Has the Outcome for Patients Who Undergo Resection of Primary Retroperitoneal Sarcoma Changed Over Time? A Study of Time Trends During the Past 15 years

BACKGROUND

This study aimed to investigate changes in treatment strategy and outcome for patients with primary retroperitoneal sarcoma (RPS) undergoing resection at referral centers during a recent period.

METHODS

The study enrolled consecutive adult patients with primary non-metastatic RPS who underwent resection with curative intent between 2002 and 2017 at 10 referral centers. The patients were grouped into three periods according to date of surgery: t1 (2002-2006), t2 (2007-2011), and t3 (2012-2017). Five-year overall survival (OS), disease-specific survival (DSS), and crude cumulative incidence (CCI) of local recurrence (LR) and distant metastasis (DM) were calculated. Multivariable analyses for OS and DSS were performed.

RESULTS

The study included 1942 patients. The median follow-up period after resection varied from 130 months (interquartile range [IQR], 124-141 months) in t1 to 37 months (IQR, 35-39 months) in t3. The 5-year OS was 61.2% (95% confidence interval [CI], 56.4-66.3%) in t1, 67.0% (95 CI, 63.2-71.0%) in t2, and 71.9% (95% CI, 67.7-76.1%) in t3. The rate of macroscopically incomplete resection (R2) was 7.1% in t1 versus 4.7% in t3 (p = 0.066). The median number of resected organs increased over time (p < 0.001). In the multivariable analysis resection during t3 was associated with better OS and DSS. The 90-day postoperative mortality improved over time (4.3% in t1 to 2.3% in t3; p = 0.031). The 5-year CCI of LR and DM did not change significantly over time.

CONCLUSIONS

The long-term survival of patients who underwent resection for primary RPS has increased during the past 15 years. This increased survival is attributable to better patient selection for resection, quality of surgery, and perioperative patient management.

Robotic surgery for gastric gastrointestinal stromal tumors: A single center case series

BACKGROUND AND OBJECTIVES

The aim of surgical treatment of gastrointestinal stromal tumors (GIST) is a microscopically complete resection. Initial indications for laparoscopic surgery were limited to smaller tumors, in favorable locations. Over time, indications for minimal invasive surgery (MIS) have expanded, however concerns remain when considering resection of larger GISTs. Our aims were to assess the utility of robotic resection of gastric GISTs for challenging tumors.

METHODS

GIST resections, in this study were performed using the Intuitive Da Vinci Surgical Xi System. GIST's were considered challenging if tumor size was >50 mm at the time of surgery and/or the location of the tumor was type II, III, or IV using Privette/Al-Thanai classification.

RESULTS

Robotic resections were performed on 12 consecutive patients, 83% were considered challenging cases, 6 out of 12 for location and 5 out of 12 for size. Initial median tumor size on imaging was 53.7 mm, and post-imatinib was 45.8 mm. All tumors were removed with clear margins (R0) via wedge resections, with no complications. Median operative time was 192 minutes (95-250). Length of hospital stay was 2 days (2-6).

CONCLUSIONS

Robotic resection of gastric GIST's appears oncologically safe, and may expand the benefits of MIS to a greater cohort of complex cases.

Epithelioid malignant peripheral nerve sheath tumor arising in schwannoma

Epithelioid malignant peripheral nerve sheath tumor (EMPNST, malignant epithelioid schwannoma) is a rare variant of malignant peripheral nerve sheath tumor that has morphologic and immunophenotypic overlap with a variety of epithelioid neoplasms. Because of its rarity it may be potentially underrecognized. We describe a case arising in the subcutis of the thigh in a 25 year-old female, and discuss the pathologic features and differential diagnosis.

Adequate surgical margins for dermatofibrosarcoma protuberans - A multi-centre analysis

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive tumour. Adequate margins have a positive impact on recurrence rates. The aim of this study is to assess how adequate margins are achieved and secondly which additional treatment modalities might be necessary to achieve adequate margins.

MATERIAL & METHODS

Patients with DFSP treated between 1991 and 2016 at three tertiary centres were included. Patient- and tumour characteristics were obtained from a prospectively held database and patient files.

