RESUMEN
Objective To investigate the therapeutic effect and prognostic significance of lateral lymph node dissection (LPLND) in patients with lateral lymph node (LPLN) metastasis. Methods The clinicopathological data of rectal cancer patients who underwent total mesorectal excision (TME) combined with LPLND and pathologically confirmed as LPLN metastasis after operation were retrospectively analyzed. The clinicopathological characteristics and metastasis rules of patients with LPLN metastasis were discussed, and the survival prognosis after LPLND was analyzed. Results A total of 102 rectal cancer patients with pathologically confirmed LPLN metastasis were included. The common sites of LPLN metastasis were internal iliac vessels lymph nodes (n=68, 66.7%), followed by obturator lymph nodes (n=44, 43.1%), and common iliac vessels or external iliac vessels lymph nodes (n=12, 11.8%). There were 10 patients (9.8%) with bilateral LPLN metastases, and the mean number of LPLN metastases was 2.2±2.4, among which 16 patients (15.7%) had LPLN metastases number≥2. The 3-year OS (66.8% vs. 7.7%, P < 0.001) and DFS (39.1% vs. 10.5%, P=0.012) of patients with LPLN metastases to the external iliac or common iliac lymph node were significantly lower than those with metastases to the internal iliac or obturator lymph node. The multivariate analysis showed that LPLN metastasis to external iliac or common iliac lymph node was an independent risk factor both for OS (HR=3.53; 95%CI: 1.50-8.31; P=0.004) and DFS (HR=2.40; 95%CI: 1.05-5.47; P=0.037). Conclusion LPLN mainly metastasizes to the internal iliac or obturator lymph node areas. The survival of patients with metastasis to the external iliac or common iliac lymph node cannot be improved by LPLND, and thus systemic comprehensive treatment is often the optimal treatment option.
RESUMEN
Lateral pelvic lymph node (LPLN) metastasis is a poor prognostic factor for rectal cancer, which is more common in low site, T 3-T 4 stage, and positive lymph nodes in mesorectum. However, there is no accurate predictor of metastasis. At present, high-resolution MRI is the optimal diagnosis of LPLN metastasis, but the threshold value is still unclear. The treatment mode of LPLN metastasis in locally advanced rectal cancer is controversial worldwide. European and American countries advocate chemoradiotherapy combined with total mesorectal resection, while Japan recommends total mesorectal resection combined with LPLN dissection. The combination of radiotherapy and surgery could achieve good local control. Further more, by using the information of lateral lymph nodes before and after radiotherapy, patients with high risk can be screened for intensive treatment, such as LPLN dissection or dose-escalation approaches. Currently, there is still a lack of high-quality evidence on the efficacy of various approaches in the treatment of LPLN metastasis, and more research is needed to improve the treatment strategies.