Clinicopathologic Characteristics of Gastric Cancer Patients according to the Timing of the Recurrence after Curative Surgery

The clinicopathological and genetic differences among gastric cancer patients with no recurrence, early recurrence, and late recurrence after curative surgery

BACKGROUND

To date, few reports have investigated the genetic alterations and clinicopathological features among gastric cancer (GC) patients with no tumor recurrence, early recurrence, and late recurrence following curative surgery.

METHODS

A total of 473 GC patients undergoing curative surgery were included. The clinicopathological characteristics, patient prognosis, recurrence patterns, and genetic alterations were compared between GC patients with early recurrence and late recurrence.

RESULTS

Among the 473 GC patients, 119 had early recurrence (<2 years) and 45 had late recurrence (≥2 years). Patients with early recurrence had tumor size larger than 5 cm, fewer superficial-type tumors, more lymphovascular invasion, more advanced pathological T and N categories and Tumor, Node, Metastasis (TNM) stages, and worse 5-year overall survival than patients with late recurrence and no recurrence. For intestinal-type GC, patients with no tumor recurrence had more Helicobacter pylori infection than patients with early recurrence and late recurrence; for diffuse-type GC patients, the frequency of PIK3CA amplification was the highest in early recurrence, followed by late recurrence and no recurrence. GC patients with single-site recurrence had more ARID1A mutations than those with multiple-site recurrence. Multivariate analysis demonstrated that age, tumor recurrence, and pathological N categories were independent prognostic factors.

CONCLUSION

PIK3CA amplifications were more common in diffuse-type GC with early recurrence, whereas ARID1A mutations were more common in patients with single-site recurrence. Targeted therapy and immunotherapy might be helpful for these patients.

A molecular approach integrating genomic and DNA methylation profiling for tissue of origin identification in lung-specific cancer of unknown primary

BACKGROUND

Determining the tissue of origin (TOO) is essential for managing cancer of unknown primary (CUP). In this study, we evaluated the concordance between genome profiling and DNA methylation analysis in determining TOO for lung-specific CUP and assessed their performance by comparing the clinical responses and survival outcomes of patients predicted with multiple primary or with metastatic cancer.

METHODS

We started by retrospectively screening for CUP patients who presented with both intra- and extrathoracic tumors. Tumor samples from included patients were analyzed with targeted sequencing with a 520-gene panel and targeted bisulfite sequencing. TOO inferences were made in parallel via an algorithm using genome profiles and time interval between tumors and via machine learning-based classification of DNA methylation profiles.

RESULTS

Four hundred patients were screened retrospectively. Excluding patients definitively diagnosed with conventional diagnostic work-up or without available samples, 16 CUP patients were included. Both molecular approaches alone enabled inference of clonality for all analyzed patients. Genome profile enabled TOO inference for 43.8% (7/16) patients, and the percentage rose to 68.8% (11/16) after considering inter-tumor time lag. On the other hand, DNA methylation analysis was conclusive for TOO prediction for 100% (14/14) patients with available samples. The two approaches gave 100% (9/9) concordant inferences regarding clonality and TOO identity. Moreover, patients predicted with metastatic disease showed significantly shorter overall survival than those with multiple primary tumors.

CONCLUSIONS

Genome and DNA methylation profiling have shown promise as individual analysis for TOO identification. This study demonstrated the feasibility of incorporating the two methods and proposes an integrative scheme to facilitate diagnosing and treating lung-specific CUPs.

Construction, Validation, and Visualization of Two Web-Based Nomograms to Predict Overall and Cancer-Specific Survival in Patients with Gastric Cancer and Lung Metastases

Background

The lung is one of the most common sites of metastasis in gastric cancer. Our study developed two nomograms to achieve individualized prediction of overall survival (OS) and cancer-specific survival (CSS) in patients with gastric cancer and lung metastasis (GCLM) to better guide follow-up and planning of subsequent treatment.

Methods

We reviewed data of patients diagnosed with GCLM in the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. The endpoints of the study were the OS and CSS. We used the “caret” package to randomly divide patients into training and validation cohorts in a 7 : 3 ratio. Multivariate Cox regression analysis was performed using univariate Cox regression analysis to confirm the independent prognostic factors. Afterward, we built the OS and CSS nomograms with the “rms” package. Subsequently, we evaluated the two nomograms through calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA). Finally, two web-based nomograms were built on the basis of effective nomograms.

