Estimation of lymph node metastasis by size in patients with intrathoracic oesophageal cancer

Extent of Lymphadenectomy and Long-term Survival in Esophageal Cancer

OBJECTIVE

To examine the hypothesis that survival in esophageal cancer increases with more removed lymph nodes during esophagectomy up to a plateau, after which it levels out or even decreases with further lymphadenec-tomy.

SUMMARY OF BACKGROUND DATA

There is uncertainty regarding the ideal extent of lymphadenectomy during esophagectomy to optimize long-term survival in esophageal cancer.

METHODS

This population-based cohort study included almost every patient who underwent esophagectomy for esophageal cancer in Sweden or Finland in 2000-2016 with follow-up through 2019. Degree of lymphadenectomy, divided into deciles, was analyzed in relation to all-cause 5-year mortality. Multivariable Cox regression provided hazard ratios (HR) with 95% confidence intervals (95% CI) adjusted for all established prognostic factors.

RESULTS

Among 2306 patients, the second (4-8 nodes), seventh (21-24 nodes) and eighth decile (25-30 nodes) of lymphadenectomy showed the lowest all-cause 5-year mortality compared to the first decile [hazard ratio (HR) = 0.77, 95% CI 0.61-0.97, HR = 0.76, 95% CI 0.59-0.99, and HR = 0.73, 95% CI 0.57-0.93, respectively]. In stratified analyses, the survival benefit was greatest in decile 7 for patients with pathological T-stage T3/T4 (HR = 0.56, 95% CI0.40-0.78), although it was statistically improved in all deciles except decile 10. For patients without neoadjuvant chemotherapy, survival was greatest in decile 7 (HR = 0.60, 95% CI 0.41-0.86), although survival was also statistically significantly improved in deciles 2, 6, and 8.

CONCLUSION

Survival in esophageal cancer was not improved by extensive lymphadenectomy, but resection of a moderate number (20-30) of nodes was prognostically beneficial for patients with advanced T-stages (T3/T4) and those not receiving neoadjuvant therapy.

Optimal Size Criterion for Malignant Lymph Nodes and a Novel Lymph Node Clinical Staging System for Unresectable Esophageal Squamous Cell Carcinoma: Evaluation by Multislice Spiral Computed Tomography

Objectives: The current Chinese draft nodal clinical staging system for unresectable esophageal cancer is controversial. Our study aimed to propose a new diagnostic criterion for lymph node metastasis (LNM) detected by multislice spiral computed tomography (MSCT) in nonsurgically treated esophageal squamous cell carcinoma (ESCC) patients and then develop a novel lymph node (LN) clinical staging system for better individual prognostic prediction. Methods: The short-axis diameters of regional LNs were measured in 393 nonsurgical patients. Regional nodes were considered positive for malignancy if the nodal size exceeded the optimal size, which was determined by Kaplan-Meier survival analysis. The novel LN clinical staging system was then constructed using the LASSO model based on the relative prognostic importance of different LN stations. Validation cohort was included to confirm the prognostic performance. Results: Regional nodes were considered positive for malignancy if they were larger than 10 mm in the low cervical and upper thoracic segments, 7 mm in the middle thoracic segment, and 8 mm in the lower thoracic and celiac segments. Using the LASSO model, stations 2R, 3A, 7 and 16 were qualified in the model. Further analysis showed that our LN clinical staging system had better homogeneity, discriminatory ability and clinical value than the draft nodal staging system. Conclusions: Our results show that the new diagnostic criterion may improve the diagnostic value of MSCT in metastatic LNs. The novel LN clinical staging system can stratify nonsurgically treated ESCC patients into different risk groups, providing valuable information for decision making and outcome prediction.

Clinical TNM staging for esophageal, gastric, and colorectal cancers in the era of neoadjuvant therapy: A systematic review of the literature

AIM

Clinical staging is vital for selecting appropriate candidates and designing neoadjuvant treatment strategies for advanced tumors. The aim of this review was to evaluate diagnostic abilities of clinical TNM staging for gastrointestinal, gastrointestinal cancers.

METHODS

We conducted a systematic review of recent publications to evaluate the accuracy of diagnostic modalities on gastrointestinal cancers. A systematic literature search was performed in PubMed/MEDLINE using the keywords "TNM staging," "T4 staging," "distant metastases," "esophageal cancer," "gastric cancer," and "colorectal cancer," and the search terms used in Cochrane Reviews between January 2005 to July 2020. Articles focusing on preoperative diagnosis of: (a) depth of invasion; (b) lymph node metastases; and (c) distant metastases were selected.

