Capacity Approximations for Gaussian Relay Networks

Associations of exposure to per- and polyfluoroalkyl substances mixture with the numbers of lymph nodes in colorectal cancer patients

Significance of Extranodal Extension of Regional Lymph Nodes in Surgically Resected Non-small Cell Lung Cancer

In Asia, esophageal squamous cell carcinoma (ESCC) accounts for more than 90% of esophageal cancer cases and can be treated with minimally invasive esophagectomy (MIE); however, MIE has certain technical limitations in resecting lymph nodes. The advantages of robot-assisted minimally invasive esophagectomy (RAMIE) surgery, such as the high-definition three-dimensional (3D) vision and the presence of the EndoWrist, facilitates movement in challenging anatomical regions. However, few studies have compared the postoperative outcomes between RAMIE with MIE for the lymph node dissection of patients with ESCC. We identified 285 patients with ESCC who underwent surgical resection between January 2019 and April 2023. Of these patients, 270 met the screening criteria and were enrolled in our study. These patients were then divided into two groups according to the thoracic approach: MIE (n=168) or RAMIE cohort (n=102). The aim of this study was to investigate the possible advantages in terms of postoperative outcomes of RAMIE over MIE for thoracic lymph node dissection. Most patients were male (97.4%). According to the pathological-stage of esophageal cancer, 5 (1.9%), 99 (37.1%), 72 (27.0%), 82 (30.7%), and 9 (3.4%) patients were pathological-stage 0, I, II, III, and IV, respectively. The number of regional lymph node resections in the RAMIE cohort was significantly higher than that in the MIE group for the following regions: the left tracheobronchial lymph nodes (106tbL) (P<0.001), paratracheal lymph nodes [106pre] (P=0.011), the sub-longitudinal lymph nodes [107] (P<0.001), the left main bronchial lymph nodes [109L] (P<0.001), the right main bronchial lymph nodes [109R] (P<0.001), the sub-thoracic periesophageal lymph nodes [110] (P=0.004), and the supradiaphragmatic lymph nodes [111] (P<0.001). By comparing MIE cohort with RAMIE cohort, the transthoracic approach with RAMIE yielded a greater total number of thoracic lymph nodes dissected [MIE: mean 20.82, standard deviation (SD) 9.45; RAMIE: mean 26.07, SD 9.28; P<0.001] and a greater total number of lymph node groups that underwent thoracic lymph node dissection (MIE: mean 5.28, SD 1.94; RAMIE: mean 7.29, SD 1.77; P<0.001). Our study shows that RAMIE may be more effective than MIE in terms of the number thoracic lymph nodes dissected and the extent of dissection. Moreover, RAMIE may be not associated with additional surgical complications.

BACKGROUND: The question of what constitutes adequate lymphadenectomy in colorectal cancer has been discussed for several generations without a definitive conclusion being reached. METHODS: Review of the literature. RESULTS: Our guidelines recommend the radical en-bloc resection of the tumor-bearing bowel with central ligation of its vessels, although evidence supporting this is limited. The resection includes a systematic lymphadenectomy of the lymphatic drainage along its arterial blood supply, and should be performed with a no-touch technique. The lymphatic dissection determines the extent of bowel resection, which should include – depending on the tumor infiltration depth (pT) – a 5–10 cm resection margin proximally and distally. The lymph node status (pN) is one of the most important prognostic factors. The calculation of the total number of resected lymph nodes and the lymph node ratio allows greater accuracy in tumor staging and a more precise estimation of prognosis. The total number of lymph nodes can be influenced by the surgeon, the patient, and the pathologist. CONCLUSIONS: New studies exist, which show that only small subgroups of patients receive a prognostic benefit from radical lymphadenectomy. Because we cannot yet identify these patients pre- or intraoperatively, we continue to perform radical lymphadenectomy.

Despite their widespread utilization, little is known about the quality of pathologists' assistants' services. Pathologists' assistants' performance was compared with pathology residents' performance using the metrics of lymph node retrieval and tissue resubmission rates. Lymph node retrieval was calculated by retrospective review of surgical pathology reports from a sample of axillary dissection, mastectomy, and colorectal specimens. Tissue resubmission rates were calculated by retrospective review of a sample of general surgical pathology reports. Pathologists' assistants retrieved a significantly greater total number of lymph nodes compared with pathology residents; however, there was no difference in the total number of positive lymph nodes retrieved. Cases for which pathologists' assistants performed the gross examination had a significantly decreased resubmission rate compared with those performed by residents. In this setting, the gross examination performance of pathologists' assistants was equivalent to or superior to that of pathology residents. These results provide the first information available relating to pathologists' assistants' performance in surgical pathology.

