Value of computed tomography in addition to ultrasound for preoperative staging of gastric cancer

Construction of a Nomogram Model for Predicting Peritoneal Dissemination in Gastric Cancer Based on Clinicopathologic Features and Preoperative Serum Tumor Markers

Background

Peritoneal dissemination (PD) is the most common mode of metastasis for advanced gastric cancer (GC) with poor prognosis. It is of great significance to accurately predict preoperative PD and develop optimal treatment strategies for GC patients. Our study assessed the diagnostic potential of serum tumor markers and clinicopathologic features, to improve the accuracy of predicting the presence of PD in GC patients.

Methods

In our study, 1264 patients with GC at Fudan University Shanghai Cancer Center and Wenzhou people’s hospital from 2018 to 2020 were retrospectively analyzed, including 316 cases of PD and 948 cases without PD. All patients underwent enhanced CT scan or magnetic resonance imaging (MRI) before surgery and treatment. Clinicopathological features, including tumor diameter and tumor stage (depth of tumor invasion, nearby lymph node metastasis and distant metastasis), were obtained by imaging examination. The independent risk factors for PD were screened through univariate and multivariate logistic regression analyses, and the results were expressed with 95% confidence intervals (CIs). A model of PD diagnosis and prediction was established by using Cox proportional hazards regression model of training set. Furthermore, the accuracy of the prediction model was verified by ROC curve and calibration plots.

Results

Univariate analysis showed that PD in GC was significantly related to tumor diameter (odds ratio (OR)=12.06, p<0.0006), depth of invasion (OR=14.55, p<0.0001), lymph node metastases (OR=5.89, p<0.0001), carcinoembryonic antigen (CEA) (OR=2.50, p<0.0001), CA125 (OR=11.46, p<0.0001), CA72-4 (OR=4.09, p<0.0001), CA19-9 (OR=2.74, p<0.0001), CA50 (OR=5.20, p<0.0001) and CA242 (OR=3.83, p<0.0001). Multivariate analysis revealed that clinical invasion depth and serum marker of CA125 and CA72-4 were independent risk factors for PD. The prediction model was established based on the risk factors using the R program. The area under the curve (AUC) of the receiver operating characteristics (ROC) was 0.931 (95% CI: 0.900–0.960), with the accuracy, sensitivity and specificity values of 90.5%, 86.2% and 82.2%, respectively.

Conclusion

The nomogram model constructed using CA125, CA72-4 and depth of invasion increases the accuracy and sensitivity in predicting the incidence of PD in GC patients and can be used as an important tool for preoperative diagnosis.

Preoperative Folate Receptor-Positive Circulating Tumor Cells Are Associated With Occult Peritoneal Metastasis and Early Recurrence in Gastric Cancer Patients: A Prospective Cohort Study

Background

The aim of this study is to explore the clinical feasibility of detecting folate receptor-positive circulating tumor cells (FR+ CTCs) for predicting peritoneal metastasis and short-term outcome in gastric cancer patients.

Methods

This is a prospective, single-center, observational study. We applied ligand-targeted enzyme-linked polymerization method to detect preoperative FR+ CTC levels in peripheral blood. We evaluated the diagnostic value of FR+ CTCs and other biomarkers in predicting peritoneal metastasis. Prognostic factors for recurrence-free survival (RFS) were investigated in univariate and multivariate analyses.

Results

A total of 132 patients with gastric cancer and 9 patients with benign disease were recruited. Gastric cancer patients had a significantly higher CTC level compared to that of patients with benign disease (p < 0.01). Combined model including CTC level and other biomarkers presented high sensitivity (100%) and moderate specificity (59.3%) in predicting peritoneal metastasis. Univariate analysis revealed that decreased serum prealbumin, decreased peripheral lymphocyte count, FR+ CTCs, carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and lymph node metastasis were significantly associated with shorter RFS. FR+ CTC level [≥12.6 folate units (FU)/3 ml, hazard ratio (HR) = 6.957, p = 0.005] and CA19-9 (>34 ng/ml, HR = 3.855, p = 0.037) were independent prognostic factors in multivariate analysis.

Conclusions

Our findings for the first time suggested the diagnostic value of preoperative CTC levels in predicting peritoneal metastasis in gastric cancer. Moreover, the FR+ CTC level could be a novel and promising prognostic factor for the recurrence of gastric cancer in patients who underwent surgery.

