The Efficacy and Safety of (Neo)Adjuvant Therapy for Gastric Cancer: A Network Meta-analysis

Targeting gut-microbiota for gastric cancer treatment: a systematic review

Background

Preclinical research has identified the mechanisms via which bacteria influence cancer treatment outcomes. Clinical studies have demonstrated the potential to modify the microbiome in cancer treatment. Herein, we systematically analyze how gut microorganisms interact with chemotherapy and immune checkpoint inhibitors, specifically focusing on how gut bacteria affect the pharmacokinetics and pharmacodynamics of cancer treatment.

Method

This study searched Web of Science, Scopus, and PubMed until August 2023. Studies were screened by their title and abstract using the Rayyan intelligent tool for systematic reviews. Quality assessment of studies was done using the JBI critical appraisal tool.

Result

Alterations in the gut microbiome are associated with gastric cancer and precancerous lesions. These alterations include reduced microbial alpha diversity, increased bacterial overgrowth, and decreased richness and evenness of gastric bacteria. Helicobacter pylori infection is associated with reduced richness and evenness of gastric bacteria, while eradication only partially restores microbial diversity. The gut microbiome also affects the response to cancer treatments, with higher abundances of Lactobacillus associated with better response to anti-PD-1/PD-L1 immunotherapy and more prolonged progression-free survival. Antibiotic-induced gut microbiota dysbiosis can reduce the anti-tumor efficacy of 5-Fluorouracil treatment, while probiotics did not significantly enhance it. A probiotic combination containing Bifidobacterium infantis, Lactobacillus acidophilus, Enterococcus faecalis, and Bacillus cereus can reduce inflammation, enhance immunity, and restore a healthier gut microbial balance in gastric cancer patients after partial gastrectomy.

Conclusion

Probiotics and targeted interventions to modulate the gut microbiome have shown promising results in cancer prevention and treatment efficacy.Systematic review registration: https://osf.io/6vcjp.

Neoadjuvant Chemotherapy Improves Oncological Outcomes and Long-Term Survival Among Elderly Patients with Locally Advanced Gastric Cancer: A Propensity Score Matched Analysis

INTRODUCTION

In the USA, approximately half of newly diagnosed patients with GC are 75 years or older. The objective of the current population-based study was to investigate the impact of neoadjuvant chemotherapy (NAC) on the outcomes of elderly patients with locally advanced GC.

PATIENTS AND METHODS

Patients aged > 75 years were identified from the National Cancer Database (NCDB). The primary outcome of the study was overall survival (OS). Secondary outcomes included lymph node (LN) harvest, surgical margin status, and 30-day mortality. To minimize the effect of selection bias on the assessed outcome between the two study groups (NAC versus no NAC), propensity score matching (PSM) was performed.

RESULTS

After PSM, a total of 1958 patients were included in both groups. NAC utilization increased from 2013 to 2019 (21% versus 42.7%, ptrend < 0.001). On pathologic analysis, patients who received NAC were more likely to have ≥ 16 LNs evaluated (NAC 60.1% versus no NAC 55.5%, p = 0.044) and negative resection margins (NAC 88.6% versus no NAC 83%, p = 0.001). Patients who received NAC were also less likely to experience 30-day mortality following resection (NAC 4.1% versus no NAC 7.1%). Receipt of NAC was associated with improved 1-year (73.9% versus 68.3%), 3-year (48.2% versus 43.5%), and 5-year OS (36.9% versus 30.5%) compared with patients who underwent upfront surgery (p = 0.01).

CONCLUSIONS

Receipt of NAC was associated with improved oncological outcomes among elderly patients undergoing resection for locally advanced GC.

Outcome evaluation of ECF, DCF, FOLFOX, and FLOT chemotherapy regimens as perioperative treatment in elderly patients with resectable gastric cancer; A retrospective comparative study

Background

The incidence of gastric cancer is known to be high in the elderly population. Identification of the best perioperative chemotherapy regimen is challenging in patients with resectable gastric cancer. In this study, we aimed to evaluate and compare the outcomes and safety of epirubicin, cisplatin, and 5-fluorouracil (ECF), docetaxel, cisplatin, and 5-fluorouracil (DCF), oxaliplatin plus 5-Fluorouracil and leucovorin (FOLFOX), and docetaxel, oxaliplatin, leucovorin, and 5-Fluorouracil (FLOT) chemotherapy regimens to identify the most appropriate treatment option for elderly patients with resectable gastric cancer.

Materials and Methods

In this retrospective observational cohort study, data were extracted from the medical archives (2017-2021) of Omid Hospital, which is a tertiary oncology referral hospital in Isfahan, Iran. Patients with resectable gastric cancer, above 60 years of age, who were perioperatively treated with one of the mentioned chemotherapy regimens and met the inclusion criteria, were enrolled in this study. The survival parameters and safety profile of the regimens were evaluated and compared in this population.

