Clinical implications of incomplete surgical resection

Several investigators have clearly and consistently shown the prognostic significance of complete resection of retroperitoneal disease [3,7]. Stenning and colleagues [35] reported that the risk of disease progression for patients without complete resection of all residual masses was approximately four times the risk for those with complete resection [35,36].

Data from Indiana University and more recently, MSKCC, clearly show that patients requiring reoperative retroperitoneal surgery are significantly compromised regardless of other risk factors [3,7]. Donohue and colleagues [7] reported that the relapse rates for primary versus redo post-chemotherapy surgery were 20.6% and 51.6%, respectively. Furthermore, the survival rates decrease from 84% in the primary PC-RPLND group to 55% in the redo group. McKiernan and colleagues [3] reported a 56% disease-specific survival for patients requiring reoperation compared with 90% for those undergoing initial PC-RPLND (Fig. 1) [3].

Survival is also compromised in patients requiring reoperative retroperitoneal surgery following initial primary RPLND. In the MSKCC series, 5-year survival dropped from 99.3% to 86.0% for 22 patients requiring redo-RPLND [3]. Of note 20 (90%) of the 22 patients had received cisplatin-based chemotherapy between the first and second operation, including three or four cycles of induction cisplatin-based chemotherapy because of incomplete resection. This underscores the fact that effective cisplatin-based chemotherapy will not compensate for inadequate surgery.

The findings of multiple series underscore the need for meticulous and complete resection of teratomatous elements to avoid local recurrence and possible malignant transformation. McKiernan and colleagues [3] reported that 10 (45%) of 22 patients undergoing primary RPLND and 20 (59%) of 34 patients undergoing PC-RPLND had teratomatous elements present at the initial RPLND before retroperitoneal recurrence. Teratoma is the most common histo-logic finding in the reoperative setting following both primary RPLND and PC-RPLND, suggesting that incompletely resected teratoma is a lifelong risk factor for redo surgery. Although teratoma is histologically benign, its biologic and clinical potential is unpredictable. Incompletely resected teratoma may grow, obstruct, or invade local structures. Furthermore, they may undergo malignant transformation with development of non-germ cell elements like sarcoma or carcinoma [8].

Unresected teratoma may result in late relapse [8,24,37]. Holzik and colleagues [38] reported two patients who died from progressive malignant transformation of teratoma after suffering late relapse in the retroperitoneum following prior resection of mature teratoma. Loehrer and associates [37] noted that 10 (19%) of 51 patients with tera-toma developed late recurrence. Most recurrences developed locally implying incomplete resection and a significant proportion had undergone malignant transformation [8]. McKiernan and colleagues [3] reported only a 20% survival rate in patients whose reoperative retroperitoneal specimen was teratoma with malignant transformation (TMT).

In the reoperative setting, the most significant factors that affect survival are serum tumor marker status at reoperation, histologic findings at surgery, and completeness of resection [3,39,40]. McKiernan and colleagues [3] reported a 52% 2-year survival in 10 patients who underwent reoperative surgery with elevated markers compared with 80% with normal markers. The disease-specific survival rate for patients with resected teratoma or fibrosis was 80% that dropped to 44% and 20%, respectively, if viable GCT or TMT was found [3].

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