Clinical Trial Registration

Chinese Clinic Trial Registry, identifier ChiCTR2100050514.

Synchronous peritoneal metastases of gastric cancer origin: incidence, treatment and survival of a nationwide Dutch cohort

INTRODUCTION

The peritoneum is a predilection site for gastric cancer metastases. Current standard treatment for gastric cancer patients with synchronous peritoneal metastases is palliative systemic therapy. However, its efficacy is largely unknown. The aim of this study was to investigate the incidence, treatment and survival patterns of gastric cancer patients with synchronous peritoneal metastases in the Netherlands.

METHODS

All newly diagnosed gastric adenocarcinoma patients with synchronous peritoneal metastases between 1999 and 2017 were selected from the Netherlands Cancer Registry (NCR). Incidence, treatment and survival patterns were analyzed.

RESULTS

In total, 3,773 patients were identified from the NCR. The incidence of synchronous peritoneal metastases in gastric cancer patients increased from 18% in 2008 to 27% in 2017. The use of systemic therapy increased from 15% in 1999-2002 to 43% in 2013-2017 (p < 0.001). The median survival of the entire cohort did not significantly increase over time. Median survival of patients treated with systemic therapy increased from 7.4 months in 1999-2002 to 9.4 months in 2013-2017 (p = 0.005). In contrast, median survival of patients not treated with systemic therapy decreased from 3.3 months in 1999-2002 to 2.1 months in 2013-2017 (p < 0.001). Some clinical and pathological data such as the extent of the peritoneal metastases were not available.

CONCLUSION

Synchronous peritoneal metastases are increasingly diagnosed in gastric cancer patients. In recent years, more patients were treated with systemic treatment and survival of these patients increased. However, as survival of the entire group did not improve over time, the effect of systemic therapy remains unknown.

A novel laparoscopic near-infrared fluorescence spectrum system for photodynamic diagnosis of peritoneal dissemination in pancreatic cancer

BACKGROUND

Diagnosing peritoneal dissemination is essential for selecting the appropriate therapeutic strategy for patients with pancreatic cancer. Intraoperative laparoscopic diagnosis enables the selection of less invasive surgical strategies. Photodynamic diagnosis using 5-aminolevulinic acid may improve gastrointestinal cancer diagnostic accuracy, although weak fluorescence is not easily detected. Here we aimed to improve this sensitivity using laparoscopic spectrophotometry.

METHODS

Photodynamic diagnosis was performed using serial dilutions of protoporphyrin IX, and its detectability using laparoscopic spectrophotometry was compared with that using naked-eye observation. Five-aminolevulinic acid-photodynamic diagnosis was performed for pancreatic cancer cell lines, and a murine peritoneal disseminated nodule model was established. We compared laparoscopic spectrophotometry and naked-eye observation results using white and fluorescent lights and compared them to routine histopathological examination results. Photodynamic diagnoses were made in 2017 and 2018 in eight patients with pancreatic cancer.

RESULTS

Weaker fluorescence of the diluted protoporphyrin IX samples was better detected with spectrophotometry than with naked-eye observation. Moreover, a spectrograph of protoporphyrin IX in multiple cell lines was detected by spectrophotometry. In the murine model, the detection rates were 62 %, 78 %, and 90 % for naked-eye observation with white light, fluorescent light, and spectrophotometry, respectively. Comparisons of fluorescent light-negative peritonea with and without pathological metastases showed significantly higher spectrophotometric intensities in the former (P < 0.010). In clinical studies, three fluorescent light-negative spectrophotometry-positive pathologically metastatic lesions were observed.

CONCLUSIONS

Laparoscopic spectrophotometry in the murine model and extraperitoneally photodynamic diagnoses using spectrophotometry in clinical practice are sensitive photodynamic diagnostic techniques.

Clinical Significance of Serum CA125, CA19-9, CA72-4, and Fibrinogen-to-Lymphocyte Ratio in Gastric Cancer With Peritoneal Dissemination

Background: Relevant serum tumor markers have been indicated to be associated with peritoneal dissemination (PD) of gastric cancer (GC). Fibrinogen has been shown to play an important role in the systemic inflammatory response (SIR) and in tumor progression. However, the clinical significance of the fibrinogen-to-lymphocyte ratio (FLR) in GC with PD has not been studied.

