Effect of adjuvant chemoradiotherapy on overall survival of gastric cancer patients submitted to D2 lymphadenectomy

A generalized Gompertz promotion time cure model and its fitness to cancer data

The cure models based on standard distributions like exponential, Weibull, lognormal, Gompertz, gamma, are often used to analyze survival data from cancer clinical trials with long-term survivors. Sometimes, the data is simple, and the standard cure models fit them very well, however, most often the data are complex and the standard cure models don't fit them reasonably well. In this article, we offer a novel generalized Gompertz promotion time cure model and illustrate its fitness to gastric cancer data by three different methods. The generalized Gompertz distribution is as simple as the generalized Weibull distribution and is not computationally as intensive as the generalized F distribution. One detailed real data application is provided for illustration and comparison purposes.

Evaluating the benefit of adjuvant radiotherapy after extensive lymph node dissection for gastric cancer: a single-institute retrospective study

Objective:

This study aimed to evaluate whether adjuvant radiotherapy (RT) can improve the treatment outcome of patients with locally advanced gastric cancer who underwent extensive lymph node dissection (ELND).

Materials and Methods:

This retrospective study included patients with gastric cancer pathological stages IIA–IIIC at Taipei Tzu Chi Hospital between 2008 and 2015. Patients (a) aged >80 years, (b) with distant metastasis at diagnosis, (c) with coexisting malignancies, (d) who did not complete the prescribed RT course, and (e) who died 1 month after surgery were excluded. Among 420 patients diagnosed with gastric cancer, 98 were included.

Results:

The median follow-up was 24.5 months. Of 39 patients who underwent adjuvant RT, 38 also received adjuvant chemotherapy (CT). Of 59 patients who did not receive adjuvant RT, only 34 received adjuvant CT. ELND was performed in 67.3% of the patients. The 5-year overall survival (OS) rate was 40%. In the univariate analyses, adjuvant CT regimen, 5-fluorouracil + leucovorin, was associated with worst outcome, while TS-1 was associated with better survival outcome (P = 0.018). The number of involved lymph nodes was strongly related to the OS and disease-free survival (DFS) (P < 0.001). We tried using different numbers of involved lymph nodes as a cutoff point and found that adjuvant RT significantly improved both OS and DFS in patients whose involved lymph nodes were ≥4 (OS, P = 0.017; DFS, P = 0.015). In multivariate analyses, better DFS was associated with negative surgical margin (P = 0.04), earlier disease stage (P = 0.001), adjuvant radiotherapy (P = 0.045), and adjuvant CT regimen TS-1 (P = 0.001).

Conclusion:

Adjuvant RT could improve DFS of patients with locally advanced gastric cancer with or without ELND. When the number of involved lymph nodes is ≥4, adjuvant RT is strongly suggested.

Distinguish the Role of Radiotherapy From Chemoradiotherapy for Gastric Cancer With Behavior of Metastasis-Indolent in Lymph Node

BACKGROUND

Although the landmark INT-0116 trial and National Comprehensive Cancer Network (NCCN) guidelines recommended pT3-4Nx gastric cancer (GC) patients to receive chemoradiotherapy, the role of radiotherapy has not been distinguished from chemoradiotherapy.

METHODS

GC with behavior of metastasis-indolent in lymph node (MILN) being confirmed with more than 15 examined LNs after gastrectomy were identified using the Surveillance, Epidemiology and End Result (SEER) database. The cancer-specific survival (CSS) of subgroups for radiotherapy, chemotherapy, chemoradiotherapy and non-adjuvant-treatment were compared. Propensity score matching (PSM) was performed between radiotherapy and non-radiotherapy subgroups to further distinguish the role of radiotherapy from chemoradiotherapy. Cox regression was performed to identify whether radiotherapy or chemotherapy could independently improve prognosis.

RESULTS

We identified 690 MILN GC patients in SEER database. 5-year CSS was 71.9% in radiotherapy subgroup and 75.1% in non-radiotherapy subgroup(HR = 1.013, 95% CI = 0.714-1.438, p = 0.940), 75.6% in chemotherapy subgroup and 68.5% in non-chemotherapy subgroup(HR = 0.616, 95% CI = 0.430-0.884, p = 0.008), 52.5% in radiotherapy-alone subgroup and 71.9% in non-adjuvant treatment group (HR = 1.604, 95% CI = 0.575-4.471, p = 0.360), 72.9% in chemoradiotherapy subgroup and 79.5% in chemotherapy-alone subgroup (HR = 1.365, 95% CI = 0.859-2.172, p = 0.185), respectively. Further, PSM markedly improved balance of variables between radiotherapy subgroup and non-radiotherapy subgroup. After PSM, the role of the variables of radiotherapy and chemotherapy in contributing to improving CSS are consistent with that before PSM. Cox regression showed chemotherapy, tumor size, tumor invasiveness and Lauren classification were independent prognostic factors, but not including radiotherapy.