RESULTS

After a full-text search, a final set of 55 studies (17 esophageal cancer studies, 26 gastric cancer studies, and 12 colorectal cancer studies) were used to evaluate the accuracy of clinical TNM staging. Positron emission tomography-computed tomography (PET-CT) and/or magnetic resonance imaging (MRI) were the best modalities to assess distant metastases. Fat and fiber mode of CT may be useful for T4 staging of esophageal cancer, CT was a partially reliable modality for lymph node staging in gastric cancer, and CT combined with MRI was the most reliable modality for liver metastases from colorectal cancer.

CONCLUSION

The most reliable diagnostic modality differed among gastrointestinal cancers depending on the type of cancer. Therefore, we propose diagnostic algorithms for clinical staging for each type of cancer.

Preoperative lymph node status on computed tomography influences the survival of pT1b, T2 and T3 esophageal squamous cell carcinoma

PURPOSE

The preoperative lymph node status is critical for tailoring optimal treatments for esophageal squamous cell carcinoma (ESCC). This study aimed to evaluate the prognostic impact of a diagnostic criterion based solely on the short-axis diameters of lymph nodes depicted on computed tomography (CT) in ESCC patients undergoing upfront esophagectomy.

METHODS

We retrospectively reviewed 246 pT1b-T3 ESCC patients undergoing upfront esophagectomy. Clinically positive lymph node metastasis (cN+) was defined as nodes with a short-axis diameter of at least 8 mm on CT.

RESULTS

Ninety-three patients had a cN+ status according to this criterion. The overall and recurrence-free survival rates were significantly lower in the cN+ group than in the cN- group (P < 0.001). The overall survival rate was markedly lower in the "pN2/3 and cN+" group than in the other groups (vs. pN0: P < 0.001, vs. pN1: P = 0.002, vs. "pN2/3 and cN-": P < 0.001). However, the overall survival rate of the "pN2/3 and cN-" group was similar to that of the pN0-1 groups. A multivariate analysis showed that cN+ (P = 0.002), major complications (P = 0.001), and pT3 (P = 0.021) were independently associated with a poor prognosis.

CONCLUSION

A diagnostic criterion based solely on the short-axis diameters of lymph nodes depicted on CT was useful for stratifying the survival in ESCC patients.

Near-Infrared Lymphatic Mapping of the Recurrent Laryngeal Nerve Nodes in T1 Esophageal Cancer

BACKGROUND

It is still unclear that dissection of recurrent laryngeal nerve nodes is mandatory in patients with cT1 middle or lower thoracic esophageal squamous cell carcinoma when the nodes are negative in preoperative staging workup. We aimed to evaluate the feasibility of near-infrared image-guided lymphatic mapping of bilateral recurrent laryngeal nerve nodes.

METHODS

The day before operation, we injected indocyanine green (ICG) into the submucosal layer by endoscopy. At the time of upper mediastinal dissection, ICG-stained basins were identified along the bilateral recurrent laryngeal nerves and retrieved under guidance of the Firefly system. After the operation, remnant ICG-unstained basins were dissected from the specimen to assess the presence of metastasis.

RESULTS

Of 29 patients enrolled, ICG-stained basins could be identified in 25 patients (86.2%), and 6 of them (24.0%) had nodal metastasis; 4 in the right recurrent laryngeal nerve chain, 1 in the left recurrent laryngeal nerve chain, and 1 in both recurrent laryngeal nerve chains. On pathologic examination of 345 recurrent laryngeal nerve nodes, two metastatic nodes were identified in ICG-unstained basins along the left recurrent laryngeal nerve in a patient who had lymph node metastases in ICG-stained basins along both recurrent laryngeal nerves. Negative predictive value in detection of nodal metastasis was 100% for the right recurrent laryngeal nerve chain and 98.2% for the left recurrent laryngeal nerve chain.

CONCLUSIONS

Real-time assessment of recurrent laryngeal nerve nodes with near-infrared image was technically feasible, and we could detect lymphatic basins that most likely have nodal metastasis. Our technique might be useful in determining the optimal extent of lymphadenectomy.

