Stratification of Postsurgical Computed Tomography Surveillance Based on the Extragastric Recurrence of Early Gastric Cancer

Harmful effect of repetitive intravenous iodinated contrast media administration on the long-term renal function of patients with early gastric cancer

This retrospective study investigated whether repetitive exposure to intravenous iodinated contrast media (ICM) affects long-term renal function in patients who undergo curative surgery for early gastric cancer (EGC) collected from the Korean Health Insurance and Review Assessment (HIRA) database. Patients diagnosed with gastric cancer between January 2010 and December 2013 underwent regular computed tomography (CT) scans to monitor for extragastric recurrence. Patients who already had chronic kidney disease (CKD) before cancer diagnosis or had undergone chemotherapy or repeated surgery were excluded. A nested case-control study design was chosen to analyze the effect of repetitive ICM exposure to long-term renal function by comparing patients who developed CKD 2 years after cancer diagnosis and patients who did not. Among 59,971 patients collected according to inclusion and exclusion criteria, 1021 were diagnosed with CKD 2 years after cancer diagnosis. Using 1:5 matching after adjusting for age, sex and date of cancer diagnosis, 5097 control patients were matched to 1021 CKD patients. Conditional logistic regression showed that the number of CTs taken using ICM slightly increased the odds of CKD (odds ratio, 1.080; 95% confidence interval (CI): 1.059, 1.100; P < 0.0001). Thus, the administration of ICM might contribute to chronic renal function impairment.

Radiomics signature for prediction of long-term survival and recurrence patterns in patients with gastric cancer after radical gastrectomy: A multicenter study

BACKGROUND

This study aimed to develop and validate a radiomics score to predict the long-term survival and patterns of recurrence of gastric cancer (GC).

METHODS

A total of 513 patients who underwent radical gastrectomy for GC after curative resection between 2008 and 2016 at two institutions were analyzed. A radiomics score was generated using the least absolute shrinkage and selection operator Cox regression model on 327 patients and was validated in 186 patients. A nomogram consisting of the radiomics score and clinicopathological factors was created and compared with the tumor-lymph node-metastasis (TNM) staging system. Model performance was assessed using calibration, discrimination, and clinical usefulness.

RESULTS

The radiomics score was established based on five selected features. A higher score was significantly associated with poorer recurrence-free survival (RFS) and overall survival (OS) rates, both in the training and validation cohorts (P < 0.05). Multivariate analysis demonstrated that the radiomics score was an independent prognostic factor for both RFS and OS (P < 0.05). A nomogram incorporating the radiomics score had a significantly better prognostic value than the TNM system alone. Moreover, a high score was significantly associated with an increased risk of distant recurrence, a medium score was significantly associated with an increased risk of peritoneal recurrence, and a low score was significantly associated with an increased risk of locoregional recurrence, in the entire cohort (P < 0.05).

CONCLUSIONS

The newly proposed radiomics score may be a powerful predictor of long-term outcomes and recurrence patterns of GC. Further studies are warranted to confirm these findings.

Extragastric recurrence in patients who underwent surgical resection of stage I gastric cancer: Incidence, risk factors, and value of abdominal computed tomography as a postoperative surveillance method

Extragastric recurrence after radical resection of stage I gastric cancer is very rare. We investigated the incidence of extragastric recurrence and risk factors in patients who underwent surgical resection of stage I gastric cancer and evaluated the value of abdominal CT as a surveillance tool. This retrospective study enrolled 914 patients with stage I gastric cancer who underwent surgical resection at a single tertiary hospital. We investigated extragastric recurrence during the follow-up period, and disease-free survival (DFS) was assessed. Over a median follow-up period of 39 months, the overall incidence of extragastric recurrence was 2.2% (20/914). Risk factors for extragastric recurrence included deep submucosal invasion (SM2-3), muscularis propria invasion, and lymph node metastasis (hazard ratio [HR]=10.37, 28.101, and 6.843; P = .028, .002, and .001, respectively). Based on the number of risk factors, patients were stratified into 3 subgroups: low-risk (pT1aN0, pT1b(SM1)N0, 496/914), moderate-risk (pT1aN1, pT1b(SM1)N1, pT1b(SM2-3)N0, pT2N0, 369/914), and high-risk (pT1b(SM2-3)N1, 49/914). DFS was significantly longer in the low-risk group, followed by the moderate-risk and high-risk groups. We propose that postoperative CT surveillance should be omitted for stage 1A cases involving the mucosa and SM1 because of the extreme rarity of extragastric recurrence.

Evaluation of post-operative surveillance strategies for esophageal and gastric cancers: a systematic review and meta-analysis

BACKGROUND

There is no consensus or guidelines internationally to inform clinicians of how patients should be monitored for recurrence after esophagogastric resections.