Methods: The clinical data of 391 patients with GC were collected, including 86 cases of PD. Then, 1:3 matching was performed by propensity score matching (PSM), and the clinical data of the matched 344 patients were analyzed by univariate and multivariate conditional logistic regression. Classification tree analysis was used to obtain the decision rules and a random forest algorithm to extract the important risk factors of PD in GC. A nomogram model for risk assessment of PD in GC was established by using the rms package of R software.

Results: Univariate analysis showed that the factors related to PD in GC were: carbohydrate antigen (CA) 125 (P < 0.0001), CA19-9 (P < 0.0001), CA72-4 (P < 0.0001), FLR (P < 0.0001), neutrophil-to-lymphocyte ratio (NLR) (P < 0.0001), albumin-to- lymphocyte ratio (ALR) (P < 0.0001), platelet-to-lymphocyte ratio (PLR) (P = 0.013), and carcinoembryonic antigen (CEA) (P = 0.031). Conditional logistic regression found that CA125 (OR: 1.046; P < 0.0001), CA19-9 (OR: 1.002; P < 0.0001), and FLR (OR: 1.266; P = 0.024) were independent risk factors for GC with PD. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of the decision rules for detecting PD of GC were 89.5, 77.4, 94.0, 82.8, and 91.8%, respectively. According to the important variables identified by the classification tree and random forest algorithm, the risk assessment model of PD in GC was established. The accuracy, sensitivity, and specificity of the model were 91, 89.5, and 79.5%, respectively.

Conclusion: CA125 > 17.3 U/ml, CA19-9 > 27.315 U/ml, and FLR > 2.555 were the risk factors for GC with PD. The decision rules and nomogram model constructed by CA125, CA19-9, CA72-4, and FLR can correctly predict the risk of PD in GC.

Clinical significance of computed tomography-detected ascites in gastric cancer patients with peritoneal metastases

Patients with peritoneal metastases (PM) are generally considered incurable; therefore, the presence of PM is a critical factor in deciding between palliative surgery and curative resection as a therapeutic strategy. Previous studies have not determined the predictive value of ascites detected on computed tomography (CT) for the presence of PM. We aimed to analyze the factors that are associated with PM in patients with CT-detected ascites.A total of 2207 consecutive patients who were diagnosed with gastric cancer between 2004 and 2013 were identified. Eleven patients with liver cirrhosis or chronic renal insufficiency with ascites and 57 patients who received previous treatment were excluded. Ninety-eight patients who had definite evidence of distant metastasis or PM on CT and 64 patients who did not undergo surgery were excluded. A total of 91 patients were enrolled in the study to analyze the association between CT-detected ascites and surgically confirmed PM.Seventy-six patients underwent curative resection and 15 patients underwent palliative surgery. Twelve patients exhibited peritoneal seeding and 37 patients showed regional lymph node metastasis. Regional lymph node metastasis, advanced gastric cancer, undifferentiated pathology, and the amount of ascites were significantly associated with PM. Multivariable logistic regression analysis identified the amount of ascites to be an independent risk factor for the presence of PM.Regional lymph node metastasis, advanced gastric cancer, undifferentiated pathology, and the amount of ascites were associated with PM. The amount of ascites was found to be an independent risk factor for PM.

Computed tomographic characteristics for patients with unresectable gastric cancer harboring low-volume peritoneal carcinomatosis

Although current staging workups could differentiate most patients with operable from inoperable advanced gastric cancers, there are still some patients with low-volume peritoneal carcinomatosis, defined as only metastasis with multiple subcentimeter lesions in peritoneum, receiving unnecessary open-close procedures. The computed tomography (CT) of the patients with unresectable advanced gastric cancer harboring low-volume peritoneal carcinomatosis was retrospectively identified and then thoroughly reviewed by two independent radiologists unaware of the peritoneal carcinomatosis status. Of the 798 patients with newly diagnosed gastric cancer between January 2007 and December 2010, 52 patients harboring advanced gastric cancer with low-volume peritoneal carcinomatosis receiving surgery with curative intent were identified. Descriptive statistic was used for the radiologic characteristics. The most common radiologic characteristic of CT was omental fat stranding (57.7%), followed by omental clustered subcentimeter nodules (53.8%), distant enlarged lymph node (40.4%), distant grouping of small lymph nodes (36.5%), peritoneal nodules or thickening (34.6%), minimal loculated ascites (21.2%), intestinal wall thickening or irregularity (9.6%), and hydronephrosis or hydroureter without stone or urothelial lesion (5.8%). Comprehensively reviewing the radiologic characteristics of CT may identify the patients harboring advanced gastric cancer with low-volume peritoneal carcinomatosis.

