Oncologic Results of Laparoscopic D3 Lymphadenectomy for Male Sigmoid and Upper Rectal Cancer with Clinically Positive Lymph Nodes

Abstract

Many Japanese surgeons routinely perform extended D3 lymph node dissection for the treatment of advanced rectosigmoid cancer with a view to achieving better tumor control. However, the application of a laparoscopic approach to perform D3 lymphadenectomy has been challenging. This phase 2 prospective study aimed to explore the oncologic results of this surgical approach. The study was conducted during a 6-year period, in consideration of median follow-up time being >3 years. The study subjects were tumor, node, metastasis system stage III rectosigmoid cancer staged by clinical images. The extent of D3 dissection and the postoperative lymph node mapping were according to the guidelines of the Japanese Society for Cancer of the Colon and Rectum. Patients were stratified according to the histopathologically proved highest level of involved lymph nodes and placed into N0, N1, N2, and N3 groups. The primary end points of the study were the estimated time to recurrence and 5-year recurrence rate of cancer after laparoscopic D3 dissection. The estimated 5-year recurrence rate (20% in the N0 group [n = 10]; 25% in N1 [n = 44]; 33.3% in N2 [n = 30]; and 42.8% in N3 [n = 14]), time to recurrence (mean [95% confidence interval] 59.8 [42.6–76.9] months in the N0 group; 56.8 [48.3–65.2] months in N1; 46.8 [37.5–56.1] months in N2; and 43.9 [28.3–59.4] months in N3), and recurrence patterns were without significant difference (all P values >.05) among N0, N1, N2, and N3 groups. Therefore, by laparoscopic wide anatomic dissection, patients with lymph node involvement could be treated as well as those without lymph node metastasis. Laparoscopic D3 dissection facilitated the collection of more lymph nodes (mean ± standard deviation, 27.4 ± 4.2) for histopathologic examination. Mapping of dissected lymph nodes showed that 18.2% (16 of 88) patients had skip lymph node metastasis. D3 dissection facilitated upstaging of cancer (from N0 to N3) in five patients (5.1%). However, this procedure resulted in transient voiding dysfunction in 77.5% patients and loss of ejaculatory function in 91.7%. By laparoscopic approach, the D3 lymph node dissection was safely performed through small wounds, resulting in quick functional recovery and only moderate blood loss (324.8 ± 44.5 mL), but at the expense of a long operation time (294.4 ± 34.8 minutes). The good short-term oncologic results and quick convalescence mean that the laparoscopic D3 dissection may be recommended for patients with stage III rectosigmoid cancer who could accept the genitourinary dysfunction.