BackgroundPatient outcomes in rectal cancer with synchronous liver metastases remain heterogeneous, underscoring the need for reliable prognostic factors to guide individualized treatment strategies. This study sought to assess the influence of lymph node-related indices on the survival of rectal cancer patients with synchronous liver metastases who underwent preoperative chemoradiotherapy and to construct a novel nomogram for this patient population.MethodsData on rectal cancer patients with synchronous liver metastases who underwent preoperative chemoradiotherapy between 2010 and 2019 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. X-tile software was employed to determine the optimal cutoff point of lymph node-related indices. The Kaplan-Meier method and log-rank test were used to assess survival differences. Cox univariate and multivariate analyses were conducted to identify the prognostic factors for overall survival (OS). We constructed a novel nomogram to predict individual survival probability. The concordance index (C-index) and calibration curve were used to determine the predictive accuracy and discriminative ability of the nomogram.ResultsA total of 547 rectal cancer patients with synchronous liver metastases were enrolled. The OS of patients with total number of lymph nodes (TLN) <7 was significantly worse than that of patients with TLN ≥7 (3-year OS rate: 46.6% vs. 62.7%; 5-year OS rate: 22.9% vs. 43.8%, P=0.001). Patients with number of positive lymph nodes (PLN) <7 had better OS than that of patients with PLN ≥7 significantly (3-year OS rate: 63.5% vs. 36.0%; 5-year OS rate: 44.1% vs. 12.6%, P<0.001). The 3-year OS rate was 49.7% for patients with number of negative lymph nodes (NLN) <11 compared with 68.6% for patients with NLN ≥11; and the 5-year OS rate was 23.9% and 53.6% for patients with NLN <11 and patients with NLN ≥11, respectively (P<0.001). Multivariate analysis showed that TLN, NLN and PLN were independent prognostic factors for OS [TLN: hazard ratio (HR) =0.571, 95% confidence interval (CI): 0.408–0.799, P=0.001; NLN: HR =0.593, 95% CI: 0.456–0.770, P<0.001; PLN: HR =1.736, 95% CI: 1.201–2.509, P=0.003]. A novel nomogram was established based on the independent prognostic factors indicated in the multivariate Cox analysis. The C-index for prognostic nomogram was 0.67 (95% CI: 0.63–0.71). The calibration plot for the probability of 3-year survival demonstrated an optimal agreement between the predicted and actual survival.ConclusionsLymph node (LN)-related indices are significant prognostic factors for OS in rectal cancer patients with synchronous liver metastases, offering insights into survival prediction and enabling personalized treatment strategies.

We present a natural and low-complexity technique for achieving the capacity of the Gaussian relay network in the high SNR regime. Specifically, we propose the use of end-to-end structured lattice codes with the amplify-and-forward strategy, where the source uses a nested lattice code to encode the messages and the destination decodes the messages by lattice decoding. All intermediate relays simply amplify and forward the received signals over the network to the destination. We show that the end-to-end lattice-coded amplify-and-forward scheme approaches the capacity of the layered Gaussian relay network in the high SNR regime. Next, we extend our scheme to non-layered Gaussian relay networks under the amplify-and-forward scheme, which can be viewed as a Gaussian intersymbol interference (ISI) channel. Compared with other schemes, our approach is significantly simpler and requires only the end-to-end design of the lattice precoding and decoding. It requires little knowledge of the network topology or the individual channel gains.

Purpose: Adequate lymph node analysis is critical for appropriate staging in colorectal cancer. The aim of this study is to determine whether 12 or more nodes recovered in stage III rectal cancer results in improved oncologic outcomes. Methods: Two hundred and forty-eight patients with stage III rectal cancer from 1995 through 2004 were reviewed. They were categorized into 2 subgroups by the number of nodes retrieved (＜12 and ≥12), and oncologic outcomes in terms of 5-year overall and disease-free survival were analyzed for all patients, patients with American Joint Committee on Cancer (AJCC) N1 disease (N=145), and those with AJCC N2 (N=103). Results: Five-year overall and disease-free survival was 79.0% and 58.4%, respectively. There was no significant difference in clincopathologic features between ＜12 retrieval group and ≥12 group. Although there was significant difference in overall survival and disease-free survival between the number (＜12 and ≥12) of lymph nodes removed in N2 disease (P=0.043; P=0.022) in univariate analysis, the total number of lymph nodes retrieved was not a prognostic factor affecting survival in multivariate analysis. The N2 stage and lateral margin involvement were prognostic factors affecting survival in multivariate analysis. Conclusion: This study showed that the total number of lymph nodes analyzed for stage III rectal cancer is not a prognostic factor on overall or disease-free survival in multivariate analysis. (J Korean Surg Soc 2009;77:262-266)