Results

The OS analysis included 640 patients, and the results of the multivariate Cox regression analysis showed that grade, chemotherapy, and liver metastasis were independent prognostic factors for patients with GCLM. The CSS analysis included 524 patients, and the results of the multivariate Cox regression analysis showed that the independent prognostic factors for patients with GCLM were chemotherapy, liver metastasis, marital status, and tumor site. The ROC curves, calibration curves, and DCA revealed favorable predictive power in the OS and CSS nomograms. We created web-based nomograms for OS (https://zhenghh.shinyapps.io/aclmos/) and CSS (https://zhenghh.shinyapps.io/aslmcss/).

Conclusions

We created two web-based nomograms to predict OS and CSS in patients with GCLM. Both web-based nomograms had satisfactory accuracy and clinical usefulness and may help clinicians make individualized treatment decisions for patients.

Detection of asymptomatic recurrence improves survival of gastric cancer patients

BACKGROUND

The effect of long-term surveillance for asymptomatic patients after curative resection of gastric cancer is being debated. We compared the prognosis of Korean patients with recurrent gastric cancer according to the presence or absence of cancer-related symptoms at the time of recurrence detection.

METHODS

We retrospectively reviewed the medical records of 305 Korean patients who experienced recurrence after curative resection of primary gastric cancer between March 2002 and February 2017 at Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea.

RESULTS

The median follow-up duration was 169.8 months (1-267.2), and the median age at first recurrence was 58.1 years (23.4-81.9). Among 305 patients with recurrence, 97 of 231 (42.0%) patients with early recurrence (≤5 years after curative surgical resection) and 47 of 74 (63.5%) patients with late recurrence (>5 years after curative surgical resection) had cancer-related symptoms at recurrence (p = 0.001). For survival after recurrence, detection of asymptomatic recurrence was an independent favorable factor (hazard ratio, 0.527; 95% confidence interval, 0.409-0.681; p < 0.001) accompanied with the possibility of subsequent treatment, targeted-, or immunotherapy for recurrent disease, and locoregional recurrence only. In the late-recurrence group, the patients with asymptomatic detection of recurrence showed favorable post-recurrence survival (median, 33.3 months vs. 14.7 months; p = 0.002), overall survival (median, 136.3 months vs. 106.1 months; p = 0.010), and cancer-specific survival (median, 177.5 months vs. 106.1 months; p = 0.005) than the patients with symptomatic detection.

CONCLUSION

The detection of gastric cancer recurrence in patients without cancer-related symptoms may be related to improved survival, suggesting the potential benefit of long-term surveillance.

Perineural Invasion and Postoperative Complications are Independent Predictors of Early Recurrence and Survival Following Curative Resection of Gastric Cancer

Purpose

To investigate the clinicopathological and prognostic factors related to early gastric cancer recurrence after curative resection.

Patients and Methods

Between October 2006 and August 2018, a total of 149 patients with recurrence of gastric cancer/adenocarcinoma of the esophagogastric junction after curative resection were enrolled from our treatment group. A retrospective clinical analysis was performed on these patients with gastric cancer recurrence after curative resection.

Results

Among the 149 patients, 99 (66.4%) had only one recurrence pattern, and 50 (33.6%) had multiple recurrence patterns. The median recurrence-free survival (RFS) was 18.2 months (95% CI 15.0–21.4). Ninety-four patients (63.1%) experienced early recurrence (recurrence within 24 months after curative resection), and 55 patients (36.9%) experienced late recurrence (recurrence beyond 24 months after curative resection). The univariate analysis showed that perineural invasion (P=0.002), depth of invasion (P=0.026), postoperative chemotherapy (P=0.036) and postoperative complications (P=0.004) were significant factors associated with early recurrence after curative resection for gastric cancer. Perineural invasion (P=0.003), postoperative chemotherapy (P=0.036) and postoperative complications (P=0.042) were independent factors associated with early recurrence after curative resection in the multivariate analysis. The survival analysis showed that perineural invasion (P=0.011) and postoperative complications (P=0.007) were independent prognostic factors. The median survival time of early recurrence patients was significantly shorter than that of late recurrence patients (25.4 vs 62.9 months, P<0.001).

Conclusion

Perineural invasion, postoperative chemotherapy and postoperative complications were independent factors associated with early recurrence after curative resection. Patients with early recurrence after curative resection had poorer survival.