Total laparoscopic subtotal gastrectomy with transvaginal specimen extraction is feasible in advanced gastric cancer

PURPOSE

Natural orifice specimen extraction (NOSE) is an ever-evolving advanced laparoscopic technique. NOSE minimizes surgical injury, involving a low risk of wound complications, fewer incisional hernias, faster recovery and less postoperative pain. Laparoscopic gastrectomy combined with NOSE is a procedure that can potentiate the advantages of both minimal invasive techniques. We aim to demonstrate the feasibility of laparoscopic subtotal gastrectomy with transvaginal specimen extraction in advanced gastric cancer.

CASE

A 72-year-old woman with a 2cm adenocarcinoma in gastric antrum was treated by laparoscopic subtotal gastrectomy and lymph node dissection. A totally laparoscopic Roux-en-Y gastrojejunostomy was constructed. Specimen was extracted through the posterior fornix of vagina without difficulty. Histopathology confirmed pT3pN0 tumor. After a 10-month follow-up the patient was asymptomatic and getting adjuvant chemoradiotherapy.

CONCLUSIONS

Transvaginal specimen extraction after laparoscopic gastric resection for advanced gastric cancer is a feasible procedure. It is offered to selected patients and of course only to female patients. Natural orifice surgery may provide faster recovery and decrease the wound related complications which may cause a delay on postoperative adjuvant chemo-radio therapies. We have presented, as far as we know, the first human case of a transvaginal extraction of an advanced gastric cancer after laparoscopic gastrectomy.

En masse resection of pancreas, spleen, celiac axis, stomach, kidney, adrenal, and colon for invasive pancreatic corpus and tail tumor

Providing a more comfortable life and a longer survival for pancreatic corpus/tail tumors without metastasis depends on the complete resection. Recently, distal pancreatectomy with celiac axis resection was reported as a feasible and favorable method in selected pancreatic corpus/tail tumors which had invaded the celiac axis. Additional organ resections to the celiac axis were rarely required, and when necessary it was included only a single extra organ resection such as adrenal or intestine. Here, we described a distal pancreatic tumor invading most of the neighboring organs-stomach, celiac axis, left renal vein, left adrenal gland, and splenic flexure were treated by en bloc resection of all these organs. The patient was a 60-year-old man without any severe medical comorbidities. Postoperative course of the patient was uneventful, and he was discharged on postoperative day eight without any complication. Histopathology and stage of the tumor were adenocarcinoma and T4 N1 M0, respectively. Preoperative back pain of the patient was completely relieved in the postoperative period. As a result, celiac axis resection for pancreatic cancer is an extensive surgery, and a combined en masse resection of the invaded neighboring organs is a more extensive surgery than the celiac axis resection alone. This more extensive surgery is safe and feasible for selected patients with pancreatic cancer.

A systematic review of the accuracy and indications for diagnostic laparoscopy prior to curative-intent resection of gastric cancer

BACKGROUND

Despite improved preoperative imaging techniques, patients with incurable or unresectable gastric cancer are still subjected to non-therapeutic laparotomy. Diagnostic laparoscopy (DL) has been advocated by some to be essential in decision-making in gastric cancer. We aimed to identify and synthesize findings on the value of DL for patients with gastric cancer, in this era of improved preoperative imaging.

METHODS

Electronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 31, 2009. We calculated the change in management and avoidance of laparotomy based on the addition of DL and laparoscopic ultrasound (LUS). The accuracy, agreement (kappa), sensitivity, and specificity of DL in assessing tumor extent, nodal involvement, and the presence of metastases with respect to the gold standard (pathology) were also calculated.

RESULTS

Twenty-one articles were included. DL showed moderate to substantial agreement with final pathology for T stage, but only fair agreement for N stage. For M staging, DL had an overall accuracy, sensitivity, and specificity ranging from 85-98.9%, 64.3-94%, and 80-100%, respectively. The use of DL altered treatment in 8.5-59.6% of cases, avoiding laparotomy in 8.5-43.8% of cases. LUS provided additional benefit in 5.8-7.2% of cases.