The total number of lymph nodes examined after salvage colectomy for endoscopically removed malignant polyps was evaluated and an attempt was made to determine whether there was an optimal number of lymph nodes that should be harvested. From 2000 to 2009, 531 patients underwent segmental resection for non-metastatic colon cancer. Of these, 22 underwent a salvage colectomy for an endoscopically removed malignant polyp, the main indication for which was a resection margin of < 1 mm. The surgical procedure was identical to that used for all colon cancers. The mean number of lymph nodes examined was 11.6 ± 7.6 for the 22 patients with an endoscopically removed malignant polyp and 26.2 ± 13.9 for the remaining 509 patients (P = 0.0006). Fewer than 12 lymph nodes were examined in 62 (12%) of the 509 patients and in 13 (59%) of the 22 patients with an endoscopically removed malignant polyp (P < 0.0001). In the group of 22 patients who underwent a salvage colectomy, the total number of lymph nodes examined ranged from 2 to 33. At a mean follow up of 41 ± 15.6 months, no local or distant recurrence was observed in the 22 patients. The total number of lymph nodes examined after colectomy for endoscopically removed malignant polyps varies and is less than the recommended number of 12 in most cases: this does not appear to have long-term prognostic significance. There is no biological reason to explain this clinical observation.

Objective: To identify the clinicopathological factors affecting the number of lymph nodes yielded from specimens obtained by laparoscopic-assissted resection of rectal cancer, and discuss further the possible causes of insufficient lymph nodes retrieval (<12). Methods: The clinicopathological data of 422 consecutive rectal cancer cases, who underwent radical laparoscopic rectal resection (R0) at our department during January to October 2015, were analyzed retrospectively. The correlation between the clinicopathological factors and the number of lymph nodes yielded from the surgical specimens was assessed statistically. Results: Age of the patient, length of specimen, tumor size and operating surgeon were significantly associated with the lymph node yield (all P<0.05). The total number of lymph nodes yielded in 351 patients without neoadjuvant therapy ranged 8-49, with an average of 22.5, and the lymph node metastasis rate was 0-100% with an average of 7.6%.The total number of lymph nodes yielded from the 71 patients receiving neoadjuvant therapy ranged 9-70, with an average of 18.3, and the lymph node metastasis rate was 0-73.0%, with an average of 7.6%. Neoadjuvant therapy decreased the total lymph node yield obviously (P<0.001), but didn't decrease the lymph node metastasis rate (P=0.636). Of all the patients investigated, 19 cases had less than 12 dissected lymph nodes, and 403 cases had at least 12 lymph nodes removed. Gender, tumor size and neoadjvant therapy were independent risk factors for yield of twelve or more lymph nodes (all P<0.05). Conclusions: Age of the patient, length of specimen, tumor size, operating surgeons and neoadjuvant therapy are significantly correlated with the total number of lymph nodes yielded from laparoscopically resected specimens of rectal cancer. Neoadjvant therapy may obviously decrease the number of yielded lymph nodes, while not decreases the lymph node metastasis rate. Male gender, small size of the tumor, and neoadjvant therapy are possible risk factors for harvesting less than 12 lymph nodes.

A variety of different lymph node (LN) staging systems have been developed to describe the lymph node status accurately. We aim to compare the prognostic accuracy of American Joint Committee on Cancer seventh N stage relative to negative number of lymph node (nLN), lymph node ratio (LNR) and log odds of metastatic lymph nodes (LODDS) in rectal adenocarcinoma (RC). A total of 19 167 Stage II-III rectal cancer patients who underwent surgical resection of rectal adenocarcinoma were identified from Surveillance, Epidemiology and End Results database. Akaike's Information Criterion (AIC) and the Harrell's concordance index (c statistic) were used to evaluate the relative discriminative power of the different LN staging systems. Of the 19 167 patients, 10 958 received preoperative radiotherapy (pre-RT cohort) and 8209 patients were treated with surgical resection directly (SURG cohort). When assessed using categorical cutoff values, LNR has a somewhat better prognostic accuracy both in pre-RT (c-index: 0.62; AIC: 2988.6) and SURG groups (c-index: 0.60; AIC: 3359.8). Further analysis based on different total number of lymph node (TNLN) suggested that when less than 10 lymph nodes were retrieved, LNR exhibited significant superiority (pre-RT: c-index: 0.597, AIC: 1006.8; SURG: c-index: 0.560, AIC: 810.5). When analyzed as a continuous variable, the LODDS system performed the best and was not impacted by TNLN. When assessed as a categorical variable, LNR was the most powerful method to predict survival for Stage II-III RC patients with limited TNLN. Rather, LODDS was the most accurate staging system regardless of the TNLN when LN status was modeled as continuous variable.