Neoadjuvant therapy in relation to lymphadenectomy and resection margins during surgery for oesophageal cancer

Differences in lymph node yield and tumour-involved resection margins comparing neoadjuvant therapy plus surgery with surgery alone for oesophageal cancer are unclear. Patients who underwent oesophageal cancer surgery in Sweden in 1987–2010 were included. Patients treated with neoadjuvant therapy were compared with those who underwent surgery alone. Outcomes were the number of examined lymph nodes (main outcome), number metastatic lymph nodes, and resection margin status. Rate ratios (RRs) and 95% CIs of lymph node yield were calculated by Poisson regression, and odds ratios (ORs) and 95% CIs of resection margin status by multivariable logistic regression, both adjusted for confounders. Among 1818 patients, 587 (32%) had received neoadjuvant therapy and 1231 (68%) had not. Lymph node yield was lower in the neoadjuvant therapy group (median 6 versus 8; adjusted RR 0.75, 0.73–0.78). Fewer metastatic nodes were identified following neoadjuvant therapy (median 0 versus 1; adjusted RR 0.76, 0.69–0.84). Neoadjuvant therapy associated to decreased risk of tumour-involved resection margins when adjusted for confounders except T-stage (OR 0.52, 0.38–0.70), but the association did not remain after adjustment for T-stage (OR 0.91, 0.64–1.29). Neoadjuvant therapy seems to decrease the lymph node yield and decrease the risk of tumour-involved resection margins by shrinking primary tumour.

Supracarinal dissection of the oesophagus and lymphadenectomy by MIE

Since 1995, video-assisted thoracoscopic oesophagectomy (VATS), according the same surgical principles as the Japanese open surgery, has been completed in 700 patients with oesophageal cancer. Our indication for VATS is (I) no extensive pleural adhesion; (II) no contiguous tumor spread; (III) pulmonary function capable of sustaining single-lung ventilation, and (IV) non radiated patients. We use 4 ports around a 5 cm mini-thoracotomy on 5th intercostal space. We laid emphasis on utilizing magnifying effect of video (5 to 20 magnifications), obtained by positioning the camera at close vicinity to the dissection. Magnified view facilitates recognizing the fine layer structure of the mediastinum. The dissection should be performed following this layer structure just like open the page of a book. Tearing the layer makes the dissection irrational and cause unnecessary bleeding and invasiveness. The microanatomies we recognize during upper mediastinal dissection are (I) the most outer layer below the mediastinal pleura are branches from the vagus nerve and thoracic sympathetic trunk; (II) there is no vessel flow in the nerves or out, in the field of dissection; (III) the ideal layer of dissection along the nerve is exposing the epineurium; (IV) the strongest fixing structures in the mediastinum are the vagal nerves and nerves form thoracic sympathetic trunk; (V) the stump of thoracic duct shows particular appearance because of the intramural smooth muscle; (VI) the lymphonodes in the mediastinum are fixed strongly with nerves and gently with vessels; (VII) the aorta is covered with fine fibrous membrane consisting of branches form thoracic sympathetic trunk, etc. Magnified view shows the microstructure of the lymph node such as the afferent lymphatics penetrating the capsule and the hilum structure consisting the efferent lymphatics, artery, vein and nerve. The direction of the hilum of nodes is defined in each region. Therefore, understanding the hilum direction facilitates rational dissection. The hospital mortality was four patients (0.6%). The rate of regional control was 95%. The 5-year survival rates of the patients with pStage 0, 1, 2, 3, 4 were 92%, 88%, 69%, 52% and 24%, respectively, which were favorably compared with open surgery.

Use of Imaging for GI Cancers

GI cancers are a heterogeneous group of neoplasms that differ in their biologic and physical behaviors depending on the organ of origin, location within the organ, and degree of differentiation. As a result, evaluation of these tumors is complex, requiring integration of information from a patient's clinical history, physical examination, laboratory data, and imaging. With advances in anatomic and functional imaging techniques, we now have tools for assessing patients with these tumors at diagnosis, staging, and treatment assessment. It is difficult for a single imaging modality to provide all the necessary information for a given GI tumor. However, well-chosen combinations of available imaging modalities based on the indications, strength, and limitations of the modalities will provide optimal evaluation of patients with these malignancies.

Advantages of FDG-PET/CT over CT alone in the preoperative assessment of lymph node metastasis in patients with esophageal cancer

PURPOSE

The aim of this study was to determine the benefits of (18)F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) compared to CT alone in the preoperative assessment of lymph node metastasis in patients with esophageal cancer.

METHODS

One-hundred and seven patients who underwent esophagectomy with lymph node dissection between March 2007 and December 2009 were eligible. Sixty-seven patients were treated with surgery alone (SA group), while 40 patients received preoperative treatment prior to surgery (PT group). The pathological results of 1,403 dissected lymph node stations were compared with the results obtained using each imaging modality.

RESULTS

PET/CT showed a significantly higher specificity and positive predictive value (PPV) than CT alone (97.7 vs. 94.1 % and 64.6 vs. 44.0 %, respectively), when analyzed by the lymph node stations. The PPV of PET/CT for N1 cases was significantly better than that of CT alone (78.9 vs. 53.9 %), particularly in the PT group (91.3 vs. 65.4 %). Among the patients in the SA group, the number of metastatic nodes was significantly higher in PET-N1 cases than in PET-N0 cases (5.78 vs. 1.90).

