Did outcomes improve in retroperitoneal sarcoma surgery?

Learning curve in retroperitoneal sarcoma surgery

INTRODUCTION

Retroperitoneal sarcoma (RPS) surgery poses unique challenges. This retrospective study aimed to analyze the learning curve (LC) in RPS surgery, assessing the relationship between surgical experience and outcomes.

MATERIALS AND METHODS

Cumulative sum (CUSUM) analysis was used to analyze 62 RPS surgeries performed by a single surgeon between 2016 and 2022 at our center.

RESULTS

The number of cases where the surgeon acted as first operator increased from 3 in 2016 to 13 in 2022. The surgeon operated with his mentor in 66.7 % of cases in 2016, whereas in 7.7 % of cases in 2022. LC consisted of 3 phases. Phase 1 (16 cases), with a negative slope, represented shorter operative time (OT) and fewer number of resected organs (RO). Phase 2 (30 cases) was the plateau phase. Phase 3 (16 cases), with a positive slope, indicated longer OT and more RO. Statistically significant differences were observed in terms of size (p = 0.003), presentation (p = 0.048), number of resected organs (p = 0.046), pattern of resection (p = 0.033), OT (p = 0.006), and length of stay (p = 0.026) between the three phases.

CONCLUSION

This study focused on the critical role of LC in RPS surgery, emphasizing its influence on outcomes. We identified three phases, highlighting the surgeon's evolution. This offers a framework for educating sarcoma surgeons and ensuring exposure to increasing surgical complexity. In discussions on sarcoma referral centers and the correlation between case volume and outcomes, this study underlines the importance of evaluating LC to distinguish surgeons qualified to manage sarcoma cases within a referral center.

Advancements in Diagnosis and Multimodal Treatment Strategies for Retroperitoneal Tumors: A Comprehensive Review

Retroperitoneal tumors (RPTs) encompass both benign and malignant entities, constituting ~0.1% to 0.2% of all malignant tumors, of which 70% to 80% manifest malignancy. Predominantly, retroperitoneal sarcomas (RPS) represent the most prevalent subtype among RPT. With over 70 histologic forms identified, liposarcomas and leiomyosarcomas emerge as the primary constituents of RPS. Accurate diagnosis of RPTs necessitates preoperative core-needle biopsy and comprehensive imaging assessment. The current staging protocol for RPS relies on the eighth edition of the American Joint Committee on Cancer/TNM classification. Surgical excision remains the established gold standard for treating RPS. Therapeutic approaches vary according to the underlying pathophysiology. Although chemotherapy and radiotherapy exhibit efficacy in managing metastatic and recurrent unresectable RPS, their role in primary RPS remains unresolved, necessitating further clinical trials for validation. Concurrently, ongoing research explores the potential of targeted therapies and immunotherapy. This literature review aims to provide a comprehensive overview of existing research, delineating diagnostic pathways and optimal therapeutic strategies for RPT.

Case Report: Successful R0 resection in locally advanced retroperitoneal sarcomas

We present a case series of three successfully resected tumors in our center at Al-Makassed Hospital in Jerusalem, Palestine, all of which primarily involved or invaded adjacent structures and needed a multidisciplinary approach to achieve R0 resection. Our first patient is a 42-year-old previously healthy female with intermittent attacks of dull aching abdominal pain. Her tumor was a leiomyosarcoma that involved major vessels and other adjacent vital structures. Ultimately, she needed major highly advanced surgery necessitating the need for vascular reconstruction of the IVC, as well as R0 resection. The surgery was performed by a multidisciplinary team of highly specialized surgeons in related fields. Our second case is a 75-year-old female patient with a well-differentiated liposarcoma invading the upper pole of the right kidney, necessitating a nephrectomy. Consequently, this case demanded the interdisciplinary involvement of nephrology. Our third patient is a 59-year-old male with dedifferentiated liposarcoma that involved the spleen, pancreas, and splenic flexure while engulfing the left kidney and ureter. Beyond the removal of the tumor, multiorgan resection was imperative to achieve microscopic margin-free resection. This extensive local spread needed broad collaboration from the medical team and other surgical subspecialties. All surgeries went well, and their outcomes were promising. All patients had an uneventful follow-up and, to date, no recurrence. Invasive retroperitoneal sarcomas of different histological types and clinical stages represent a technical challenge. Careful preoperative investigation and an experienced, dedicated multidisciplinary team of surgeons and non-surgeons from related fields, including vascular, urologic, and hepatobiliary surgeons, are usually needed for a safe and successful R0 resection despite extensive tumor involvement in light of difficulty achieving early diagnosis.