RESULTS

A total of 279 patients with a median age of 39 (Interquartile range [IQ], 31-50) years and a median follow-up of 50 (IQ, 18-96) months were included. When DFSP was preoperatively confirmed by biopsy and resected with an oncological operation in a tertiary centre, in 86% was had clear pathological margins after one excision. Wider resection margins were significantly correlated with more reconstructions (p = 0.002). A substantial discrepancy between the primary surgical macroscopic and the pathological margins was found with a median difference of 22 (range, 10-46) mm (Fig. 1). There was no significant influence of the width of the pathological clear margins (if > 1 mm) and the recurrence rate (p = 0.710).

CONCLUSION

The wider the resection margins, the more likely it is to obtain clear pathological margins, but the more likely patients will need any form of reconstruction after resection. The aim of the primary excision should be wide surgical resection, where the width of the margin should be balanced against the need for reconstructions and surgical morbidity.

Development and external validation of a dynamic prognostic nomogram for primary extremity soft tissue sarcoma survivors

BACKGROUND

Prognostic nomograms for patients with extremity soft tissue sarcoma (eSTS) typically predict survival or the occurrence of local recurrence or distant metastasis at time of surgery. Our aim was to develop and externally validate a dynamic prognostic nomogram for overall survival in eSTS survivors for use during follow-up.

METHODS

All primary eSTS patients operated with curative intent between 1994 and 2013 at three European and one Canadian sarcoma centers formed the development cohort. Patients with Fédération Française des Centres de Lutte Contre le Cancer (FNCLCC) grade II and grade III eSTS operated between 2000 and 2016 at seven other European reference centers formed the external validation cohort. We used a landmark analysis approach and a multivariable Cox model to create a dynamic nomogram; the prediction window was fixed at five years. A backward procedure based on the Akaike Information Criterion was adopted for variable selection. We tested the nomogram performance in terms of calibration and discrimination.

FINDINGS

The development and validation cohorts included 3740 and 893 patients, respectively. The variables selected applying the backward procedure were patient's age, tumor size and its interaction with landmark time, tumor FNCLCC grade and its interaction with landmark time, histology, and both local recurrence and distant metastasis (as first event) indicator variables. The nomogram showed good calibration and discrimination. Harrell C indexes at different landmark times were between 0.776 (0.761-0.790) and 0.845 (0.823-0.862) in the development series and between 0.675 (0.643-0.704) and 0.810 (0.775-0.844) in the validation series.

INTERPRETATION

A new dynamic nomogram is available to predict 5-year overall survival at different times during the first three years of follow-up in patients operated for primary eSTS. This nomogram allows physicians to update the individual survival prediction during follow-up on the basis of baseline variables, time elapsed from surgery and first-event history.

The adequacy of tissue microarrays in the assessment of inter- and intra-tumoural heterogeneity of infiltrating lymphocyte burden in leiomyosarcoma

The characterisation and clinical relevance of tumour-infiltrating lymphocytes (TILs) in leiomyosarcoma (LMS), a subtype of soft tissue sarcoma that exhibits histological heterogeneity, is not established. The use of tissue microarrays (TMA) in studies that profile TIL burden is attractive but given the potential for intra-tumoural heterogeneity to introduce sampling errors, the adequacy of this approach is undetermined. In this study, we assessed the histological inter- and intra-tumoural heterogeneity in TIL burden within a retrospective cohort of primary LMS specimens. Using a virtual TMA approach, we also analysed the optimal number of TMA cores required to provide an accurate representation of TIL burden in a full tissue section. We establish that LMS have generally low and spatially homogenous TIL burdens, although a small proportion exhibit higher levels and more heterogeneous distribution of TILs. We show that a conventional and practical number (e.g. ≤3) of TMA cores is adequate for correct ordinal categorisation of tumours with high or low TIL burden, but that many more cores (≥11) are required to accurately estimate absolute TIL numbers. Our findings provide a benchmark for the design of future studies aiming to define the clinical relevance of the immune microenvironments of LMS and other sarcoma subtypes.

