Oncological Impact of Gross Proximal Margin Length in Distal Gastrectomy for Gastric Cancer: Is the Japanese Recommendation Valid?

A Case of Laparoscopic Resection of Gastric Cancer Using Novel Laparoscopic Fluorescence Spectrum System and Near-Infrared Fluorescent Clips

INTRODUCTION

In laparoscopic gastrectomy, accurate marking of the lesion site is essential in determining the resection line of the stomach, owing to the lack of haptics and the direct link between negative pathological margins and prognosis. Intraoperative endoscopy may require personnel and prolong the operation time, whereas preoperative endoscopic tattooing using India ink faces problems related to the spread of ink and visibility. ZEOCLIP FS (Zeon Medical, Tokyo, Japan) is a clip made of fluorescent resin, covered by insurance since March 2019. It can be visualized from the serosal side using a near-infrared scope; however, its weak fluorescence intensity often poses viewing difficulties. Lumifinder (ADVANTEST, Tokyo, Japan) is a laparoscopic fluorescence spectrum system available for clinical use since February 2023. It can measure fluorescence intensity using a near-infrared laser and detect weak fluorescent signals. We report a case of gastric cancer in which the location of the lesion was confirmed intraoperatively using ZEOCLIP FS and Lumifinder.

CASE PRESENTATION

A man in his 80s was diagnosed with gastric cancer following an examination for anemia. Two lesions were found: a 0-IIc type (cT1) at the lesser curvature of the gastric angle and a type 1 tumor (cT2) at the anterior wall of the upper gastric body. The preoperative assessment indicated no lymph node or distant metastasis. The tumor was diagnosed as cStage I and laparoscopic distal gastrectomy was planned. Two ZEOCLIP FS clips were placed on the oral side of the tumor on the anterior wall of the upper gastric body on the day before surgery. During surgery, fluorescent signals from the clips were detected using Lumifinder, enabling easy confirmation of the lesion location and determination of the gastric resection line.

CONCLUSIONS

The combined use of ZEOCLIP FS and Lumifinder was a useful new method for identifying the appropriate resection line of the stomach. We plan to evaluate this method further in additional cases to enhance the detection efficacy.

Diagnostic Performance of Near-Infrared Fluorescent Marking Clips in Laparoscopic Gastrectomy

INTRODUCTION

Accurate tumor localization and resection margin acquisition are essential in gastric cancer surgery. Preoperative placement of marking clips in laparoscopic gastrectomy as well as intraoperative gastroscopy can be used for gastric cancer surgery. However, these procedures are not available at all institutions. We conducted a prospective clinical trial to investigate the diagnostic performance of near-infrared fluorescent clips (ZEOCLIP FS) in laparoscopic gastrectomy.

MATERIALS AND METHODS

Patients with gastric cancer or neuroendocrine tumor in whom laparoscopic distal, pylorus-preserving, or proximal gastrectomy was planned were enrolled (n = 20) in this study. Fluorescent clips were placed proximal and/or distal to the tumor via gastroscopy on the day before surgery. During surgery, the clips were detected using a fluorescent laparoscope, and suturing was performed where fluorescence was detected. The clip locations were then confirmed via gastroscopy, and the stomach was transected. The primary endpoint was the detection rate of the marking clips using fluorescence, and the secondary endpoints were complications and distance between the clips and stitches.

RESULTS

Among the 20 patients enrolled, distal and pylorus-preserving gastrectomies were performed in 18 and 2 patients, respectively. All clips were detected in 15 patients, indicating a detection rate of 75.0% (90% confidence interval: 54.4%-89.6%). Furthermore, no complications related to the clips were observed. The median distance between the clips and stitches was 5 (range, 0-10) mm.

CONCLUSIONS

We report the feasibility and safety of preoperative placement and intraoperative detection of near-infrared fluorescent marking clips in laparoscopic gastrectomy.

Adequate gross resection margin length ensuring pathologically complete resection in gastrectomy for gastric cancer: A systematic review and meta-analysis

Aim

A positive resection margin (RM) is associated with poor survival after gastrectomy for gastric cancer (GC). However, the adequate RM length to avoid a positive RM remains controversial. We performed a systematic review to examine the RM length required to avoid a positive RM in gastrectomy for GC.