High sensitive detection of circulating tumor cell by multimarker lipid magnetic nanoparticles and clinical verifications

Tumor cells with heterogeneity and diversity can express different markers. At present, positive separation of circulating tumor cells (CTC) taking EpCAM as the marker was used in most cases which could be one-sided, while this study successfully prepared four antibody-modified magnetic immunoliposomes (MIL) by using the self-assembled liposome with antibody derivatives. This study aims to explore the separation efficiency and clinical detection feasibility of single or combined use of MIL with multi-tumor markers on different tumors. Captured CTC were stained with CK-FITC, CD45-PE and DAPI, and fluorescence microscope was used for the observation, analysis and calculation. The result indicated that the CTC number positive rate in blood samples of four different magnetic balls on the same patient could be up to 87.5% in 32 patients with 14 different kinds tumors. While the effect of directly mixed separation by four kinds of magnetic balls was not satisfying. It suggested that the MIL of multi-tumor markers could be a powerful tool for CTC separation in application of tumor screening and prognosis.

Prognostic relevance of FGFR2 expression in stage II/III gastric cancer with curative resection and S-1 chemotherapy

Curative gastrectomy and adjuvant chemotherapy using S-1 is a standard treatment for stage II/III gastric cancer in Japan. The purpose of the present study was to evaluate the prognostic relevance of fibroblast growth factor receptor (FGFR)2 expression in patients with stage II/III gastric cancer that underwent postoperative adjuvant chemotherapy with S-1. Formalin-fixed paraffin-embedded surgical specimens were retrospectively examined in 167 patients with stage II/III gastric cancer that underwent curative gastrectomy followed by adjuvant S1 chemotherapy. FGFR2 expression was measured using immunohistochemistry (IHC) staining. The IHC results for FGFR2 were as follows: Grade 1+, 32; grade 2+, 80; grade 3+, 55 patients. The FGFR2 expression level was not significantly associated with relapse-free or overall survival rates. However, in the diffuse type, the FGFR2 expression level tended to be negatively correlated with relapse-free survival. In particular, the proportion of patients who recurred >5 years following surgery was significantly larger in the FGFR2 grade 3+ group than in the grade 1+, 2+ group (4/22 vs. 1/35; P=0.047). The recurrent sites of long-term failure were mostly peritoneum among the diffuse type. To the best of our knowledge, the present study indicated for the first time that FGFR2 could predict long-term failure of adjuvant S-1 chemotherapy in curative advanced gastric cancer. There was no interaction between FGFR2 expression and patient survival outcomes in stage II/III gastric cancer. Patients with FGFR2 3+ in stage II/III gastric cancer should carefully be followed-up for >5 years after surgery.

The patterns and timing of recurrence after curative resection for gastric cancer in China

Background

The recurrence of gastric cancer after curative resection had adverse effects on patients’ survival. The treatment presence varied from different countries. The aims of this study were to understand the recurrence incidence, patterns, and timing and to explore the risk factors in China.

Methods

One thousand three hundred four patients who undergoing curative resection from more than 100 hospitals between January 1st 1986 and September 1st 2013, were surveyed in detail. Clinical pathological factors were examined as potential risk factors of each recurrence pattern using univariate and multivariate analyses. Recurrence timing was also analyzed based on disease-free survival.

Results

Among 1304 gastric cancer patients, 793 patients (60.8%) experienced recurrence and 554 patients (42.5%) experienced recurrence within 2 years after operation. The median disease-free survival was 29.00 months (interquartile range [IQR] 12.07, 147.23). Receiving operation in general hospitals was one of independent risk factors of local-regional recurrence (OR = 1.724, 95% CI 1.312 to 2.265) and distant metastasis (OR = 1.496, 95% CI 1.164 to 1.940). Patients would suffer lower risk of distant metastasis if they received no more than 3 cycles adjuvant chemotherapy (OR = 0.640, 95% CI 0.433 to 0.943). Adjuvant radiotherapy could reduce the risk of recurrence (OR 0.259, 95% CI 0.100 to 0.670), especially distant metastasis (OR = 0.260, 95% CI 0.083 to 0.816).

Conclusions

More than 60% patients experienced recurrence after curative resection for gastric cancer, especially within 2 years after surgery. Risk factors were clarified between various recurrence patterns. Advanced gastric cancer and undergoing operation in general hospitals contributed to increased recurrence risk and worse survival. Enough number of lymph nodes harvest and standard D2 lymphadenectomy could reduce recurrence. Chinese patients would benefit from adjuvant chemotherapy and radiotherapy.