Diagnostic performance of MRI and histology in assessment of deep lipomatous tumours

BACKGROUND

Deep lipomatous tumours can be benign lipomas or intermediate/locally recurring atypical lipomatous tumours (ALTs). Differentiating between these two entities clinically and radiologically is difficult. The aims of this study were to report a series of deep lipomatous tumours, comparing the clinical, radiological and pathological features of ALTs and lipomas; and to predict the likelihood of a lipomatous tumour being ALT based on anatomical site and MRI characteristics.

METHODS

This was a retrospective review of patients with deep lipomatous tumours presenting over 6 years to a tertiary sarcoma centre, with preoperative MRI, and preoperative or postoperative histology including MDM2 gene analysis. Sensitivity, specificity, predictive values and accuracy in diagnosing ALT were calculated for MRI and histopathological features.

RESULTS

Some 248 patients were included; 81 (32·7 per cent) had a final diagnosis of ALT. ALTs were larger than lipomas (median 19 versus 10 cm; P < 0·001); there was no ALT smaller than 5 cm. A tumour presenting in the lower limb was more likely to be an ALT than a lesion at any other site (48·4 versus 13·5 per cent; P < 0·001). In patients with lipomatous tumours at sites other than the lower limbs, MRI had a negative predictive value of 95 per cent for excluding ALT.

CONCLUSION

Despite concern, most deep lipomatous tumours (nearly 70 per cent) are benign lipomas. Certain features imply that tumours are almost never ALT: smaller than 5 cm or located outside the lower limb with no suspicious characteristics on MRI. Tumours with these features might safely and confidently be managed outside tertiary sarcoma centres.

STRASS (EORTC 62092): A phase III randomized study of preoperative radiotherapy plus surgery versus surgery alone for patients with retroperitoneal sarcoma

11001

Background: The predominant pattern of failure of retroperitoneal sarcoma (RPS), frequently associated with subsequent death, is locoregional recurrence. Unlike in limbs, the efficacy of radiotherapy (RT) combined with surgery is not established. Methods: STRASS is a randomized, multicentre, international trial. Eligible patients had histologically-proven localized primary RPS, operable and suitable for radiotherapy. Patients were randomized 1:1 to preoperative RT (3D-CRT or IMRT) 50.4 Gy followed by surgery (RT/S group) or surgery alone (S group), stratified by hospital and performance status (0-1 vs 2). Primary endpoint is abdominal recurrence-free survival (ARFS; local relapse after complete resection, peritoneal sarcomatosis, R2 surgery, progressive disease during RT or unresectable disease). IDMC recommended a sensitivity analysis in which local progression on RT is not regarded as an event for patients who subsequently achieve complete surgical resection. Secondary endpoints were recurrence-free survival, overall survival, acute toxicity profile of RT, perioperative and late complications, and QoL. The study was designed to provide 90% power to show an increase of 20% in the 5-year ARFS rate, from 50% to 70% (corresponding to a HR of 0.52) at 2-sided 5% significance level. Results: 266 patients from Europe, USA and Canada were randomized between January 2012 and April 2017; 198 patients (74.5 %) had liposarcoma (LPS). Eighteen patients were designated ineligible. Overall rate of re-operation for any complication was 10.1%: 13 (10.9%) and 12 (9.4%) patients in RT/S versus S groups. 19 pts (14%) progressed during RT, 4 of whom did not undergo surgery. 3-year ARFS was 60.4% (95% Confidence interval (CI) 51.4-68.2%) and 58.7% (49.5- 66.7%) (HR = 1.01, 95%CI 0.71-1.44, p=0.954) in RT/S versus S groups. In the sensitivity analysis, 3-year ARFS was 66.0% (57.1-73.5%) and 58.7% (49.5-66.7%) in RT/S versus S groups (HR = 0.84, 95% CI 0.58-1.21, p=0.340). In the LPS subgroup, 3-year ARFS (sensitivity analysis) was 71.6% (61.3-79.6%) and 60.4% (49.8-69.5%) in RT/S versus S groups (HR = 0.64, 95%CI 0.40-1.01, p =0.049). Conclusion: STRASS failed to demonstrate a benefit of pre-operative RT for RPS. In the exploratory analysis, preoperative RT may benefit the LPS subgroup. Funding Source: EORTC and EUROSARC FP7 278472. Clinical trial information: EORTC 62092.

