Clinical utility of perioperative staging laparoscopy for advanced gastric cancer

A total of 178 gastric cancer patients who were preoperatively diagnosed with tumors deeper than T2 at Kagoshima University Hospital (Japan) were consecutively enrolled. Of the 178 gastric cancer patients, six underwent staging laparoscopy after the detection of postoperative peritoneal metastases, 71 were preoperatively suspected as having distant metastases, and the remaining 101 planned to undergo R0 gastrectomy. Type 4 tumors were diagnosed in 55 patients (Additional file1: Table S1). Clinicopathological features were assessed using the Japanese Classification of Gastric Carcinoma (JCGC, 13th edition)[12]. This research was carried out in compliance with the Helsinki Declaration.

The indications for staging laparoscopy included suspected serosal invasion of the carcinoma, the possibility of peritoneal metastases, positive cytology or the presence of ascetic fluid. Staging laparoscopy was performed under general anesthesia immediately before surgery. An incision was made at the umbilicus and a 12-mm trocar was directly introduced into the abdomen to be used as the scope port. The second and third trocars were 5 mm in diameter and were inserted at the right and left lower abdominal regions and used as the working ports. The abdominal cavity was explored systematically. First, peritoneal lavage was performed with 300 cc of saline for cytological examination of the peritoneal fluid. When the cancer cells were found in the peritoneal washing, the patient was classified as positive cytology (CY1). The condition of the peritoneum was examined. The bilateral subphrenic spaces, lesser omentum and surface of the stomach, distant peritoneum including the rectouterine pouch, and the surface of the entire bowel were first examined. Then, the omental bursa was opened and the surfaces of the pancreas and the stomach were examined. If suspicious peritoneal nodules were detected, the lesion was excised and processed into frozen sections for intraoperative histological diagnosis. When the pathological examination of the peritoneal nodule revealed adenocarcinoma, the patient was diagnosed with positivity of peritoneal metastasis (P1). In patients showing P1 and/or CY1, treatment by gastrectomy was changed to intensive chemotherapy (Figure 1). Patients with P1 and/or CY1 were mainly treated with a combination of S-1 and paclitaxel as previously reported[13].

After confirming P0 and CY0 by staging laparoscopy, laparoscopic R0 gastrectomy plus bursectomy was performed[14]. If P1 or CY1 was identified by histological examination, gastrectomy with curative intent was discontinued and intensive chemotherapy was indicated. Furthermore, these patients received laparoscopic interventions to abate the clinical symptoms of gastric cancer. When second-look laparoscopy after intensive chemotherapy revealed neither P1 nor CY1, R0 gastrectomy was indicated (Figure 1).

P1 and CY1 were detected in 59 (34%) and 62 (35%) patients, respectively, according to the staging laparoscopy results. P1 and/or CY1 were detected for the first time in 23 patients by laparoscopy (Figure 2). A total of 13 patients were diagnosed preoperatively, and 6, 21 and 13 patients were stage II (n =3), IIIA (n =5) and IIIB (n =5), respectively (Additional file2: Table S2). The detection rate of P1 and/or CY1 in stage III patients was significantly higher than that in stage IB patients (P <0.05). P1 or CY1 was detected for the first time in 23 (15%) patients (Figure 3). Thirteen patients were converted from gastrectomy to intensive chemotherapy after detection of P1 or CY1.

After the staging laparoscopy, various types of surgery were performed in different patients to reduce the clinical symptoms using a laparoscopic approach. An intraperitoneal reservoir port was inserted in 54 patients, a metallic stent was inserted in five patients, ileostomy was required in six patients for stricture of the colon, and jejunostomy and gastrojejunostomy for alimental bypass were performed in 19 and 16 patients, respectively (Additional file3: Table S3). The cytological examination was repeated from the intraperitoneal port during intensive chemotherapy.

A total of eight patients underwent R0 gastrectomy after P0 and CY0 were confirmed by second-look laparoscopy. During the follow-up period of 12 to 68 months, 3 of these patients showed peritoneal recurrence despite confirmation of P0 and CY0 status. At present, four out of five living patients are free from recurrence of carcinoma. All of the patients with recurrence of the disease showed Grade 1 histological effect of the primary tumor after chemotherapy (Additional file4: Table S4).