The characteristics of the serum carcinoembryonic antigen and carbohydrate antigen 19-9 levels in gastric cancer cases

PURPOSE

Although carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 are the most commonly used tumor markers in gastric cancer, the differences in the characteristics of these two markers remain unclear, because most previous studies have included many patients who were positive for both markers.

METHODS

We analyzed the available data on 1050 patients with gastric cancer who underwent R0 resection. The background characteristics and recurrence-free survivals (RFS) were compared between the single-positive patients for CEA or CA 19-9 and double-negative patients.

RESULTS

Among these 1050 patients, 86 patients (8.2 %) were positive for CEA only, 77 patients (7.3 %) were positive for CA 19-9 only, and 867 patients (82.6 %) were double negative for both markers. Patients who were elderly, male and had a differentiated histology were more commonly observed in the CEA-positive group than in the double-negative group (P = 0.004, P = 0.009, and P = 0.001). The patients who were positive for either CEA or CA 19-9 had a significantly worse RFS than the patients who were negative for both (P < 0.001 and P < 0.001). The most frequent site of recurrence was the liver (9.3 %) in the CEA-positive group and the peritoneum (11.7 %) in the CA 19-9-positive group.

CONCLUSION

Age, sex, and histological type were thus found to be associated with CEA positivity. CEA is, therefore, considered to be a sensitive marker for liver recurrence, while CA 19-9 is a sensitive marker for peritoneal recurrence.

Risk factors for lymph node metastasis and long-term outcomes of patients with early gastric cancer after non-curative endoscopic submucosal dissection

BACKGROUND

The long-term outcomes after non-curative gastric endoscopic submucosal dissection (ESD) are still unknown. We aimed to clarify the pathological risk factors for lymph node metastasis (LNM) of early gastric cancer (EGC) and the long-term outcomes among patients who were judged to have had non-curative ESD.

METHODS

From September 2002 to December 2012, 506 patients who were judged to have had non-curative gastric ESD were enrolled and classified into two groups: (1) those who subsequently underwent additional surgical resection (surgical group, n = 323) and (2) those followed up without additional surgical resection (nonsurgical group, n = 183). We analyzed pathological risk factors for LNM of EGC in the surgical group. Additionally, we compared long-term outcomes in the two groups.

RESULTS

LNM was found pathologically in 9.3 % of the surgical group (30/323) at the additional surgical resection after non-curative ESD. In the multivariate logistic regression analysis, lymphovascular invasion (LVI) was an independent risk factor for LNM in the surgical group (odds ratio 8.57, 95 % confidence interval 2.76-38.14, P < 0.0001). The 5-year cause-specific survival rate was similar in the surgical and nonsurgical groups (98.7 and 96.5 %, respectively; log-rank test, P = 0.07). In contrast, the 5-year cause-specific survival rate of patients with LVI in the surgical group was better than that in the nonsurgical group (98.2 and 79.1 %, respectively; log-rank test, P < 0.0001).

CONCLUSIONS

A detailed assessment of LVI is essential to the pathological evaluation of endoscopically resected specimens. An additional surgical resection should be strongly recommended for patients with LVI.

Characteristics of gastric cancer recurrence five or more years after curative gastrectomy

OBJECTIVE

To investigate the characteristics of recurrences that occurred 5 or more years after curative resection for gastric cancer.

METHODS

We analyzed recurrences among 1,299 patients with gastric cancer who underwent curative operations at the Department of Surgery, Inje University Seoul Paik Hospital between September 1998 and December 2002. Recurrences were classified as within 2 years (early), 2-5 years (intermediate), and more than 5 years (late) after gastrectomy. The clinicopathologic findings of the patients with late recurrence were compared with those of patients in the other two recurrence groups, with special reference to the patterns of recurrence. Both univariate and multivariate analyses were performed, incorporating factors such as operation type, T-stage, N-stage, stage, lymphatic invasion, neural invasion, histology, tumor size, and recurrence site.