Radiotherapy for retroperitoneal liposarcoma: A report from the Transatlantic Retroperitoneal Sarcoma Working Group

Background

The current study investigated the role of radiotherapy (RT) in patients with primary nonmetastatic retroperitoneal liposarcomas.

Methods

A total of 607 patients with localized retroperitoneal well‐differentiated liposarcomas (WDLPS) and dedifferentiated liposarcomas (DDLPS) underwent surgical resection with or without RT at 8 high‐volume sarcoma centers (234 patients with WDLPS, 242 patients with grade 1 to 2 DDLPS, and 131 patients with grade 3 DDLPS; grading was performed according to the National Federation of Centers for the Fight Against Cancer [Federation Nationale des Centres de Lutte Contre le Cancer; FNCLCC]). RT was administered in 19.7%, 34.7%, and 35.1%, respectively, of these 3 cohorts. Overall survival (OS) was estimated using the Kaplan‐Meier method, and the incidences of local recurrence and distant metastasis (DM) were estimated in a competing risk framework. To account for bias consistent with nonrandom RT assignment, propensity scores were estimated. Cox univariable analysis of the association between RT and oncological endpoints was performed by applying inverse probability of treatment weighting (IPTW) using propensity scores.

Results

Age, tumor size, and the administration of chemotherapy were found to be significantly imbalanced between patients who did and did not undergo RT in all cohorts. IPTW largely removed imbalances in key prognostic variables. Although the 8‐year local recurrence incidences in patients treated with surgery plus RT versus surgery only were 11.8% and 39.2%, respectively, for patients with WDLPS (P = .011;); 29.0% and 56.7%, respectively, for patients with grade 1 to 2 DDLPS (P = .008); and 29.8% and 43.7%, respectively, for patients with grade 3 DDLPS (P = .025), this significant benefit was lost after IPTW analyses. There were no significant differences noted with regard to DM and OS between irradiated and unirradiated patients across all 3 cohorts.

Conclusions

Perioperative RT was found to be associated with better local control in univariable unadjusted analysis in all 3 cohorts, but not after accounting for imbalances in prognostic variables. RT did not impact on DM or OS. The appropriate selection of RT in this disease remains challenging. The results of the European Organization for Research and Treatment of Cancer (EORTC)–Soft Tissue and Bone Sarcoma Group (STBSG) 62092‐22092 prospective randomized trial are awaited.

In the current study, the addition of radiotherapy to curative surgery is analyzed in a large, retrospective, multi‐institutional series of patients with primary retroperitoneal liposarcoma. Although there appears to be an association with better local control and outcome, this benefit is lost after propensity score adjustment. The authors currently are awaiting the results of the European Organization for Research and Treatment of Cancer–Soft Tissue and Bone Sarcoma Group 62092‐22092 prospective randomized trial examining the value of preoperative radiotherapy.

Regional chemotherapy by isolated limb perfusion prior to surgery compared with surgery and post-operative radiotherapy for primary, locally advanced extremity sarcoma: a comparison of matched cohorts

Background

Induction chemotherapy by isolated limb perfusion (ILP) with melphalan and tumour necrosis factor-α is an effective strategy to facilitate limb-conserving surgery in locally advanced extremity sarcoma. In a comparison of cohorts matched for grade, size and surgical resectability, we compared the outcome of patients undergoing induction ILP prior to limb-conserving surgery and selective post-operative radiotherapy with patients undergoing limb-conserving surgery and routine post-operative radiotherapy.

Methods

Patients with primary, grade 2/3 sarcomas of the lower limbs over 10 cm in size were identified from prospectively maintained databases at 3 centres. Patients treated at a UK centre underwent limb-conserving surgery and post-operative radiotherapy (Standard cohort). Patients at two German centres underwent induction ILP, limb-conserving surgery and selective post-operative radiotherapy (ILP cohort).