Methods

This systematic review involved all relevant articles identified in PubMed, the Cochrane Library, Web of Science, and ClinicalTrials.gov until August 2023. The incidence of a positive RM related to the RM length and the possible incidence of a positive RM estimated from the discrepancy between the gross and pathological RM length were evaluated. The Newcastle-Ottawa Scale was used to quantify study quality.

Results

Thirteen studies involving 8983 patients were analyzed. Investigation of the incidence of a positive RM in relation to the RM length showed that a proximal RM length of 6 cm guaranteed a negative RM in gastrectomy. Analyses of the possible incidence of a positive RM revealed that a negative RM would be guaranteed if the proximal RM length was 6 cm in distal gastrectomy, if the esophageal resection length was 2 cm in total gastrectomy for GC without esophageal invasion and 2.5 cm in total or proximal gastrectomy for GC with esophageal invasion or esophagogastric junction cancer, and if the distal RM length was 4 cm in proximal gastrectomy for early GC.

Conclusions

The adequate RM lengths to ensure a pathologically negative RM in each type of gastrectomy for GC were herein suggested.

Oncological impact of unexpected horizontal tumor spread in gastric cancer that requires total gastrectomy

BACKGROUND

Gastric cancer often exhibits discrepancies between the gross and pathological tumor boundaries, and the degree of discrepancy may be a tumor characteristic. However, whether these discrepancies influence oncological outcomes remains unclear.

METHODS

The data of patients who underwent total gastrectomy for gastric cancer from 2005 to 2018 were collected. A new parameter, ΔPM, which corresponds to the length of the discrepancy between the gross and pathological proximal boundaries, was calculated and the patients were divided into two groups: patients with long ΔPM and those with short ΔPM. Oncological outcomes were compared between the two groups.

RESULTS

A length of 8 mm was determined as the cutoff value for long or short ΔPM. Tumor size, growth pattern, pathological type, depth, and esophageal invasion were associated with ΔPM > 8 mm. Overall survival of the ΔPM > 8 mm group was significantly worse than that of the ΔPM ≤ 8 mm group (5-year overall survival: 58% vs 78%; p < 0.0001). Multivariate analysis revealed that ΔPM > 8 mm was an independent risk factor for poor survival and peritoneal metastasis. The likelihood ratio test revealed a significant interaction between pT status and ΔPM (p = 0.0007). Circumferential involvement and gross esophageal invasion were poorer survival factors in the ΔPM > 8 mm group.

CONCLUSIONS

ΔPM > 8 mm is related to several clinicopathological characteristics and is an independent risk factor for poorer survival and peritoneal metastasis but not local recurrence. ΔPM > 8 mm combined with circumferential involvement or esophageal invasion is associated with relatively poor survival outcomes.

Required esophageal resection length beyond the tumor boundary to ensure a negative proximal margin for gastric cancer with gross esophageal invasion or esophagogastric junction cancer

BACKGROUND

To obtain a pathologically negative proximal margin (PM) for gastric cancer with gross esophageal invasion (EI) or esophagogastric junction (EGJ) cancer, we should transect the esophagus beyond the proximal boundary of gross EI with a safety margin because of a discrepancy between the gross and pathological boundaries of cancer. However, recommendations regarding the esophageal resection length for these cancers have not been established.

METHODS

Patients who underwent proximal or total gastrectomy for gastric cancer with gross EI or EGJ cancer were enrolled. A parameter ΔPM, which corresponded to the length of a discrepancy between the gross and pathological proximal boundary of the tumor, was evaluated. The maximum ΔPM, which corresponded to the minimum length ensuring a pathologically negative PM, was first determined in all patients. Then subgroup analyses according to factors associated with ΔPM ≥ 10 mm were performed to identify alternative maximum ΔPMs.

RESULTS

A total of 289 patients with gastric cancer with gross EI or EGJ cancer were eligible and analyzed in this study. The maximum ΔPM was 25 mm. Clinical tumor (cTumor) size and growth and pathological types were independently associated with ΔPM ≥ 10 mm. In subgroup analyses, the maximum ΔPM was 15 mm for cTumor size ≤ 40 mm and superficial growth type. Furthermore, the maximum ΔPM was 20 mm in the expansive growth type.

CONCLUSIONS

Required esophageal resection lengths to ensure a pathologically negative PM for gastric cancer with gross EI or EGJ cancer are proposed.

