Study design
The present study was approved by the Internal Institutional Review
Board (Cerrahpasa Medical Faculty, approval number
21263603-604.02.01-86518). The hospital medical records and charts of
the patients were retrospectively reviewed. The data included
demographics, tumor characteristics, operative findings, pathological
outcomes, postoperative follow-up, and survival outcomes.
Preoperative comorbidities were assessed according to the Charlson
Comorbidity Index [8]. The performance status was measured for each
patient using the Eastern Cooperative Oncology Group performance score
(ECOG PS) [9]. The Mayo Clinic system was used to classify the
thrombus level [10]. Preoperative physical status was evaluated by
the American Society of Anesthesiologists (ASA) scoring [11].
Surgery-associated complications were assessed based on the Clavien
classification [12]. All pathological specimens were examined by a
single pathologist team according to the recommendations of the
UICC/American Joint Committee on Cancer [13]. Tumor nuclear grade
was determined according to the Fuhrman grading system [14]
Overall survival (OS) was described as the time from the operation to
the last visit in 18 surviving patients and as the time from the
operation to death in 15 deceased patients. Disease-free survival (DFS)
was defined as the time from the procedure to the metastatic process in
15 preoperative clinic M0 patients and as the time from the operation to
the last visit in nine preoperative and postoperative clinical M0
patients.