web-based nomogram was developed based on the established nomogram. Eventually, 226 patients from the SEER database who were diagnosed with LMS and underwent primary lesion resection combined with lung metastasis were enrolled in the training cohort, and 17 patients from TJMUCH were enrolled in the validation cohort. Sex, race, grade, tumor size, chemotherapy, and bone metastasis were correlated with overall survival in patients with LMS. The C-index were 0.65 and 0.75 in the SEER and Chinese set, respectively. Furthermore, the applicable AUC values of the ROC curve in the SEER cohort to predict the 1-, 3-, 5- years survival rate were 0.646, 0.682, and 0.689, respectively. The corresponding AUC values in the Chinese cohort were 0.970, 0.913, and 0.881, respectively. The calibration curve showed that the nomogram performed well in predicting the overall survival in post-resection LMS patients with lung metastasis. A web-based nomogram (https://weijunqiang.shinyapps.io/survival_lms_lungmet/) was established. The web-based nomogram (https://weijunqiang.shinyapps.io/survival_lms_lungmet/) is an accurate and personalized tool for predicting the overall survival of post-resection LMS with lung metastasis.

Epidemiology and survival factors for sarcoma patients in minority populations: a SEER-retrospective study

Background

Epidemiologic studies have demonstrated race as a predictor of worse oncological outcomes. To better understand the effect of race on oncological outcomes, we utilized the Surveillance, Epidemiology, and End Results (SEER) database to determine what treatment courses are provided to minority patients and how this impacts survival.

Materials and methods

A retrospective review of bone and soft tissue sarcoma cases was performed using the SEER database for a minimum 5-year survival rate (SR) using Kaplan-Meier curves. Categorical variables were compared using Pearson's χ2 test and Cramer V. Kaplan-Meier curves were used to determine survival rates (SR) and Cox regression analysis was used to determine hazard ratios (HRs).

Results

Races that had an increased risk of death included Native American/Alaska Native (NA/AN) [hazard ratio (HR): 1.36, 95% confidence interval (CI): 1.049-1.761, p = 0.020) and Black (HR = 1.17, 95% CI: 1.091-1.256, p < 0.001). NA/AN individuals had the lowest SR (5-year SR = 70.9%, 95% CI: 63.8-78.0%, p < 0.001). The rate of metastasis at diagnosis for each race was 13.07% - Hispanic, 10.62% - NA/AN, 12.77% - Black, 10.61% - Asian/Pacific Islander (A/PI), and 9.02% - White individuals (p < 0.001). There were increases in the rate of metastasis at diagnosis and decreases in rates of surgical excision for Hispanic and Black patients (p < 0.001).

Conclusion

Race is determined to be an independent risk factor for death in NA/AN and Black patients with sarcomas of the extremities. Access to healthcare and delay in seeking treatment may contribute to higher rates of metastasis upon diagnosis for minority patients, and decreased rates of surgical excision could be associated with poor follow up and lack of resources.

Web-based nomogram to predict postresection risk of distant metastasis in patients with leiomyosarcoma: retrospective analysis of the SEER database and a Chinese cohort

OBJECTIVES

This study investigated risk factors and constructed an online tool to predict distant metastasis (DM) risk in patients with leiomyosarcoma (LMS) after surgical resection.

METHODS

Data regarding patients with LMS who underwent surgical resection between 2010 and 2018 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Data were collected regarding patients with LMS who underwent surgical resection at Tianjin Medical University Cancer Hospital and Institute (TJMUCH) between October 2010 and July 2018. Patients were randomly divided into training and validation sets. Logistic regression analyses were performed; a nomogram was established. The area under the curve (AUC) and calibration curve were used to evaluate the nomogram, which served as the basis for a web-based nomogram.

RESULTS

This study included 4461 and 76 patients from the SEER database and TJMUCH, respectively. Age, ethnicity, grade, T stage, N stage, radiotherapy, and chemotherapy were associated with DM incidence. C-index values were 0.815 and 0.782 in the SEER and Chinese datasets, respectively; corresponding AUC values were 0.814 and 0.773, respectively. A web-based nomogram (https://weijunqiang-leimyosarcoma-seer.shinyapps.io/dynnomapp/) was established.

CONCLUSIONS

Our web-based nomogram is an accurate and user-friendly tool to predict DM risk in patients with LMS; it can aid clinical decision-making.

County Rurality is Associated with Increased Tumor Size and Decreased Survival in Patients with Ewing Sarcoma

Background

Ewing Sarcoma (ES) is an aggressive tumor affecting adolescents and young adults. Prior studies investigated the association between rurality and outcomes, although there is a paucity of literature focusing on ES.

Objective

This study aims to determine whether ES patients in rural areas are subject to adverse outcomes.

Methods

This study utilized the Surveillance, Epidemiology, and End Results (SEER) database. A Poisson regression model was used with controls for race, sex, median county income, and age to determine the association between rurality and tumor size. A multivariate Cox Proportional Hazard Model was utilized, controlling for age, race, gender, income, and tumor size.

Results

There were 868 patients eligible for analysis, with a mean age of 14.14 years. Of these patients, 97 lived in rural counties (11.18%). Metropolitan areas had a 9.50% smaller tumor size (p<0.0001), compared to non-metropolitan counties. Patients of Black race had a 14.32% larger tumor size (p<0.0001), and male sex was associated with a 15.34% larger tumor size (p<0.0001). The Cox Proportional Hazard model estimated that metropolitan areas had a 36% lower risk of death over time, compared to non-metropolitan areas (HR: 0.64, p ≤ 0.04).