RESULTS

At the time of last follow-up, recurrence occurred in 266 (20.5%) patients. Recurrence times were classified as <2 years (182 patients), 2-5 years (61 patients), or >5 years (23 patients). The late recurrence rate was 8.6%. The occurrence of recurrence >5 years after gastrectomy was significantly correlated with age, operation type, T-stage, N-stage, stage, lymphatic invasion, neural invasion, histology, tumor size, location and recurrence site (P<0.05). The main recurrence patterns in the 23 patients with late recurrence were locoregional metastasis (10 patients, 43.5%), peritoneal seeding (8 patients, 34.8%), hematogenous metastasis (2 patients, 8.7%), and multiple metastasis (3 patients, 13.0%). A multivariate analysis showed that larger tumor size and younger age were independent prognostic factors for late recurrence. Additionally, locoregional and peritoneal recurrences were significantly more common than hematogenous recurrences.

CONCLUSIONS

Although late recurrence was uncommon, younger age and larger tumor size were associated with high risk. Follow-up surveillance is recommended for locoregional and peritoneal metastasis.

Preoperative smoking cessation can reduce postoperative complications in gastric cancer surgery

BACKGROUND

Despite the close link between cigarette smoking and the development of gastric cancer, little is known about the effects of cigarette smoking on surgical outcomes after gastric cancer surgery. The aim of this study was to investigate whether preoperative smoking status and the duration of smoking cessation were associated with short-term surgical consequences in gastric cancer surgery.

METHODS

Among 1,489 consecutive patients, 1,335 patients who underwent curative radical gastrectomy at the Samsung Medical Center between January and December 2009 were included in the present study. The smoking status was determined using questionnaires before surgery. Smokers were divided into four groups according to the duration of smoking cessation preoperatively (<2, 2-4, 4-8, and >8 weeks). The primary endpoint was postoperative complications (wound, lung, leakage, and bleeding); secondary endpoints were 3-year recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Five hundred twenty-two patients (39.1 %) were smokers. Smokers had a significantly higher overall incidence of postoperative complications than nonsmokers (12.3 vs. 5.2 %, P < 0.001, respectively), especially in impaired wound healing, pulmonary problems, and leakage. Smokers also had more severe complications than nonsmokers. After adjusting for other risk factors, the odds ratio (95 % CI) for the development of postoperative complications in the subgroups who stopped smoking <2 weeks, 2-4, 4-8, and >8 weeks preoperatively were 3.35 (1.92-5.83), 0.99 (0.22-4.38), 2.18 (1.00-4.76), and 1.32 (0.70-2.48), respectively, compared with the nonsmokers. There were no significant differences in 3-year RFS (P = 0.884) and OS (P = 0.258) between smokers and nonsmokers.

CONCLUSIONS

Preoperative smoking cessation for at least 2 weeks will help to reduce the incidence of postoperative complications in gastric cancer surgery.

Surgery combined with chemotherapy for recurrent gastric cancer achieves better long-term prognosis

BACKGROUNDS

Recurrence is the most important factor associated with death of gastric cancer patients after surgery. The aim of this study was to explore the prognosis factors and the effective therapy for recurrent gastric cancer (RGC) patients after radical resection.

METHODS

The clinical data of 144 RGC patients who underwent radical resection from January 1999 to March 2004 were reviewed. The 15 clinicopathological factors and treatment modalities on the survival were analyzed. Univariate and multivariate analyses were performed to investigate the prognostic significance of these factors for RGC.

RESULTS

The early recurrence (<2 years) was found in 90 patients, while late recurrence (≥2 years) occurred in 54 patients. The 2-year cumulative survival rates were 23.8 % for recurrent patients receiving chemotherapy plus surgery vs. 1.2 % in patients having chemotherapy only (p < 0.001), while the median survival time was 11.0 months vs. 6.0 months (p < 0.001). Multivariate analysis indicated TNM stage after the first operation (p = 0.048), iASPP overexpression (p = 0.013), time to recurrence (p < 0.001) and treatment of recurrence (p < 0.001) as independent prognostic factors.

CONCLUSIONS

Surgery combined with chemotherapy for recurrent gastric cancer patients achieves ideal long-term prognosis, which should perform actively.

Docetaxel, capecitabine and concurrent radiotherapy for gastric cancer patients with postoperative locoregional recurrence

AIMS AND BACKGROUND

This study aimed to assess the efficacy of concurrent chemoradiotherapy (CCRT) with docetaxel and capecitabine versus docetaxel and capecitabine chemotherapy for gastric cancer patients with postoperative locoregional recurrence.