Results

A total of 63 patients were included in this study. The median follow-up period of the patients was 24 months (range, 7-51 months). The results of survival analysis revealed that the FLOT and DCF regimens were significantly associated with longer overall survival (OS) as compared to the other regimens (median OS: 38 and 33 months, respectively). Based on the results, the progression-free survival was longer in the DCF regimen (median: 24 months) compared to the other regimens; however, only the difference with the ECF regimen (median: 14 months) was significant. The results of Cox regression analysis showed no significant difference in the overall adjusted hazard ratio of mortality between the FLOT and DCF regimens (P = 0.802). The DCF and FOLFOX regimens accounted for the highest and lowest rates of adverse events (e.g., neutropenia and mucositis), respectively.

Conclusion

Considering the higher rate of adverse events in the DCF group, besides the significant improvement of OS and the acceptable adverse event profile of patients treated with the FLOT regimen, it can be proposed that this chemotherapy regimen is the most appropriate treatment option for elderly patients with resectable gastric cancer.

Neoadjuvant chemotherapy outcome with taxane-based versus non-taxane protocols in gastric cancer

BACKGROUND

Gastric cancer is the fifth most common cancer worldwide. One of the chemotherapy agents, taxanes is important in increasing patients' survival. The purpose of this study is to assess the efficacy of taxane-based drugs versus non-taxanes in neoadjuvant chemotherapy in non-metastatic gastric adenocarcinoma (GA) in Iranian patients.

MATERIALS AND METHODS

In a historical cohort method, 65 patients between 18 and 75 years old who suffered from non-metastatic GA were included. Nineteen and 21 and 25 patients, had undergone DCF (docetaxel, cisplatin, 5fluorouracil) and FLOT (5fluorouracil, leucovorin, oxaliplatin, docetaxel) and FOLFOX6 (oxaliplatin, leucovorin, 5fluorouracil) regimens, respectively, between 2018 and 2021. Survival criteria consisting of progression-free survival (PFS), overall survival (OS), progression rate, and mortality rate were evaluated using the Kaplan-Meier method, in a three-year follow-up period.

RESULTS

The majority of patients were male (72.3%), with a median age of 65 years. Most of the patients had lesions with tumor, node, metastasis (TNM) stage IIIb (27.7%) and poor differentiated pathological grade (49.2%). OS time had a significant correlation with the low TNM stage (P = 0.01), well-differentiated pathological grade (P = 0.005), and FLOT vs. FOLFOX protocol (20.3 vs. 12.2 months, respectively. P =0.04). FLOT regimen had significantly better OS survival vs. DCF regimen (20.3 vs. 15.4 months, respectively, P = 0.03). No significant correlation was observed between survival criteria and other factors like gender, age, past medical history, Karnofsky scale, and tumor location in the stomach. The taxane-based arm (sum of DSF and FLOT) had no superiority over the non-taxane arm in survival criteria.

CONCLUSION

FLOT protocol, as a taxane-based regimen had better survival compared to FOLFOX protocol in neoadjuvant chemotherapy in gastric non-metastatic adenocarcinoma.

Novel Drug Delivery Systems as an Emerging Platform for Stomach Cancer Therapy

Cancer has long been regarded as one of the world's most fatal diseases, claiming the lives of countless individuals each year. Stomach cancer is a prevalent cancer that has recently reached a high number of fatalities. It continues to be one of the most fatal cancer forms, requiring immediate attention due to its low overall survival rate. Early detection and appropriate therapy are, perhaps, of the most difficult challenges in the fight against stomach cancer. We focused on positive tactics for stomach cancer therapy in this paper, and we went over the most current advancements and progressions of nanotechnology-based systems in modern drug delivery and therapies in great detail. Recent therapeutic tactics used in nanotechnology-based delivery of drugs aim to improve cellular absorption, pharmacokinetics, and anticancer drug efficacy, allowing for more precise targeting of specific agents for effective stomach cancer treatment. The current review also provides information on ongoing research aimed at improving the curative effectiveness of existing anti-stomach cancer medicines. All these crucial matters discussed under one overarching title will be extremely useful to readers who are working on developing multi-functional nano-constructs for improved diagnosis and treatment of stomach cancer.

Triplet Chemotherapy with Cisplatin versus Oxaliplatin in the CRITICS Trial: Treatment Compliance, Toxicity, Outcomes and Quality of Life in Patients with Resectable Gastric Cancer