Conclusion

Patients in metropolitan areas had a smaller tumor size at time of diagnosis and had a more favorable survival rate for cancer-specific mortality compared to patients residing in rural areas. Further work is needed to examine interventions to reduce this discrepancy and investigate the effect of extremely rural and urban settings and why racial disparities occur.

Soft Tissue Sarcomas in Octogenarian Patients: Are Treatment Options and Oncological Outcomes Different? A SEER Retrospective Study

AIMS

As the US population continues to age, oncological strategies and outcomes for soft tissue sarcomas (STSs) should continue to be examined for varying age groups. The aim of this study was analyse and compare treatment strategies and oncological outcomes for octogenarian patients with STSs.

MATERIALS AND METHODS

Data from the Surveillance, Epidemiology and End Results (SEER) national database were used. Varying treatment modalities were studied when utilised for specific tumour staging with respect to the eighth edition of the American Joint Committee on Cancer.

RESULTS

In total, 24 666 patients were included for analysis, where 3341 (14%) were 80 years old or older. The octogenarian group was diagnosed with more advanced disease (stages II-IV), relative to their younger counterparts (85% versus 75%, P < 0.001). However, a smaller proportion of the older patients underwent surgical resection (74% versus 86%, P < 0.001). Likewise, the octogenarians received less chemotherapy (4% versus 21%, P < 0.001) and radiotherapy (29% versus 42%, P = 0.010). Surgical resection and chemotherapy significantly improved overall survival for those older patients with stage II STS, whereas surgical resection and radiotherapy improved mortality in this cohort with both stage III and IV STS. Overall survival at 1 and 5 years of follow-up was lower within the octogenarian group compared with the younger group (1 year: 68% versus 88%, P < 0.001 and 5 years: 7% versus 58%, P < 0.001).

CONCLUSIONS

Octogenarian patients, in most cases, are diagnosed with stage III or metastatic disease. Surgical resection of the primary tumour was beneficial in both age cohorts, with radiotherapy correlating to better overall survival when used in those patients with higher stage STS. Chemotherapy was associated with better mortality in the younger cohort with respect to tumour stage. The octogenarian overall survival at 1 and 5 years was lower than for younger patients.

Is the Number of National Database Research Studies in Musculoskeletal Sarcoma Increasing, and Are These Studies Reliable?

BACKGROUND

Large national databases have become a common source of information on patterns of cancer care in the United States, particularly for low-incidence diseases such as sarcoma. Although aggregating information from many hospitals can achieve statistical power, this may come at a cost when complex variables must be abstracted from the medical record. There is a current lack of understanding of the frequency of use of the Surveillance, Epidemiology, and End Results (SEER) database and the National Cancer Database (NCDB) over the last two decades in musculoskeletal sarcoma research and whether their use tends to produce papers with conflicting findings.

QUESTIONS/PURPOSES

(1) Is the number of published studies using the SEER and NCDB databases in musculoskeletal sarcoma research increasing over time? (2) What are the author, journal, and content characteristics of these studies? (3) Do studies using the SEER and the NCDB databases for similar diagnoses and study questions report concordant or discordant key findings? (4) Are the administrative data reported by our institution to the SEER and the NCDB databases concordant with the data in our longitudinally maintained, physician-run orthopaedic oncology dataset?

METHODS

To answer our first three questions, PubMed was searched from 2001 through 2020 for all studies using the SEER or the NCDB databases to evaluate sarcoma. Studies were excluded from the review if they did not use these databases or studied anatomic locations other than the extremities, nonretroperitoneal pelvis, trunk, chest wall, or spine. To answer our first question, the number of SEER and NCDB studies were counted by year. The publication rate over the 20-year span was assessed with simple linear regression modeling. The difference in the mean number of studies between 5-year intervals (2001-2005, 2006-2010, 2011-2015, 2016-2020) was also assessed with Student t-tests. To answer our second question, we recorded and summarized descriptive data regarding author, journal, and content for these studies. To answer our third question, we grouped all studies by diagnosis, and then identified studies that shared the same diagnosis and a similar major study question with at least one other study. We then categorized study questions (and their associated studies) as having concordant findings, discordant findings, or mixed findings. Proportions of studies with concordant, discordant, or mixed findings were compared. To answer our fourth question, a coding audit was performed assessing the concordance of nationally reported administrative data from our institution with data from our longitudinally maintained, physician-run orthopaedic oncology dataset in a series of patients during the past 3 years. Our orthopaedic oncology dataset is maintained on a weekly basis by the senior author who manually records data directly from the medical record and sarcoma tumor board consensus notes; this dataset served as the gold standard for data comparison. We compared date of birth, surgery date, margin status, tumor size, clinical stage, and adjuvant treatment.

