On the road to standardization of D2 lymph node dissection in a European population of patients with gastric cancer

Challenging the Dogma: Stage migration or negative lymph nodes, which of them is the main player on gastric cancer prognosis?

Expanding loco-regional nodes harvesting is expected to increase survival. This improvement may be associated to stage migration (SM). However, the great bulk of harvested lymph nodes observed in large dissections is negative. M&M: 830 patients who received R0 gastrectomy for adenocarcinoma were included. pN+ patients with <26 nodes (n = 209) were included for a simulation to "offer 26 nodes" - SM (proportional and exponential based) was simulated and analysed through machine learning algorithms. Overall Survival (OS), in native and simulated stages, were compared. OS of extended lymphadenectomies (pN+, D ≥ 26, n = 273) was compared with the simulated curves. OS of patients in the following dissection intervals of negative nodes were compared: <16 (n = 233), 16-25 (n = 258), ≥26 (n = 339). RESULTS: After simulation to 26 nodes (pN+, D < 26 patients, n = 209), staging was recomputed. OS of native vs simulated early-stages (I-II) and advanced stages (III) were not different (p > 0.05). OS of patients with lymphadenectomy (≥26) was better than simulated for early and advanced stages (p = 0.008; p = 0.005). OS of patients included in distinct intervals of negative lymph nodes were different (p < 0.001). These intervals were an independent prognostic factor (multivariate analysis). CONCLUSIONS: The influence of Stage Migration was null in this set of simulations and Will Rogers phenomenon was not observed. Extended dissection performed better in OS. But the influence of the number of negative nodes, even in large dissections, was highlighted. By emphasizing the role of negative nodes, we aim to facilitate more informed decision-making in management of gastric cancer patients, ultimately leading to improved treatment outcomes and patient care.

Impact of the introduction of formal D2 lymphadenectomy for gastric cancer in a Western setting

Background

Two members from an academic tertiary hospital went to the National Cancer Institute in Tokyo, Japan, to learn how to perform an adequate D2 lymphadenectomy and to then introduce this technique in the surgical care of patients undergoing surgery for gastric cancer at a Western hospital. We aimed to compare the perioperative outcomes and long-term survival of Western patients who underwent gastric resection, performed by these 2 surgeons, before and after the surgeons’ short-course technical training in Japan.

Methods

We conducted a retrospective comparative study of all patients (n = 27 before training and n = 79 after training) who underwent gastric resection for cancer by the same 2 surgeons between September 2007 and December 2017 at the Centre Hospitalier Universitaire de Québec — Université Laval (Québec, Canada). We collected data on patient demographic, clinical, surgical, pathological and treatment characteristics, as well as long-term survival and complications.

Results

In the post-training group, the number of sampled lymph nodes was higher (median 33 v. 14, p < 0.0001), but this increase did not result in a higher number of histologically positive lymph nodes (p = 0.35). The rate of complications was lower in the post-training group (15.2% v. 48.2%, p = 0.002). The hospital stay was shorter in the post-training group (11 [standard deviation (SD) 7] v. 23 [SD 45] d, p = 0.03). The median survival was higher in the post-training group (47 v. 29 mo, p = 0.03).

Conclusion

These results suggest that a short-course technical training in D2 lymphadenectomy, completed in Japan, improved lymph node sampling, decreased postoperative complications and improved survival of patients undergoing surgery for gastric cancer in a Western setting.

Surgeon Quality Control and Standardization of D2 Lymphadenectomy for Gastric Cancer: A Prospective Multicenter Observational Study (KLASS-02-QC)

OBJECTIVE

To qualify surgeons to participate in a randomized trial comparing laparoscopic and open distal D2 gastrectomy for advanced gastric cancer.

SUMMARY OF BACKGROUND DATA

No studies have sought to qualify surgeons for a randomized trial comparing laparoscopic and open D2 gastrectomy for advanced gastric cancer.

