Extended Surgical Resection and Histology in Retroperitoneal Sarcoma

Abstract

While several decades ago soft tissue sarcoma was often managed as one disease, we now recognize that sarcoma is an umbrella term encompassing almost 100 different pathologies, each characterized by unique genetic aberrations. In many ways, the field of sarcoma biology is on the cutting edge of personalized medicine; we routinely use histologic and molecular information to individualize management algorithms. In this issue of Annals of Surgical Oncology, Gronchi et al. present data collected over a 10-year period, and describing outcomes after resection of primary retroperitoneal sarcomas at the Instituto Nazionale Tumori (INT) in Milan and the Institute Gustave Roussy (IGR) in Paris. The study delineates rates of local and distal recurrence as they associate with histology. The results bring up numerous questions regarding our selection of patients for surgery and adjuvant therapy, as well as the manner in which we design and interpret clinical trials seeking to optimize management of retroperitoneal sarcomas.For example, the results presented by Dr Gronchi and colleagues demonstrate that retroperitoneal leiomyosarcoma has a high propensity for distal recurrence (55 % of patients in this series with 44 months' follow-up). Very few (5 %) were observed to have local recurrence without distant recurrence. A similar rate of distal recurrence-43 % at 5 years-was reported by Gladdy et al. 1 The rate continued to climb over time to 52 % at 10 years after surgery. Data of this nature have significant implications and can alter our approach to retroperitoneal leiomyosarcoma. A 40-50 % distal rate of metastasis is similar to that observed for large, high-grade extremity tumors.2 Patients with these lesions are frequently considered for neoadjuvant/adjuvant chemotherapy. Perhaps patients with retroperitoneal leiomyosarcomas should be considered for similar treatment. Similarly, if risk of local recurrence without distal disease is as low as 5 %, then this subgroup has little potential to benefit from neoadjuvant radiation. In fact, one could argue that inclusion of leiomyosarcoma patients in the ongoing EORTC phase III STRASS trial, which examines the role of neoadjuvant radiation, will compromise the power of a study in which the primary endpoint is abdominal recurrence-free survival. 3There are limitations to this study. Follow-up is short and, in some histologic subgroups, fewer than ten patients remain to be analyzed 5 years after surgery. Some potentially interesting points are not reported (e.g. do concurrent local and distal recurrences occur in dedifferentiated liposarcoma or leiomyosarcoma?), and it is arguable that patients undergoing R2 resection should have been excluded from analyses. However, in addition to the description of leiomyosarcoma outcomes discussed above, many other important points are made regarding the role of biology in predicting outcome after resection of retroperitoneal sarcomas. Well-differentiated liposarcomas do not metastasize and, when removed by an experienced surgeon, rates of local ...

Multiply recurrent retroperitoneal liposarcoma

“…Biological features of the liposarcoma can determine long‐term patient outcomes . A key biologic feature is histologic subtype.…”

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

“…Improved local control has been achieved with extended surgical resection, with evidence suggesting a corresponding survival benefit . However, tumor biology remains one of the major determinants of long‐term outcomes . To date, there are minimal data to guide treatment decisions when a patient with RPS develops recurrent disease.…”

“…6 However, tumor biology remains one of the major determinants of long-term outcomes. [7][8][9][10] To date, there are minimal data to guide treatment decisions when a patient with RPS develops recurrent disease. An understanding of the consequences of disease recurrence is vital in deciding upon an appropriate management strategy.…”

Retroperitoneal Sarcoma (RPS) High Risk Gross Tumor Volume Boost (HR GTV Boost) Contour Delineation Agreement Among NRG Sarcoma Radiation and Surgical Oncologists

“…Additional unsettled issues pertain to appropriate extent of surgery for low- versus high-grade tumors and LPS versus leiomyosarcoma and other histologies. 23,25,26 Risk–benefit in terms of resection morbidity versus risk for recurrence is likely different for each of these scenarios and is not yet fully understood. In attempt to address many of these questions, a Transatlantic Retroperitoneal Sarcoma Working Group has been established.…”