AIM

This systematic review and meta-analysis summarizes the latest evidence investigating the usefulness of surveillance protocols in patients who underwent esophagectomy or gastrectomy.

METHODS

A systematic review of the literature was performed using MEDLINE, EMBASE, the Cochrane Review and Scopus databases. Articles were evaluated for the use of surveillance strategies including history-taking, physical examination, imaging modalities and endoscopy for monitoring patients post-gastrectomy or esophagectomy. Studies that compared surveillance strategies and reported detection of recurrence and post-recurrence survival were also included in the meta-analysis.

RESULTS

Fifteen studies that described a surveillance protocol for post-operative patients were included in the review. Seven studies were used in the meta-analysis. Random-effects analysis demonstrated a statistically significant higher post-recurrence survival (standardized mean difference [SMD] 14.15, 95% CI 1.40-27.26, p = 0.03) with imaging-based planned surveillance post-esophagectomy. However, the detection of recurrence (OR 1.76, 95% CI 0.78-3.97, p = 0.17) for esophageal cancers as well as detection of recurrence (OR 0.73, 95% CI 0.11-5.12, p = 0.76) and post-recurrence survival (SMD 6.42, 95% CI -2.16-18.42, p = 0.14) for gastric cancers were not significantly different with planned surveillance.

CONCLUSION

There is no consensus on whether surveillance carries prognostic survival benefit or how surveillance should be carried out. Surveillance may carry prognostic benefit for patients who underwent surgery for esophageal cancer. Randomized controlled trials are required to evaluate the survival benefits of intensive surveillance strategies, determine the ideal surveillance protocol and tailor it to the appropriate population.

SFRP4 and CDX1 Are Predictive Genes for Extragastric Recurrence of Early Gastric Cancer after Curative Resection

Extragastric recurrence of early gastric cancer (EGC) after curative resection is rare, but prognosis has been poor in previous reports. Recently, single patient classifier (SPC) genes, such as secreted frizzled-related protein 4 (SFRP4) and caudal-type homeobox 1 (CDX1), were associated with prognosis and chemotherapy response in stage II–III gastric cancer. The aim of our study is, therefore, to elucidate predictive factors for extragastric recurrence of EGC after curative resection, including with the expression of SPC genes. We retrospectively reviewed electronic medical records of 1974 patients who underwent endoscopic or surgical curative resection for EGC. We analyzed clinicopathological characteristics to determine predictive factors for extragastric recurrence. Total RNA was extracted from formalin-fixed, paraffin-embedded (FFPE) tumor tissue and amplified by real-time reverse transcription polymerase chain reaction to evaluate expression of SPC genes. Overall incidences of extragastric recurrence were 0.9%. In multivariate analysis, submucosal invasion (odds ratio [OR] = 6.351, p = 0.032) and N3 staging (OR = 171.512, p = 0.012) were independent predictive factors for extragastric recurrence. Mean expression of SFRP4 in extragastric recurrence (−2.8 ± 1.3) was significantly higher than in the control group (−4.3 ± 1.6) (p = 0.047). Moreover, mean expression of CDX1 in extragastric recurrence (−4.6 ± 2.0) was significantly lower than in the control group (−2.4 ± 1.8) (p = 0.025). Submucosal invasion and metastasis of more than seven lymph nodes were independent predictive factors for extragastric recurrence. In addition, SFRP4 and CDX1 may be novel predictive markers for extragastric recurrence of EGC after curative resection.

Development of a predictive model for extragastric recurrence after curative resection for early gastric cancer

BACKGROUND

Stratification of patients who undergo curative resection for early gastric cancer (EGC) is warranted due to the heterogeneity in the risk of developing extragastric recurrence (EGR). Therefore, we aimed to stratify the need for postoperative surveillance for EGR detection in patients with EGC by developing a model for predicting EGR-free survival.

METHODS

This retrospective cohort study included patients who underwent postoperative surveillance after curative resection of EGC (n = 4149). Cox proportional hazard models were used to identify predictors to build a model for predicting EGR-free survival. Bootstrap-corrected c-index and calibration plots were used for internal and external (n = 2148) validations.

RESULTS

A risk-scoring system was constructed using variables significantly associated with EGR-free survival: pathologic T stage (pT1b[sm1], hazard ratio [HR] 4.928; pT1b[sm2], HR 5.235; pT1b[sm3], HR 7.748) and N stage (pN1, HR 4.056; pN2, HR 9.075; pN3, HR 30.659). Patients were dichotomized into a very-low-risk group or a low-or-greater-risk group. The 5-year EGR-free survival rates differed between the two groups (99.9 vs. 97.3%). The discriminative performance of the model was 0.851 (Uno's c-index) and 0.751 in the internal and external cohorts, respectively. The calibration slope was 0.916 and 1.131 in the internal and external cohorts, respectively.