METHODS

We conducted a multicenter prospective observational study evaluating unedited videos of laparoscopic and open D2 gastrectomy performed by 27 surgeons. Surgeons performed 3 of each laparoscopic and open distal gastrectomies with D2 lymphadenectomy for gastric cancer. Five peers reviewed each unedited video using a video assessment form. Based on experts' review of videos, a separate review committee decided surgeons as "Qualified" or "Not-qualified."

RESULTS

Twelve surgeons (44.4%) were qualified on initial evaluation whereas the other 15 surgeons were not. Another 9 surgeons were finally qualified after re-evaluation. The median score for Qualified was significantly higher than Not-qualified (P < 0.001).Significant differences between Qualified and Not-qualified were noted both in operation type and in all evaluation area of surgical skill, perigastric, and extra-perigastric lymphadenectomy, although the inter-rater variability of the assessment score was low (kappa = 0.285). However, Not-qualified surgeons' scores improved upon re-evaluation of resubmitted videos.When compared laparoscopy with open surgery, median scores were similar between the 2 groups (P = 0.680). However, open gastrectomy scores for surgical skills were significantly higher than for laparoscopic surgery (P = 0.016).

CONCLUSIONS

Our surgeon quality control study for gastrectomy represents a milestone in surgical standardization for surgical clinical trials. Our methods could also serve as a system for educating surgeons and assessing surgical proficiency.

Prognostic significance of 14v-lymph node dissection to D2 dissection for lower-third gastric cancer

BACKGROUND

Radical gastrectomy with D2 lymph node (LN) dissection is the standard surgical procedure for patients with resectable gastric cancer (GC). In the fifteenth edition of the Japanese Classification of Gastric Carcinoma, the 14v LN (LNs along the root of the superior mesenteric vein) was defined as the regional gastric LN. The efficacy of 14v LN dissection during radical distal gastrectomy for lower-third GC remains controversial.

AIM

To analyze whether the addition of 14v LN dissection improved the survival of patients with lower-third GC.

METHODS

The data from 65 patients who underwent 14v LN dissection and 65 patients treated without 14v LN dissection were selected using the propensity score-matched method from our institute database constructed between 2000 and 2012. Overall survival was compared between the groups.

RESULTS

Overall survival was similar between patients with 14v LN metastasis and those with distant metastasis (P = 0.521). Among patients with pathological stage IIIA disease, those who were treated with 14v LN dissection had a significantly higher overall survival than those treated without it (P = 0.020). Multivariate analysis showed that age < 65 years and pT2-3 stage were independent favorable prognostic factors for prolonged overall survival in patients with pathological stage IIIA disease. Patients with No. 1, No. 6, No. 8a, or No. 11p LN metastasis were at higher risk of having 14v LN metastasis.

CONCLUSION

Adding 14v LN dissection to D2 dissection during radical distal gastrectomy may improve the overall survival of patients with pathological stage IIIA lower-third GC.

Evolution in the surgical management of gastric cancer: is extended lymph node dissection back in vogue in the USA?

BACKGROUND

Gastric cancer remains a formidable treatment challenge. For decades, treatment consisted mostly of surgical intervention for this deadly disease. With improvements in the multi-disciplinary management of solid organ malignancies, the approach to this disease is being stepwise refined.

MAIN BODY

One of the prevalent controversies in the surgical management of gastric cancer rests on the need for adequate harvesting of lymph nodes. For decades, lymph node dissection is regarded as a staging technique useful in only upstaging the disease. The adoption of D2 lymphadenectomy has been particularly slow to mature. But with prevailing data from Asia consistently demonstrating a survival benefit from lymphadenectomy, it calls into question the notion of lymphadenectomy as being solely a staging procedure.

CONCLUSIONS

As gastric resection techniques are being better defined in western countries and surgical morbidities lowered on its execution, D2 lymphadenectomy is becoming more accepted as the new standard in the management of gastric cancer.