(1) Background: Perioperative chemotherapy is the current standard treatment for patients with resectable gastric cancer. Based on studies in patients with metastatic gastric cancer, oxaliplatin has replaced cisplatin in the curative setting as well. However, evidence to prefer oxaliplatin over cisplatin in the curative setting is limited. (2) Methods: We compared patient-related and tumor-related outcomes for cisplatin versus oxaliplatin in patients with resectable gastric cancer treated with perioperative chemotherapy in the CRITICS trial. (3) Results: Preoperatively, 632 patients received cisplatin and 149 patients received oxaliplatin. Preoperative severe toxicity was encountered in 422 (67%) patients who received cisplatin versus 89 (60%) patients who received oxaliplatin (p = 0.105). Severe neuropathy was observed in 5 (1%) versus 6 (4%; p = 0.009) patients, respectively. Postoperative severe toxicity occurred in 109 (60%) versus 26 (51%) (p = 0.266) patients; severe neuropathy in 2 (1%) versus 2 (4%; p = 0.209) for patients who received cisplatin or oxaliplatin, respectively. Diarrhea impacted the quality of life more frequently in patients who received oxaliplatin compared to cisplatin. Complete or near-complete pathological response was achieved in 94 (21%) versus 16 (15%; p = 0.126) patients who received cisplatin or oxaliplatin, respectively. Overall survival was not significantly different in both groups (p = 0.300). (4) Conclusions: Both cisplatin and oxaliplatin are legitimate options as part of systemic treatment in patients with resectable gastric cancer.

Impact of neoadjuvant therapy followed by laparoscopic radical gastrectomy with D2 lymph node dissection in Western population: A multi-institutional propensity score-matched study

BACKGROUND AND OBJECTIVES

In the setting of a minimally invasive approach, we aimed to compare short and long-term postoperative outcomes of patients treated with neoadjuvant therapy (NAT) + surgery or upfront surgery in Western population.

METHODS

All consecutive patients from six Italian and one Serbian center with locally advanced gastric cancer who had undergone laparoscopic gastrectomy with D2 lymph node dissection were selected between 2005 and 2019. After propensity score-matching, postoperative morbidity and oncologic outcomes were investigated.

RESULTS

After matching, 97 patients were allocated in each cohort with a mean age of 69.4 and 70.5 years. The two groups showed no difference in operative details except for a higher conversion rate in the NAT group (p = 0.038). The overall postoperative complications rate significantly differed between NAT + surgery (38.1%) and US (21.6%) group (p = 0.019). NAT was found to be related to a higher risk of postoperative morbidity in patients older than 60 years old (p = 0.013) but not in patients younger (p = 0.620). Conversely, no difference in overall survival (p = 0.41) and disease-free-survival (p = 0.34) was found between groups.

CONCLUSIONS

NAT appears to be related to a higher postoperative complication rate and equivalent oncological outcomes when compared with surgery alone. However, poor short-term outcomes are more evident in patients over 60 years old receiving NAT.

Differentiated/undifferentiated mixed type is a prognostic factor for T2/T3 gastric cancer patients

OBJECTIVES

This work aimed to find the association of mixed-type histology and prognosis of T2/T3 GC patients.

METHODS

Eligible T2/T3 gastric cancer patients at our institution were identified. The histological types and risk factors affecting OS were examined. Survival differences were assessed by log-rank tests and Kaplan-Meier curves.

RESULTS

The study identified 972 T2/T3 gastric cancer patients, including 283 differentiated-type patients, 544 undifferentiated-type patients and 145 mixed type. Mixed-type histology was associated with shorter 5-year OS (DT vs UDT vs MT:57.5% vs 44.9% vs 39.6%, P = 0.002). MT histology can be predictive for prognosis of T2/T3 GC patients (HR for OS: 1.386, 95% CI: 1.028-1.868, P = 0.032), and its malignant potential is not inferior to UDT. In the subgroup analysis, MT can potentially be independent risk factor for non-distal GC patients (P = 0.010).

CONCLUSION

This study reported that mixed histology could be regarded as a potential prognostic factor for T2/T3 gastric cancer patients, especially for those with non-distal cancer. MT patients have higher incidence of metastasis and recurrence and had poorer prognosis than those with pure histological type. It is necessary for MT patients to have preoperative pathological examination for accurate histologic classification, so as to make the comprehensive treatment strategies..

Informing Patients With Esophagogastric Cancer About Treatment Outcomes by Using a Web-Based Tool and Training: Development and Evaluation Study

Background

Due to the increasing use of shared decision-making, patients with esophagogastric cancer play an increasingly important role in the decision-making process. To be able to make well-informed decisions, patients need to be adequately informed about treatment options and their outcomes, namely survival, side effects or complications, and health-related quality of life. Web-based tools and training programs can aid physicians in this complex task. However, to date, none of these instruments are available for use in informing patients with esophagogastric cancer about treatment outcomes.

Objective

This study aims to develop and evaluate the feasibility of using a web-based prediction tool and supporting communication skills training to improve how physicians inform patients with esophagogastric cancer about treatment outcomes. By improving the provision of treatment outcome information, we aim to stimulate the use of information that is evidence-based, precise, and personalized to patient and tumor characteristics and is communicated in a way that is tailored to individual information needs.

Methods

We designed a web-based, physician-assisted prediction tool—Source—to be used during consultations by using an iterative, user-centered approach. The accompanying communication skills training was developed based on specific learning objectives, literature, and expert opinions. The Source tool was tested in several rounds—a face-to-face focus group with 6 patients and survivors, semistructured interviews with 5 patients, think-aloud sessions with 3 medical oncologists, and interviews with 6 field experts. In a final pilot study, the Source tool and training were tested as a combined intervention by 5 medical oncology fellows and 3 esophagogastric outpatients.

