Percent vital capacity predicts postoperative sarcopenia after esophagectomy in initially nonsarcopenic esophageal cancer patients: a retrospective cohort study.

PURPOSE: The development of sarcopenia after esophagectomy is reported to affect the outcomes of patients with esophageal cancer (EC); however, the characteristics of patients likely to be predisposed to postoperative sarcopenia have not been defined. This study explores the associations between preoperative respiratory function and surgery-induced sarcopenia in EC patients confirmed as nonsarcopenic preoperatively. METHODS: The subjects of this retrospective review were 128 nonsarcopenic patients who underwent esophagectomy for EC. We took body composition measurements and performed physical function tests 3 and 6 months postoperatively, to establish whether sarcopenia was present, according to the 2019 Asian Working Group for Sarcopenia guideline. We defined patients with surgery-induced sarcopenia as those with evidence of the development of sarcopenia within 6 months postoperatively or those with documented sarcopenia at 3 months but who could not be evaluated at 6 months. RESULTS: Surgery-induced sarcopenia developed in 19 of the 128 patients (14.8%), which correlated significantly with the preoperative %VC value (p < 0.01), but not with the preoperative FEV1.0% value. We set the lower quartile %VC value (91%) as the cut-off for predicting surgery-induced sarcopenia. A low %VC was independently associated with surgery-induced sarcopenia (odds ratio: 5.74; 95% confidence interval: 1.99-16.57; p < 0.01). CONCLUSIONS: Based on the findings of this study, %VC was a simple but valuable factor for predicting sarcopenia induced by esophagectomy.

The importance of ethnic-specific cut-offs of low muscle mass for survival prediction in oncology.

BACKGROUND & AIMS: While skeletal muscle index (SMI) is the most widely used indicator of low muscle mass (or sarcopenia) in oncology, optimal cut-offs (or definitions) to better predict survival are not standardized. METHODS: We compared five major definitions of SMI-based low muscle mass using an Asian patient cohort with gastrointestinal or genitourinary cancers. We analyzed 2015 patients with surgically-treated gastrointestinal (n = 1382) or genitourinary (n = 633) cancer with pre-surgical computed tomography images. We assessed the associations of clinical parameters, including low muscle mass by each definition, with cancer-specific survival (CSS) and overall survival (OS). RESULTS: During a median follow-up period of 61 months, 303 (15%) died of cancer, and 147 died of other causes. An Asian-based definition diagnosed 17.8% of patients as having low muscle mass, while the other Caucasian-based ones classified most (>70%) patients as such. All definitions significantly discriminated both CSS and OS between patients with low or normal muscle mass. Low muscle mass using any definition but one predicted a lower CSS on multivariate Cox regression analyses. All definitions were independent predictors of lower OS. The original multivariate model without incorporating low muscle mass had c-indices of 0.63 for CSS and 0.66 for OS, which increased to 0.64-0.67 for CSS and 0.67-0.70 for OS when low muscle mass was considered. The model with an Asian-based definition had the highest c-indices (0.67 for CSS and 0.70 for OS). CONCLUSIONS: The Asian-specific definition had the best predictive ability for mortality in this Asian patient cohort.

Lymphatic flow mapping using near-infrared fluorescence imaging with indocyanine green helps to predict lymph node metastasis intraoperatively in patients with esophageal or esophagogastric junction cancer not treated with neoadjuvant chemotherapy.

BACKGROUND: Lymphatic flow mapping using near-infrared fluorescence (NIR) imaging with indocyanine green (ICG) has been used for the intraoperative prediction of lymph node metastasis in esophageal or esophagogastric junction cancer. However, a consistent method that yields sufficient diagnostic quality is yet to be confirmed. This study explored the diagnostic utility of our newly established lymphatic flow mapping protocol for predicting lymph node metastasis in patients with esophageal or esophagogastric junction cancer. METHODS: We injected 0.5 mL of ICG (500 µg/mL) into the submucosal layer at four peritumoral points on the day before surgery for 54 patients. We performed lymphatic flow mapping intraoperatively using NIR imaging. After determining the NIR status and presence of metastases, evaluable lymph node stations on in vivo imaging and all resected lymph nodes were divided into four categories: ICG+meta+ (true positive), ICG+meta- (false positive), ICG-meta+ (false negative), and ICG-meta- (true negative). RESULTS: The distribution of ICG+ and meta+ lymph node stations differed according to the primary tumor site. Sensitivity and specificity for predicting meta+ lymph nodes among ICG+ ones were 50% (95% CI 41-59%) and 75% (73-76%), respectively. Predicting meta+ lymph node stations among ICG+ stations improved these values to 66% (54-77%) and 77% (74-79%), respectively. Undergoing neoadjuvant chemotherapy was an independent risk factor for having meta+ lymph nodes with false-negative diagnoses (odds ratio 4.82; 95% CI 1.28-18.19). The sensitivity of our technique for predicting meta+ lymph nodes and meta+ lymph node stations in patients who did not undergo neoadjuvant chemotherapy was 79% (63-90%) and 83% (61-94%), respectively. CONCLUSION: Our protocol potentially helps to predict lymph node metastasis intraoperatively in patients with esophageal or esophagogastric junction cancer undergoing esophagectomy who did not undergo neoadjuvant chemotherapy.

Implications of Liver-Directed Therapy for Postoperative Hepatic Metastasis from Esophageal Cancer.

