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

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.

Clinical Impact of Positive Surgical Margins in Gastric Adenocarcinoma in the Era of Preoperative Therapy

BACKGROUND

Microscopically positive (R1) surgical margins after gastrectomy increase gastric cancer recurrence risk, but optimal management after R1 gastrectomy is controversial. We sought to identify the impact of R1 margins on recurrence patterns and survival in the era of preoperative therapy for gastric cancer.

METHODS

Patients who underwent gastrectomy for adenocarcinoma during 1998-2017 at a major cancer center were enrolled. Clinicopathologic factors associated with positive margins were examined, and incidence, sites, and timing of recurrence and survival outcomes were compared between patients with positive and negative margins.

RESULTS

Of 688 patients, 432 (63%) received preoperative therapy. Thirty-four patients (5%) had R1 margins. Compared with patients with negative margins, patients with R1 margins more frequently had aggressive clinicopathologic features, such as linitis plastica (odds ratio [OR] 7.79, p < 0.001) and failure to achieve cT downstaging with preoperative treatment (OR 5.20, p = 0.005). The 5 year overall survival (OS) rate was lower in patients with R1 margins (6% vs 60%; p < 0.001), and R1 margins independently predicted worse OS (hazard ratio 2.37, 95% CI 1.51-3.75, p < 0.001). Most patients with R1 margins (58%) experienced peritoneal recurrence, and locoregional recurrence was relatively rare in this group (14%). Median time to recurrence was 8.5 months for peritoneal dissemination and 15.7 months for locoregional recurrence.

CONCLUSION

R1 margins after gastrectomy were associated with aggressive tumor biology, high incidence of peritoneal recurrence after a short interval, and poor OS. In patients with R1 margins, re-resection to achieve microscopically negative margins has to be considered with caution.

Prevention and treatment of a positive proximal margin after gastrectomy for cardia cancer

A tumour-positive proximal margin (PPM) after extended gastrectomy for oesophagogastric junction (OGJ) adenocarcinoma is observed in approximately 2-20% of patients. Although a PPM is an unfavourable prognostic factor, the clinical relevance remains unclear as it may reflect poor tumour biology. This narrative review analyses the most relevant literature on PPM after gastrectomy for OGJ cancers. Awareness of the risk factors and possible measures that can be taken to reduce the risk of PPM are important. In patients with a PPM, surgical and non-surgical treatments are available but the effectiveness remains unclear.