Necessity of adjuvant concurrent chemo-radiotherapy in D2-resected LN-positive gastric cancer

NUSAP1 promotes gastric cancer radioresistance by inhibiting ubiquitination of ANXA2 and is suppressed by miR-129-5p

BACKGROUND

Radiotherapy is an important strategy for the treatment of advanced gastric cancer (GC), while the radioresistance limits its effectiveness. Nucleolar and spindle associated protein 1 (NUSAP1) was implicated in cancer progression and chemoresistance. However, the underlying mechanisms of NUSAP1 influencing GC radioresistance remain largely unknown.

METHODS

Meta-analysis was conducted to systematically evaluate the prognostic value of NUSAP1 in human cancers. Gene set enrichment analysis (GSEA) was conducted using The Cancer Genome Atlas (TCGA) and gene expression omnibus (GEO) datasets. MRNA and protein expressions were detected by qRT-PCR and western blot, respectively. The radiosensitivity of GC cells was observed by colony formation, flow cytometry, comet, immunofluorescence, and animal assays. Immunoprecipitation assay and mass spectrometry were utilized to identify protein associations. MiRNAs binding with NUSAP1 were determined by starbase prediction, luciferase reporter, and RNA immunoprecipitation (RIP) assays.

RESULTS

NUSAP1 high expression predicted worse overall survival (OS) and disease-free survival (DFS) with no statistical heterogeneity through the meta-analysis. Downregulation of NUSAP1 significantly increased GC radiosensitivity by inhibiting colony formation, DNA damage repair, and promoting apoptosis following irradiation. Additionally, NUSAP1 silencing combined with radiation resulted in a synergistic anti-tumor effect in xenograft mouse model. Mechanistically, NUSAP1 interacted with ANXA2, protecting it against protein degradation via impeding its ubiquitination process. NUSAP1 was confirmed as a target of miR-129-5p and negatively regulated by it.

CONCLUSION

Our results suggested that NUSAP1 enhanced the radioresistance of GC cells. NUSAP1 could be a promising target to increase GC radiosensitivity.

Effect of Chemoradiotherapy on the Survival of Resectable Gastric Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Adjuvant chemotherapy (CT) and chemoradiotherapy (CRT) after surgery are necessary to reduce the risk of metastasis and recurrence for resectable gastric cancer (GC) patients. Adjuvant CT and CRT have been proven to significantly improve the prognosis for GC patients, when compared with surgery only. However, it is still unclear whether radiotherapy offers additional survival benefits to advanced gastric cancer (AGC) patients.

METHODS

PubMed, Cochrane Library, and Embase databases were systematically searched for eligible studies that compared survival benefits between CRT and CT. The endpoints of this meta-analysis were measured as HR for OS or DFS and 95% CI using fixed- or random-effect models. Additionally, side effects, completed rate, and metastatic risk, were calculated as OR. Subgroup analyses according to clinicopathological factors were presented.

RESULTS

A total of 28 eligible studies involving 20,220 patients were included in our study. Of these, 17 studies evaluated the survival benefits of additional radiotherapy on overall survival (OS) of gastric cancer patients, ten reported the impact of CRT on disease-free survival (DFS), and 26 studies showed long-term survival rate. The pooled results were significant (HR for OS 0.84, 95% CI 0.71-0.99; HR for DFS 0.76, 95% CI 0.66-0.89). The subgroup analysis showed that adjuvant CRT increased OS for patients without preoperative treatment; showed similar nausea/vomiting, but an increased risk of neutropenia; reduced the risk of locoregional recurrence; failed to improve OS for lymph node (LN)-positive GC patients; and significantly improved prognosis for R1-treated patients. Of note, DFS was improved in all the subgroups via decreasing the locoregional recurrence.

CONCLUSION

Compared with CT, adjuvant CRT can improve survival for advanced gastric cancer patients, with similar nausea/vomiting, but increased risk of neutropenia. Patients without preoperative treatment or with positive surgical margins should be strongly recommended to undergo CRT. Treatment regimens should be carefully decided by doctors based on patients' tolerance, physical status, and reaction to treatment. Moreover, CRT improves the DFS for patients regardless of subgroups, because it significantly reduced the risk of locoregional recurrence.