Results

The Standard cohort comprised 80 patients and the ILP cohort 44 patients. Both cohorts were closely matched in terms of tumour size, grade, histological subtype and surgical resectability. The median age was greater in the Standard vs the ILP cohort (60.5 years vs 56 years, p = 0.033). The median size was 13 cm in both cohorts. 5-year local-recurrence (ILP 12.2%, Standard 20.1%, p = 0.375) and distant metastases-free survival rates (ILP 49.6%, Standard 46.0% p = 0.821) did not differ significantly between cohorts. Fewer patients received post-operative radiotherapy in the ILP cohort compared with the Standard cohort (27% vs 82%, p < 0.001).

Conclusion

In comparative cohorts, the outcomes of patients undergoing induction ILP prior to surgery did not differ from those undergoing standard management, although induction ILP was associated with a reduced need for adjuvant radiation.

Endometrial Stromal Sarcoma With Hyalinizing Giant Rosettes, Mimicking Low-Grade Fibromyxoid Sarcoma

We highlight a rare variant pattern of low-grade endometrial stromal sarcoma showing extensive collagenous rosette formation, closely mimicking low-grade fibromyxoid sarcoma. Additionally, this neoplasm showed diffuse and strong expression of muscle markers, favoring an initial diagnosis of leiomyosarcoma. Reverse transcription-polymerase chain reaction showed the presence of JAZF1-SUZ12 fusion transcripts, and this highlights the broad morphologic and immunophenotypic spectrum of endometrial stromal sarcoma.

Post-relapse outcomes after primary extended resection of retroperitoneal sarcoma: A report from the Trans-Atlantic RPS Working Group

BACKGROUND

Despite a radical surgical approach to primary retroperitoneal sarcoma (RPS), many patients experience locoregional and/or distant recurrence. The objective of this study was to analyze post-relapse outcomes for patients with RPS who had initially undergone surgical resection of their primary tumor at a specialist center.

METHODS

All consecutive patients who underwent macroscopically complete resection for primary RPS at 8 high volume centers from January 2002 to December 2011 were identified, and those who developed local recurrence (LR) only, distant metastasis (DM) only, or synchronous local recurrence and distant metastasis (LR+DM) during the follow-up period were included. Overall survival (OS) was calculated for all groups, as was the crude cumulative incidence of a second recurrence after the first LR. Multivariate analyses for OS were performed.

RESULTS

In an initial series of 1007 patients with primary RPS, 408 patients developed recurrent disease during the follow-up period. The median follow-up from the time of recurrence was 41 months. The median OS was 33 months after LR (n = 219), 25 months after DM (n = 146), and 12 months after LR+DM (n = 43), and the 5-year OS rates were 29%, 20%, and 14%, respectively. Predictors of OS after LR were the time interval to LR and resection of LR, while histologic grade approached significance. For DM, significant predictors of OS were the time interval to DM and histologic subtype. The subgroup of patients who underwent resection of recurrent disease had a longer median OS than patients who did not undergo resection.

CONCLUSIONS

Relapse of RPS portends high disease-specific mortality. Patients with locally recurrent or metastatic disease should be considered for resection. Cancer 2017;123:1971-1978. © 2017 American Cancer Society.

Selective marginal resections in the management of aggressive angiomyxomas

AIM

Aggressive angiomyxomas (AA) are rare tumors, most commonly presenting in the pelvis of women of childbearing age. This study presents the results of selective marginal resection of this disease in patients managed at a single institution.

METHODS

Patients diagnosed with AA from July 2001 to July 2015 were identified from a prospectively maintained histopathology database.

RESULTS

Seventeen patients were diagnosed with AA in the study period. The median age at diagnosis was 48 years. Females were more commonly affected with a M:F of 1:8.5. The most common differential diagnoses were an ischiorectal abscess or Bartholin's cyst. Fifteen cases occurred in the pelvis, with two cases at other sites. Median maximum tumor diameter was 10 cm. Of the pelvic cases, 12 were managed operatively via perineal, abdominal, or abdominoperineal approaches. Excision was performed in a marginal fashion with minimal morbidity. Local recurrence developed in 58.3% with a median local recurrence free survival of 25 months. No patients developed metastatic disease or died from disease.