CONCLUSION

PET/CT is useful for selecting patients with multiple lymph node metastases and also for detecting residual metastatic nodes after PT, and thus is beneficial to decide on the appropriate treatment strategy for patients with esophageal cancer.

Learning of thoracoscopic radical esophagectomy: how can the learning curve be made short and flat?

Attainment of proficiency in video-assisted thoracoscopic radical esophagectomy (VATS) for thoracic esophageal cancer requires much experience. We have mastered this procedure safely under the direction of an experienced surgeon. After adoption of the procedure, the educated surgeon directed induction of this surgical procedure at another institution. We evaluated the efficacy of instruction during the induction period by comparing the results at the two institutions in which VATS had been newly induced. We defined the induction period as the time from the beginning of VATS to the time when the last instruction was carried out. From January 2003 to December 2007, 53 patients were candidates for VATS at Kanazawa University (institution 1). Of these, 46 patients underwent curative VATS by a single operator. We divided this period into three parts: the induction period of VATS, post-induction period, and proficient period when the educated surgeon of institution 1 directed the procedure at Maebashi Red Cross Hospital (institution 2). At institution 1, 12 VATS were scheduled, and nine procedures (75%) (group A) including eight instructions were completed during the induction period (from January 2003 to August 2004). Thereafter, VATS was performed without instruction. In the post-induction period, nine VATS were scheduled, and eight procedures (88.8%) (group B) were completed from September 2004 to August 2005. Subsequently, 32 VATS were scheduled, and 29 procedures (90.6%) (group C) were completed during the proficient period (from September 2005 to December 2007). The surgeon at Maebashi Red Cross Hospital (institution 2) started to perform VATS under the direction of the surgeon who had been educated at institution 1 from September 2005. VATS was completed in 13 (76.4%) (group D) of 17 cases by a single surgeon including seven instructions during the induction period at institution 2 from September 2005 to December 2007. No lethal complication occurred during the induction period at both institutions. We compared the results of VATS among four groups from the two institutions. There were no differences in the background and clinicopathological features among the four groups. The number of dissected lymph nodes and amount of thoracic blood loss were similar in the four groups (35 [22-52] vs 41 [26-53] vs 32 [17-69] vs 29 [17-42] nodes, P = 0.139, and 170 [90-380] vs 275 [130-550] vs 220 [10-660] vs 210 [75-543] g, P = 0.373, respectively). There was no difference in the duration of the thoracic procedure during the induction period at the two institutions. However, the duration of the procedure was significantly shorter in the proficient period of institution 1 (group C: 266 [195-555] minutes) than in the induction period of both institutions (group A: 350 [280-448] minutes [P = 0.005] and group D: 345 [270-420] mL [P = 0.002]). There were no surgery-related deaths in any of the groups. The incidence of postoperative complications did not differ among the four groups. Thoracoscopic radical esophagectomy can be mastered quickly and safely with a flat learning curve under the direction of an experienced surgeon. The educated surgeon can instruct surgeons at another institution on how to perform thoracoscopic esophagectomy. The operation time of thoracoscopic surgery is shortened by experience.

Reduction rate of lymph node metastasis as a significant prognostic factor in esophageal cancer patients treated with neoadjuvant chemoradiation therapy

Tumor regression is used widely as a measure of tumor response following radiation therapy or chemoradiation therapy (CRT). In cases of esophageal cancer, a different pattern of tumor shrinkage is often observed between primary tumors and metastatic lymph nodes (MLNs). Regression of MLNs surrounded by normal tissue may be a more direct measure of the response to CRT than regression of a primary tumor as exfoliative mechanical clearance does not participate in shrinkage of MLNs. In this study we evaluated the significance of the reduction rate (RR) of MLNs as a prognostic factor in esophageal cancer patients treated with neoadjuvant CRT. Forty-two patients with marked MLNs were selected from 93 patients with esophageal carcinoma who had received neoadjuvant CRT. The RRs of the primary tumor and the MLNs were calculated from computed tomography scans. In 20 patients, surgical resection was carried out following CRT. Univariate analysis was used to determine which of the following variables were related to survival: size of the primary tumor and MLNs; RRs of both lesions; degree of lymph node (LN) metastasis; clinical stage; and surgical resection. Multivariate analysis was then performed to assess the prognostic relevance of each variable. The primary tumor was larger than the MLNs in 69% of patients before CRT and in 40% of patients after CRT. In 79% of the patients, the RR of the primary tumor was greater than the RR of the MLNs. The results of the univariate analyses showed that a high RR of the MLNs and surgical resection after CRT were associated with significantly improved survival. The multivariate analysis demonstrated that the RR of MLNs had the strongest influence on survival. The RR of LN metastasis should be evaluated as an important prognostic predictor in patients with marked LN metastasis of esophageal cancer treated with CRT.

