Resection of Some—But Not All—Clinically Uninvolved Adjacent Viscera As Part of Surgery for Retroperitoneal Soft Tissue Sarcomas

Abstract

This issue of Journal of Clinical Oncology includes two retrospective studies evaluating aggressive surgery with wide margins (including resection of clinically uninvolved organs) in patients with primary and recurrent retroperitoneal soft tissue sarcomas. 1,2 These reports are thought provoking and should be carefully considered as we evaluate treatment options for patients with retroperitoneal sarcomas. Issues that warrant further discussion in interpreting these findings include the underlying hypothesis, methodologies used, and case selection. The underlying hypothesis behind both reports is that a surgical approach designed to achieve wide macroscopically negative surgical margins may lead to lower rates of microscopically positive surgical margins and presumably lower risks for local recurrence. In the retroperitoneal space, the only way to achieve this objective is to resect clinically uninvolved adjacent organs in an en-bloc fashion. In both studies, patients generally underwent resection of uninvolved ipsilateral kidney, colon, and/or psoas muscle. It is well accepted that the kidney and segments of the colon can usually be resected with relatively low morbidity and that the psoas muscle can be resected with low morbidity if care is taken to preserve the femoral nerve and its roots. However, retroperitoneal sarcomas are also often situated adjacent to other uninvolved retroperitoneal and intra-abdominal viscera (such as the pancreas, spleen, duodenum, and liver), large blood vessels (such as the inferior vena cava, aorta, and portal vein), and functionally significant muscles (such as the rectus abdominis and diaphragm). These adjacent viscera, vessels, and muscles can also be resected when they are clinically involved, but not without substantially greater risks for morbidity and death. The authors of the two retrospective reports did not perform routine resection of these other adjacent viscera, vessels, and muscles, even though these structures were likely just as close to the primary tumor as the colon, kidney, and psoas. Thus the approach of resecting uninvolved adjacent organs was used only selectively—some adjacent organs and muscles were resected en-bloc, but not all adjacent structures that affect final microscopic margins were resected. This is a critical point that is underemphasized in both articles. This strategy extends some, but likely not all, resection margins around sarcomas in the anatomically complex retroperitoneum—a fundamental limitation of the technique that makes it unlikely to confer a clinical benefit for many if not the majority of patients with retroperitoneal sarcomas. Both studies are retrospective and thus have limitations related to the methodology used. Bonvalot et al 2 abstracted data from operative reports, pathology reports, and other medical records of 382 patients who underwent surgery at an unspecified number of institutions