CONCLUSIONS

Chemoradiotherapy confers superior prognosis to MILN GC patients compared with surgery alone might only be attributed to chemotherapy rather than radiotherapy.

Prognostic impact of Borrmann classification on advanced gastric cancer: a retrospective cohort from a single institution in western China

Background

Due to the controversy over the prognostic significance of Borrmann type in patients with gastric cancer (GC), the present study was to investigate the clinical value of Borrmann type in advanced GC.

Methods

We retrospectively evaluated 2092 patients with advanced GC and subsequently examined the clinicopathological characteristics and prognosis of patients stratified by Borrmann type.

Results

Patients were divided into three groups according to Borrmann type (Borrmann types I+II, III, and IV). Patients with Borrmann types III and IV had larger size, more poorly differentiated tumor type, more advanced tumor stage, and higher chance of involving the entire stomach. The overall survival (OS) rates were significantly different among the three groups (p < 0.001). Stratification analysis revealed significant OS rates among the three groups in tumor-node-metastasis (TNM) stage III (p < 0.001) and TNM stage IV (p = 0.008). Multivariate analysis revealed that Borrmann types, adjuvant chemotherapy, curative resection, and TNM stage were all independent predictors of OS among GC patients. The subgroup analysis indicated that Borrmann type was an independent predictor of OS among GC patients who undergone curative resection and with TNM stage III cancer. However, curative resection and postoperative chemotherapy failed to prolong the survival of patients with Borrmann type IV.

Conclusions

The clinicopathological characteristics and prognosis of patients with three Borrmann types of GC were different. Borrmann type can be simply used as a valuable factor to predict survival in advanced GC patients, especially in those TNM stage III undergoing curative resection. Additionally, more attention should be paid to the treatment for Borrmann type IV GC.

Adjuvant Chemoradiotherapy for Non-Pretreated Gastric Cancer

BACKGROUND

While the curative approach to gastric cancer includes perioperative regimens in several countries, a substantial proportion of patients may not receive treatment prior to surgery. This study examines the adjuvant provision of chemoradiotherapy (CRT) for non-pretreated patients with cancer of the stomach including the gastric cardia.

METHODS

All surgically treated patients with primary adenocarcinoma of the stomach and gastric cardia diagnosed between January 2004-December 2013 were selected from the Netherlands Cancer Registry. Patients who did not receive neoadjuvant treatment were included. Early gastric cancers (cT1), postoperative deaths within 90 days, patients with metastatic disease (M1), patients who received adjuvant chemotherapy and patients with macroscopic tumor after surgery (R2) were excluded.

RESULTS

Some 3277 patients underwent surgery, and 99 patients (3%) received adjuvant CRT. Treatment was more often administered in patients with a younger age (<65 years) and a high socioeconomic status (SES), in case of non-cardia cancer, positive lymph nodes, and positive resection margins (R1). Median survival time was 28 months (95% CI 17-39), compared to 35 months (95% CI 33-38) in CRT-naïve patients. After adjustment for confounders, a small net benefit for adjuvant CRT was found (hazard ratio, HR: 0.75, 95% CI 0.58-0.96). In subgroup analyses, benefit was most pronounced for patients with seven or more lymph metastases.

CONCLUSIONS

Marginal survival benefit was observed for adjuvant CRT in gastric cancer patients who did not receive neoadjuvant treatment. Treatment could be considered for patients with disease involving nodal invasion and those left with microscopic residual disease after surgery.

Postoperative chemoradiotherapy versus chemotherapy for R0 resected gastric cancer with D2 lymph node dissection: an up-to-date meta-analysis

BACKGROUND

This meta-analysis aims to provide more evidence on the role of postoperative chemoradiotherapy (CRT) for gastric cancer (GC) patients in Asian countries where D2 lymphadenectomy is prevalent.

METHODS

We conducted a systematic review of randomized controlled trials (RCTs), extracted data of survival and toxicities, and pooled data to evaluate the efficacy and toxicities of CRT compared with chemotherapy (CT) after D2 lymphadenectomy.

RESULTS

A total of 960 patients from four RCTs were selected. The results showed that postoperative CRT significantly reduced loco-regional recurrence rate (LRRR: RR = 0.50, 95 % CI = 0.34-0.74, P = 0.0005) and improved disease-free survival (DFS: HR = 0.73, 95 % CI = 0.60-0.89, P = 0.002). However, CRT did not affect distant metastasis rate (DMR: RR = 0.81, 95 % CI = 0.60-1.08, P = 0.15) and overall survival (OS: HR = 0.91, 95 % CI = 0.74-1.11, P = 0.34). The main grade 3-4 toxicities manifested no significant differences between the two groups.

CONCLUSIONS

Overall, CRT after D2 lymphadenectomy may reduce LRRR and prolong DFS. The role of postoperative CRT should be further investigated in the population with high risk of loco-regional recurrence.