CONCLUSIONS

Despite evolving preoperative imaging techniques, diagnostic laparoscopy continues to be of substantial value in staging patients with gastric cancer and in avoiding unnecessary laparotomy. The current data support DL for all patients with advanced gastric cancer.

How useful is preoperative imaging for tumor, node, metastasis (TNM) staging of gastric cancer? A meta-analysis

BACKGROUND

Surgery is the fundamental curative option for gastric cancer patients. Imaging scans are routinely prescribed in an attempt to stage the disease prior to surgery. Consequently, the correlation between radiology exams and pathology is crucial for appropriate treatment planning.

METHODS

Systematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 1, 2009. We calculated the accuracy, overstaging rate, understaging rate, Kappa statistic, sensitivity, and specificity for abdominal ultrasound (AUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) with respect to the gold standard (pathology). We also compared the performance of CT by detector number and image type. A meta-analysis was performed.

RESULTS

For pre-operative T staging MRI scans had better performance accuracy than CT and AUS; CT scanners using ≥ 4 detectors and multi-planar reformatted (MPR) images had higher staging performances than scanners with <4 detectors and axial images only. For pre-operative N staging PET had the lowest sensitivity, but the highest specificity among modalities; CT performance did not significantly differ by detector number or addition of MPR images. For pre-operative M staging performance did not significantly differ by modality, detector number, or MPR images.

CONCLUSIONS

The agreement between pre-operative TNM staging by imaging scans and post-operative staging by pathology is not perfect and may affect treatment decisions. Operator dependence and heterogeneity of data may account for the variations in staging performance. Physicians should consider this discrepancy when creating their treatment plans.

Prognostic significance of computed tomography defined ascites in advanced gastric cancer

PURPOSE

The aim of this study was to investigate the clinicopathologic features and prognosis in patients with computed tomography (CT) findings of ascites, with a focus on the correlation with peritoneal carcinomatosis.

METHODS

This study included a total of 157 patients who underwent surgery for advanced gastric cancer from 2003 to 2008 at the Department of Surgery, Hallym University Kangdong Sacred Heart Hospital, Seoul, Korea, which were analyzed retrospectively.

RESULTS

Fourteen patients (8.9%) presented ascites on their CT scan. Among them, 10 patients had peritoneal carcinomatosis, and showed significant difference with CT ascites positive group in the incidence of peritoneal carcinomatosis. The presence of CT ascites was significantly correlated with pathologic T stage, tumor size, histologic type, CT T and N stages, CT peritoneal nodularity and curability of surgery, statistically. The prognosis of CT ascites positive group was much poorer in the total advanced gastric cancer patients (P < 0.001), as well as in patients with pathologic T4 (P = 0.002). Also in patients without peritoneal carcinomatosis, CT ascites positive subgroup tended to have a worse prognosis than CT ascites negative subgroup (P = 0.086). Tumor size, CT T and N stages and the presence of CT peritoneal nodularity and ascites influenced the prognosis significantly; among which, if a tumor size larger than 5 cm, CT T4 stage and the presence of CT ascites were identified as independent prognostic factors.

CONCLUSION

The presence of ascites was closely associated with peritoneal metastasis, and was the most significant independent prognostic factor in advanced gastric cancer in the present study.

Imaging in assessing hepatic and peritoneal metastases of gastric cancer: a systematic review

BACKGROUND

Hepatic and peritoneal metastases of gastric cancer are operation contraindications. Systematic review to provide an overview of imaging in predicting the status of liver and peritoneum pre-therapeutically is essential.

METHODS

A systematic review of relevant literatures was performed in Pubmed/Medline, Embase, The Cochrane Library and the China Biological Medicine Databases. QUADAS was used for assessing the methodological quality of included studies and the bivariate model was used for this meta-analysis.

RESULTS

Totally 33 studies were included (8 US studies, 5 EUS studies, 22 CT studies, 2 MRI studies and 5 18F-FDG PET studies) and the methodological quality of included studies was moderate. The result of meta-analysis showed that CT is the most sensitive imaging method [0.74 (95% CI: 0.59-0.85)] with a high rate of specificity [0.99 (95% CI: 0.97-1.00)] in detecting hepatic metastasis, and EUS is the most sensitive imaging modality [0.34 (95% CI: 0.10-0.69) ] with a specificity of 0.96 (95% CI: 0.87-0.99) in detecting peritoneal metastasis. Only two eligible MRI studies were identified and the data were not combined. The two studies found that MRI had both high sensitivity and specificity in detecting liver metastasis.

