Influence of positive margins on tumour recurrence and overall survival after gastrectomy for gastric cancer

Laparoscopic versus open total gastrectomy for T4a gastric cancer: a propensity score-matched analysis of long-term outcomes

Evidence of implementation of laparoscopic total gastrectomy (LTG) for surgical T4a stage (sT4a) gastric cancer (GC) remains inadequate. This study aimed to compare short- and long-term outcomes of LTG versus open total gastrectomy (OTG) for sT4a GC. This retrospective cohort study was conducted using data from patients with sT4a GC underwent total gastrectomy from 2014 to 2020. Short-term outcomes included operative characteristics and postoperative complications. Long-term oncological outcomes focused on 3-, and 5-year overall survival (OS) and disease-free survival (DFS). Propensity score matching (PSM) was applied to reduce potential biases in baseline characteristics between groups. There was a total of 161 patients, in which 96 underwent LTG and 65 underwent OTG. After PSM, both groups consisted of 51 patients each, with balanced baseline characteristics. There were no significant differences between the two groups regarding blood loss, length of proximal resected margin, postoperative hospital stays, and overall and major postoperative complications. Most of the complications were classified as minor according to the Clavien-Dindo classification. Operating time was significantly longer in the LTG group (mean: 257 min vs. 231 min, p = 0.006). LTG was superior to OTG groups in time to flatus (mean: 3.0 days vs 3.9 days, p < 0.001). Five-year OS and DFS rates were similar between the two groups (44% and 33% vs. 43% and 28% in the LTG and OTG groups, respectively). Our findings indicate that LTG is a feasible and safe technique, exhibiting comparable long-term oncological outcomes to OTG for sT4a GC. LTG may be an acceptable alternative to OTG for the treatment of sT4a GC.

Real-time tracking of a diffuse reflectance spectroscopy probe used to aid histological validation of margin assessment in upper gastrointestinal cancer resection surgery

SIGNIFICANCE

Diffuse reflectance spectroscopy (DRS) allows discrimination of tissue type. Its application is limited by the inability to mark the scanned tissue and the lack of real-time measurements.

AIM

This study aimed to develop a real-time tracking system to enable localization of a DRS probe to aid the classification of tumor and non-tumor tissue.

APPROACH

A green-colored marker attached to the DRS probe was detected using hue-saturation-value (HSV) segmentation. A live, augmented view of tracked optical biopsy sites was recorded in real time. Supervised classifiers were evaluated in terms of sensitivity, specificity, and overall accuracy. A developed software was used for data collection, processing, and statistical analysis.

RESULTS

The measured root mean square error (RMSE) of DRS probe tip tracking was 1.18  ±  0.58  mm and 1.05  ±  0.28  mm for the x and y dimensions, respectively. The diagnostic accuracy of the system to classify tumor and non-tumor tissue in real time was 94% for stomach and 96% for the esophagus.

CONCLUSIONS

We have successfully developed a real-time tracking and classification system for a DRS probe. When used on stomach and esophageal tissue for tumor detection, the accuracy derived demonstrates the strength and clinical value of the technique to aid margin assessment in cancer resection surgery.