Results

The Source tool contains personalized prediction models and data from meta-analyses regarding survival, treatment side effects and complications, and health-related quality of life. The treatment outcomes were visualized in a patient-friendly manner by using pictographs and bar and line graphs. The communication skills training consisted of blended learning for clinicians comprising e-learning and 2 face-to-face sessions. Adjustments to improve both training and the Source tool were made according to feedback from all testing rounds.

Conclusions

The Source tool and training could play an important role in informing patients with esophagogastric cancer about treatment outcomes in an evidence-based, precise, personalized, and tailored manner. The preliminary evaluation results are promising and provide valuable input for the further development and testing of both elements. However, the remaining uncertainty about treatment outcomes in patients and established habits in doctors, in addition to the varying trust in the prediction models, might influence the effectiveness of the tool and training in daily practice. We are currently conducting a multicenter clinical trial to investigate the impact that the combined tool and training have on the provision of information in the context of treatment decision-making.

Perioperative chemotherapy versus adjuvant chemotherapy strategies in resectable gastric and gastroesophageal cancer: A Markov decision analysis

BACKGROUND

Perioperative chemotherapy has been shown to improve overall survival (OS) for operable gastric and gastroesophageal cancer. However, optimal sequence of surgery and chemotherapy has not been clearly identified. Markov models are useful for analyzing the outcomes of different treatment strategies in the absence of adequately powered randomized clinical trials. In this study, we use Markov decision analysis models to compare median OS (mOS), quality-adjusted mOS, life expectancy (LE), and quality-adjusted life expectancy (QALE) of perioperative chemotherapy with adjuvant chemotherapy strategies in resectable gastric and gastroesophageal cancer patients.

METHODS

Markov models are constructed to compare two strategies: adjuvant chemotherapy after surgery and preoperative chemotherapy followed by cancer resection and postoperative chemotherapy. LE and QALE are calculated analytically, and mOS are obtained by simulation. Parameters used in the models are computed from prospective clinical trial data published in PUBMED from January 2000 to July 2020.

RESULTS

Total of 8088 patients from 25 prospective studies were included in this analysis. Regardless of R0 resection ratio, the analyses of the models show a higher mOS for patients in the perioperative therapy arm compared to adjuvant chemotherapy. For R0 resected patients, the perioperative therapy arm provided an additional 11.0 mOS months (61.3 months vs. 50.3 months). For R1 resected patients, the perioperative therapy arm had mOS of 17.0 months vs. 10.7 months in adjuvant therapy.

CONCLUSIONS

The Markov models indicate that perioperative chemotherapy improves mOS, quality-adjusted mOS, LE, and QALE for resectable gastric and gastroesophageal cancer patients compared to adjuvant chemotherapy strategies.

Prediction of Sensitivity and Efficacy of Clinical Chemotherapy Using Larval Zebrafish Patient-Derived Xenografts of Gastric Cancer

Background

Perioperative chemotherapy has been accepted as one of the most common approaches for locally advanced gastric cancer. However, the efficacy of chemotherapy varies among patients, and there is no effective method to predict the chemotherapy efficacy currently. We previously established the first larval zebrafish patient-derived xenografts (zPDXs) of gastric cancer as a platform for the translational research and personalized treatment. The objective of this study was to investigate the feasibility of screening individualized chemotherapeutics using the zPDXs.

Methods

We further optimized this zPDXs platform including administration route, drug dosing, and rhythm to develop a stable and reliable protocol for chemotherapeutics screening. Using the novel platform, we investigated the chemosensitivity of 5-fluorouracil, cisplatin, docetaxel, and doxorubicin for gastric cancer patients.

Results

We showed that the engrafted zebrafish retained the original prominent cell components of the corresponding human tumor tissues, and we successfully obtained the results of chemosensitivity of 5-fluorouracil, cisplatin, docetaxel, and doxorubicin for 28 patients with locally advanced gastric cancer. These patients underwent radical gastrectomy for curative intent and 27 cases received postoperative adjuvant chemotherapy. We revealed that the chemosensitivity obtained from zPDXs was consistent with the clinical responses in these patients (P = 0.029). More importantly, the responder drug(s) from zPDXs used or not was the only risk factor for early-stage recurrence in these 27 patients (P = 0.003).

Conclusion

Our study with the largest sample size so far suggests that larval zPDXs help to predict the chemotherapeutics response and to achieve precise chemotherapy for gastric cancer.

Beyond the Guidelines: The Grey Zones of the Management of Gastric Cancer. Consensus Statements from the Gastric Cancer Italian Network (GAIN)

BACKGROUND

Management of gastric and gastroesophageal junction (GEJ) adenocarcinoma remains challenging, because of the heterogeneity in tumor biology within the upper gastrointestinal tract. Daily clinical practice is full of grey areas regarding the complexity of diagnostic, staging, and therapeutic procedures. The aim of this paper is to provide a guide for clinicians facing challenging situations in routine practice, taking a multidisciplinary consensus approach based on available literature.

