Subpopulation analysis of survival in high-risk T1 colorectal cancer: surgery versus endoscopic resection only.

BACKGROUND AND AIMS: This study aimed to assess the long-term survival of patients with T1 colorectal cancer (CRC) after local or surgical resection considering the type and number of risk factors for lymph node metastasis. METHODS: This study included patients with high-risk T1 CRC who underwent therapeutic resection at the National Cancer Center, Korea between January 2001 and December 2014. Risk factors included positive resection margin, high-grade histology, deep submucosal invasion, vascular invasion, budding, and no background adenoma (BGA). We statistically divided the population into favorable or unfavorable subpopulations. The favorable subpopulation included the following 5 combinations of risk factors: positive margin only or unconditional for margin status, deep submucosal invasion only, budding only, no BGA only, and budding + no BGA. We analyzed the survival rate according to the resection type (local or surgical) in the total cohort and in each subpopulation. RESULTS: Eighty-one and 466 patients underwent local and surgical resections, respectively. The distant recurrence-free survival (DRFS) and overall survival (OS) rates were significantly high in the surgical group (hazard ratio [HR], .20; 95% confidence interval [CI], .06-.61; P = .0045 and HR, .41; 95% CI, .25-.70; P = .0010, respectively). In the favorable subpopulation, both DRFS and OS rates were not significantly different between the surgical and local groups (HR, .26; 95% CI, .02-4.19; P = .3431 and HR, .58; 95% CI, .27-1.23; P = .1534, respectively). CONCLUSIONS: Intensive surveillance without additional surgery may be another option in selected cases after of high-risk T1 CRC endoscopic resection.

Feasibility of Selective Lateral Node Dissection Based on Magnetic Resonance Imaging in Rectal Cancer After Preoperative Chemoradiotherapy.

BACKGROUND: Lateral pelvic node metastasis is one of the major causes of local recurrence in advanced rectal cancer after preoperative chemoradiotherapy (CRT). However, lateral pelvic node dissection (LPND) is still a challenging surgical procedure in terms of surgical morbidity. This study aimed to investigate the feasibility and safety of LPND in patients with advanced rectal cancer after preoperative CRT. MATERIALS AND METHODS: Records of 80 consecutive patients who underwent total mesorectal excision (TME) with LPND for initially enlarged lateral pelvic nodes (LPNs) (short-axis diameter ≥5 mm on magnetic resonance imaging before preoperative CRT) between 2011 and 2016 were retrospectively reviewed. Surgical outcomes of these patients were compared with those of 281 patients who underwent TME alone. RESULTS: Ninety-nine LPND procedures were performed, including 19 bilateral LPNDs. Pathologically proven LPN metastasis was identified in 32 (32.3%) LPND cases after preoperative CRT. Multiple (odds ratio = 12.908, 95% confidence interval: 3.355-49.660, P < 0.001) and persistently enlarged LPNs (odds ratio = 27.093, 95% confidence interval: 6.072-120.896, P < 0.001) were independently associated with LPN metastasis. The rates of overall postoperative 30-d morbidity (42.5% versus 32.4%, P = 0.093) and urinary retention (11.3% versus 7.1%, P = 0.230) were similar between the TME with LPND and TME-only groups. CONCLUSIONS: The postoperative morbidity of TME with LPND was comparable with TME-only group. The rate of LPN metastasis remained high after preoperative CRT, especially in patients with multiple or persistently enlarged LPNs.

Is lateral pelvic node dissection necessary after preoperative chemoradiotherapy for rectal cancer patients with initially suspected lateral pelvic node?

BACKGROUND: Little is known about the effect of lateral pelvic node dissection after preoperative chemoradiotherapy on rectal cancer patients with initially suspected lateral pelvic nodes. The purpose of this study was to identify a subgroup of patients receiving preoperative chemoradiotherapy who can benefit from lateral pelvic node dissection. METHODS: The study included 580 patients who underwent preoperative chemoradiotherapy and total mesorectal excision. The lateral pelvic node responses to preoperative chemoradiotherapy were divided: group I (no suspected lateral pelvic node), lateral pelvic node <5 mm pre- and post-chemoradiotherapy; group II (responsive lateral pelvic node), lateral pelvic node ≥5 mm pre-chemoradiotherapy but <5 mm post-chemoradiotherapy; and group III (persistent lateral pelvic node), lateral pelvic node ≥5 mm pre- and post-chemoradiotherapy. Prognostic factors for lateral pelvic node recurrence-free survival, locoregional recurrence-free survival, relapse-free survival, and overall survival were analyzed. RESULTS: In a multivariate analysis, lateral pelvic node response was an independent factor associated with lateral pelvic node recurrence-free survival, locoregional recurrence-free survival, relapse-free survival, and overall survival (P < .05). Group III had significantly poorer lateral pelvic node recurrence-free survival, locoregional recurrence-free survival, relapse-free survival, and overall survival than groups II and I (74.1%, 93.4%, and 98.6%; 71.7%, 89.4%, and 97%; 56.9%, 76.6%, and 81.7%; 74.9%, 85.7%, and 89.1%, respectively; P < .05). Group II tended to have poorer lateral pelvic node recurrence-free survival, locoregional recurrence-free survival, relapse-free survival, and overall survival than group I, and the differences in relapse-free survival and overall survival between the 2 groups were not significant (P > .05). CONCLUSION: Our data suggest that the subgroup with lateral pelvic nodes responsive to preoperative chemoradiotherapy may not benefit from lateral pelvic node dissection, and the subgroup with persistent lateral pelvic node may benefit from lateral pelvic node dissection.