CONCLUSION

US, EUS, CT and 18F-FDG PET did not obtain consistently high sensitivity and specificity in assessing liver and peritoneal metastases of gastric cancer. The value of laparoscopy, PET/CT, DW-MRI, and new PET tracers such as 18F-FLT needs to be studied in future.

Neoadjuvant docetaxel, capecitabine and cisplatin (DXP) in patients with unresectable locally advanced or metastatic gastric cancer

BACKGROUND

This phase II study was conducted to evaluate the efficacy of neoadjuvant chemotherapy with docetaxel, cisplatin and capecitabine (DXP) in patients with unresectable locally advanced and/or intra-abdominal metastatic gastric cancers.

METHODS

Patients with advanced gastric cancer (AGC), clinically unresectable because of local invasion or limited intra-abdominal metastasis in para-aortic lymph nodes and/or the peritoneum based on multidetector row computed tomography, were enrolled. DXP consisted of docetaxel 60 mg/m(2) i.v. and cisplatin 60 mg/m(2) i.v. on day 1, and capecitabine 937.5 mg/m(2) twice daily p.o. on days 1-14 every 21 days. Surgery was performed after 4-6 cycles of DXP.

RESULTS

Thirty-six (74%) of the 49 patients enrolled underwent surgery, and 31 (63%) had an R0 resection. R0 resection was possible in 15 of 21 patients (71%) with unresectable locally advanced lesions, 12 of 17 patients (70%) with para-aortic lymph node metastasis but only 4 of 11 patients (36%) with peritoneal metastasis. Grade 3/4 toxicities included neutropenia (69%), febrile neutropenia (4%) and hand-foot syndrome (8%).

CONCLUSIONS

Neoadjuvant DXP may offer a reasonable chance of curative surgery in AGC patients with unresectable locally advanced or para-aortic lymph node metastasis.

Gastric cancer

Gastric cancer is the second most frequent cause of cancer death worldwide, although much geographical variation in incidence exists. Prevention and personalised treatment are regarded as the best options to reduce gastric cancer mortality rates. Prevention strategies should be based on specific risk profiles, including Helicobacter pylori genotype, host gene polymorphisms, presence of precursor lesions, and environmental factors. Although adequate surgery remains the cornerstone of gastric cancer treatment, this single modality treatment seems to have reached its maximum achievable effect for local control and survival. Minimally invasive techniques can be used for treatment of early gastric cancers. Achievement of locoregional control for advanced disease remains very difficult. Extended resections that are standard practice in some Asian countries have not been shown to be as effective in other developed countries. We present an update of the incidence, causes, pathology, and treatment of gastric cancer, consisting of surgery, new strategies with neoadjuvant and adjuvant chemotherapy or radiotherapy, or both, novel treatment strategies using gene signatures, and the effect of caseload on patient outcomes.

Gastric cancer

Gastric cancer is the second most frequent cause of cancer death worldwide, although much geographical variation in incidence exists. Prevention and personalised treatment are regarded as the best options to reduce gastric cancer mortality rates. Prevention strategies should be based on specific risk profiles, including Helicobacter pylori genotype, host gene polymorphisms, presence of precursor lesions, and environmental factors. Although adequate surgery remains the cornerstone of gastric cancer treatment, this single modality treatment seems to have reached its maximum achievable effect for local control and survival. Minimally invasive techniques can be used for treatment of early gastric cancers. Achievement of locoregional control for advanced disease remains very difficult. Extended resections that are standard practice in some Asian countries have not been shown to be as effective in other developed countries. We present an update of the incidence, causes, pathology, and treatment of gastric cancer, consisting of surgery, new strategies with neoadjuvant and adjuvant chemotherapy or radiotherapy, or both, novel treatment strategies using gene signatures, and the effect of caseload on patient outcomes.

Helical CT evaluation of the preoperative staging of gastric cancer in the remnant stomach

OBJECTIVE

The objective of our study was to evaluate the diagnostic performance of helical CT for evaluating the preoperative staging of gastric cancer in the remnant stomach.

