Benchmarks and Geographic Differences in Gallbladder Cancer Surgery: An International Multicenter Study

BACKGROUND

High-quality surgery plays a central role in the delivery of excellent oncologic care. Benchmark values indicate the best achievable results. We aimed to define benchmark values for gallbladder cancer (GBC) surgery across an international population.

PATIENTS AND METHODS

This study included consecutive patients with GBC who underwent curative-intent surgery during 2000-2021 at 13 centers, across seven countries and four continents. Patients operated on at high-volume centers without the need for vascular and/or bile duct reconstruction and without significant comorbidities were chosen as the benchmark group.

RESULTS

Of 906 patients who underwent curative-intent GBC surgery during the study period, 245 (27%) were included in the benchmark group. These were predominantly women (n = 174, 71%) and had a median age of 64 years (interquartile range 57-70 years). In the benchmark group, 50 patients (20%) experienced complications within 90 days after surgery, with 20 patients (8%) developing major complications (Clavien-Dindo grade ≥ IIIa). Median length of postoperative hospital stay was 6 days (interquartile range 4-8 days). Benchmark values included ≥ 4 lymph nodes retrieved, estimated intraoperative blood loss ≤ 350 mL, perioperative blood transfusion rate ≤ 13%, operative time ≤ 332 min, length of hospital stay ≤ 8 days, R1 margin rate ≤ 7%, complication rate ≤ 22%, and rate of grade ≥ IIIa complications ≤ 11%.

CONCLUSIONS

Surgery for GBC remains associated with significant morbidity. The availability of benchmark values may facilitate comparisons in future analyses among GBC patients, GBC surgical approaches, and centers performing GBC surgery.

Conditional Recurrence-Free Survival after Oncologic Extended Resection for Gallbladder Cancer: An International Multicenter Analysis

BACKGROUND

Data to guide surveillance following oncologic extended resection (OER) for gallbladder cancer (GBC) are lacking. Conditional recurrence-free survival (C-RFS) can inform surveillance. We aimed to estimate C-RFS and identify factors affecting conditional RFS after OER for GBC.

PATIENTS AND METHODS

Patients with ≥ T1b GBC who underwent curative-intent surgery in 2000-2018 at four countries were identified. Risk factors for recurrence and RFS were evaluated at initial resection in all patients and at 12 and 24 months after resection in patients remaining recurrence-free.

RESULTS

Of the 1071 patients who underwent OER, 484 met the inclusion criteria; 290 (60%) were recurrence-free at 12 months, and 199 (41%) were recurrence-free at 24 months. Median follow-up was 24.5 months for all patients and 47.21 months in survivors at analysis. Five-year RFS rates were 47% for the overall population, 71% for patients recurrence-free at 12 months, and 87% for the patients without recurrence at 24 months. In the entire cohort, the risk of recurrence peaked at 8 months. T3-T4 disease was independently associated with recurrence in all groups: entire cohort [hazard ratio (HR) 2.16, 95% confidence interval (CI) 1.49-3.13, P < 0.001], 12-month recurrence-free (HR 3.42, 95% CI 1.88-6.23, P < 0.001), and 24-month recurrence-free (HR 2.71, 95% CI 1.11-6.62, P = 0.029). Of the 125 patients without these risk factors, only 2 had recurrence after 36 months.

CONCLUSION

C-RFS improves over time, and only T3-T4 disease remains a risk factor for recurrence at 24 months after OER for GBC. For all recurrence-free survivors after 36 months, the probability of recurrence is similar regardless of T category or disease stage.

Role of tumour location and surgical extent on prognosis in T2 gallbladder cancer: an international multicentre study

BACKGROUND

In gallbladder cancer, stage T2 is subdivided by tumour location into lesions on the peritoneal side (T2a) or hepatic side (T2b). For tumours on the peritoneal side (T2a), it has been suggested that liver resection may be omitted without compromising the prognosis. However, data to validate this argument are lacking. This study aimed to investigate the prognostic value of tumour location in T2 gallbladder cancer, and to clarify the adequate extent of surgical resection.

METHODS

Clinical data from patients who underwent surgery for gallbladder cancer were collected from 14 hospitals in Korea, Japan, Chile and the USA. Survival and risk factor analyses were conducted.