RESULTS

The number of musculoskeletal sarcoma studies using the SEER and the NCDB databases has steadily increased over time in a linear regression model (β = 2.51; p < 0.001). The mean number of studies per year more than tripled during 2016-2020 compared with 2011-2015 (39 versus 13 studies; mean difference 26 ± 11; p = 0.03). Of the 299 studies in total, 56% (168 of 299) have been published since 2018. Nineteen institutions published more than five studies, and the most studies from one institution was 13. Orthopaedic surgeons authored 35% (104 of 299) of studies, and medical oncology journals published 44% (130 of 299). Of the 94 studies (31% of total [94 of 299]) that shared a major study question with at least one other study, 35% (33 of 94) reported discordant key findings, 29% (27 of 94) reported mixed key findings, and 44% (41 of 94) reported concordant key findings. Both concordant and discordant groups included papers on prognostic factors, demographic factors, and treatment strategies. When we compared nationally reported administrative data from our institution with our orthopaedic oncology dataset, we found clinically important discrepancies in adjuvant treatment (19% [15 of 77]), tumor size (21% [16 of 77]), surgery date (23% [18 of 77]), surgical margins (38% [29 of 77]), and clinical stage (77% [59 of 77]).

CONCLUSION

Appropriate use of databases in musculoskeletal cancer research is essential to promote clear interpretation of findings, as almost two-thirds of studies we evaluated that asked similar study questions produced discordant or mixed key findings. Readers should be mindful of the differences in what each database seeks to convey because asking the same questions of different databases may result in different answers depending on what information each database captures. Likewise, differences in how studies determine which patients to include or exclude, how they handle missing data, and what they choose to emphasize may result in different messages getting drawn from large-database studies. Still, given the rarity and heterogeneity of sarcomas, these databases remain particularly useful in musculoskeletal cancer research for nationwide incidence estimations, risk factor/prognostic factor assessment, patient demographic and hospital-level variable assessment, patterns of care over time, and hypothesis generation for future prospective studies.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Trends in Overall Survival among Patients Treated for Sarcoma at a Large Tertiary Cancer Center between 1986 and 2014

Sarcomas are relatively rare malignancies accounting for about 1% of all cancer diagnoses. Studies on sarcomas comprising large cohorts covering extended time periods are lacking. Therefore, this study aimed to evaluate the impact of demographic, behavioral, and clinical characteristics on overall survival (OS) among individuals diagnosed with soft tissue sarcoma (STS) or bone sarcoma at the Moffitt Cancer Center between 1986 and 2014. Unadjusted and multivariable Cox proportional hazard regression (CPHR) models were constructed to generate hazard ratios (HRs) and 95% confidence intervals (CIs) to evaluate associations between a range of demographic, behavioral, and clinical characteristics, and OS. Additionally, Kaplan-Meier survival curves, associated log-rank statistics, and adjusted CPHR models were generated by time periods based on the year of first contact (1986-1994, 1995-1999, 2000-2005, 2006-2010, 2011-2014) to evaluate for temporal differences in OS. Of the 2570 patients, 2037 were diagnosed with STS, whereas 533 were diagnosed with bone sarcoma. At the time of analysis, 50% of the population were alive. In multivariable analyses, we observed poorer survival for patients ≥ 40 years of age (HR = 1.54, 95% CI = 1.34-1.78), current smokers (HR = 1.18, 95% CI = 1.01-1.37), patients with metastasis (HR = 2.19, 95% CI = 1.95-2.47), and patients not receiving first-line surgery treatment (HR = 2.11, 95% CI = 1.82-2.45). We discovered limited improvements in OS over time among individuals diagnosed with STS or bone sarcomas with the exception of gastrointestinal stromal tumors (GIST), which showed a significant improvement in OS across time periods (p = 0.0034). Overall, we identified well-established characteristics associated with OS (e.g., metastasis) in addition to factors (e.g., smoking status) not previously reported to impact OS. Improvements in survival over time have been relatively modest, suggesting the need for improved therapeutic options, especially for those diagnosed with less frequent sarcomas.

Tumor grade and symptoms at presentation are survival risk factors in Chinese patients with primary retroperitoneal sarcoma

Background and Aim

No cohort studies have been performed on Chinese primary retroperitoneal sarcoma (RPS) patients. Data derived from western cohort studies may not be directly superimposable on Asian counterparts. Furthermore, the risk factors for survival of RPS are currently unknown for Chinese patients. The objectives were therefore to (1) gain insight into RPS incidence and patient demographics and clinical details; (2) determine the risk factors for overall survival (OS) and disease-free survival (DFS); and (3) critically appraise the Asian cohort data in relation to information obtained in western cohort studies.

Methods

In this retrospective cohort study, the health records of patients that had been diagnosed with primary localized RPS with curative intent between 2009 and 2020 were analyzed. Cox proportional hazards analysis was conducted to evaluate the risk factors for OS and DFS.

Results

A total of 261 patients met the inclusion criteria. Ninety-six (36.8%) patients had been diagnosed with well-differentiated liposarcoma, 63 patients (24.1%) with dedifferentiated liposarcoma, 41 patients (15.7%) with leiomyosarcoma (LMS), 22 patients (8.4%) with solitary fibroma, 7 patients (2.7%) with malignant peripheral nerve sheath tumor (MPNST), and 32 patients (12.3%) with another type of RPS. The study further revealed that (1) the 5-y OS and DFS in RPS patients was 67.8% and 51.3%, respectively, with the highest OS and DFS observed in MPNST (100% and 100%, respectively) and the lowest 5-y OS and DFS attributed to LMS (42.6% and 28.9%, respectively); (2) symptoms at presentation, Federal National Cancer Center (FNCLCC) grade, and number of combined resections are independent risk factors in OS; (3) symptoms at presentation, FNCLCC grade, chemotherapy, and hospital length of stay are independent risk factors for DFS; and (4) patients at high risk (symptoms at presentation and high-grade tumors) have less than half the chance of survival at 5 y post-diagnosis than patients with a low-risk profile.