CONCLUSIONS

Our model for predicting EGR-free survival based on the pathologic T and N stages may be useful for stratifying patients who have undergone curative surgery for EGC. The results suggest that patients in the very-low-risk group may be spared from postoperative surveillance considering their extremely high EGR-free survival rate.

A Non-Invasive Scoring System to Differential Diagnosis of Clear Cell Renal Cell Carcinoma (ccRCC) From Renal Angiomyolipoma Without Visible Fat (RAML-wvf) Based on CT Features

Background

Renal angiomyolipoma without visible fat (RAML-wvf) and clear cell renal cell carcinoma (ccRCC) have many overlapping features on imaging, which poses a challenge to radiologists. This study aimed to create a scoring system to distinguish ccRCC from RAML-wvf using computed tomography imaging.

Methods

A total of 202 patients from 2011 to 2019 that were confirmed by pathology with ccRCC (n=123) or RAML (n=79) were retrospectively analyzed by dividing them randomly into a training cohort (n=142) and a validation cohort (n=60). A model was established using logistic regression and weighted to be a scoring system. ROC, AUC, cut-off point, and calibration analyses were performed. The scoring system was divided into three ranges for convenience in clinical evaluations, and the diagnostic probability of ccRCC was calculated.

Results

Four independent risk factors are included in the system: 1) presence of a pseudocapsule, 2) a heterogeneous tumor parenchyma in pre-enhancement scanning, 3) a non-high CT attenuation in pre-enhancement scanning, and 4) a heterogeneous enhancement in CMP. The prediction accuracy had an ROC of 0.978 (95% CI, 0.956–0.999; P=0.011), similar to the primary model (ROC, 0.977; 95% CI, 0.954–1.000; P=0.012). A sensitivity of 91.4% and a specificity of 93.9% were achieved using 4.5 points as the cutoff value. Validation showed a good result (ROC, 0.922; 95% CI, 0.854–0.991, P=0.035). The number of patients with ccRCC in the three ranges (0 to <2 points; 2–4 points; >4 to ≤11 points) significantly increased with increasing scores.

Conclusion

This scoring system is convenient for distinguishing between ccRCC and RAML-wvf using four computed tomography features.

Risk of Second Primary Malignancies among Patients with Early Gastric Cancer Exposed to Recurrent Computed Tomography Scans

Simple Summary

Cancer risk after radiation exposure during childhood has been extensively documented in the literature, although cancer risk associated with recurrent computed tomography (CT) scans during adulthood is less understood. We found a significant relationship between the frequency of CT scans and the subsequent incidence of secondary primary malignancies in patients who have undergone curative resection for early gastric cancer (EGC). On the basis of the low incidence of extragastric recurrence and the risk of radiation exposure, we suggest that overzealous CT surveillance should be avoided in adult patients with EGC.

Abstract

Although computed tomography (CT) scans are very useful for identification or surveillance of malignancy, they are also associated with the risk of cancer caused by ionizing radiation. We investigated the risk of second primary malignancies (SPMs) after frequent abdominopelvic CT scans in a cohort of Korean patients with early gastric cancer (EGC). We performed a cohort study of 11,072 patients who underwent resection for EGC at Samsung Medical Center and validated the results using data from 7908 patients in a Korean National Health Insurance Service cohort. Cox proportional hazards regression model was used to estimate hazard ratios (HRs) for intra-abdominal SPM. During 43,766.5 person-years of the follow-up at our center, 322 patients developed intra-abdominal SPMs. Patients who underwent receiving >8 abdominopelvic CT scans had a significantly greater risk of developing SPM (HR, 2.73; 95% CI, 1.66–4.50; p < 0.001) than those who had with ≤8 scans. For each additional abdominopelvic CT scan, the adjusted HR for SPM was 1.09 (95% confidence interval (CI), 1.03–1.14). Similar results were observed in the Korean National Health Insurance Service cohort (adjusted HR, 1.14; 95% CI, 1.07–1.22). Significantly elevated risk of SPM was still observed when considering a 2-year latency period (adjusted HR, 2.43; 95% CI, 1.37–4.48) and a 3-year latency period (adjusted HR, 2.17; 95% CI, 1.06–4.47). Frequent abdominopelvic CT scans are associated with an elevated risk of SPMs after the treatment of EGC. Thus, physicians need to weigh carefully the clinical benefits of CT examinations against the potential risks of radiation exposure.

A matched cohort study of the failure pattern after laparoscopic and open gastrectomy for locally advanced gastric cancer: does the operative approach matter?

