Evaluating predictive factors for determining the presence of lateral pelvic node metastasis in rectal cancer patients following neoadjuvant chemoradiotherapy

Abstract

Aim The need or otherwise for lateral pelvic node dissection (LPND) in rectal cancer patients with clinical lateral pelvic node metastasis (LPNM) after neoadjuvant chemoradiotherapy (nCRT) is controversial. This study was designed to explore the predictive factors for pathological LPNM in rectal cancer patients with clinical LPNM after nCRT.Method From January 2010 to February 2018, a consecutive series of patients with rectal cancer and clinical LPNM after nCRT who underwent total mesorectal excision and LPND were reviewed. Patient demographics, operative and pathological outcomes were collected and analysed.Results A total of 76 consecutive cases were included in this study: 53 (69.7%) patients underwent unilateral LPND and 23 (30.3%) bilateral LPND. The pathological results showed that LPNM was found in 13 (17.1%) patients. Multivariate logistic regression analysis showed that the post-nCRT lateral pelvic node size ≥ 5 mm (OR = 7.67, 95% CI = 1.45-40.63, P = 0.017) and mucinous/signet-ring adenocarcinoma (OR = 4.60, 95% CI = 1.11-19.08, P = 0.035) were independent risk factors for pathological LPNM.Conclusion Post-nCRT lateral pelvic node size ≥ 5 mm and mucinous/signet-ring adenocarcinoma were independent predictive factors of pathological LPNM for rectal cancer patients with clinical LPNM after nCRT, and patients with these characteristics may benefit from LPND.What does this paper add to the literature? The aim of this paper was to determine the optimal indication for lateral pelvic node dissection after neoadjuvant chemoradiotherapy for mid/low rectal cancer, so as to avoid the occurrence of overtreatment in clinical work.

Risk factors and prognostic significance of lateral pelvic lymph node dissection after neoadjuvant chemoradiotherapy for rectal patients with clinically suspected lateral lymph node metastasis

“…In previous studies, the incidence of LPNM for patients with stage II-III rectal cancer was demonstrated to be 10–20% [ 1 , 2 ]. All the patients included in the present study were suspected of having LPNM by preoperative MRI evaluation, and the rate of pathological LPNM was only 20.5%, which is related to the relatively loose imaging diagnostic criteria of LPNM.…”

“…The lateral pelvic lymph node (LPN) is one of the common lymphatic metastasis areas of middle-low rectal cancer, and it has been reported that approximately 10–20% of rectal cancer patients with stage II-III disease develop LPN metastasis (LPNM) outside the field of total mesorectal excision (TME) [ 1 , 2 ]. Most hospitals in Japan adopt a more active treatment attitude, and a prospective multicentre RCT (JCOG0212) conducted in Japan demonstrated that TME with ‘prophylactic’ LPN dissection (LPND) significantly decreased local recurrence rates compared with TME alone for patients who do not have LPN enlargement before surgery (7.4% vs 12.6%) [ 3 ].…”

Neoadjuvant chemoradiotherapy followed by lateral pelvic lymph node dissection for rectal cancer patients: A retrospective study of its safety and indications

“…Although open surgery was sometimes needed, most patients were placed in the modified lithotomy position for laparoscopic procedures regularly. The details of the LPND procedure have been described previously 12 . Briefly, unilateral or bilateral LPND was performed after removal of the rectum.…”

“…Informed consent has been obtained and procedures followed were Clinical LPNM was diagnosed by two imaging specialists who specialized in colorectal cancer based on MRI before treatment. The assessment criteria were described in our previous study 12 : (1) ≥0.8 cm in short diameter; (2) inhomogeneous or intense enhancement; and (3) irregular shape and rough edges. LPNM was diagnosed when one or more of the above criteria were met.…”

“…The details of the LPND procedure have been described previously. 12 Briefly, unilateral or bilateral LPND was performed after removal of the rectum. The extent of LLD was defined in Japanese Society for Cancer of the Colon and Rectum guidelines, including common iliac vessels, internal iliac vessels, external iliac vessels, obturators and aortic bifurcation lymph nodes.…”