Conclusions

Symptoms at presentation constitute a risk factor for OS and DFS. When combined with tumor grade - another risk factor for both OS and DFS - patients can be classified into a high-risk and low-risk category to gauge a patient's prognosis and, accordingly, frame an optimal clinical trajectory. Moreover, the clinicopathology and overall prognosis of RPS in Asian and Western populations are comparable and hence superimposable.

Relevance for Patients

The present study identifies the risk factors of survival in RPS and suggests symptoms at presentation should be considered in the preoperative consultation and added in prognostic grouping.

Survival of Patients With Primary Osseous Malignancies of the Mobile Spine Is Associated With Access to "Standard Treatment" Protocols

INTRODUCTION

Malignancies of the mobile spine carry high morbidity and mortality. This study sought to examine factors associated with receipt of "standard" treatment and survival for patients with primary mobile spine tumors in the California Cancer Registry (CCR).

METHODS

The CCR (1988 to 2016) data were obtained for patients with primary tumors of the mobile spine and at least 1-year follow-up. Sacrum/pelvis tumors were excluded. Age at diagnosis, sex, race, neighborhood socioeconomic status, insurance, Charlson Comorbidity Index, histologic diagnosis, stage at diagnosis, and treatment at a National Cancer Institute-designated Cancer Center (NCICC) were collected. Multivariate analyses were done to identify factors associated with all-cause mortality and receipt of "standard" treatment.

RESULTS

Four hundred eighty-four patients (64% White, 56% low neighborhood socioeconomic status, and 36% privately insured) were included. Chordoma (37%) was the most common diagnosis. Only 16% had metastatic disease at presentation. Only 29% received treatment at an NCICC. Lower age, Charlson Comorbidity Index, less extensive stage of disease, and private insurance were associated with lower all-cause mortality (all P < 0.05). Medicaid/public insurance (hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.13 to 2.41) and Medicare (HR, 1.80; 95% CI, 1.25 to 2.59) were associated with higher mortality compared with private insurance. Patients who received no known treatment (HR, 2.41; CI, 1.51 to 3.84) or treatment other than the "standard" (HR, 1.45; CI, 1.11 to 1.91) had higher mortality compared with those who received the standard protocols. A critical predictor of receiving the standard treatment protocol was being treated at an NCICC. If patients did not receive care at such institutions, they received optimal treatment only 40% of the time (HR, 0.5; P = 0.004).

CONCLUSIONS

Receipt of defined "standard treatment" protocols was associated with care received at an NCICC and lower all-cause mortality in patients with primary osseous malignancies of the mobile spine. Patients with public insurance are vulnerable to worse outcomes, regardless of age, disease burden, or receipt of standard treatment.

LEVEL OF EVIDENCE

III.

Clinical characteristics and survival analysis of patients with limb epithelioid sarcoma

Limb epithelioid sarcoma (LES) is a rare and aggressive soft tissue sarcoma, which is scarcely reported. Therefore, the current study was performed to analyze the clinicopathologic features and risk factors of survival among patients with LES. By using the Surveillance, Epidemiology, and End Results database, data were obtained regarding patients who were diagnosed with LES for the period between 2010 and 2016. We first analyzed overall survival (OS) and cancer-specific survival (CSS) by applying univariate Cox regression analysis. Then we performed multivariate analysis to confirm independent predictors of survival. In total, we identified 475 patients with LES for survival analysis, of which 291 were males (61.3%) and 184 females (38.7%). The mean and median age at diagnosis were 38 and 36 years, respectively. The 5-year OS and CSS rates among Patients with LES were 65.4% and 69.5%, respectively. Gender, age, tumor stage, tumor size, and treatment type were significant predictors of OS on both univariate and multivariate analyses (P < .05). As for CSS, multivariable analysis revealed that age <60 years, localized stage, and tumor size <5 cm were significantly associated with increased survival (P < .05). Predictors of improved survival for LES patients include gender, age, tumor stage, tumor size, and treatment type. Surgery only was recommended for treating LES patients. Future studies are warranted to determine effective treatment types for LES patients.

Racial and ethnic differences in abdominal soft tissue sarcoma incidence in New Zealand: a retrospective audit

BACKGROUND

Soft tissue sarcomas are a rare and heterogenous group of tumours. Anecdotally there seems to be an over representation of patients of Māori ethnicity presented at the Auckland Regional Sarcoma Multidisciplinary Meeting (MDM). To date no study has reported on ethnicity demographics of abdominal and retroperitoneal sarcoma in New Zealand. The aim of this study is to characterize the ethnicity distribution of patients discussed at the regional MDM.

METHODS

A retrospective audit was performed of patients presented at the Auckland Regional Sarcoma MDM between January 2015 and December 2020 with abdominal sarcoma. Ethnicity documentation for these patients was reviewed.

RESULTS

One hundred and twenty-four patients with intra-abdominal and retroperitoneal tumours were discussed at MDM with 61 proceeding for resection, of those 43 (70.5%) were primary tumours, 10 (16.4%) were recurrent tumours and 8 (13.1%) had metastatic disease. Liposarcoma made up 56 (45.2%) cases, Leiomyosarcoma 33 (26.6%), Other 35 (28.2%). Ethnicities for this group specifically were European 64 (51.6%), Māori 31 (25.0%), Pacific Peoples 17 (13.7%), Asian 6 (4.8%) and Other/unknown 3(2.4%). This was found to be statistically significantly different to the expected ethnicity distribution based on 2018 census data from North Island DHBs (χ²  = 19.55, p = 0.00), with Māori and Pacific Peoples being over-represented and Asian patients being under-represented. Recommendation for surgery did not appear to be related to ethnicity.