BACKGROUND

Due to lacking evidence for confirming the efficacy of performing laparoscopic surgery for locally advanced gastric cancer (LAGC). Therefore, this study aimed to compare the static and dynamic failure patterns after laparoscopic gastrectomy (LG) and open gastrectomy (OG) in LAGC.

METHODS

A total of 1792 LAGC patients who underwent radical resection between January 2010 and January 2017 were divided into the LG group (n = 1557) and the OG group (n = 235). Propensity score matching was performed to balance the two groups. Dynamic hazard rates of failure were calculated using the hazard function. Early and late failure were defined as failure occurring before and after 2 years since surgery, respectively.

RESULTS

A total of 1175 patients with LAGC were included after matching (LG group, n = 940; OG, n = 235). The failure rate of the whole cohort was 43.2% (508/1175), accounting for 41.4% (389/940) and 50.6% (119/235) in the LG and OG groups, respectively. Although the two groups showed no significant differences in failure rate for any failure type, landmark analysis showed a lower early distant recurrence rate in the stage IIa-IIIb subgroup of the LG group (OG versus LG: 30.3% versus 21.1%, P = 0.004). The dynamic hazard rate peaked at 9.4 months (peak rate = 0.0186) before gradually declining. In stage IIa-IIIb patients, the hazard rate of the OG group remained significantly higher than that of the LG group within the first 2 years in terms of distant recurrence (peak rate: OG versus LG, 0.0091 versus 0.0055).

CONCLUSION

Given the differences in early failure between LG and OG, more intensive surveillance for distant recurrence within the first 2 years should be considered for patients with stage IIa-IIIb after OG.

Reappraise role of lymph node status in patterns of recurrence following curative resection of gastric adenocarcinoma

Objective

To examine the association between lymph node status and recurrence patterns in completely resected gastric adenocarcinoma.

Methods

We retrospectively assessed 1,694 patients who underwent curative gastrectomy from January 2010 to August 2014. Patients stratified according to lymph node status and recurrence patterns among different subgroups were compared.

Results

Of all, 517 (30.5%) patients developed recurrent disease, and complete data of recurrence could be obtained in 493 (95.4%) patients. For pN0 patients, the patterns of recurrence were different according to pT stage: locoregional recurrence was most common in patients with pT1−2 disease (57.1%), distant recurrence was most common in patients with pT3 disease (57.1%), and peritoneal recurrence was most common in patients with pT4a disease (66.7%). For pN+ patients, distant metastasis was most common pattern irrespective of pT stage. The site-specific trend of recurrence showed that locoregional recurrence increased within 5 years in patients with pN0−2 disease but plateaued 3 years after surgery in patients with pN3 disease. Time to recurrence was significantly longer for the pN0 patients compared with the pN+ patients (median: 25 vs. 16 months, P=0.001). Moreover, post-recurrence survival was significantly better for the pN0 patients than for the pN+ patients (median: 12 vs. 6 months, P<0.001), especially in patients with non-peritoneal recurrence, late recurrence, single recurrence, and receipt of potential curative treatment.

Conclusions

Among clinicopathologic factors, lymph node status is the most important factor associated with recurrence patterns after curative gastrectomy. Lymph node status may be used as an adjunct in clinical decision-making about postoperative therapeutic and follow-up strategies.

Development and External Validation of a Nomogram to Predict Recurrence-Free Survival After R0 Resection for Stage II/III Gastric Cancer: An International Multicenter Study

Background: The benefit of adjuvant chemotherapy varies widely among patients with stage II/III gastric cancer (GC), and tools predicting outcomes for this patient subset are lacking. We aimed to develop and validate a nomogram to predict recurrence-free survival (RFS) and the benefits of adjuvant chemotherapy after radical resection in patients with stage II/III GC.

Methods: Data on patients with stage II/III GC who underwent R0 resection from January 2010 to August 2014 at Fujian Medical University Union Hospital (FMUUH) (n = 1,240; training cohort) were analyzed by Cox regression to identify independent prognostic factors for RFS. A nomogram including these factors was internally and externally validated in FMUUH (n = 306) and a US cohort (n = 111), respectively.

Results: The multivariable analysis identified age, differentiation, tumor size, number of examined lymph nodes, pT stage, pN stage, and adjuvant chemotherapy as associated with RFS. A nomogram including the above 7 factors was significantly more accurate in predicting RFS compared with the 8^th AJCC-TNM staging system for patients in the training cohort. The risk of peritoneal metastasis was higher and survival after recurrence was significantly worse among patients calculated by the nomogram to be at high risk than those at low risk. The nomogram's predictive performance was confirmed in both the internal and external validation cohorts.

Conclusion: A novel nomogram is available as a web-based tool and accurately predicts long-term RFS for GC after radical resection. The tool can also be used to determine the benefit of adjuvant chemotherapy by comparing scores with and without this intervention.