Intra and extra pelvic multidisciplinary surgical approach of retroperitoneal sarcoma: Case series report

BACKGROUND

Retroperitoneal sarcoma (RPS) is a rare malignancy arising from mesenchymal cells that most commonly presents as an abdominal mass and is associated with poor prognosis. Although several studies have assessed the survival benefits of wide excision, few have reported detailed methods for achieving wide excision in patients with RPS.

AIM

To describe our experience with multidisciplinary surgical resection of RPS using intra- and extra-pelvic approaches.

METHODS

Multidisciplinary surgery is an anatomical approach that combines intra- and extra-peritoneal access within the same surgery to achieve complete RPS removal. This retrospective review of the records of patients who underwent multidisciplinary surgery for RPS analyzed surgical and survival outcomes.

RESULTS

Eight patients underwent 10 intra- and extra-pelvic surgical resections, and their median mass size was 12.75 cm (range, 6-45.5 cm). Using an intrapelvic approach, laparoscopy-assisted surgery was performed in four cases and laparotomy surgery in six. Using an extrapelvic approach, ilioinguinal and posterior approaches were used in four cases each, and the prone position and midline skin incision were shared in one. All patients’ RPS masses were removed completely, and four achieved R0 resection through intra- and extra-pelvic surgery. The median estimated blood loss was 2000 mL (range, 300-20000 mL) and the median hospitalization was 12.6 d (range, 9-69 d). Reoperation was needed in two patients (one for wound necrosis and the other for bowel perforation and wound necrosis). The median overall survival rate and median progression-free survival were 64.6 and 13.7 mo, respectively.

CONCLUSION

RPS is therapeutically challenging because of its location and high risk of recurrence. Therefore, intra- and extra-pelvic surgical approaches can improve the macroscopic security of the surgical margin.

Retroperitoneal Sarcomas: a Current Review on Management

Retroperitoneal sarcomas are heterogeneous tumours with variable disease biology and outcomes. The prognosis is primarily related to tumour histology and grade as well as the ability to achieve margin negative resection. Surgery involves compartment or contiguous organ resection to achieve the above goal. Careful utilization of neoadjuvant and adjuvant strategies like radiotherapy and/or chemotherapy can lead to improvement in margin status, thereby contributing to better local control and possibly reducing systemic dissemination. Use of targeted therapies has paved newer pathways of treatment integration centred on molecular and genetic targets. The aim of this review is to update the reader on all aspects of retroperitoneal sarcoma management including emphasis on pertinent and landmark trials in this regard.

Management of Locally Recurrent Retroperitoneal Sarcoma in the Adult: An Updated Consensus Approach from the Transatlantic Australasian Retroperitoneal Sarcoma Working Group

BACKGROUND

Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS.

METHODS

An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor.

RESULTS

Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS.

CONCLUSIONS

Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery.

A novel nomogram for predicting local recurrence-free survival after surgical resection for retroperitoneal liposarcoma from a Chinese tertiary cancer center

BACKGROUND

Local recurrence is the most difficult postoperative challenge and the leading cause of death in patients with retroperitoneal liposarcoma (RLPS). We aimed to establish a postoperative nomogram exclusively focused on RLPS for predicting local recurrence-free survival (LRFS).

METHODS

A cohort of 124 patients after surgical resection with curative intent in the Peking University Cancer Hospital Sarcoma Center were included in the study. Demographic, clinicopathologic, and treatment variables were analyzed using the Cox regression model. Significant clinically relevant variables in multivariable analysis were incorporated into the RLPS-specific nomogram. The discriminative ability and predictive accuracy of the nomogram were assessed by calculating the concordance index and drawing a calibration plot.

RESULTS

At a median follow-up of 26.5 (interquartile range 10.9-39.4) months, 71 patients had recurrent disease. The 3-year and 5-year LRFS rates were 35.6% (95% confidence interval, 27.0-46.9%) and 28.2% (95% CI 15.8-38.6%), respectively. Multivariate analysis identified the French Federation of Cancer Centers Sarcoma Group (FNCLCC) grade and completeness of resection as independent predictors of LRFS. Variables included in our nomogram were: presentation status, multifocality, completeness of resection, histologic subtypes, and FNCLCC grade. The concordance index of our nomogram was 0.732 (95% CI 0.667-0.797) and the calibration plot was excellent.