CONCLUSION

Our descriptive data shows a higher proportion of patients of Māori ethnicity discussed through the North Island regional sarcoma MDM than we would expect comparted to ethnicity distribution in the general population. It is unclear whether this represents a true difference in incidence based on ethnicity.

Impact of comorbidities on oncological outcomes of Japanese patients with high grade soft tissue sarcomas

BACKGROUND

Considering the invasiveness of standard multidisciplinary approaches used for the treatment of soft tissue sarcoma, including surgery with wide margins, intensive chemotherapy, and radiotherapy, evaluation of comorbidities in high-grade soft tissue sarcoma patients is essential. Several previous studies have reported the impact of comorbidities on the survival of soft tissue sarcoma patients. Patient health status differs between nationalities or ethnic groups and only limited data has been reported with respect to the impact of comorbidities on Japanese soft tissue sarcoma patients.

METHODS

The incidence of each comorbidity, relationship between comorbidities and underlying clinicopathological factors, relationship between treatment status and comorbidities, and impact of comorbidities on disease-specific death in 136 patients with high-grade soft tissue sarcoma at the authors' institution were analyzed. For the evaluation of comorbidities, the updated Charlson comorbidity index was applied.

RESULTS

Of the patients, 25% presented with more than one comorbidity. Elderly patients showed a significantly higher incidence of comorbidities (p < 0.0001). Patients with congestive heart failure (p = 0.004), dementia (p < 0.0001), hemiplegia/paraplegia (p < 0.0001), and renal disease (p < 0.0001) showed worse prognosis. Tumor grade (p = 0.01) and updated Charlson comorbidity index (p < 0.0001) were independent risk factors for disease-specific death.

CONCLUSIONS

Comorbidity status was a significant risk factor for disease-specific death in Japanese patients with high-grade soft tissue sarcoma. Innovations in comorbidity management may be a means for the improvement of oncological outcomes in soft tissue sarcoma. Given the difficulties in conducting standard randomized control studies in this field, data accumulation from real-world cases appears to be the most practical approach in establishing and applying strategies for the treatment of patients with comorbidities or elderly patients.

Analysis of Trends in Race and Gender Disparities in Incidence-Based Mortality in Patients Diagnosed with Soft Tissue Sarcomas from 2000 to 2016

Background

The clinical course of soft tissue sarcomas is often dependent on the grade of the tumor. The variability of incidence-based mortality in low-grade and high-grade soft tissue sarcomas (STS) with respect to gender and race over the past decade has not been well studied. This study analyzes the rates of incidence-based mortality from the years 2000 to 2016 amongst the grades, genders and racial groups of patients with STS.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was queried to conduct a nation-wide analysis for the years 2000 to 2016. Incidence-based mortality for all stages of low-grade and high-grade soft tissue sarcomas was queried and the results were grouped by race (Caucasian/White vs African American/Black) and gender. All stages and ages were included in the analysis and trend from 2000 to 2016 was analyzed.

Results

The incidence-based mortality rates for Caucasians are similar to African Americans in both grades and genders. Rates were not analyzed for American Indian and Asian/Pacific Islanders due to small sample size. Mortality rates of high-grade soft tissue sarcomas were significantly higher compared to low-grade tumors. A higher rate of mortality is noted in Caucasian males compared to African Americans males despite past observations of higher incidence in African Americans. There was no significant change in the rate when trended over the past decade (2007 to 2016).

Conclusion

This study highlights the higher rate of incidence-based mortality in Caucasian males compared to African American males in the past 15 years despite a lower incidence reported in the 1995 to 2008 period. With no significant change in mortality rates/year noted during this time period, this study implies that soft tissue sarcomas in Caucasian males have worse outcomes. Further research is needed to understand the mechanism underlying this disparity.

Socio-economic factors do not affect overall survival in soft tissue sarcoma when patients treated at a single high-volume center

BACKGROUND

Treatments for soft tissue sarcoma (STS) include extensive surgical resection, radiation and chemotherapy, and can necessitate specialized care and excellent social support. Studies have demonstrated that socioeconomic factors, such as income, marital status, urban/rural residence, and educational attainment as well as treatment at high-volume institution may be associated with overall survival (OS) in STS.

METHODS

In order to explore the effect of socio-economic factors on OS in patients treated at a high-volume center, we performed a retrospective analysis of STS patients treated at a single institution.

RESULTS

Overall, 435 patients were included. Thirty-seven percent had grade 3 tumors and 44% had disease larger than 5 cm. Patients were most commonly privately insured (38%), married (67%) and retired or unemployed (43%). Median distance from the treatment center was 42 miles and median area deprivation index (ADI) was 5 (10 representing most deprived communities). The majority of patients (52%) were treated with neoadjuvant therapy followed by resection. As expected, higher tumor grade (HR 3.1), tumor size > 5 cm (HR 1.3), and involved lymph nodes (HR 3.2) were significantly associated with OS on multivariate analysis. Demographic and socioeconomic factors, including sex, age at diagnosis, marital status, employment status, urban vs. rural location, income, education, distance to the treatment center, and ADI were not associated with OS.