RESULTS

Data from 937 patients were available for evaluation. The overall 5-year disease-free survival rate was 70·6 per cent, 74·5 per cent for those with T2a and 65·5 per cent among those with T2b tumours (P = 0·028). Regarding liver resection, extended cholecystectomy was associated with a better 5-year disease-free survival rate than simple cholecystectomy (73·0 versus 61·5 per cent; P = 0·012). The 5-year disease-free survival rate was marginally better for extended than simple cholecystectomy in both T2a (76·5 versus 66·1 per cent; P = 0·094) and T2b (68·2 versus 56·2 per cent; P = 0·084) disease. Five-year disease-free survival rates were similar for extended cholecystectomies including liver wedge resection versus segment IVb/V segmentectomy (74·1 versus 71·5 per cent; P = 0·720). In multivariable analysis, independent risk factors for recurrence were presence of symptoms (hazard ratio (HR) 1·52; P = 0·002), R1 resection (HR 1·96; P = 0·004) and N1/N2 status (N1: HR 3·40, P < 0·001; N2: HR 9·56, P < 0·001). Among recurrences, 70·8 per cent were metastatic.

CONCLUSION

Tumour location was not an independent prognostic factor in T2 gallbladder cancer. Extended cholecystectomy was marginally superior to simple cholecystectomy. A radical operation should include liver resection and adequate node dissection.

Comparison of oncological outcomes after open and laparoscopic re-resection of incidental gallbladder cancer

BACKGROUND

The safety and oncological efficacy of laparoscopic re-resection of incidental gallbladder cancer have not been studied. This study aimed to compare laparoscopic with open re-resection of incidentally discovered gallbladder cancer while minimizing selection bias.

METHODS

This was a multicentre retrospective observational cohort study of patients with incidental gallbladder cancer who underwent re-resection with curative intent at four centres between 2000 and 2017. Overall survival (OS) and recurrence-free survival (RFS) were analysed by intention to treat. Inverse probability of surgery treatment weighting using propensity scoring was undertaken.

RESULTS

A total of 255 patients underwent re-resection (190 open, 65 laparoscopic). Nineteen laparoscopic procedures were converted to open operation. Surgery before 2011 was the only factor associated with conversion. Duration of hospital stay was shorter after laparoscopic re-resection (median 4 versus 6 days; P < 0·001). Three-year OS rates for laparoscopic and open re-resection were 87 and 62 per cent respectively (P = 0·502). Independent predictors of worse OS were residual cancer found at re-resection (hazard ratio (HR) 1·91, 95 per cent c.i. 1·17 to 3·11), blood loss of at least 500 ml (HR 1·83, 1·23 to 2·74) and at least four positive nodes (HR 3·11, 1·46 to 6·65). In competing-risks analysis, the RFS incidence was higher for laparoscopic re-resection (P = 0·038), but OS did not differ between groups. Independent predictors of worse RFS were one to three positive nodes (HR 2·16, 1·29 to 3·60), at least four positive nodes (HR 4·39, 1·96 to 9·82) and residual cancer (HR 2·42, 1·46 to 4·00).

CONCLUSION

Laparoscopic re-resection for selected patients with incidental gallbladder cancer is oncologically non-inferior to an open approach. Dissemination of advanced laparoscopic skills and timely referral of patients with incidental gallbladder cancer to specialized centres may allow more patients to benefit from this operation.

Incidental versus non-incidental gallbladder cancer: index cholecystectomy before oncologic re-resection negatively impacts survival in T2b tumors

BACKGROUND

Conflicting data exists whether non-oncologic index cholecystectomy (IC) leading to discovery of incidental gallbladder cancer (IGBC) negatively impacts survival. This study aimed to determine whether a subgroup of patients derives a disadvantage from IC.

METHODS

Patients with IGBC and non-IGBC treated at an academic USA and Chilean center during 1999-2016 were compared. Patients with T1, T4 tumor or preoperative jaundice were excluded. T2 disease was classified into T2a (peritoneal-side tumor) and T2b (hepatic-side tumor). Disease-specific survival (DSS) and its predictors were analyzed.

RESULTS

Of the 196 patients included, 151 (77%) had IGBC. One hundred thirty-six (90%) patients of whom 118 (87%) had IGBC had T2 disease. Three-year DSS rates were similar between IGBC and non-IGBC for all patients. However, for T2b patients, 3-year survival rate was worse for IGBC (31% vs 85%; p = 0.019). In multivariate analysis of T2 patients, predictors of poor DSS were hepatic-side tumor hazard ratio [HR], 2.9; 95% CI, 1.6-5.4; p = 0.001) and N1 status (HR, 2.4; 95% CI, 1.6-3.6; p < 0.001).