METHODS

The GAIN (GAstric cancer Italian Network) group was established with the aims of reviewing literature evidence, discussing key issues in prevention, diagnosis, and management of gastric and GEJ adenocarcinoma, and offering a summary of statements. A Delphi consensus method was used to obtain opinions from the expert panel of specialists.

RESULTS

Forty-nine clinical questions were identified in six areas of interest: role of multidisciplinary team; risk factors; diagnosis; management of early gastric cancer and multimodal approach to localized gastric cancer; treatment of elderly patients with locally advanced resectable disease; and treatment of locally advanced and metastatic cancer.

CONCLUSIONS

The statements presented may guide clinicians in practical management of this disease.

Real-World Long-Term Outcomes with Perioperative EOX in D2 Gastrectomy: a Meaningful Look While We Switch to FLOT-4

INTRODUCTION

Data regarding long-term survival and prognosis in loco-regionally advanced, non-metastatic gastric cancers (GC) using perioperative chemotherapy and D2 lymphadenectomies from India is scarce.

MATERIALS AND METHODS

The study is a retrospective evaluation of locally advanced gastric cancers who received epirubicin-oxaliplatin-capecitabine (EOX) as perioperative therapy from May 2013 to December 2015 at Tata Memorial Hospital, Mumbai. The report concentrates on long-term survival outcomes and prognostic factors. Event-free survival (EFS) and overall survival (OS) were calculated using Kaplan-Meier method.

RESULTS

Two hundred and sixty-eight patients were started on EOX regimen, of which 200 patients (74.6%) underwent definitive resection with D2 lymphadenectomy. With a median follow-up of 52.7 months, the estimated median 3-year and 5-year EFS were 38.5% and 36.3% respectively. The estimated median 3-year and 5-year OS were 41.7% and 37.6% respectively. Patients younger than age 40 years [HR 1.55 (1.034-2.321); p = 0.034] and with poorly differentiated histology [HR 0.65 (0.446-0.944); p = 0.024] had inferior OS compared to their counterparts.

CONCLUSIONS

Long-term OS in Indian patients in non-metastatic GC with EOX chemotherapy and D2 lymphadenectomy is similar to previously published Western data. Younger Indian patients fare worse than their older counterparts and this needs further evaluation.

Short-term outcomes of gastrectomy after neoadjuvant chemotherapy for clinical stage III gastric cancer: propensity score-matched analysis of a multi-institutional database

PURPOSE

Preoperative chemotherapy for gastric cancer may be effective from the standpoint of compliance, although there is insufficient evidence of its efficacy. We analyzed a multicenter database to clarify whether preoperative chemotherapy influenced the short-term outcomes of gastrectomy.

METHODS

We analyzed, retrospectively, 3571 patients who underwent gastrectomy between January, 2010 and December, 2014. Patients with clinical stage-III gastric adenocarcinoma were divided into a neoadjuvant chemotherapy (NAC) group and a non-NAC group. We performed propensity-matched comparative analysis to stratify the groups according to age, sex, tumor region, tumor type, preoperative stage, procedure, lymph node dissection, and tumor differentiation. Preoperative blood data, surgical findings, and postoperative complications were analyzed.

RESULTS

Analysis of the matched NAC (n = 64) and non-NAC (n = 128) groups revealed that the preoperative values of neutrophils, platelets, and Hb were significantly lower in the NAC group. Blood loss during surgery was significantly higher, surgical times were longer, and the rate of repeat surgery was significantly lower in the NAC group; however, the rates of rehospitalization did not differ between the groups and mortality was 0% in both groups. Postoperative complications were not significantly different between the groups.

CONCLUSIONS

NAC did not increase the complication rate of gastrectomy for gastric cancer.

Impact of Neoadjuvant Therapy on Minimally Invasive Surgical Outcomes in Advanced Gastric Cancer: An International Propensity Score-Matched Study

BACKGROUND

No international consensus on the treatment of advanced gastric cancer (AGC) exists. In the absence of well-designed, comparative studies between neoadjuvant versus adjuvant strategies, concerns about increased risk of postoperative complications remain barriers to neoadjuvant chemotherapy (NAC) for AGC. We evaluated surgical outcomes of AGC patients who received minimally invasive radical gastrectomy with D2 lymphadenectomy after NAC.

METHODS

We collected data from two high-volume gastric cancer programs in the United States and China between January 2015 and December 2019 with the last follow-up in February 2020. AGC patients undergoing minimally invasive radical surgery were included. After propensity score-matching, surgical outcomes were analyzed. Risk-factor of complications was analyzed in the whole cohort.