CONCLUSIONS

In contrast to prior studies, we did not identify a significant association between socioeconomic factors and OS of patients with STS when patients were treated at a single high-volume center. Treatment at a high volume institution may mitigate the importance of socio-economic factors in the OS of STS.

Identifying Modifiable and Non-modifiable Risk Factors of Readmission and Short-Term Mortality in Osteosarcoma: A National Cancer Database Study

BACKGROUND

There are limited data to inform risk of readmission and short-term mortality in musculoskeletal oncology. The goal of this study was to identify factors independently associated with 30-day readmission and 90-day mortality following surgical resection of osteosarcoma.

METHODS

We retrospectively reviewed patients (n = 5293) following surgical resection of primary osteosarcoma in the National Cancer Database (2004-2015). Univariate and multivariate methods were used to correlate variables with readmission and short-term mortality.

RESULTS

Of 210 readmissions (3.97%), risk factors independently associated with unplanned 30-day readmission included comorbidity burden (odds ratio [OR] 2.4, p = 0.042), Medicare insurance (OR 1.9, p = 0.021), and axial skeleton location (OR 1.5, p = 0.029). A total of 91 patients died within 90 days of their surgery (1.84%). Risk factors independently associated with mortality included age (hazard ratio 1.1, p < 0.001), increasing comorbidity burden (OR 6.6, p = 0.001), higher grade (OR 1.7, p = 0.007), increasing tumor size (OR 2.2, p = 0.03), metastatic disease at presentation (OR 8.5, p < 0.001), and amputation (OR 2.0, p = 0.04). Chemotherapy was associated with a decreased risk of short-term mortality (p < 0.001).

CONCLUSIONS

Several trends were clear: insurance status, tumor location and comorbidity burden were independently associated with readmission rates, while age, amputation, grade, tumor size, metastatic disease, and comorbidity burden were independently associated with short-term mortality.

The Interval Between Preoperative Radiation and Surgery Is Not Associated with Overall Survival for Soft-tissue Sarcomas: An Analysis of the National Cancer Database

BACKGROUND

Most cancer centers prefer preoperative radiation therapy (preRT) over postoperative therapy to treat soft-tissue sarcoma (STS) to limit long-term fibrosis, joint stiffness, and edema. Surgery is often delayed after preRT to allow for tissue recovery and to reduce wound complications. However, the association between the time interval between preRT and surgery and survival is unknown.

QUESTIONS/PURPOSES

(1) What factors are associated with the preRT-surgery interval in patients with STS? (2) Is the preRT-surgery interval associated with overall survival?

METHODS

The National Cancer Database, a nationwide registry that includes 70% of all new cancers in the United States with 90% follow-up, was reviewed to identify 6378 patients who underwent preRT and surgical resection for a localized extremity or pelvic STS from 2004 to 2014. Patients were excluded if they had lymphatic or metastatic disease at diagnosis (23%; n = 1438), underwent neoadjuvant chemotherapy (24%; 1531), were missing vital status (8%; 487), had chemosensitive histologies (9%; 603), underwent radiation other than external beam (1%; 92), were missing preRT-surgery interval (1%; 45), or had a preRT-surgery interval greater than 120 days (< 1%; 6). A total of 2176 patients were included for analysis, with a mean preRT-surgery interval of 35 ± 16 days. A multiple linear regression model was generated to assess demographic, clinicopathologic, and treatment characteristics associated with the preRT-surgery interval. A Kaplan-Meier survival analysis was then conducted, stratified by the preRT-surgery interval, to assess survival over 10 years. Finally, a multivariate Cox regression analysis model was constructed to further evaluate the association between the preRT-surgery interval and overall survival, adjusted for demographic, clinicopathologic, and treatment characteristics.

RESULTS

A longer preRT-surgery interval was associated with higher age (β = 0.002 per year [95% CI 0.0 to 0.004]; p = 0.026), tumor location in the pelvis (compared with the lower extremity; β = 0.15 [95% CI 0.082 to 0.22]; p < 0.001), and malignant peripheral nerve sheath tumor subtype (compared with undifferentiated pleomorphic sarcoma; β = 0.17 [95% CI 0.044 to 0.29]; p = 0.008). A shorter preRT-surgery interval was associated with higher facility volume (β = -0.002 per case [95% CI -0.003 to -0.002]; p = 0.026) and higher tumor stage (compared with Stage I; β = -0.066 [95% CI -0.13 to -0.006]; p = 0.03 for Stage II; β = -0.12 [95% CI -0.17 to -0.065]; p < 0.001 for Stage III). The 5-year overall survival rates were similar across all preRT-surgery interval groups: less than 3 weeks (66% [95% CI 60 to 72]), 3 to 4 weeks (65% [95% CI 60 to 71]), 4 to 5 weeks (65% [95% CI 60 to 71]), 5 to 6 weeks (66% [95% CI 60 to 72]), 6 to 7 weeks (63% [95% CI 54 to 72]), 7 to 9 weeks (66% [95% CI 58 to 74]), and more than 9 weeks (59% [95% CI 48 to 69]). Over 10 years, no difference in overall survival was observed when stratified by the preRT-surgery interval (p = 0.74). After controlling for potentially confounding variables, including age, sex, Charlson/Deyo comorbidity score, histology, tumor size, stage and surgery type, the preRT-surgery interval was not associated with survival (hazard ratio = 1 per day [95% CI 1 to 1]; p = 0.88).