CONCLUSIONS

Patients with T2b gallbladder cancer specifically benefit from a single operation. These patients should be identified preoperatively and referred to hepatobiliary center.

Optimal surgical treatment in patients with T1b gallbladder cancer: An international multicenter study

BACKGROUND

There is no consensus on the optimal treatment of T1b gallbladder cancer (GBC) due to the lack of evidence and the difficulty of anatomy and pathological standardization.

METHODS

A total of 272 patients with T1b GBC who underwent surgical resection at 14 centers with specialized hepatobiliary-pancreatic surgeons and pathologists in Korea, Japan, Chile, and the United States were studied. Clinical outcomes including disease-specific survival (DSS) rates according to the types of surgery were analyzed.

RESULTS

After excluding patients, the 237 qualifying patients consisted of 90 men and 147 women. Simple cholecystectomy (SC) was performed in 116 patients (48.9%) and extended cholecystectomy (EC) in 121 patients (51.1%). The overall 5-year DSS was 94.6%, and it was similar between SC and EC patients (93.7% vs. 95.5%, P = 0.496). The 5-year DSS was similar between SC and EC patients in America (82.3% vs. 100.0%, P = 0.249) as well as in Asia (98.6% vs. 95.2%, P = 0.690). The 5-year DSS also did not differ according to lymph node metastasis (P = 0.688) or tumor location (P = 0.474).

CONCLUSIONS

SC showed similar clinical outcomes (including recurrence) and survival outcomes as EC; therefore, EC is not needed for the treatment of T1b GBC.

Positive cystic duct margin at index cholecystectomy in incidental gallbladder cancer is an important negative prognosticator

BACKGROUND

Prognostic factors following index-cholecystectomy in patients with incidental gallbladder cancer (IGBC) are poorly understood. The aim of this study was to assess the value of the initial cystic duct margin status as a prognosticator factor and to aid in clinical decision making to move forward with curative intent oncologic extended resection (OER).

METHODS

This retrospective study included patients with IGBC who underwent subsequent OER with curative intent at 2 centers (USA and Chile) between 1999 and 2016., Patients with and without evidence of residual cancer (RC) at OER were included. Pathologic features were examined, and predictors of overall survival (OS) were analyzed.

RESULTS

The study included 179 patients. Thirty-three patients (17%) had a positive cystic duct margin at the index cholecystectomy. Forty-two patients (23%) underwent resection of the common bile duct. OS was significantly worse in the patients with a positive cystic duct margin at index cholecystectomy (OS rates at 5 years, 34% vs 57%; p = 0.032). Following multivariate analysis, only a positive cystic duct margin at index cholecystectomy was predictive of worse OS in patients with no evidence of residual cancer (RC) at OER (hazard ratio, 1.7 95%CI 1.04-2.78; p = 0.034).

CONCLUSIONS

A positive cystic duct margin at index-cholecystectomy is a strong independent predictor of worse OS even if no further cancer is found at OER. In patients with positive cystic duct margin and no RC at OER common bile duct resection leads to improved outcomes.

Extended Lymphadenectomy Is Required for Incidental Gallbladder Cancer Independent of Cystic Duct Lymph Node Status

BACKGROUND

We examined whether the incidental cystic duct nodal status predicts the status of the hepatoduodenal ligament (D1) or common hepatic artery, the pancreaticoduodenal and paraaortic lymph nodes (D2), and the overall prognosis and thus indicates whether an oncologic extended resection (OER) is required.

METHODS

The study included patients who underwent OER for incidental gallbladder cancer (IGBC) during 1999-2015. Associations between a positive cystic duct node and D2 nodal status and disease-specific survival (DSS) were analyzed.

RESULTS

One-hundred-eight-seven patients were included. Seventy-three patients (39%) had the incidental cystic duct node retrieved. Cystic duct node positivity was associated with positive D1 (odds ratio 5.2, p = 0.012) but not with D2. Among all patients, a positive cystic duct node was associated with worse DSS (hazard ratio [HR] 2.09). Patients without residual cancer at OER and positive incidental cystic duct node had similar DSS to patients with negative nodes 70 vs 60% (p = 0.337). Positive D1 (HR 6.07) or positive D2 (HR 13.8) was predictive of worse DSS.