Impact of Radiotherapy on Kidney Function among Patients Who Received Adjuvant Treatment for Gastric Cancer: Logistic and Linear Regression Analyses

Simple Summary

Purpose of the present study was to investigate the incidence of renal function impairment after adjuvant treatment for gastric cancer and the impact of radiotherapy on estimated glomerular filtration rate (eGFR) five years after gastric surgery. Of the 663 patients who were followed up for ≥5 years without disease recurrence and whose baseline kidney function was normal, only 2.0% of patients developed renal function impairment after adjuvant treatment for gastric cancer. While radiotherapy was negatively associated with the five-year eGFR in linear regression analysis, its impact was minimal if the kidneys were properly shielded. This study could serve as a partial basis for further research on radiation-related renal function impairment in patients who received radiotherapy for abdominal malignancy.

Abstract

We investigated the incidence of renal function impairment after adjuvant treatment for gastric cancer and analyzed the impact of radiotherapy on estimated glomerular filtration rate (eGFR) five years after gastric surgery. We reviewed the medical records of 1490 patients with stomach cancer who underwent curative surgery and adjuvant treatment for gastric cancer. Finally, we included 663 patients who were followed up for ≥5 years without disease recurrence and whose baseline eGFR was ≥60 mL/min/1.73 m². Logistic and linear regression analyses were performed to determine independent factors associated with the five-year eGFR. A total of 13 (2.0%) patients developed renal function impairment (five-year eGFR <60 mL/min/1.73 m²). In logistic regression analysis, the baseline eGFR was identified as a prognostic factor for renal function impairment (odds ratio (OR), 0.878; 95% confidence interval (CI), 0.831–0.927; p < 0.001), but radiotherapy was not (OR, 1.130; 95% CI, 0.366–3.491; p = 0.832). In linear regression analysis, age (B = −0.350, p < 0.001), baseline eGFR (B = 0.576, p < 0.001), cisplatin (B = −2.056, p = 0.010), and radiotherapy (B = −2.628, p < 0.001) were predictive variables for the five-year eGFR. Among patients who received adjuvant radiotherapy, age (B = −0.277, p < 0.001), hypertension (B = −4.986, p = 0.004), baseline eGFR (B = 0.665, p < 0.001), and volume of the kidneys receiving ≥20 Gy (B = −0.209, p = 0.012) were predictive variables for the five-year eGFR. Development of renal function impairment after adjuvant treatment for gastric cancer was rare among patients with normal baseline kidney function. While radiotherapy was negatively associated with the five-year eGFR, its impact would have been minimal if the kidneys were properly shielded. Further studies are needed to confirm the impact of radiotherapy in patients with poor kidney function.

A randomized phase III trial comparing adjuvant single-agent S1, S-1 with oxaliplatin, and postoperative chemoradiation with S-1 and oxaliplatin in patients with node-positive gastric cancer after D2 resection: the ARTIST 2 trial☆

BACKGROUND

Adjuvant chemotherapy and chemoradiotherapy are some of the standards of care for gastric cancer (GC). The Adjuvant chemoRadioTherapy In Stomach Tumors (ARTIST) 2 trial compares two adjuvant chemotherapy regimens and chemoradiotherapy in patients with D2-resected, stage II or III, node-positive GC.

PATIENTS AND METHODS

The ARTIST 2 compared, in a 1:1:1 ratio, three adjuvant regimens: oral S-1 (40-60 mg twice daily 4 weeks on/2 weeks off) for 1 year, S-1 (2 weeks on/1 week off) plus oxaliplatin 130 mg/m² every 3 weeks (SOX) for 6 months, and SOX plus chemoradiotherapy 45 Gy (SOXRT). Randomization was stratified according to surgery type (total or subtotal gastrectomy), pathologic stage (II or III), and Lauren histologic classification (diffuse or intestinal/mixed). The primary endpoint was disease-free survival (DFS) at 3 years; a reduction of 33% in the hazard ratio (HR) for DFS with SOX or SOXRT, when compared with S-1, was considered clinically meaningful. The trial is registered at clinicaltrials.gov (NCT0176146).

RESULTS

A total of 546 patients were recruited between February 2013 and January 2018 with 182, 181, and 183 patients in the S-1, SOX, and SOXRT arms, respectively. Median follow-up period was 47 months, with 178 DFS events observed. Estimated 3-year DFS rates were 64.8%, 74.3%, and 72.8% in the S-1, SOX, and SOXRT arms, respectively. HR for DFS in the control arm (S-1) was shorter than that in the SOX and SOXRT arms: S-1 versus SOX, 0.692 (P = 0.042) and S-1 versus SOXRT, 0.724 (P = 0.074). No difference in DFS was found between SOX and SOXRT (HR 0.971; P = 0.879). Adverse events were as anticipated in each arm, and were generally well-tolerated and manageable.