RESULTS

After 1:1 propensity score-matching, 97 patients were included in each cohort. NAC + surgery cohort was younger (58.2 ± 10.3 vs. 61.3 ± 9.6, P = 0.036) with lower preoperative WBC count (5.7 ± 2.8 vs. 6.9 ± 2.1 × 10⁹/ml) than the surgery upfront cohort. NAC was not a risk-factor for postoperative complications (odds ratio [OR], 0.859; 95% confidence interval [CI], 0.46-1.60; P = 0.633). Overall risk-factors of postoperative complications included age ≥ 60 years (OR, 21.338; 95% CI, 5.00-91.05; P < 0.001), tumor size ≥ 5 cm (OR, 1.24; 95% CI, 1.08-1.83; P < 0.001), operation time ≥ 240 min (OR, 5.53; 95% CI, 1.26-24.26; P = 0.012), and ASA classification ≥ II (OR, 13.14; 95% CI, 4.12-24.73; P < 0.001).

CONCLUSIONS

NAC before minimally invasive radical gastrectomy with D2 lymphadenectomy does not increase postoperative complications, and these findings support broader application of NAC and MIS for AGC. Additional studies are required to determine the effect of NAC on long-term survival.

What is Elective Oncologic Surgery in the Time of COVID-19? A Literature Review of the Impact of Surgical Delays on Outcomes in Patients with Cancer

Background

The impact of the COVID-19 pandemic has spread beyond those infected with SARS-CoV-2. Its widespread consequences have affected cancer patients whose surgeries may be delayed in order to minimize exposure and conserve resources.

Methods

Experts in each surgical oncology subspecialty were selected to perform a review of the relevant literature. Articles were obtained through PubMed searches in each cancer subtype using the following terms: delay to surgery, time to surgery, outcomes, and survival.

Results

Delays in surgery > 4 weeks in breast cancer, ductal carcinoma in situ, T1 pancreatic cancer, ovarian cancer, and pediatric osteosarcoma, negatively impacted survival. Studies on hepatocellular cancer, colon cancer, and melanoma (Stage I) demonstrated reduced survival with delays > 3 months.

Conclusion

Studies have shown that short-term surgical delays can result in negative impacts on patient outcomes in multiple cancer types as well as in situ carcinoma. Conversely, other cancers such as gastric cancer, advanced melanoma and pancreatic cancer, well-differentiated thyroid cancer, and several genitourinary cancers demonstrated no significant outcome differences with surgical delays.

The role of bursectomy in the surgical management of gastric cancer: a meta-analysis and systematic review

In order to delineate the exact role of bursectomy (BS) in gastric cancer surgery, we designed and conducted the present meta-analysis. This meta-analysis adhered to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. A systematic literature review of the electronic databases (Medline, Scopus, Web of Science) was performed. Trial sequential analysis (TSA) was introduced for the validation of the pooled analyses. The level of evidence was attributed based on the GRADE approach. Overall, nine studies and 3599 patients were included in our meta-analysis. BS did not lead to an increase in the overall morbidity rate (OR 1.17, 95% CI 0.97-1.42, p = 0.09). Equivalence was, also, identified in all specific postoperative complications. Similarly, mortality rates were comparable (p = 0.69). Moreover, BS was related to a significantly higher operative time (p < 0.001) and perioperative blood loss (p = 0.002). Finally, resection of the omental bursa was not associated with improved R0 excision rates (p = 0.92), lymph node harvest (p = 0.1) or survival outcomes (OS p = 0.15 and DFS p = 0.97). BS displayed a suboptimal perioperative performance without any significant oncological efficacy. Due to certain limitations and the low level of evidence, further high-quality RCTs are required.

Radiotherapy benefited the survival of patients with intestinal-type gastric adenocarcinoma: a SEER population-based study

BACKGROUND

Currently, the role of adjuvant radiotherapy (RT) in the treatment of patients with intestinal-type gastric adenocarcinoma (IGA) has not been well established. This study aimed to elucidate the survival impact of RT on such patients.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was utilized to select eligible patients. The recruited patients were dichotomized into those not received RT versus those received RT. The 1:1 propensity score matching (PSM) analysis was conducted to balance the confounding factors between the two comparison groups. The categorical variables were assessed by Chi-square test. Cancer-specific survival (CSS) and overall survival (OS) of the patients were compared by Kaplan-Meier (KM) methods. Cox proportional hazard models were used to identify prognostic factors associated with CSS.

RESULTS

A total of 3572 eligible patients were enrolled for our analysis, of which, 2896(81.1%) patients did not receive RT and 676(18.9%) patients received RT. Before PSM, except race and tumor size, significant differences in patients' baseline characteristics were observed in no RT versus RT group. The KM plots before PSM indicated that RT exerted significant survival benefits for the recruited patients (p < 0.001). After PSM, most confounders were well balanced between the two comparison groups. The KM plots showed significantly superior CSS and OS in the RT group (p < 0.05). Grade IV, stage II-IV, and N3 were identified as independent risk factors, while LN examined > 15 and RT were independent protective factors for favorable prognosis. Subgroup survival analysis revealed that RT brought a significant CSS advantage for the stage IV patients.