CONCLUSIONS

Our novel nomogram for patients with resected RLPS could improve recurrence risk stratification to explore molecular analysis associated with recurrence.

Retroperitoneal tumors: Review of diagnosis and management

Retroperitoneal tumors are extremely rare tumors occurring in the retroperitoneum. Retroperitoneal tumors are divided into benign tumors and malignant tumors, including retroperitoneal sarcoma. Approximately 70-80% of primary retroperitoneal soft-tissue tumors are malignant; however, these only account for 0.1-0.2% of all malignancies. Retroperitoneal sarcoma is an orphan malignant disease with a low incidence. The information on benign retroperitoneal tumors is limited. The American Joint Committee on Cancer/TNM classification updated to the 8th edition in 2017. In 2010, three new drugs for soft tissue sarcoma were approved based on the results of phase III trials, but the histological subtypes of the patients enrolled in the trials of each drug differed. Recently, in addition to surgery for retroperitoneal sarcoma, the effectiveness of perioperative radiation therapy has become interesting. For malignant retroperitoneal tumors and retroperitoneal sarcoma, survival improvement and locoregional recurrence prevention can be undertaken by carrying out surgery to secure negative margins with wide and combined resection of some adjacent organs, and cooperation with a trained medical team comprising of radiologists, pathologists and medical oncologists in centralized hospitals. Some clinical trials aimed at further improving treatment results by adding preoperative chemotherapy and radiation therapy based on histological confirmation using a correct needle biopsy are in progress. In recent years, molecular profiling has been used to select eligible patients for chemotherapy. In the future, precision medicine with next-generation sequencing technology will be expected among the diverse and potential future treatments for retroperitoneal sarcoma. In this review, we summarized the current state of retroperitoneal tumors and retroperitoneal sarcoma.

Downregulation of RRM2 Attenuates Retroperitoneal Liposarcoma Progression via the Akt/mTOR/4EBP1 Pathway: Clinical, Biological, and Therapeutic Significance

Background

Retroperitoneal liposarcoma (RLPS) is a rare tumor with high recurrence rate. Ribonucleotide reductase small subunit M2 (RRM2) protein is essential for DNA synthesis and replication. Our previous study has demonstrated that RRM2 downregulation inhibited the proliferation of RLPS cells, but further association between RRM2 and RLPS and relevant mechanisms remains to be explored.

Methods

RRM2 expression was evaluated in RLPS tumor tissues and cell lines by using real-time PCR and immunohistochemical analysis. The effect of RRM2 downregulation on cell proliferation, apoptosis, cell cycle, cell migration and invasion was tested by lentivirus. The effect of RRM2 inhibition on tumor growth in vivo was assessed by using patient-derived tumor xenograft (PDX) of RLPS and RRM2 inhibitor. The underlying mechanisms of RRM2 in RLPS were explored by protein microarray and Western blotting.

Results

The results showed that RRM2 mRNA expression was higher in RLPS tissues than in normal fatty tissues (P<0.001). RRM2 expression was higher in the dedifferentiated, myxoid/round cell, and pleomorphic subtypes (P=0.027), and it was also higher in the high-grade RLPS tissues compared to that in the low-grade RLPS tissues (P=0.004). There was no correlation between RRM2 expression and overall survival (OS) or disease-free survival (DFS) in this group of RLPS patients (P>0.05). RRM2 downregulation inhibited cell proliferation, promoted cell apoptosis, facilitated cell cycle from G1 phase to S phase and inhibited cell migration and invasion. Inhibition of RRM2 suppressed tumor growth in NOD/SCID mice. Protein microarray and Western blot verification showed that activity of Akt/mammalian target of rapamycin/eukaryotic translation initiation factor 4E binding protein 1 (Akt/mTOR/4EBP1) pathway was downregulated along with RRM2 downregulation.

Conclusion

RRM2 was overexpressed in RLPS tissues, and downregulation of RRM2 could inhibit RLPS progression. In addition, suppression of RRM2 is expected to be a promising treatment for RLPS patients.