CONCLUSION

With the numbers available, this study demonstrates that a delay in surgery up to 120 days after radiation is not associated with poorer survival. Therefore, clinicians may be able to delay surgery to minimize the risks of wound complications and modifiable comorbidities without affecting overall survival.Level of Evidence Level III, therapeutic study.

Actual long-term survival after resection of stage III soft tissue sarcoma

Background

Actuarial survival based on the Kaplan–Meier method can overestimate actual long-term survival, especially among those with factors of poor prognosis. Patients with American Joint Committee on Cancer stage III soft tissue sarcoma (STS) represent a subset with a high risk of STS-specific mortality. Therefore, we aimed to characterize the clinicopathological characteristics associated with actual long-term survival in patients with stage III STS.

Methods

We retrospectively reviewed 116 patients who underwent surgical resection for stage III STS with curative intent between March 2000 and December 2013. Long-term survivors (n = 61), defined as those who survived beyond 5 years, were compared with short-term survivors (n = 36), who died of STS within 5 years.

Results

Multivariate logistic regression analyses showed that a tumor size < 10 cm [odds ratio (OR) 3.95, p = 0.047], histological grade of 2 (OR 8.12, p = 0.004), and American Society of Anesthesiologists (ASA) score of 1 (OR 11.25, p = 0.001) were independently associated with actual 5-year survival. However, 66% of the long-term survivors exhibited factors of poor prognosis: 36% had a tumor size > 10 cm and 48% had a histological grade of 3. Leiomyosarcoma (3 of 10) was negatively associated with actual long-term survival.

Conclusions

Actual 5-year survival after resection of stage III STS was associated with tumor size, histological grade, and ASA score. However, majority of the actual 5-year survivors exhibit factors of poor prognosis, suggesting that aggressive treatment should be offered for a chance of long-term survival in these patients.

Chemotherapy and Survival in Patients with Primary High-Grade Extremity and Trunk Soft Tissue Sarcoma

The use of upfront chemotherapy for primary localized soft tissue sarcoma (STS) of the extremity and trunk is debated. It remains unclear if chemotherapy adds clinical benefit, which patients are likely to benefit, and whether the timing of therapy affects outcomes. We used the National Cancer Database (NCDB) to examine the association between overall survival (OS) and chemotherapy in 5436 patients with the five most common subtypes of STS with primary disease localized to the extremity or trunk, mirroring the patient population of a modern phase 3 clinical trial of neoadjuvant chemotherapy. We then examined associations between timing of multi-agent chemotherapy (neoadjuvant or adjuvant) and OS. We used a Cox proportional hazards model and propensity score matching (PSM) to account for covariates including demographic, patient, clinical, treatment, and facility factors. In the overall cohort, we observed no association between multi-agent chemotherapy or its timing and improved OS. Multi-agent chemotherapy was associated with improved OS in several subgroups, including patients with larger tumors (>5 cm), those treated at high-volume centers, or those who received radiation. We also identified an OS benefit to multi-agent chemotherapy among the elderly (>70 years) and African American patients. Multi-agent chemotherapy was associated with improved survival for patients with tumors >5 cm, who receive radiation, or who receive care at high-volume centers. Neither younger age nor chemotherapy timing was associated with better outcomes. These 'real-world' findings align with recent randomized trial data supporting the use of multi-agent chemotherapy in high-risk patients with localized STS.

The new horizon of liquid biopsy in sarcoma: the potential utility of circulating tumor nucleic acids

The diagnosis, treatment and prognosis of sarcoma are mainly dependent on tissue biopsy, which is limited in its ability to provide a panoramic view into the dynamics of tumor progression. In addition, effective biomarkers to monitor the progression and therapeutic response of sarcoma are lacking. Liquid biopsy, a recent technological breakthrough, has gained great attention in the last few decades. Nucleic acids (such as DNA, mRNAs, microRNAs, and long non-coding RNAs) that are released from tumors circulate in the blood of cancer patients and can be evaluated through liquid biopsy. Circulating tumor nucleic acids reflect the intertumoral and intratumoral heterogeneity, and thus liquid biopsy provides a noninvasive strategy to examine these molecules compared with traditional tissue biopsy. Over the past decade, a great deal of information on the potential utilization of circulating tumor nucleic acids in sarcoma screening, prognosis and therapy efficacy monitoring has emerged. Several specific gene mutations in sarcoma can be detected in peripheral blood samples from patients and can be found in circulating tumor DNA to monitor sarcoma. In addition, circulating tumor non-coding RNA may also be a promising biomarker in sarcoma. In this review, we discuss the clinical application of circulating tumor nucleic acids as blood-borne biomarkers in sarcoma.