CONCLUSION

Based on PSM analysis of the cohort from SEER database, RT showed significant survival benefits for patients with IGA. Our study supports adjuvant RT for this specific cohort.

Gastric Cancer: Epidemiology, Risk Factors, Classification, Genomic Characteristics and Treatment Strategies

Gastric cancer (GC) is one of the most common malignancies worldwide and it is the fourth leading cause of cancer-related death. GC is a multifactorial disease, where both environmental and genetic factors can have an impact on its occurrence and development. The incidence rate of GC rises progressively with age; the median age at diagnosis is 70 years. However, approximately 10% of gastric carcinomas are detected at the age of 45 or younger. Early-onset gastric cancer is a good model to study genetic alterations related to the carcinogenesis process, as young patients are less exposed to environmental carcinogens. Carcinogenesis is a multistage disease process specified by the progressive development of mutations and epigenetic alterations in the expression of various genes, which are responsible for the occurrence of the disease.

Development and validation of a prognostic nomogram for predicting early recurrence after curative resection of stage II/III gastric cancer

Background

The biological behavior of early recurrence is more invasive and the prognosis is worse in gastric cancer (GC). The risk of early recurrence (ER) for GC in stage II/III has not been reported of which the majority of GC patients are in China. Therefore, it is necessary to analyze the ER of gastric cancer in stage II/III.

Methods

The medical records of 1511 consecutive stage II/III GC patients who received resections were retrospectively reviewed. They were randomly classified into either a development or validation group at a ratio of 7:3. The nomogram was constructed based on prognostic factors using logistic regression analysis and was validated by bootstrap resampling and validation dataset, respectively. Concordance index (C-index) values and calibration curves were used to evaluate the predictive accuracy and discriminatory capability.

Results

Three hundred eleven patients experienced ER, accounting for 20.58% of the GC patients investigated. Multivariate logistic regression analysis identified tumors located at upper, middle third, or mixed, a positive lymph node ratio ≥ 0.335, pTNM stage III, lymphocyte count < 1.5 × 10⁹/L, postoperative infection complications and adjuvant chemotherapy < 6 cycles were all independent predictors for ER after curative resection of stage II/III GC. The C-index value obtained for the model was 0.780 (95% CI, 0.747–0.813), and the calibration curves of validation group yielded a C-index value of 0.739 (95% CI, 0.684–0.794), suggesting the practicability of the model.

Conclusions

The nomogram which was developed for predicting ER of stage II/III GC after surgery had good accuracy and was verified through both internal and external validation. The nomogram established can assist clinicians in determining the optimal therapy strategies in counseling, adjuvant treatments, and subsequent follow-up planning.

Postoperative complication rate and survival of patients with gastric cancer undergoing immunonutrition: A retrospective study

OBJECTIVES

This study aimed to evaluate the effect of preoperative immunonutrition on the rate of postoperative complication and survival of patients with gastric cancer.

METHODS

A retrospective cohort was formed after data collection of patients hospitalized with gastric cancer. Postoperative complications classified according to the Clavien-Dindo classification system, length of hospital stay, readmissions, and rates of survival at 6 mo, 1 y, and 5 y were analyzed. A χ² or Fisher's exact test, Student or Mann-Whitney t test, and Kaplan-Meier and Cox regressions were used in the statistical analysis.

RESULTS

A total of 164 patients were included in the study, with 56 patients assigned to the immunonutrition group and 108 to the conventional group. There were no significant differences in postoperative complications between the immunonutrition and conventional groups (51.8% versus 58.3%; P = 0.423). The most frequent complications were fistula and surgical wound infection. Length of hospital stay did not differ between the groups (median of 7.0 d: P = 0.615) and the presence of readmissions did not differ either (12.5% versus 15.7%; P = 0.648). In the multivariate Cox regression, in a pooled model for group, age, sex, body mass index, Charlson comorbidity index, staging, neoadjuvant chemotherapy, and type of surgery, there was a significant difference in survival rates at 6 mo (P = 0.011), 1 y (P = 0.006), and 5 y (P < 0.001).

CONCLUSIONS

Preoperative immunonutrition in patients with gastric cancer did not reduce postoperative complications or length of hospital stay. More studies are needed to confirm the benefit of immunonutriton supplementation for overall survival when associated with other protective factors.

