Definition of tumor rupture in gastrointestinal stromal tumor / 中华胃肠外科杂志

ABSTRACT

Tumor rupture is a common clinical event in the process of tumorigenesis, progression, diagnosis and treatment of gastrointestinal stromal tumor, which is closely associated with tumor recurrence, metastasis and poor prognosis. Tumor rupture may be associated with some intrinsic biological aggressiveness qualities, such as large tumor size, high mitotic count, and KIT exon 11 deletion mutations involving codons 557 and 558, and may be relatively more frequent with small intestine GIST and excellent response to imatinib neoadjuvant therapy resulting in tumor tissue rapid liquefacient and necrosis. The triggering factors involve sudden increase in abdominal pressure, external pressure, collision and improper surgical operation, etc. Tumor rupture is considered as an important risk factor of recurrence after macroscopically complete resection of tumor, and an indication for determining interval or even lifelong adjuvant therapy with imatinib according to guidelines. However, there is no consensus or universally accepted definition of tumor rupture, and, consequently, its incidence varies greatly across reported series and lacks detailed epidemiological data. Without pre-defined criteria, it is difficult to assess the clinical significance of rupture. We reviewed the relevant literature and international guidelines, and generally divided tumor rupture into spontaneous rupture and iatrogenic rupture. Based on the Oslo criteria, we proposed the following six definitions for tumor rupture (1) tumor fracture or spillage; (2) blood-stained ascites; (3) gastrointestinal perforation at the tumor site; (4) microscopic infiltration of an adjacent organ; (5) intralesional dissection or piecemeal resection; (6) incisional biopsy. The following types of minor defects of tumor integrity should not be defined as rupture (1) mucosal defects or spillage contained within the gastrointestinal lumen; (2) microscopic tumor penetration of the peritoneum or iatrogenic damage only to the serosa; (3) uncomplicated transperitoneal needle biopsy; (4) R1 resection. In addition, we further emphasize the importance of identifying risk factors of tumor rupture, prevention and positive intervention.