MATERIALS AND METHODS

Preoperative helical CT images of 67 patients with gastric cancer in the remnant stomach were independently analyzed regarding staging of the tumor by two radiologists who were blinded to histopathologic and surgical results. The differences in their assessments were resolved by consensus including the opinion of a third radiologist. The radiologists were asked to determine the depth of tumor invasion of the gastric wall (T stage), classifying it as </= T2, T3, or T4; local lymph node involvement (N stage); and solid organ metastasis or peritoneal involvement (M stage). TNM staging on CT was correlated with the histopathologic results of the resected specimen or with the surgical findings. Interobserver agreement was assessed using weighted kappa statistics.

RESULTS

The overall accuracy of T staging for reviewers 1 and 2 and for the consensus reading were 83.6%, 78.2%, and 85.4%, respectively. Five of 34 </= T2 lesions were misdiagnosed as T3. The cause of the overstaging was the misconception of the postoperative fibrotic change of the anastomotic site as perigastric tumoral infiltration. Three of 18 T4 lesions were understaged because of inadequate gastric distention (n = 1) and misinterpretation of adjacent organ involvement as partial volume averaging (n = 2). The accuracy of N staging and M staging were 81.8% and 94.0% for reviewer 1; 78.2% and 91.0% for reviewer 2; and 81.8% and 94.0% for the consensus reading, respectively. The weighted kappa values of T staging, N staging, and M staging were 0.676, 0.619, and 0.924, respectively.

CONCLUSION

Contrast-enhanced helical CT can be used successfully to preoperatively evaluate the staging of remnant stomach cancer in patients who have undergone previous gastric resection.

[Value of spiral computed tomography for the preoperative detection of lymph node involvement in gastric cancer]

BACKGROUND AND OBJECTIVE

Knowledge regarding the presence of metastatic lymph node in gastric cancer is of obvious importance when thinking of neoadjuvant therapy, yet it is full of uncertainty. Computed tomography (CT) is one of the first-line diagnostic tools, in spite of controversial results. We aimed to establish the performance of spiral CT in predicting lymph node involvement in gastric cancer.

PATIENTS AND METHOD

Sixty-two consecutive patients diagnosed of gastric cancer were enrolled in the study. All the patients were examined by CT and imaging results were compared with the corresponding histopathological findings following surgery. We analyzed the sensitivity, specificity, positive and negative reasons, accuracy and efficiency. We also assessed the distribution and number of isolated lymph nodes, the diameter of the largest single nodes and the N distribution according the TNM classification system.

RESULTS

Compared with the histological results, CT achieved a sensitivity of 0.43, specificity of 0.96, an accuracy of 0.55 and an efficiency of 0.67. An in-depth analysis of the histological lymph node size revealed significant differences between the groups with and without lymph node involvement, with an average size of 16.29mm (95% confidence interval, 7.1-15.6) and 10.25mm (95% confidence interval, 4.8-25.5), respectively (p<0.05). We also observed a diminished accuracy for the N1 and N2 groups.

CONCLUSIONS

Spiral CT shows a poor performance for the preoperative evaluation of lymph node involvement. Nevertheless, in case of a positive result, spiral CT is helpful for treatment decision-making in gastric cancer as a first-line staging technique.

Endoscopic ultrasound can improve the selection for laparoscopy in patients with localized gastric cancer

BACKGROUND

The majority of newly diagnosed patients with gastric cancer have disease that is not resectable because of local extension or metastatic (M1) disease. Laparoscopy is a recommended staging evaluation to identify occult peritoneal metastatic disease. We determined if endoscopic ultrasound (EUS) could improve the selection of patients for laparoscopy.

STUDY DESIGN

Gastric cancer patients being screened for a preoperative chemotherapy clinical trial were prospectively examined. Patients underwent standard preoperative assessment. Those without obvious metastatic disease were referred for EUS and laparoscopy. EUS divided patients into risk categories for metastatic disease: low risk (T1-2, N0) and high risk (T3-4, N+, or both). Laparoscopy categories were M1 and M0. The ability of EUS to predict subradiographic peritoneal metastatic disease was evaluated.

RESULTS

Ninety-four patients were studied. The majority were EUS high risk (72%). Occult metastatic disease was identified in 19 patients, 18 of whom had high-risk EUS stage. The yields of identifying M1 disease by laparoscopy in EUS high- and low-risk patients were 25% (95% CI, 15% to 37%) and 4% (95% CI, 0.1% to 20%), respectively. The negative predictive value of low-risk EUS for laparoscopy and pathologic M0 was 96% (exact 95% CI, 80% to 100%).