The Use of (Network) Meta-Analysis in Clinical Oncology

Meta-analysis is important in oncological research to provide a more reliable answer to a clinical research question that was assessed in multiple studies but with inconsistent results. Pair-wise meta-analysis can be applied when comparing two treatments at once, whereas it is possible to compare multiple treatments at once with network meta-analysis (NMA). After careful systematic review of the literature and quality assessment of the identified studies, there are several assumptions in the use of meta-analysis. First, the added value of meta-analysis should be evaluated by examining the comparability of study populations. Second, the appropriate comparator in meta-analysis should be chosen according to the types of comparisons made in individual studies: (1) Experimental and comparator arms are different treatments (A vs. B); (2) Substitution of a conventional treatment by an experimental treatment (A+B vs. A+C); or (3) Addition of an experimental treatment (A+B vs. B). Ideally there is one common comparator treatment, but when there are multiple common comparators, the most efficacious comparator is preferable. Third, treatments can only be adequately pooled in meta-analysis or merged into one treatment node in NMA when considering likewise mechanism of action and similar setting in which treatment is indicated. Fourth, for both pair-wise meta-analysis and NMA, adequate assessment of heterogeneity should be performed and sub-analysis and sensitivity analysis can be applied to objectify a possible confounding factor. Network inconsistency, as statistical manifestation of violating the transitivity assumption, can best be evaluated by node-split modeling. NMA has advantages over pair-wise meta-analysis, such as clarification of inconsistent outcomes from multiple studies including multiple common comparators and indirect effect calculation of missing direct comparisons between important treatments. Also, NMA can provide increased statistical power and cross-validation of the observed treatment effect of weak connections with reasonable network connectivity and sufficient sample-sizes. However, inappropriate use of NMA can cause misleading results, and may emerge when there is low network connectivity, and therefore low statistical power. Furthermore, indirect evidence is still observational and should be interpreted with caution. NMA should therefore preferably be conducted and interpreted by both expert clinicians in the field and an experienced statistician. Finally, the use of meta-analysis can be extended to other areas, for example the identification of prognostic and predictive factors. Also, the integration of evidence from both meta-analysis and expert opinion can improve the construction of prognostic models in real-world databases.

MAP3K1 rs889312 genotypes influence survival outcomes of Chinese gastric cancer patients who received adjuvant chemotherapy based on platinum and fluorouracil regimes

Background

For patients with gastric cancer (GC), adjuvant chemotherapy is a standard therapy. However, the responses to the treatment are quite different. Mitogen-activated protein kinase (MAPK) pathway is a core pathway that modulates the efficacy of anticancer drugs. The purpose of our study was to investigate the clinical significance of one pivotal functional gene polymorphism in the MAPK pathway – MAP3K1 rs889312 – in patients with stage II GC to stage III GC.

Methods

The genotypes of MAP3K1 rs889312 were analyzed in 591 GC patients enrolled in this study who had received radical gastrectomy. Among them, 204 patients accepted adjuvant chemotherapy based on platinum and fluorouracil (PF) regimens after an operation. Cox regression analysis, log-rank test and Kaplan–Meier method were used to explore the link between MAP3K1 rs889312 variant and overall survival (OS) of GC.

Results

Compared with the AA genotype (mean OS of 68.12 months), MAP3K1 rs889312 AC/CC significantly reduced the mean OS of 56.83 months in patients who received adjuvant chemotherapy only. In addition, AC/CC genotype had a negative impact on OS of patients who received oxaliplatin-based therapy (HR, 8.253; 95% CI: 1.119–60.853, log-rank p=0.013). Stratification analysis showed that MAP3K1 rs889312 AC/CC significantly reduced OS of patients with tumors smaller than or equal to 5 cm in size (HR, 3.706; 95% CI: 1.329–10.335, p=0.012), poorly differentiated tumors (HR, 3.002; 95% CI: 1.076–8.377, p=0.036) and intestinal tumors (HR, 4.780; 95% CI: 1.138–20.073, p=0.033).

Conclusion

Our findings suggested that MAP3K1 rs889312 single-nucleotide polymorphism may be considered as a biomarker for adjuvant chemotherapy reaction and can predict prognosis of GC patients who received PF-based therapy.

Low Expression of GLIS2 Gene Might Associate with Radiosensitivity of Gastric Cancer

Human gene GLIS family zinc finger 2 (GLIS2) is a member of GLI-similar zinc finger protein family. Previous studies indicated GLIS2 gene involved in tumorigenesis mechanisms. However, the association between GLIS2 expression and radiosensitivity of gastric cancer has not been well understood. In this study, we used the gastric cancer database in TCGA, and significant association was observed between the low expression of GLIS2 and radiosensitivity of patients with gastric cancer. The adjusted HR values for radiotherapy were 0.162(0.035-0.756) and 0.089(0.014-0.564), with p values 0.021 and 0.010, respectively, in training and testing data, for these patients with low expression of GLIS2, while for patients with high expression of GLIS2, there was no significant survival difference between radiotherapy and nonradiotherapy groups. The adjusted HR were 0.676(0.288-1.586) and 0.508(0.178-1.450), with p values 0.368 and 0.206 in training and testing data, respectively. Further study showed that, for low expression patients, radiotherapy did not significantly increase new tumor event rate and disease progression rate, which partially supported our assumption. These results suggested that low expression of GLIS2 might significantly associate with the radiosensitivity of patients with gastric cancer. The GLIS2 gene might be a potential effective molecular marker of gastric cancer for precise radiotherapy.