METHODS

From 2008 to 2011, 81 patients with locoregional recurrence after curative resection of gastric cancer were enrolled. Thirty-nine (CCRT group) received involved-field radiotherapy with oral capecitabine (twice daily, 5 days/week) and intravenous infusion of docetaxel (once weekly). The remaining 42 patients (chemotherapy group) were treated with oral capecitabine (twice daily, days 1-14) followed by intravenous infusion of docetaxel (days 1 and 8). The overall response rate, overall symptom control rate, toxicity or adverse reactions, and overall survival (OS) were compared.

RESULTS

The overall response rate (CR+PR) was significantly higher in the CCRT group (79.5%) than the chemotherapy group (54.8%). In CCRT individuals, the control rates for bleeding, pain, and dysphagia/obstruction were 87.5%, 75%, and 71.4%, respectively, versus 63.2%, 50%, and 28.6% in the chemotherapy group. CCRT patients had a better symptom control rate than the chemotherapy group (52.5% vs. 80%). Adverse reactions were nonsignificantly more severe in CCRT patients. Finally, median OS was longer in the CCRT vs. chemotherapy group (14.2 vs. 6.4 months).

CONCLUSIONS

Involved-field radiotherapy with docetaxel and capecitabine was effective and well tolerated. These findings provide further insight into the role of CCRT in gastric cancer. However, this was not a randomized controlled study and the number of patients was relatively small, suggesting that cautious interpretation of cumulative estimates is warranted.

A case of local recurrence and distant metastasis following curative endoscopic submucosal dissection of early gastric cancer

Currently in Japan, differentiated-type gastric submucosal invasive cancers <500 μm with negative lymphovascular involvement are included in expanded pathological criteria for curative endoscopic treatment. This categorization is based on a retrospective examination of surgical resection cases in which patients suitable for such expanded criteria were determined to have a negligible risk of lymph node metastasis. We performed endoscopic submucosal dissection on a 66-year-old man with early gastric cancer in June 2004, and pathology revealed a well-differentiated adenocarcinoma, 16 × 8 mm in size, minute submucosal invasion depth (100 μm), and negative lymphovascular invasion or ulceration as well as tumor-free margins, so the case was diagnosed as a curative resection. In this case, however, local recurrence and distant metastasis resulted in August 2011. The patient received systemic chemotherapy but died of gastric cancer 23 months after recurrence.

Timing of chemotherapy and survival in patients with resectable gastric adenocarcinoma

AIM: To evaluate the timing of chemotherapy in gastric cancer by comparing survival outcomes in treatment groups.

METHODS: Patients with surgically resected gastric adenocarcinoma from 1988 to 2006 were identified from the Los Angeles County Cancer Surveillance Program. To evaluate the population most likely to receive and/or benefit from adjunct chemotherapy, inclusion criteria consisted of Stage II or III gastric cancer patients > 18 years of age who underwent curative-intent surgical resection. Patients were categorized into three groups according to the receipt of chemotherapy: (1) no chemotherapy; (2) preoperative chemotherapy; or (3) postoperative chemotherapy. Clinical and pathologic characteristics were compared across the different treatment arms.

RESULTS: Of 1518 patients with surgically resected gastric cancer, 327 (21.5%) received perioperative chemotherapy. The majority of these 327 patients were male (68%) with a mean age of 61.5 years; and they were significantly younger than non-chemotherapy patients (mean age, 70.7; P < 0.001). Most patients had tumors frequently located in the distal stomach (34.5%). Preoperative chemotherapy was administered to 11.3% of patients (n = 37) and postoperative therapy to 88.7% of patients (n = 290). An overall survival benefit according to timing of chemotherapy was not observed on univariate or multivariate analysis. Similar results were observed with stage-specific survival analyses (5-year overall survival: Stage II, 25% vs 30%, respectively; Stage III, 14% vs 11%, respectively). Therefore, our results do not identify a survival advantage for specific timing of chemotherapy in locally advanced gastric cancer.

CONCLUSION: This study supports the implementation of a randomized trial comparing the timing of perioperative therapy in patients with locally advanced gastric cancer.