CONCLUSIONS

Patients with no residual cancer at OER and regional disease limited to their incidental cystic duct node have similar DSS to pN0 patients. The status of the cystic duct node only predicts the status of hepatic pedicle nodes.

A comparative study of risk factors for pancreatic fistula after pancreatoduodenectomy or distal pancreatectomy

BACKGROUND

Evidence associates various biometric and histological variables such as steatosis and absence of fibrosis as risk factors for post-operative pancreatic fistula (POPF) after pancreatoduodenectomy (PD). Following distal pancreatectomy (DP), the association between these factors and POPF is less clear. This study of patients, drawn from the same background population, undergoing PD or DP at a single centre is a comparative study of the risk factors for POPF after these two operations.

METHODS

Associations between POPF and patient characteristics, pre-operative blood tests, data from pre-operative computed tomography (CT) imaging, assessment of histological steatosis and fibrosis were explored.

RESULTS

26/107 (24%) and 26/90 (29%) patients developed POPF after PD and DP respectively. Absence of fibrosis was associated with POPF (p < 0.001) after PD and its presence correlated with pancreatic duct width (p < 0.001). Steatosis was not associated with POPF (p = 0.910). Multivariable analysis showed pancreatic duct width (p = 0.016) and fibrosis (p = 0.025) to be independent predictors of POPF after PD. The only variable associated with POPF after DP was underlying pathology (p = 0.005).

CONCLUSION

Pancreatic duct width is the most important variable related to POPF after PD and is correlated with fibrosis. Steatosis was not related to POPF. In contrast, after DP POPF appears to be related to the underlying disease.

Stage-stratified prognosis of signet ring cell histology in patients undergoing curative resection for gastric adenocarcinoma

BACKGROUND

The prognosis of signet ring cell (SRC) gastric adenocarcinoma is regarded as poor, although studies addressing outcomes in relation to non-SRC tumors are conflicting. Our objective was to compare the survival of SRC tumors with stage-matched intestinal-type tumors in a cohort of Western patients.

METHODS

Review of a prospectively maintained database identified 569 patients undergoing curative resection (R0) from 1990 to 2009. Patients were divided into three histologic groups on the basis of the Lauren classification: SRC (n = 210), intestinal well- or moderately differentiated (WMD, n = 242) disease, and intestinal poorly differentiated (PD, n = 117) disease. Patient demographics, clinicopathologic features, and postoperative outcomes were determined. Stage-stratified disease-specific mortality was calculated and multivariate analysis performed.

RESULTS

When compared with WMD and PD tumors, SRC tumors were associated with younger age (63 years SRC vs. 71 years WMD and 72 years PD, p < 0.0001) and with female sex (58 % SRC vs. 40 % WMD and 40 % PD, p = 0.0003). Median follow-up was 115 months. Patients with stage Ia SRC lesions had a better 5-year disease-specific mortality compared with stage-matched intestinal-type tumors (0 % SRC vs. 8 % WMD and 24 % PD, p = 0.001). In contrast, SRC patients with stage III disease fared significantly worse (78 % SRC vs. 54 % WMD and 72 % PD, p = 0.001). On multivariate analysis, the risk of death from gastric cancer comparing all three groups was lowest for SRC in stage I and highest for SRC in stage III disease (stage III hazard ratio: SRC 1 vs. 0.47 WMD and 0.85 PD).

CONCLUSIONS

When compared with intestinal-type tumors, SRC tumors at early stages are not necessarily associated with poor outcomes.

Isolation of a strong suppressor of nonsense mutations in Bacillus subtilis

By treatment of Bacillus subtilis MO-101-P spoA- met thr- su- with ethyl methanesulfonate, a strong suppressor strain of nonsense mutations, B. subtilis MO-101-P spoA- [met-]+thr- su+44, was isolated. This strain does not suppress phage phi 29 mutant susB47, selected on a B. subtilis strain containing the su+3 suppressor isolated by Georgopoulos. A revertant from this mutant, susB610, was isolated, being suppressed by both the su+3 and su+44 suppressor strains. The efficiency of suppression by strain su+44 is about 50%. The experiments shown in this paper suggest that strain su+44 contains an amber and strain su+3 an ochre suppressor.