CONCLUSIONS

This study suggested that laparoscopy can be avoided in patients with EUS early-stage gastric cancer. Patients with more advanced disease are at higher risk of occult peritoneal disease and require laparoscopy. Validation with greater numbers is warranted, but, based on these data, we propose a new staging algorithm allowing EUS low-risk patients to proceed directly to resection.

Clinical and diagnostic significance of preoperative computed tomography findings of ascites in patients with advanced gastric cancer

BACKGROUND

The relationship between ascites, as detected by preoperative computed tomography (CT), and peritoneal metastasis of gastric cancer requires clarification because of its likely significance for clinical outcome.

METHODS

A retrospective analysis of 293 patients with advanced gastric cancer investigated the association between preoperative CT findings of ascites and surgical findings of peritoneal washing cytology and peritoneal metastasis.

RESULTS

Forty-five of 293 patients (15%) presented with ascites on preoperative CT. Positive ascites on CT predicted the presence of free tumor cells with 40% sensitivity and 97% specificity, and peritoneal metastasis with 51% sensitivity and 97% specificity. Ascites on CT was an independent prognostic factor by univariate (P < .001) and multivariate (relative risk, 2.03; 95% confidence interval, 1.39-2.96; P < .001) analyses. The median survival time was 6.0 months in patients with positive ascites on CT.

CONCLUSIONS

The presence of ascites on CT suggests the presence of peritoneal metastasis and indicates a poor prognosis. The presence of peritoneal metastasis should be confirmed by diagnostic laparoscopy in gastric cancer patients with ascites.

Clinical significance of CT-defined minimal ascites in patients with gastric cancer

AIM: To study the clinical significance of minimal ascites, which was only defined by the CT and whose nature was not determined preoperatively, in the relationship with the peritoneal carcinomatosis.

METHODS: The medical records and the dynamic CT films of 118 patients with gastric cancer were reviewed. Factors associated with peritoneal carcinomatosis were analyzed in 40 patients who had CT-defined ascites of which the nature was surgically confirmed.

RESULTS: Only 12.5-25% of the CT-defined minimal ascites, whose volume was estimated to be less than 50 mL, were associated with peritoneal carcinomatosis. When the estimated CT-defined ascitic volume was 50 mL or more, peritoneal carcinomatosis was identified in 75–100%. When CT-defined lymph node enlargements were not found beyond the regional gastric area, perigastric invasions were not suspected, and the size of tumor was less than 3 cm, peritoneal carcinomatosis seemed significantly less accompanied at the univariate analysis. However, except for the minimal volume of CT-defined ascites in comparison with the mild or more, other factors were not confirmed multivariately.

CONCLUSION: In the patients with gastric cancer, CT-defined minimal ascites alone is rarely associated with peritoneal carcinomatosis, if it does not accompany other signs suggestive of malignant seeding. Therefore, consideration of active curative resection should not be hesitated, if CT-defined minimal ascites is the only delusive sign.

Multiorgan resection for gastric cancer: intraoperative and computed tomography assessment of locally advanced disease is inaccurate

Multiorgan resection of locally advanced gastric cancer has previously been associated with increased morbidity. This study was performed to determine the actual prevalence of pathologic T4 disease in multiorgan gastric resection specimens excised for presumed clinical T4 gastric cancer. A prospective oncology database was queried to identify gastric cancer patients who underwent en bloc multiorgan resection for clinical T4 lesions. Four hundred eighteen patients with gastric cancer underwent gastrectomy between 1990 and 2002. Multiorgan resection was performed in 21 of 418 (5%) patients. Multiorgan resection was not associated with a significant increase in morbidity or mortality. Pathologically confirmed T4 disease was present in only 8 of 21 (38%) patients; the pathologic T stage in all remaining patients was T3 (13 [62%]). Fifteen patients were evaluated by preoperative computed tomography scan. Preoperative computed tomography was inaccurate in assessing T4 lesions, with a positive predictive value of only 50%. Multiorgan resection was safely performed in patients with locally advanced gastric cancer. Pathologic T4 disease was present in only one third of multiorgan resections performed for en bloc excision of locally advanced gastric cancer. Improved methods for intraoperative assessment of disease extension to adjacent viscera should be investigated.