ObjectiveTo explore the impact of number of positive regional lymph nodes (nPRLN) in N1 stage on the prognosis of non-small cell lung cancer (NSCLC) patients. MethodsPatients with TxN1M0 stage NSCLC who underwent lobectomy and mediastinal lymph node dissection from 2010 to 2015 were screened from SEER database (17 Regs, 2022nov sub). The optimal cutoff value of nPRLN was determined using X-tile software, and patients were divided into 2 groups according to the cutoff value: a nPRLN≤optimal cutoff group and a nPRLN>optimal cutoff group. The influence of confounding factors was minimized by propensity score matching (PSM) at a ratio of 1∶1. Kaplan-Meier curves and Cox proportional hazards models were used to evaluate overall survival (OS) and lung cancer-specific survival (LCSS) of patients. ResultsA total of 1316 patients with TxN1M0 stage NSCLC were included, including 662 males and 654 females, with a median age of 67 (60, 73) years. The optimal cutoff value of nPRLN was 3, with 1165 patients in the nPRLN≤3 group and 151 patients in the nPRLN>3 group. After PSM, there were 138 patients in each group. Regardless of before or after PSM, OS and LCSS of patients in the nPRLN≤3 group were superior to those in the nPRLN>3 group (P<0.05). N1 stage nPRLN>3 was an independent prognostic risk factor for OS [HR=1.52, 95%CI (1.22, 1.89), P<0.001] and LCSS [HR=1.72, 95%CI (1.36, 2.18), P<0.001]. ConclusionN1 stage nPRLN>3 is an independent prognostic risk factor for NSCLC patients in TxN1M0 stage, which may provide new evidence for future revision of TNM staging N1 stage subclassification.
ObjectiveLymph node metastasis status directly influences surgical strategies for right-sided colon cancer. This real-world study aimed to clarify the patterns of regional and extra-regional lymph node metastasis to provide evidence for clinical decision-making and future research. MethodsA total of 123 patients who underwent laparoscopic right hemicolectomy with complete mesocolic excision (CME) at the Department of Gastrointestinal Surgery, Deyang People’s Hospital from September 2022 to May 2024 were included. Lymph nodes were dissected, classified, and analyzed according to the Japanese Society for Cancer of the Colon and Rectum Guidelines for Colorectal Cancer Treatment (7th edition). Clinicopathological data were analyzed. ResultsOverall lymph node metastasis rate:42.3% (52/123). The metastasis rate of para-intestinal lymph nodes (N1) was 33.3%(41/123), intermediate lymph node(N2) 10.6%(13/123), and central lymph node (N3) 13.8% (16/123). Cecal cancer: Ileocolic artery lymph node metastasis rate: 40.0% (10/25), right colic artery: 0% (0/6) and middle colic artery: 4.0% (1/25). Transverse colon cancer: Ileocolic artery lymph node metastasis rate: 0%(0/18) and middle colic artery: 33.3% (6/18). Of 45 patients with infrapyloric lymph node dissection, only 1 (2.2%) with hepatic flexure cancer showed metastasis. No ileal lymph node metastasis was observed. N3 metastasis rates: 9.3% (8/86) in well/moderately differentiated tumors vs. 21.6% (8/37) in poorly differentiated tumors. No N3 lymph node metastasis occurred in T1～2 tumors. T3 and T4 tumors exhibited N3 metastasis rates of 13.3% (13/98) and 21.4% (3/14), respectively. ConclusionsFor cancer of the ileocecal region, lymph node metastasis beside the colic middle artery almost never occurs. And for transverse colon cancer, no lymph node metastasis beside the ileocolic artery has been found. suggesting that when the tumor is located in these areas, excessive resection of the intestine is not necessary, and a right hemicolectomy with ileocecal preservation can be performed to better preserve organ function. For poorly differentiated cancers and right-sided colon cancers on T3 and T4 stages, the N3 lymph node metastasis rates are very high, respectively, and D3 lymph node dissection is still recommended. The rate of extra-regional lymph node metastasis is extremely low, and routine dissection is not recommended.