CONCLUSION

AA are rare tumors with a propensity for local recurrence. Atypical presentations of other perineal pathologies should prompt further investigation. Surgery should be reserved for symptomatic patients and is associated with low rates of morbidity. J. Surg. Oncol. 2016;114:828-832. © 2016 2016 Wiley Periodicals, Inc.

Endometriosis of Extra-Abdominal Soft Tissues

While endometriosis, defined as the presence of endometrial tissue in extrauterine sites, is most frequently encountered within the peritoneal cavity, a small but significant proportion of cases occur at extra-abdominal soft tissue sites, particularly in relation to previous abdominal surgery. We reviewed the cases of endometriosis of soft tissue sites seen at a tertiary soft tissue center. All cases of extra-abdominal soft tissue endometriosis diagnosed at this institution over a 13-year period were reviewed, and clinical and pathologic findings were recorded. Forty-five patients had diagnoses of soft tissue endometriosis and there were 34 diagnostic biopsies and 26 surgical excision specimens. All but 1 case were abdominal wall lesions, with 1 located in the upper arm. A total of 33 patients presented with lesions in scars of previous operations (31 in Pfannenstiel incisions for Caesarean sections, presenting with a median interval of 6 years (range 1-16 years) following surgery). The lesions ranged in size from 1 to 8 cm (median 3.5 cm). One case showed decidualized stroma with trophoblast cells, while 2 had secondary adenocarcinoma arising from endometriosis. Eighteen cases were tested for β-catenin expression immunohistochemically, of which 5 showed at least focal nuclear positivity in the surrounding fibrous tissue (although not within glands or stroma). Soft tissue endometriosis is seen most commonly in surgical scars, particularly following Caesarean sections. Spontaneous endometriosis also most commonly occurs in the abdominal wall, although can occur exceptionally at unusual sites, such as extremities. Secondary changes, including carcinomas, can arise from endometriosis. The differential diagnosis of these lesions includes fibromatosis, which may be erroneously diagnosed on small, nonrepresentative core biopsy specimens.

Patterns of disease relapse in primary extremity soft-tissue sarcoma

Background

Extremity soft-tissue sarcomas comprise a range of distinct histological subtypes. This study aimed to characterize the patterns of disease relapse in patients undergoing resection of primary extremity soft-tissue sarcoma.

Methods

All patients who had resection of primary extremity soft-tissue sarcoma at the Royal Marsden Hospital between January 2004 and January 2014 were identified from an institutional database.

Results

In the period examined, 556 patients underwent resection. The most common histological subtypes were undifferentiated pleomorphic sarcoma (169 patients, 30·4 per cent), well differentiated liposarcoma (63, 11·3 per cent), myxoid liposarcoma (62, 11·2 per cent), myxofibrosarcoma (54, 9·7 per cent) and leiomyosarcoma (39, 7·0 per cent). Local recurrence-free survival (LRFS) did not differ significantly between histological subtypes (P = 0·222). Distant metastasis-free survival (DMFS) and disease-specific survival (DSS) were found to differ significantly between subtypes (P &lt; 0·001 for both DMFS and DSS), with the worst outcomes in patients with undifferentiated pleomorphic sarcoma (5-year survival rate: 56·8 (95 per cent c.i. 52·5 to 61·1) per cent for DMFS; 60·1 (55·6 to 64·6) per cent for DSS). However, on multivariable analysis, histological subtype was not found to be independently prognostic for LRFS, DMFS or DSS. Metastatic disease developed in 149 patients, with the lungs being the most common site of first metastasis (120 patients, 80·5 per cent). The site of first metastasis differed between subtypes, with extrapulmonary metastases predominant in myxoid liposarcoma (11 of 13 patients; P &lt; 0·001).

Conclusion

Although histological subtype was not found to be an independent prognostic factor for oncological outcomes, the site of first metastasis differed significantly between subtypes.