Enhancement patterns of gastric carcinoma on contrast-enhanced ultrasonography: relationship with clinicopathological features

The aim of this study was to assess the relationship between the enhancement patterns and clinicopathological features of gastric cancer using intravenous contrast-enhanced ultrasonography (CEUS). In this Ethics Committee-approved prospective study, five hundred fifty two patients with gastric cancer who gave informed consent were examined preoperatively with CEUS. The enhancement pattern of each tumor was analyzed visually. Gross and histopathological findings on the postoperative specimens were compared with the preoperative CEUS findings. The most common CEUS pattern in differentiated gastric cancer was homogeneous enhancement, whereas heterogeneous enhancement was the most common pattern in undifferentiated gastric cancer. The proportion of heterogeneous enhancement was significantly different between the two histological subtypes (Chi- square = 146.735, P<0.001). The sensitivity and specificity of early heterogeneous enhancement on CEUS in diagnosing undifferentiated gastric cancer were 78.84% and 72.59% respectively. Gastric cancers with heterogeneous enhancement were more often Borrmann III and IV macroscopic types than those with homogeneous enhancement (66.56% vs. 30.80%, P<0.001), more commonly T3 and T4 depth of invasion than those with homogeneous enhancement (71.52% vs. 59.60%, P<0.05), more often showed lymphatic invasion than those with homogeneous enhancement (84.44% vs. 76.40%, P<0.05), and were less likely to receive curative gastrectomy than those with homogeneous enhancement (74.83% vs. 86.40%, P<0.005). The intra- and inter-observer reproducibility were both almost perfect for assessing enhancement patterns, with Kappa values of 0.916 (P<0.001) for intra-observer and 0.842 (P<0.001) for inter-observer reproducibility. CEUS provided detailed information about tumor vascularity and contrast enhancement patterns in gastric cancer. CEUS is promising as a new and useful method to predict the histological type of gastric cancer.

Time-varying pattern of recurrence risk for gastric cancer patients

This study analyzed the time-varying pattern of the recurrence risk for gastric cancer after surgery. A total of 1,222 gastric patients undergoing D2 resection surgery were studied retrospectively. The annual recurrence hazard curve for all of the populations showed one early peak and a late rise within 10 years after the surgery. The first major recurrence peak covers the first 3 years after the surgery, rising to a maximum at 1.5 years after surgery, followed by a decline until 7.5 years after the surgery, at which point the curve began to rise again. A subgroup analysis of this pattern also revealed that the curves of the patients with bigger tumors, poorly differentiated/undifferentiated adenocarcinomas, lymphatic/venous invasion, T3 and T4, node positive or with fewer lymph nodes retrieved were steeper. Chemotherapy can reduce the hazard rate for recurrence of gastric cancer. Our study confirms the time-varying pattern of the recurrence risk for gastric cancer, and it further supports the hypothesis of tumor dormancy after surgery. To effectively reduce the recurrence risk, new adjuvant therapies beyond chemotherapy may be needed.

Robot versus laparoscopic gastrectomy for cancer by an experienced surgeon: comparisons of surgery, complications, and surgical stress

BACKGROUND

No previous robotic studies present an equivalent surgical quality comparison in an experienced setting for gastric cancer. In addition, a reliable postoperative complication assessment is needed to accurately evaluate surgical outcomes.

METHODS

After 20 cases of robotic-assisted gastrectomy (RAG), a total of 121 consecutive gastric cancer patients underwent gastrectomy (38 RAG vs 83 laparoscopic-assisted gastrectomy [LAG]) from February 2009 to November 2010 at the Department of Surgery, Korea University Anam Hospital, Seoul, Korea. The Clavien-Dindo (C-D) classification was used to classify surgical complications. The granulocyte-to-lymphocyte (G:L) ratio was analyzed to evaluate surgical stress.

RESULTS

The baseline characteristics, with the exception of age, were similar. The mean total operation time for RAG (234.4 ± 48.0 min) was not significantly different than that for LAG (220.0 ± 60.6 min; P = 0.198). However, in obese patients, fewer lymph nodes were harvested by RAG (23.4 ± 7.0) than by LAG (32.2 ± 12.5, P = 0.006). Overall C-D complications were more common for RAG (47.3 vs 38.5 %), but the difference was not significant (P = 0.361). The mean hospital stay was similar for the 2 groups. Surgical stress as estimated by the G:L ratio was comparable between the 2 groups.

CONCLUSIONS

RAG performed by an experienced surgeon resulted in similar postoperative outcomes and complications to those of LAG. Assessment of operation time, C-D complication grade, and G:L ratio revealed that RAG is a practical and feasible alternative to LAG, with the possible exception of obese patients.