Laparoscopic Function-Preserving Gastrectomy for Proximal Gastric Cancer or Esophagogastric Junction Cancer: A Narrative Review

Function-preserving procedures to maintain postoperative quality of life are an important aspect of treatment for early gastric cancer. Laparoscopic proximal gastrectomy (LPG) and laparoscopic distal gastrectomy with a small remnant stomach, namely laparoscopic subtotal gastrectomy (LsTG), are alternative function-preserving procedures for laparoscopic total gastrectomy of early proximal gastric cancer. In LPG, esophagogastrostomy with techniques to prevent reflux and double-tract and jejunal interposition including esophagojejunostomy is usually chosen for reconstruction. The double-flap technique is currently a preferred reconstruction technique in Japan as an esophagogastrostomy approach to prevent reflux esophagitis. However, standardized reconstruction methods after LPG have not yet been established. In LsTG, preservation of the esophagogastric junction and the fundus prevents reflux and malnutrition, which may maintain quality of life. However, whether LsTG is an oncologically and nutritionally acceptable procedure compared with laparoscopic total gastrectomy or LPG is a concern. In this review, we summarize the status of reconstruction in LPG and the oncological and nutritional aspects of LsTG as a function-preserving gastrectomy for early proximal gastric or esophagogastric junction cancer.

Minimum resection length to ensure a pathologically negative distal margin and the preservation of a larger remnant stomach in proximal gastrectomy for early upper gastric cancer

BACKGROUND

In proximal gastrectomy (PG), a longer distal margin (DM) length should be maintained to obtain a pathologically negative DM. However, a shorter DM length is preferred to preserve a large remnant stomach for favorable postoperative outcomes. Evidence regarding the minimum DM length to ensure a pathologically negative DM is useful.

METHODS

Patients who underwent PG or total gastrectomy for cT1N0M0 gastric cancer limited to the upper third were enrolled. A new parameter, ΔDM, which corresponded to the pathological extension distal to the gross tumor boundary towards the resection stump, was evaluated. The maximum ΔDM, which is the length ensuring a pathologically negative DM, was first determined. Furthermore, the possible incidences of pathologically positive DM were calculated for each pathological type and clinical tumor (cTumor) size.

RESULTS

Of 361 patients eligible for this study, 190 and 171 were assigned to differentiated (Dif) and undifferentiated types (Und), respectively. The maximum ΔDM was 30 and 40 mm in Dif and Und, respectively. Considering a correlation between cTumor size and ΔDM, and possible incidences of pathologically positive DM, 10, 20, and 30 mm were the minimal gross DM lengths in Dif when cTumor size was ≤ 15 mm, > 15 and ≤ 50 mm, and > 50 mm, respectively. In Und, the incidences of pathologically positive DM were 0.59% and 2.3% for gross DM lengths of 30 and 20 mm, respectively.

CONCLUSION

The minimum DM lengths to ensure a pathologically negative DM in PG are proposed according to the pathological type of early upper gastric cancer.

Risk factors and oncological impact of positive resection margins in gastrectomy for cancer: are they salvaged by an additional resection?

BACKGROUND

The situation of positive resection margins (PRMs) varies notably between Western and Asian countries. In the West, PRMs are associated with advanced disease and R1, whereas in Asia, PRMs are also considered in early disease because stomach preservation was recently prioritized. Furthermore, PRMs are usually resected to obtain R0. However, the oncological impact of PRMs and additional resection remains unclear. The aim of this study is to evaluate the oncological impact of PRMs in laparoscopic gastrectomy (LG) for clinical stage (cStage) I gastric cancer.

METHODS

A total of 2121 patients who underwent LG for cStage I gastric cancer between 2007 and 2015 were enrolled. Survival outcomes were compared between patients with PRMs (group P) and those without (group N). Furthermore, prognostic factors were analyzed using multivariate analysis.

RESULTS

Twenty-seven patients (1.3%) had PRMs. Patients in group P had upper and more advanced disease, and the 5-year relapse-free survival (RFS) rate was worse in group P compared with group N (76.3% vs. 95.1%, P = 0.003). The 5-year RFS of patients with pT2 or deeper (pT2-4) disease in group P was significantly worse than that of patients in group N (66.7% vs. 89.5%, P = 0.030) although that of patients with pT1 was not. Likelihood ratio tests showed that there was a significant interaction between pT status and PRM (P = 0.005).

CONCLUSION

PRM in cStage I gastric cancer is associated with advanced upper disease. It remains an independent prognostic factor in pT2-4 disease even after an additional resection to obtain R0.