CONCLUSIONS

In patients with curatively D2-resected, stage II/III, node-positive GC, adjuvant SOX or SOXRT was effective in prolonging DFS, when compared with S-1 monotherapy. The addition of radiotherapy to SOX did not significantly reduce the rate of recurrence after D2 gastrectomy.

The prognostic value of the lymph node ratio for local advanced gastric cancer patients with intensity-modulated radiation therapy and concurrent chemotherapy after radical gastrectomy in China

BACKGROUND

Nearly 50% of new gastric cancer cases and gastric cancer-related deaths worldwide occur in China. No global consensus has been reached about the optimal management of locally advanced gastric cancer. Although the Guidelines for the Diagnosis and Treatment of Gastric Cancer from the National Health Commission of China, which has been updated three times since 2010, explicitly emphasize the necessity of adjuvant chemoradiation, few clinical institutions in China routinely adhere to the recommended radiotherapy guidelines. This study aimed to examine the efficacy, in terms of locoregional control and long-term survival, and the safety of adjuvant radiotherapy using intensity-modulated radiation therapy (IMRT) with concurrent and adjuvant fluoropyrimidine-based chemotherapy for gastric cancer.

METHODS

This was a retrospective evaluation of 156 patients with high-risk gastric cancer who underwent adjuvant chemoradiotherapy between September 2008 and May 2019. The prescribed planning target volume median dose was 45 Gy in 1.8 Gy daily fractions, and all patients received concurrent and adjuvant fluoropyrimidine-based chemotherapy. Locoregional control, distant metastasis, and overall survival rates were estimated. Clinicopathological characteristics and patterns of failure were retrospectively reviewed to identify factors associated with survival and recurrence.

RESULTS

The median follow-up duration was 56 months (range 3-130 months) for all patients. Of the patients, 11 (7.1%) were lost to follow-up, and 49 (31.4%) and 104 (66.7%) had stage II or III disease according to the eighth edition of the American Joint Committee on Cancer tumor-node-metastasis staging criteria. The frequencies of acute grade 3 or 4 gastrointestinal and hematological toxicity were 9.6% and 10.9%, respectively. In total, 152 patients (97.4%) completed the entire chemoradiation regimen. No toxicity-related deaths occurred. Nineteen patients (12.2%) had locoregional recurrence, 26 (16.7%) had distant metastases, and 12 (7.7%) had peritoneal metastasis. The overall survival (OS) rates were 83.5%, 65.0%, and 59.5%, while the disease-free survival rates were 75.1%, 61.0%, and 55.6% at 1, 3, and 5 years, respectively. In the multivariate analysis, age, pathological T stage and lymph node ratio (LNR) were found to be independent predictors of OS.

CONCLUSION

Postoperative concomitant IMRT and chemotherapy were well tolerated, with acceptable toxicities and encouraging locoregional tumor control and long-term survival. The LNR can be used as an important prognostic indicator for OS. Adjuvant chemoradiotherapy should be considered for all patients with a high risk of locoregional recurrence, especially in China.

Effect of baseline sarcopenia on adjuvant treatment for D2 dissected gastric cancer: Analysis of the ARTIST phase III trial

BACKGROUND AND PURPOSE

This study evaluated the clinical significance of preoperative sarcopenia according to adjuvant concurrent chemo-radiotherapy (XP-RT) or chemotherapy alone (XP) in the D2 dissected gastric cancer patient cohort of the ARTIST trial.

MATERIALS AND METHODS

Skeletal muscles at the L3 vertebra level from preoperative computed tomography images among the ARTIST trial participants were measured using validated in-house software. Skeletal muscle index (SMI) was defined as the measured skeletal muscle area divided by the square of the height, and sarcopenia was defined according to the Korean-specific cutoff, i.e. L3 SMI ≤ 49 cm²/m² for men and ≤31 cm²/m² for women.

