Laparoscopic lateral pelvic lymph node dissection combined with removal of the internal iliac vessels in rectal cancer: how to standardize this surgical procedure.

BACKGROUND: Lateral pelvic lymph node dissection (LLND) combined with removal of the internal iliac vessels is a challenging surgical procedure in minimally invasive surgery. We herein report our dissection approach and short-term outcomes. METHODS: We conducted a study on rectal cancer patients who underwent laparoscopuic LLND combined with removal of the internal iliac vessels at our institution in March 2017-December 2019. In performing the surgery, we identified and dissected along the three pelvic sidewall fasciae (ureterohypogastric, umbilical prevesical and parietal pelvic fascia), located the internal ilial vein at the level of the common iliac vessels and carried out our dissection along the medial anterior surface of the internal iliac before transecting the vein. The duration of LLND was recorded as was the blood loss. RESULTS: There were 16 patients (10 males, mean age 65.4 ± 10.8 years). Five patients had primary surgery, and 11 had surgery for recurrence. The median blood loss of LLND was 10 ml (range, 0-250 ml), the median operating time was 173 min (range, 65-358 min), and post-operative complications were relatively mild. Seven of 16 patients (43.8%) were diagnosed with positive lateral nodes. The 2-year local recurrence-free and disease-free survival rates were 87.5% and 58.0%. CONCLUSION: Recognizing the pelvic anatomical points illustrated in the present study contributes to the surgical safety of LLND combined with removal of the internal iliac vessels.

UGT1A1 polymorphisms in rectal cancer associated with the efficacy and toxicity of preoperative chemoradiotherapy using irinotecan.

The purpose of the present study was to assess the efficacy and toxicity of preoperative chemoradiotherapy using irinotecan against locally advanced lower rectal cancer according to UDP-glucuronosyltransferase 1A1 (UGT1A1) polymorphisms. Between 2009 and 2016, 46 patients with resectable rectal cancer (T3-T4, N0-N2, M0) received preoperative chemoradiotherapy consisting of 80 mg/m2 per day tegafur/gimeracil/oteracil (S-1; days 1-5, 8-12, 22-26, and 29-33), 60 mg/m2 per day irinotecan (days 1, 8, 22, and 29), and 45 Gy radiation (1.8 Gy/day, 5 days per week for 5 weeks). Six to eight weeks after completing chemoradiotherapy, total mesorectal excision was carried out. Patients with UGT1A1 polymorphisms were divided into WT (n = 26), heterozygous (n = 15), and homozygous (n = 5) groups, the latter including double heterozygosities. We evaluated associations between clinical characteristics, including UGT1A1 polymorphisms, and chemoradiotherapy efficacy and toxicity. Incidence rates of grade 3+ neutropenia and diarrhea were 17.0% and 30.4%, respectively. Relative dose intensity was 89.3%. Pathological complete response rate (grade 3) was 26.1%, and the good response (grade 2/3) rate was 84.8%. UGT1A1 polymorphisms were significantly associated with neutropenia and pathological good responses, but not with diarrhea. UGT1A1 polymorphism was the only predictive factor for pathological good responses. Our results indicate that UGT1A1 polymorphism is a predictive factor to determine the clinical efficacy of preoperative chemoradiotherapy and hematological toxicity induced by chemoradiotherapy using irinotecan in locally advanced rectal cancer patients.