Clinical and pathological characteristics
All patients successfully underwent macroscopically complete surgical resection (Figure 1A, 1B), and there were no deaths during the perioperative period. Table 1 describes the clinical and pathologic characteristics of the 113 patients included in this study in detail. The median age at first diagnosis was 36 years (range 15-71), and the cohort was predominantly female (73.5%, n = 83). The average body mass index (BMI) was 22.6 ± 3.1 kg/m2. Most patients (89.4%, n = 101) had primary tumors, and the median tumor size was 5.5 cm (range 1.4-30). The common symptoms were abdominal pain (14.2%, n = 16), changes in bowel habits (5.3%, n = 6), obstructions (2.7%, n = 3), anemia (2.7%, n = 3), and hydronephrosis (1.8%, n = 2). Resection margins were positive in 10 (8.8%) patients, and adjuvant radiotherapy was performed in 9 (8.0%) patients after surgery. The surgical outcomes and postoperative complications are listed in Table 2. The mean operation time and intraoperative blood loss were 138.5 ± 83.6 min (range 40-360) and 70.6 ± 114.4 ml (range 10-400), respectively. A total of 21 (18.6%) patients experienced postoperative complications, and the most common complication was chronic pain (7.1%, n = 8), followed by wound infection (6.2%, n = 7), anastomosis leakage (3.5%, n = 4), ileus (2.7%, n = 3), incisional hernia (1.8%, n = 2) and neurological problems (0.9%, n = 1).
According to the tumor sites, 113 patients were assigned to the abdominal wall group (n = 66) or the intra-abdominal cavity group (n = 47). Figure 2 shows the distribution of various tumor sites in the abdominal cavity, including stomach (n = 2, 4.3%), pancreas (n = 1, 2.1%), duodenum (n = 2, 4.3%), small intestine mesentery (n = 25, 53.2%), ileocecal mesentery (n = 7, 14.9%), transverse mesentery (n = 8, 17.0%) and sigmoid mesentery (n = 2, 4.3%). The proportion of female patients in the abdominal wall group was significantly higher than that in the intra-abdominal group (93.9% vs. 44.7%, P<0.001). In contrast, the proportion of patients aged 35 years or older was significantly higher in the intra-abdominal group than in the abdominal wall group (91.5% vs 63.6%, P=0.001). There were more patients with a previous history of cesarean section in the abdominal wall group than in the intra-abdominal group (34.8% vs. 6.4%, P<0.001). In addition, patients with lesions in the abdominal wall were less likely to present with clinical symptoms than patients with intra-abdominal lesions (13.6% vs. 40.4%, P = 0.001). The number of patients in the intra-abdominal group with lesions greater than 10 cm was significantly higher than that in the abdominal wall group (27.7% vs. 7.6%, P = 0.011), and the lesions in the intra-abdominal group were mostly adhered to important nerves or vasculature (42.6% vs. 13.6%, P = 0.001). In terms of surgical outcomes, the abdominal wall group had a significantly shorter operation time (98.7 ± 50.0 min vs. 194.5 ± 90.3 min, P<0.001) and a lower amount of intraoperative blood loss than the intra-abdominal group (24.1 ± 41.1 ml vs. 136.0 ± 149.4 ml, P<0.001).
Survival analysis
The median follow-up interval was 61 months (range 9-250). Only 2 patients died at the last follow-up, and no patient died due to recurrence or complications caused by ADTs. During the whole follow-up period, a total of 12 patients developed recurrence after surgery with or without adjuvant radiotherapy: 2 (16.7%) cases of recurrence were found in patients presenting with intra-abdominal DTs, and 10 (83.3%) cases of recurrence were found in patients presenting with abdominal wall DTs. The estimated 5- and 10-year RFS rates for the entire cohort were 92.8% and 89.8%, respectively (Figure 3). It is worth noting that recurrence was still observed in one patient beyond 10 years. In addition, none of the 12 patients who were admitted with recurrent disease experienced recurrence during follow-up after surgical resection combined with or without radiotherapy.
According to the univariate analysis, tumor location, tumor size, and margin status significantly affected RFS (P<0.05). A significantly higher rate of local recurrence was associated with abdominal wall DTs, a tumor size >10 cm, and an R1 margin status (Figure 4A-C). According to the multivariate analysis, RFS was significantly affected by tumor location (HR: 8.407; 95% CI, 1.649-42.865; P = 0.010), tumor size (HR: 17.437; 95% CI, 3.648-83.346; P<0.001) and margin status (HR: 8.045; 95% CI, 2.388-27.099; P = 0.001).