RESULTS

Among the 440 patients in whom we were able to evaluate L3 SMI, 75 (17.0%) met the definition for preoperative sarcopenia. No differences in treatment-related toxicities or treatment compliance were observed according to the presence of preoperative sarcopenia in either treatment arm. In the subgroup of patients without preoperative sarcopenia, recurrence was significantly lower in the XP-RT arm than that in the XP arm (p = 0.02). Recurrence-free survival (RFS) was also significantly higher in the XP-RT arm (p = 0.02, hazard ratio 0.633, 95% confidence interval 0.433-0.926) in this subgroup. In the multivariate analysis, and after adjusting for significant prognostic factors, the superior outcome of XP-RT arm regarding RFS was maintained in the subgroup of the patients without preoperative sarcopenia.

CONCLUSIONS

Superior clinical outcomes of adjuvant XP-RT over XP were only observed in patients without preoperative sarcopenia.

Outcomes of Radiotherapy for Mesenchymal and Non-Mesenchymal Subtypes of Gastric Cancer

Background: The purpose of this study was to evaluate the clinical outcomes following postoperative chemotherapy (XP) versus chemoradiotherapy (XP-RT) according to mesenchymal subtype based on RNA sequencing in gastric cancer (GC) in a cohort of the Adjuvant chemoRadioTherapy In Stomach Tumor (ARTIST) trial. Methods: Of the 458 patients enrolled in the ARTIST trial, formalin-fixed, paraffin-embedded (FFPE) specimens were available from 106 (23.1%) patients for RNA analysis. The mesenchymal subtype was classified according to a previously reported 71-gene MSS/EMT signature using the NanoString assay. Results: Of the 106 patients analyzed (50 in XP arm, 56 in XP-RT arm), 36 (34.0%) patients were categorized as mesenchymal subtype by NanoString assay. Recurrence-free survival (RFS, p = 0.009, hazard ratio (HR) = 2.11, 95% confidence interval (CI): 1.21-3.70) and overall survival (OS, p = 0.003, HR = 2.28, 95% CI: 1.31-3.96) were significantly lower in the mesenchymal subtype than in the non-mesenchymal subtype. In terms of post-operative radiotherapy (RT), mesenchymal subtype was not an independent variable to predict RFS or OS regardless to the assigned arm (XP with or without RT) in this patient cohort. However, there was a trend in the adjuvant XP arm, which showed higher OS than the XP-RT arm for the mesenchymal subtype and lower OS than the XP-RT arm for the non-mesenchymal subtype. Conclusions: We could not determine any significant differences between the mesenchymal and non-mesenchymal subtypes with respect to the effects of adjuvant XP with or without RT in gastric cancer following curative surgery.

The disease burden of bronchiectasis in comparison with chronic obstructive pulmonary disease: a national database study in Korea

Background

The prevalence and disease burden of bronchiectasis in comparison to those of chronic obstructive pulmonary disease (COPD) have not been well elucidated using a nationally representative database.

Methods

We compared respiratory symptoms, physical activity, quality of life, and socioeconomic status in subjects with bronchiectasis versus those with COPD or control subjects participating in the Korea National Health and Nutrition Examination Survey 2007-2009. Participants were classified as physician-diagnosed bronchiectasis, COPD, and control (those without COPD or bronchiectasis).

Results

The prevalence of bronchiectasis in subjects aged 40 years or older was 0.8%. Compared to COPD subjects, bronchiectasis subjects were more likely to be younger (mean 59.0 years, P<0.001), female (47.6%, P<0.001), and never-smoker (50.1%, P<0.001) and have had history of pulmonary tuberculosis (40.5%, P<0.001) and osteoporosis (19.1%, P=0.025). However, as in COPD subjects, bronchiectasis subjects had low family income (P<0.001) and the proportion of subjects working as manager/professional/office workers (6.4%, P<0.001) was smaller than that of control subjects. After adjusting for covariables, compared to control, bronchiectasis subjects but not COPD subjects were more likely to have respiratory symptoms [adjusted odds ratio (OR) =7.96, 95% confidence interval (CI): 2.10-30.12], limitation in physical activity (adjusted OR =9.43, 95% CI: 1.06-83.79), and low family income (adjusted OR =3.61, 95% CI: 1.75-7.47).

Conclusions

The prevalence of bronchiectasis in subjects at least 40 years of age was 0.8% in Korea. Despite large number of young patients and low prevalence of smoking history, respiratory symptoms, limitation in physical activity, and low family income were significant burden in bronchiectasis subjects.