Common genetic variation and risk of osteosarcoma in a multi-ethnic pediatric and adolescent population

Osteosarcoma, a malignant primary bone tumor most commonly diagnosed in children and adolescents, has a poorly understood genetic etiology. Genome-wide association studies (GWAS) and candidate-gene analyses have identified putative risk variants in subjects of European ancestry. However, despite higher incidence among African-American and Hispanic children, little is known regarding common heritable variation that contributes to osteosarcoma incidence and clinical presentation across racial/ethnic groups. In a multi-ethnic sample of non-Hispanic white, Hispanic, African-American and Asian/Pacific Islander children (537 cases, 2165 controls), we performed association analyses assessing previously-reported loci for osteosarcoma risk and metastasis, including meta-analysis across racial/ethnic groups. We also assessed a previously described association between genetic predisposition to longer leukocyte telomere length (LTL) and osteosarcoma risk in this independent multi-ethnic dataset. In our sample, we were unable to replicate previously-reported loci for osteosarcoma risk or metastasis detected in GWAS of European-ancestry individuals in either ethnicity-stratified analyses or meta-analysis across ethnic groups. Our analyses did confirm that genetic predisposition to longer LTL is a risk factor for osteosarcoma (ORmeta: 1.22; 95% CI: 1.09-1.36; P = 3.8 × 10-4), and the strongest effect was seen in Hispanic subjects (OR: 1.32; 95% CI: 1.12-1.54, P = 6.2 × 10-4). Our findings shed light on the replicability of osteosarcoma risk loci across ethnicities and motivate further characterization of these genetic factors in diverse clinical cohorts.

Adult Primary Bone Sarcoma and Time to Treatment Initiation: An Analysis of the National Cancer Database

Objective

The time to treatment interval (TTI), defined as the period from diagnosis to first definitive treatment, has very limited descriptions toward understanding delays in primary bone sarcoma (PBS) care. Our primary goal was to determine the national standard for time to treatment initiation (TTI) in PBS in adults and to identify characteristics associated with TTI variability.

Methods

An analysis of the National Cancer Database identified 15,083 adult patients with PBS diagnosed from 2004 to 2013. Kruskal–Wallis analysis identified differences between covariates regarding TTI and regression modeling identified covariates that independently influenced TTI.

Results

The median TTI was 22 days. Approximately 60% of patients were definitively treated in the same center where the index diagnosis was made. Increased TTI was correlated with a transition in care institution (incidence rate ratio (IRR) = 1.89; P < 0.001), being uninsured (IRR = 1.36; P < 0.001), primary tumor site in the pelvis (IRR = 1.26; P < 0.001), Medicaid insurance status (IRR = 1.22; P < 0.001), care at an academic center (IRR = 1.14; P < 0.001), non-white race (IRR = 1.12; P=0.002), and Medicare insurance status (IRR = 1.08; P=0.017). Decreased TTI was correlated with a diagnosis of chondrosarcoma (IRR = 0.85; P < 0.001), having surgery as the index treatment (IRR = 0.88; P < 0.001), a primary tumor site of the lower (IRR = 0.91; P=0.001) or upper extremity (IRR = 0.92; P=0.023), and stage II or stage III disease (IRR = 0.91; P=0.010).

Conclusions

TTI is associated with tumor, treatment, and socioeconomic and healthcare system characteristics. Transitions in care between institutions are responsible for the greatest increase in TTI. As TTI is more commonly used as a quality metric, physicians need to be aware of the causes for prolonged TTI, as we work to improve national delays in diagnosis and treatment initiation.

Surgical resection for recurrent retroperitoneal leiomyosarcoma and liposarcoma

BACKGROUND

Retroperitoneal soft tissue sarcomas (STS) include a number of histologies but are rare, with approximately 3000 cases in the USA per year. Retroperitoneal STS have a high incidence of local and distant recurrence. The purpose of this study was to review the University of Maryland Medical Center's (UMMC) treatment experience of retroperitoneal STS, where the patient population served represents a diverse socioeconomic and ethnic catchment.

METHODS

IRB approval was obtained. We constructed a de-identified database of patients diagnosed with retroperitoneal liposarcomas (LPS) or leiomyosarcomas (LMS) treated at UMMC between 2000 and 2013. A total of 49 patients (Pts) with retroperitoneal STS met our eligibility criteria. Kaplan-Meier plots were used to graphically portray progression-free survival (PFS) and overall survival (OS). The log-rank test was used to compare time-to-event distributions.

RESULTS

The median OS for all patients (Pts) was 6.3 years, and the 2-year OS rate was 81%. The median PFS for all Pts was 1.8 years, and the 2-year PFS rate was 45%. There was no difference in OS and PFS among LMS and LPS patients; the median OS for LMS was 3.8 years vs. LPS 6.4 years (p = 0.33), and the median PFS for LMS was 1.2 years vs. LPS 2.5 years (p = 0.28). There was a significant difference between histology and race (p = 0.001). LPS were primarily Caucasian 86% vs. 14% black, whereas LMS were primarily black 52% vs. 33% Caucasian. OS was influenced by functional status, gender, American Joint Committee on Cancer (AJCC) stage, grade, histology, tumor size, and extent of resection. PFS was influenced by AJCC stage, grade, and extent of resection. Neither adjuvant chemotherapy (1 Pt) nor neoadjuvant/adjuvant radiation therapy (18 Pts) influenced OS or PFS. There was a non-significant difference that Pts who could undergo resection of local recurrence had improved 2-year OS, with 100% LMS and LPS compared to 2-year OS of 71% (LMS) and 78% (LPS) not undergoing resection of local recurrence.

CONCLUSIONS

This study suggests a higher incidence of leiomyosarcoma in the African-American population. This study confirms the prognostic importance of grade, tumor size, AJCC stage, histology, and extent of resection in patient outcomes, at a large substantially diverse academic medical center. Future research into the biological features of liposarcoma and leiomyosarcoma Pts imparting these characteristics will be important to define.