The Prognostic Superiority of Log Odds of Positive Lymph Nodes in Stage III Colon Cancer

The problem of remotely stabilizing a noisy linear time invariant plant over a Gaussian relay network is addressed. The network is comprised of a sensor node, a group of relay nodes and a remote controller. The sensor and the relay nodes operate subject to an average transmit power constraint and they can cooperate to communicate the observations of the plant's state to the remote controller. The communication links between all nodes are modeled as Gaussian channels. Necessary as well as sufficient conditions for mean-square stabilization over various network topologies are derived. The sufficient conditions are in general obtained using delay-free linear policies and the necessary conditions are arrived at using information theoretic tools. Different settings where linear policies are optimal, asymptotically optimal (in certain parameters of the system) and suboptimal have been identified. For the case with noisy multidimensional sources controlled over scalar channels, it is shown that linear time varying policies lead to minimum capacity requirements, meeting the fundamental lower bound. For the case with noiseless sources and parallel channels, nonlinear policies which meet the lower bound have been identified.

Increasing evidence have shown that regional lymph node metastasis is a critical prognostic factor in gastric cancer (GC). In addition, lymph node dissection is a key factor in determining the appropriate treatment for GC. However, the association between the number of positive lymph nodes and area of lymph node metastasis in GC remains unclear. To investigate the clinical value of regional lymph node sorting after radical gastrectomy for GC. This study included 661 patients with GC who underwent radical gastrectomy at Tianjin Medical University General Hospital between January 2012 and June 2020. The patients were divided into regional sorting and non-sorting groups. Clinicopathological data were collected and retrospectively reviewed to determine the differences in the total number of lymph nodes and number of positive lymph nodes between the groups. Independent sample t-tests were used for intergroup comparisons. Continuous variables that did not conform to a normal distribution were expressed as median (interquartile range), and the Mann-Whitney U test was used for inter-group comparisons. There were no significant differences between the groups in terms of the surgical method, tumor site, immersion depth, and degree of differentiation. The total number of lymph nodes was significantly higher in the regional sorting group (n = 324) than in the non-sorting group (n = 337) (32.5 vs 21.2, P < 0.001). There was no significant difference in the number of positive lymph nodes between the two groups. A total of 212 patients with GC had lymph node metastasis in the lymph node regional sorting group, including 89 (41.98%) cases in the first dissection station and 123 (58.02 %) cases in the second dissection station. Binary and multivariate logistic regression results showed that the number of positive lymph nodes (P < 0.001) was an independent risk factor for lymph node metastases at the second dissection station. Regional sorting of lymph nodes after radical gastrectomy may increase the number of detected lymph nodes, thereby improving the reliability and accuracy of lymph node staging in clinical practice.

We postulate that surgical sampling and pathologic evaluation of lymph nodes of surgical specimens from patients with stage I non-small-cell lung cancer (NSCLC) can have an effect on the time to recurrence and survival of these patients. We analyzed data on 442 patients with stage I NSCLC who were treated with surgical resection and some form of lymph node sampling. Associations between total lymph nodes sampled and disease-free survival (DFS) and overall survival (OS) were investigated. The effect of total lymph node stations sampled and the surgical techniques (random lymph node sampling, systematic sampling [SS], or complete mediastinal lymph node dissection [MLND]) on DFS and OS was also studied. Complete MLND and SS were defined as dissection or sampling of levels 4, 7, and 10 for right-sided lesions and levels 5 or 6 and 7 for left-sided lesions. Patients were divided into quartiles on the basis of total number of lymph nodes sampled. Improved DFS and OS were associated with greater number of lymph nodes sampled. SS and MLND were associated with improved survival compared with random lymph node sampling. The total number of lymph nodes sampled maintained strong significance in the multivariate analysis. These results indicate that examining a greater number of lymph nodes in patients with stage I NSCLC treated with resection increases the likelihood of proper staging and affects patient outcome. Such information is important not only for therapy and prognosis of individuals but also for identifying those who may benefit from adjuvant therapy.