Therapy of advanced esophageal malignancy

PURPOSE OF REVIEW

To evaluate the developments in the treatment of advanced esophageal cancer during the past year.

RECENT FINDINGS

Esophagectomy remains the treatment of choice for resectable esophageal malignancies even in locally advanced disease. Transthoracic en bloc esophagectomy with extended mediastinal lymphadenectomy seems to be superior to transmediastinal resection. Hospital and surgeon volume are the major factors that determine postoperative mortality. Promising short-term results were obtained in larger series with minimally-invasive esophagectomy, but concerns about oncologic appropriateness and the widespread applicability of this approach remain. Although neoadjuvant chemotherapy or radiochemotherapy is widely practiced, only responders appear to benefit. Positron emission tomography with fluorodeoxyglucose has been identified as a promising tool for response evaluation early after the onset of neoadjuvant treatment. Adjuvant chemotherapy or radiochemotherapy may be beneficial in a subgroup of patients after complete tumor resection.

SUMMARY

The transthoracic approach should be preferred for esophagectomy in locally advanced tumors. The surgeon's experience is the most important determinant of outcome after esophagectomy. Individualized indications for multimodality treatment appear possible.

Prognostic significance of the size of cancer nests in metastatic lymph nodes in human esophageal cancers

BACKGROUND

Postoperative survival of patients with esophageal cancers after curative surgery is strongly affected by the presence of lymph node metastasis. The number and location of lymph node metastases have been evaluated and graded, but the clinical significance of their size has not been well investigated.

METHODS

Of 322 esophageal cancer patients who underwent curative operations with radical lymph node dissection, 170 (53%) had lymph node metastasis. A total of 784 metastatic lymph nodes were obtained, and the area of the cancer nests was measured microscopically in the cross section. The data from each patient included the area of the largest cancer nest in the positive nodes (Nmax), classified as Na (<4 mm2), Nb (4-25 mm2), Nc (25-100 mm2), or Nd (>100 mm2).

RESULTS

The 170 patients were classified according to the Nmax value: Na, 31 (18.2%); Nb, 35 (20.5%); Nc, 49 (28.8%); and Nd, 55 (32.4%). The 5-year survival rate was 77.7% in patients without lymph node metastasis and 35.4% in those with lymph node metastasis. When classified by Nmax, the 5-year survival rate was 77.8% for Na, 63.9% for Nb, 18.8% for Nc, and 12.8% for Nd. There was no significant difference in the survival rate between Na patients and those without lymph node metastasis. Nmax showed significant correlation with the primary tumor size, depth of tumor invasion, and number and location of metastatic lymph nodes, but not with histologic type or primary tumor location. In multivariate analysis, the Nmax value, the number of lymph node metastases and depth of tumor invasion were independent prognostic factors, while the location of the lymph node metastases was not statistically significant.

CONCLUSIONS

The area of the largest cancer nest in the lymph nodes was one of the most significant prognostic factors for esophageal cancers. This estimation is objective and reproducible and may be of great importance when deciding the therapeutic modality for patients with esophageal cancers.

Prognostic factors after oesophagectomy and extended lymphadenectomy for squamous oesophageal cancer

BACKGROUND

The prognosis of patients without nodal metastasis of oesophageal cancer is generally good, but recurrence develops in some cases.

METHODS

Data on 88 consecutive patients with squamous oesophageal cancer who underwent three-field lymph node dissection from 1986 to September 1998 and who had no evidence of nodal disease were reviewed retrospectively. Disease status was based on histological examination of the section of each node with the largest surface area, stained with haematoxylin and eosin.

RESULTS

The 3- and 5-year survival rates of patients without lymph node metastasis were 85 and 81 per cent respectively, better than in patients with metastasis. Twelve patients died from recurrence. Recurrence was haematogenous in nine patients and locoregional in three. Survival was worse in men, for patients with lesions located in the upper thoracic oesophagus, and in those with lymphatic or blood vessel invasion. Only the presence of lymphatic invasion correlated with survival on multivariate analysis (P = 0.04).

CONCLUSION

Although survival was generally good in patients without nodal metastasis from oesophageal cancer following three-field lymph node dissection, patients with lymphatic invasion remained at risk for haematogenous dissemination.