Faculty Bibliography

OBJECTIVES: To identify the associations of lymph node metastases (pN+), number of positive nodes, and pN subclassification with cancer, treatment, patient, geographic, and institutional variables, and to recommend extent of lymphadenectomy needed to accurately detect pN+ for esophageal cancer. SUMMARY BACKGROUND DATA: Limited data and traditional analytic techniques have precluded identifying intricate associations of pN+ with other cancer, treatment, and patient characteristics. METHODS: Data on 5806 esophagectomy patients from the Worldwide Esophageal Cancer Collaboration were analyzed by Random Forest machine learning techniques. RESULTS: pN+, number of positive nodes, and pN subclassification were associated with increasing depth of cancer invasion (pT), increasing cancer length, decreasing cancer differentiation (G), and more regional lymph nodes resected. Lymphadenectomy necessary to accurately detect pN+ is 60 for shorter, well-differentiated cancers (<2.5 cm) and 20 for longer, poorly differentiated ones. CONCLUSIONS: In esophageal cancer, pN+, increasing number of positive nodes, and increasing pN classification are associated with deeper invading, longer, and poorly differentiated cancers. Consequently, if the goal of lymphadenectomy is to accurately define pN+ status of such cancers, few nodes need to be removed. Conversely, superficial, shorter, and well-differentiated cancers require a more extensive lymphadenectomy to accurately define pN+ status.

Minimally invasive surgery (MIS) for lung cancer has been associated with decreased perioperative morbidity while maintaining similar long-term survival when compared to open thoracotomy. Robotic thoracic surgery constitutes an evolutionary step in this field, beckoning dramatic advancements both in visualization as well as surgical instrument range of motion and ergonomics. As such, robotic thoracic surgery is growing in adoption worldwide. One of its oft-cited disadvantages, however, is increased operative time, especially for less-experienced surgeons. We describe an assortment of tips and tricks that we conclude can safely reduce robotic operative duration.

Robotic segmentectomy can be a useful technique for patients with suboptimal pulmonary reserve, or for small peripheral stage I tumors. Port placement and conduct of operation is described for the various segmentectomies. Results for robotic segmentectomy are comparable to that for video-assisted thoracoscopic surgery (VATS) segmentectomy.

Minimally invasive thoracic surgery, when compared with open thoracotomy, has been shown to have improved perioperative outcomes as well as comparable long-term survival. Robotic surgery represents a powerful advancement of minimally invasive surgery, with vastly improved visualization and instrument maneuverability, and is increasingly popular for thoracic surgery. However, there remains debate over the best robotic approaches for lung resection, with several different techniques evidenced and described in the literature. We delineate our method for total port approach with four robotic arms and discuss how its advantages outweigh its disadvantages. We conclude that it is preferred to other robotic approaches, such as the robotic assisted approach, due to its enhanced visualization, improved instrument range of motion, and reduced potential for injury.

We report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for patients with pathologically staged cancer of the esophagus and esophagogastric junction after resection or ablation with no preoperative therapy from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted de-identified data using standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 13,300 patients, 5,631 had squamous cell carcinoma, 7,558 adenocarcinoma, 85 adenosquamous carcinoma, and 26 undifferentiated carcinoma. Patients were older (62 years) men (80%) with normal body mass index (51%), little weight loss (1.8 kg), 0-2 ECOG performance status (83%), and a history of smoking (70%). Cancers were pT1 (24%), pT2 (15%), pT3 (50%), pN0 (52%), pM0 (93%), and pG2-G3 (78%); most involved distal esophagus (71%). Non-risk-adjusted survival for both squamous cell carcinoma and adenocarcinoma was monotonic and distinctive across pTNM. Survival was more distinctive for adenocarcinoma than squamous cell carcinoma when pT was ordered by pN. Survival for pTis-1 adenocarcinoma was better than for squamous cell carcinoma, although monotonic and distinctive for both. WECC pathologic staging data is improved over that of the 7th edition, with more patients studied and patient and cancer variables collected. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient, cancer, and treatment characteristics, and should direct 9th edition data collection. However, the role of pure pathologic staging as the principal point of reference for esophageal cancer staging is waning.