Multimodality management of locally advanced gastric cancer-the timing and extent of surgery

The optimal treatment for patients with locally advanced gastric adenocarcinoma is multimodal. Surgery is the cornerstone of therapeutic strategies with curative intent. The addition of chemotherapy or chemoradiation decreases rate of recurrence and prolongs survival. Guidelines differ between countries and there is no universal standard of care. Modern studies of patients with locally advanced gastric cancer showed that adjuvant chemotherapy improves survival over surgery alone in Asia. These studies could not be replicated in Europe. Peri-operative chemotherapy strategies, conversely, have been effective in Europe for improving overall and disease free survival. Adjuvant chemoradiation has also demonstrated improved survival when compared to surgery alone, but studies comparing chemotherapy with chemoradiation have not shown significant difference. Trials are ongoing to examine the role of chemoradiation in a neoadjuvant fashion. A D2 extent of lymphadenectomy improves cancer related survival for those who do not undergo distal pancreatectomy/splenectomy. Survival is also associated not only with the extent but also the number of lymph nodes examined. There are ongoing trials related to immunotherapy and targeted therapies, which may also impact or change the treatment paradigm for locally advanced gastric cancer.

Adjuvant Radiochemotherapy versus Chemotherapy Alone for Gastric Cancer: Implications for Target Definition

The INT0116 trial was a milestone study and laid the foundation for the adjuvant radiotherapy (RT) associated to concurrent chemotherapy (CT) for the treatment of gastric cancer (GC) after gastrectomy. However, it is still controversial whether adding RT to CT could further benefit D2-dissected GC patients. The ARTIST trial indicated that the addition of RT to CT did not have a positive impact on disease-free survival (DFS). Nevertheless, in a subgroup of 396 patients with positive pathological lymph nodes, combined treatment with RT was superior to CT alone. A similar randomized Chinese trial confirmed the superiority of adding RT to CT in terms of DFS for patients with D2 lymphadenectomy. However, several previous randomized studies provided inconsistent results with the benefits of combined treatment of RT and CT. The inconsistent results of several studies may be due to the differences between tumor epidemiology, treatment policies, and treatment outcomes. During the past decade, major progress in accurate target delineation utilizing RT technology has been observed. However, even though the use of adjuvant RT doubled after the INT-0116 trial results became public, the fraction of patients receiving adjuvant RT was still low according to the SEER database. The low rate of adjuvant RT can partially be explained by concern over toxicity while undergoing RT. Several studies have also defined the specific location of locoregional recurrence for postoperative RT in GC, but these studies are still limited. A number of retrospective studies demonstrated that the most prevalent nodal recurrence was outside the D2 dissection field. In order to overcome the restricted nature of a retrospective study and provide more individual radiation field determination, additional large-scale prospective multicenter studies are required to evaluate the optimal RT target.

Comparison of the 7th and the 8th AJCC Staging System for Non-metastatic D2-Resected Lymph Node-Positive Gastric Cancer Treated with Different Adjuvant Protocols

PURPOSE

The purpose of this study was to compare prognostic differentiation performances of the 7th and the 8th edition of American Joint Commission on Cancer (AJCC) staging system for gastric cancer (GC) patients.

Materials and Methods

A total of 1,633 GC patients who underwent curative D2 resection followed by adjuvant chemotherapy alone (CA) or concurrent chemo-radiotherapy (CCRT) from 2004 to 2013 were included. Concordance index (c-index) was applied to compare the discriminatory ability.

RESULTS

In the 8th edition, migration of stage was detected in 248 patients (15.2%). Among them, 121 patients were up-staged while 127 patients were down-staged. Overall, there was no statistically significant difference in the discriminatory ability between the 7th and 8th editions. The new edition of staging system, however, showed a trend of better prognostic performance not only in recurrence-free survival (c-index=0.734; 95% confidence interval [CI], 0.706 to 0.762 in the 7th edition vs. c-index=0.740; 95% CI, 0.712 to 0.768 in the 8th edition; p=0.14), but also in overall survival (c-index=0.717; 95% CI, 0.688 to 0.745 in the 7th edition vs. c-index=0.722; 95% CI, 0.694 to 0.751 in the 8th edition; p=0.19), especially in stage III. This finding was repeated in the subgroup analysis regardless of adjuvant CA or CCRT.

CONCLUSION

Generally, the 8th edition of AJCC staging system had failed to show a superior discriminatory ability for curatively D2 resected GC patients than the 7th edition, although there was a trend of better prognostic performance of the new edition, regardless of adjuvant treatment method.