Background: Distant recurrence of esophageal cancer (EC), even after radical resection, is common, and the most frequent site of EC metastasis is the liver. However, a multidisciplinary treatment strategy for postoperative liver metastasis (LM) from EC has yet to be established; in particular, the role of liver-directed therapy (LDT) remains uncertain. We investigated the clinicopathological features and outcomes of patients undergoing post-esophagectomy LM with versus without LDT to explore its therapeutic implications. Methods: Among 624 consecutive patients undergoing R0/R1 esophagectomy for EC, 30 were identified in whom LM had developed as the initial recurrence. Their characteristics were retrospectively reviewed. Results: Six of the 30 subjects underwent LDT for metachronous LM. Five of those 6 also received systemic chemotherapy. A comparison between the 6 LDT and 24 non-LDT cases revealed no significant differences in major clinicopathological and operative factors, except for concurrent metastasis to extrahepatic organs (1/6 vs. 15/24, p=0.044). Twenty-nine of the 30 patients died during the study period, whereas 1 who had received multimodal treatment with LDT remained alive more than 200 months after multiple LM had been detected. Kaplan-Meier analysis for survival after LM demonstrated significantly prolonged survival in LDT cases compared to non-LDT cases treated with systemic chemotherapy alone (p=0.014). Even when the analysis was limited to patients without extrahepatic metastasis, this significant prognostic advantage of LDT was maintained (p=0.047). Conclusion: Multimodal treatment combined with LDT might be beneficial for patients with metachronous LM from EC and should therefore be considered a potential treatment option.

Optimal settings of near-infrared fluorescence imaging with indocyanine green for intraoperative detection of lymph node metastasis in esophageal cancer.

Lymphatic flow mapping using near-infrared fluorescence (NIR) imaging with indocyanine green (ICG) has been used for intraoperative diagnosis of lymph node metastasis (LNM) in various cancers. Accurate prediction of LNM intraoperatively may allow minimization of the extent of lymphadenectomy. However, a consistent method and diagnostic ability, allowing application of NIR-guided lymphatic flow mapping to esophageal cancer (EC), have not been established due to the multidirectional and complex characteristics of lymphatic flow in the esophagus. Herein, we present a novel NIR-guided surgical technique for predicting lymph node stations potentially containing LNM in EC with high diagnostic accuracy derived from appropriately adjusting the ICG injection setting.

Optimal criteria for predicting lymph node metastasis in esophageal squamous cell carcinoma by anatomical location using preoperative computed tomography: a retrospective cohort study.

PURPOSE: Predicting lymph node metastasis (LNM) in esophageal squamous cell carcinoma (ESCC) is critical for selecting appropriate treatments despite the low accuracy of computed tomography (CT) for detecting LNM. Variation in potential nodal sizes among locations or patients' clinicopathological background factors may impact the diagnostic quality. This study explored the optimal criteria and diagnostic ability of CT by location. METHODS: We retrospectively reviewed preoperative CT scans of 229 patients undergoing curative esophagectomy. We classified nodal stations into six groups: Cervical (C), Right-upper mediastinal (UR), Left-upper mediastinal (UL), Middle mediastinal (M), Lower mediastinal (L), and Abdominal (A). We then measured the short-axial diameter (SAD) of the largest lymph node in each area. We used receiver operating characteristics analyses to evaluate the CT diagnostic ability and determined the cut-off values for the SAD in all groups. RESULTS: Optimal cut-offs were 6.5 mm (M), 6 mm (C, L, and A), and 5 mm (UR and UL). Diagnostic abilities differed among locations, and UR had the highest sensitivity. A multivariate analysis showed poor differentiation to be an independent risk factor for a false-negative diagnosis (p = 0.044). CONCLUSIONS: Optimal criteria and diagnostic abilities for predicting LNM in ESCC varied among locations, and poor differentiation might contribute to failure to detect LNM.

Trunk fat volume can be a predictor of postoperative complications after gastrectomy: a retrospective cohort study.

BACKGROUND: Obesity can affect postoperative outcomes of gastrectomy. Visceral fat area is superior to body mass index in predicting postoperative complications. However, visceral fat area measurement is time-consuming and is not optimum for clinical use. Meanwhile, trunk fat volume (TFV) can be easily measured via bioelectrical impedance analysis. Hence, the current study aimed to determine the ability of TFV to predict the occurrence of complications after gastrectomy. METHODS: We retrospectively reviewed patients who underwent curative gastrectomy for gastric cancer between November 2016 and November 2019. The trunk fat volume-to-the ideal amount (%TFV) ratio was obtained using InBody 770 before surgery. The patients were classified into the obese and nonobese groups according to %TFV (TFV-H group, ≥ 150%; TFV-L group, < 150%) and body mass index (BMI-H group, ≥ 25 kg/m2; BMI-L group, < 25 kg/m2). We compared the short-term postoperative outcomes (e.g., operative time, blood loss volume, number of resected lymph nodes, and duration of hospital stay) between the obese and nonobese patients. Risk factors for complications were assessed using logistic regression analysis. RESULTS: In total, 232 patients were included in this study. The TFV-H and BMI-H groups had a significantly longer operative time than the TFV-L (p = 0.022) and BMI-L groups (p = 0.006). Moreover, the TFV-H group had a significantly higher complication rate (p = 0.004) and a lower number of resected lymph nodes (p < 0.001) than the TFV-L group. In the univariate analysis, %TFV ≥ 150, total or proximal gastrectomy, and open gastrectomy were found to be potentially associated with higher complication rates (p < 0.1 for all). Moreover, the multivariate analysis revealed that %TFV ≥ 150 (OR: 2.73; 95% CI: 1.37-5.46; p = 0.005) and total or proximal gastrectomy (OR: 3.57; 95% CI: 1.79-7.12; p < 0.001) were independently correlated with postoperative morbidity. CONCLUSIONS: %TFV independently affected postoperative complications. Hence, it may be a useful parameter for the evaluation of obesity and a predictor of complications after gastrectomy.