Oncological and Clinical Outcomes following Surgery for Retroperitoneal Sarcomas of the Abdomen and Pelvis

Abstract

Retroperitoneal sarcomas (RPS) are a rare and heterogeneous group of tumours of mesenchymal origin. RPS comprise 15% of all soft tissue sarcomas.

The therapeutic strategies include surgical resection, radiotherapy and chemotherapy, or a combination of these. The dilemma is which of these is the best modality, or which combination and in what order is optimal, and finally, which tumours in this heterogenous group will respond to such therapies. Additionally, due to the close vicinity of vital retroperitoneal structures and organs, including the spine and bone, an important consideration relates to preservation of quality of life by determining how much can be resected without incurring undue morbidity.

Due to the location of RPS, surgical margins of normal tissue may not be possible due to limitations in the anatomy. Therefore, multivisceral resection is advocated for large retroperitoneal sarcomas, especially those with negative prognostic features, such as dedifferentiation in a liposarcoma.

The primary aim of this thesis is to assess the oncological and clinical outcomes following surgery for retroperitoneal sarcomas, focusing on the role of multi-visceral resections, including pelvic exenterations. The secondary aim of this thesis is to assess contemporary rates of positive surgical margins following surgery for RPS, and the impact of these on oncological and clinical outcomes.

Chapter 1 is a systematic review of the literature summarising outcomes of surgery for RPS, including types of surgical resections performed and their corresponding margin status, influence of these on recurrence and survival, and the morbidity and mortality associated with aggressive, multi-visceral resections. Chapter 2 reports on our experience with multivisceral resections including pelvic exenterations within a Multi-Disciplinary Team approach. Chapter 3 is a study assessing the role of a highly specialized surgery in the pelvis, pelvic exenteration, for retroperitoneal sarcomas.