Surgical Management of Primary Retroperitoneal Sarcomas: Rationale for Selective Organ Resection.

BACKGROUND: Recently, some have argued for routine resection of adjacent but uninvolved organs in patients with retroperitoneal sarcoma (RPS) without stipulating the rationale for such organ resection (beyond the need to achieve a macroscopically complete resection) or examining histopathologic organ invasion (HOI). This study reviewed the authors' experience with primary RPS to investigate the rate and rationale for individual organ resection and the rate of HOI.

METHODS: Operative and pathology reports for patients with primary RPS who underwent resection at our institution were retrospectively reviewed. Histopathologic organ invasion was confirmed by a dedicated sarcoma pathologist.

RESULTS: From 2002 through 2011, 118 patients underwent resection of a primary RPS, and 99 of these patients (84%) had at least one organ resected. Kidney (n = 57), colon (n = 51), and adrenal (n = 41) were the most commonly resected organs. For the 302 organs removed, the perioperative clinical rationale for the resection was suspected invasion or tumor origin (n = 52, 17%), involved end-organ vasculature (n = 39, 13%), organ encasement (n = 42, 14%), tumor adherence (n = 127, 42%), resection required for R0/R1 resection (n = 25, 8%), or other (n = 17, 6%). The presence of HOI was found in 77 (25%) of the 302 organs resected. In the reviewed studies, HOI was identified in 34 (65%) of 52 organs suspected of invasion or tumor origin, in 19% of organs resected due to tumor encasement, and in 26% of organs with adherent tumor, even when not suspected intraoperatively, but was never identified in organs resected purely as part of a liberal en bloc resection of adjacent organs. When invasion was suspected intraoperatively, HOI was confirmed in 50, 78, and 100% of resected organs respectively for well-dedifferentiated liposarcoma, dedifferentiated liposarcoma (DDLPS), and leiomyosarcoma (LMS).

CONCLUSIONS: Histologic organ invasion was observed more commonly in organs resected with suspicion of invasion than in organs resected simply to achieve a negative margin, although this reflects a degree of subjectivity and selection bias. In more than one-fourth of adherent organs, HOI was present even when not suspected intraoperatively. Histologic subtype may predict HOI because DDLPS and LMS are associated with high rates of HOI when invasion is suspected intraoperatively. Development of a data-driven, histology-specific rationale for adjacent organ resection is critical.