To address uncertainty of whether clinical stage groupings (cTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for clinically staged patients from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted data using variables with standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 22,123 clinically staged patients, 8,156 had squamous cell carcinoma, 13,814 adenocarcinoma, 116 adenosquamous carcinoma, and 37 undifferentiated carcinoma. Patients were older (62 years) men (80%) with normal body mass index (18.5-25 mg/kg2 , 47%), little weight loss (2.4 +/- 7.8 kg), 0-1 ECOG performance status (67%), and history of smoking (67%). Cancers were cT1 (12%), cT2 (22%), cT3 (56%), cN0 (44%), cM0 (95%), and cG2-G3 (89%); most involved the distal esophagus (73%). Non-risk-adjusted survival for squamous cell carcinoma was not distinctive for early cT or cN; for adenocarcinoma, it was distinctive for early versus advanced cT and for cN0 versus cN+. Patients with early cancers had worse survival and those with advanced cancers better survival than expected from equivalent pathologic categories based on prior WECC pathologic data. Thus, clinical and pathologic categories do not share prognostic implications. This makes clinically based treatment decisions difficult and pre-treatment prognostication inaccurate. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient characteristics, cancer categories, and treatment characteristics and should direct 9th edition data collection.

OBJECTIVE: The objective is to report our outcomes of teaching and performing minimally invasive robotic lobectomy. METHODS: Robotic lobectomy was divided into 19 specific sequential technical maneuvers. The number of steps residents could perform in a set period of time was recorded. Video review by the attending surgeon and coaching were used to improve what residents could safely perform. Outcomes compared were percentage of maneuvers that general surgical or cardiothoracic residents (fellows) completed, operative times, and Society of Thoracic Surgeons-defined metrics of patient outcomes. RESULTS: There were 520 consecutive robotic lobectomies over 5 years. The various maneuvers completed by general surgical residents (N = 35) and cardiothoracic residents (N = 7) increased over time, for example, steps 1 to 5 increased 20% and 70% compared with 80% and 90% (P < .001), step 8 increased 0% and 50% compared with 90% and 100% (P < .0001), and step 19 increased 30% and 50% compared with 90% and 100% (P = .001), respectively. Operative outcomes, including intraoperative blood loss, median number of lymph nodes, median length of stay, major morbidity, and 30-day and 90-day mortality, were no different. Operative time initially increased and then decreased over time. Conversion to thoracotomy (15% to 2.5%, P = .042) and major vascular injury (3% to 0%, P = .018) decreased. CONCLUSIONS: Robotic lobectomy can be safely taught to residents without compromising patient outcomes by dividing it into a series of surgical maneuvers. Recording outcomes for each step and using video review and coaching techniques may help increase the percent of maneuvers residents can complete in a set time.

To address uncertainty of whether pathologic stage groupings after neoadjuvant therapy (ypTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for pathologically staged cancers after neoadjuvant therapy from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted data using variables with standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 7,773 pathologically staged neoadjuvant patients, 2,045 had squamous cell carcinoma, 5,686 adenocarcinoma, 31 adenosquamous carcinoma, and 11 undifferentiated carcinoma. Patients were older (61 years) men (83%) with normal (40%) or overweight (35%) body mass index, 0-1 Eastern Cooperative Oncology Group performance status (96%), and a history of smoking (69%). Cancers were ypT0 (20%), ypT1 (13%), ypT2 (18%), ypT3 (44%), ypN0 (55%), ypM0 (94%), and G2-G3 (72%); most involved the distal esophagus (80%). Non-risk-adjusted survival for yp categories was unequally depressed, more for earlier categories than later, compared with equivalent categories from prior WECC data for esophagectomy-alone patients. Thus, survival of patients with ypT0-2N0M0 cancers was intermediate and similar regardless of ypT; survival for ypN+ cancers was poor. Because prognoses for ypTNM and pTNM categories are dissimilar, prognostication should be based on separate ypTNM categories and groupings. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient, cancer, and treatment characteristics and should direct 9th edition data collection.