The effect of aloe emodin-encapsulated nanoliposome-mediated r-caspase-3 gene transfection and photodynamic therapy on human gastric cancer cells

Gastric carcinoma (GC) has high incidence and mortality rates in China. Surgery and chemotherapy are the main treatments. Photodynamic therapy (PDT) has become a new treatment modality, appearing in recent experimental studies and clinical trials in various tumors. This study explores the combined effect of gene transfection with PDT on GC cells using aloe emodin (AE)-encapsulated nanoliposomes, which acted as gene carrier as well as one photosensitizer (PS). AE-encapsulated nanoliposomes (nano-AE) were prepared by reverse evaporation method. Electron microscopy and nano-ZS90 analyzer were used to detect its morphology, size, and wavelength. Western blot was used to detect the expression of the caspase-3 after transfection. MTT assay and flow cytometry were employed to determine the cytotoxic and apoptotic rates, respectively. Hoechst 33342 staining was adopted to detect the morphological changes in death gastric cancer cells. Cellular reactive oxygen species (ROS) contents were measured by DCFH-DA staining. Outcomes demonstrated that the nano-AE has good properties as gene delivery carriers as well as a PS. The group in which the recombinant plasmid of r-caspase-3 was transfected had higher protein expression of the caspase-3 than controls, meanwhile the proliferation rates of the transfected cells were inhibited by the nano-AE-mediated PDT in an energy-dependent manner. In addition, in the transfected cells, the death rate increased to 77.3% as assessed 12 h after PDT (6.4 J/cm(2) ). Hochest 33342 staining also revealed that the death rate increased significantly in the transfected group compared with other groups. Compared to control groups, the production of ROS in nano-AE PDT group had quadrupled in SGC-7901 cells as early as 1 h after PDT, while it is similar to the group of nano-AE transfection and PDT. Nano-AE-mediated r-caspase-3 gene transfection coupled with PDT could inhibit the proliferation rate and increase the apoptotic rate remarkably in human gastric cancer cells.

Adjuvant therapy for gastric cancer: What have we learned since INT0116?

Gastric cancer is one of the main cancer-related causes of death worldwide. The curative treatment of gastric cancer consists of tumor resection and lymphadenectomy. However, surgical treatment alone is associated with high recurrence rates. Adjuvant treatment strategies have been studied over the last decades, but there have been controversial results from the initial studies. The pivotal INT0116 study demonstrated that the use of adjuvant chemoradiotherapy with 5-fluorouracil increases relapse-free and overall survival, and it has been adopted across the Western world. The high toxicity of radiochemotherapy and suboptimal surgical treatment employed, with fewer than 10% of the patients submitted to D2 lymphadenectomy, were the main study limitations. Since its publication, other adjuvant treatment modalities have been studied, and radiochemotherapy is being refined to improve its efficacy and safety. A multimodal approach has been demonstrated to significantly increase relapse-free and overall survival, and it can be offered in the form of perioperative chemotherapy, adjuvant chemoradiotherapy or adjuvant chemotherapy, regardless of the extent of lymphadenectomy. The objective of the present review is to report the major advances obtained in the last decades in the adjuvant treatment of gastric cancer as well as the perspectives of treatment based on recent knowledge of the molecular biology of the disease.

Chemoradiation for gastric cancer: controversies, updates and novel techniques

The INT0116 trial established the role of adjuvant chemoradiation (CRT) in the multidisciplinary approach to the management of locally advanced gastric cancer. However, whether adjuvant CRT is indispensable for patients undergoing D2 dissection remains undefined. The adjuvant chemoradiation therapy in stomach cancer (ARTIST) trial, which was designed to compare adjuvant chemotherapy to CRT, failed to demonstrate differences in disease-free and overall survival in the whole study group; however, subgroup analysis indicated that patients with lymph node metastasis may benefit from additional radiation. A follow-up ARTIST II trial is currently under way. The efficacy of adjuvant CRT remains controversial because of variation among studies in the inclusion criteria and treatment delivery methods; however, the identification of patients who would benefit from CRT is critical. Advanced radiotherapy techniques such as intensity-modulated radiotherapy protect normal tissues via motion management and decreased radiation-induced toxicity and contribute to plan optimization. Further studies integrating clinical and molecular factors as well as neoadjuvant CRT are warranted.

Evaluation of N-ratio in selecting patients for adjuvant chemoradiotherapy after d2-gastrectomy

CONTEXT

Whether adjuvant chemoradiotherapy may contribute to improve survival outcomes after D2-gastrectomy remains controversial.

OBJECTIVE

To explore the clinical utility of N-Ratio in selecting gastric cancer patients for adjuvant chemoradiotherapy after D2-gastrectomy.

METHODS

A retrospective cohort study was carried out on gastric cancer patients who underwent D2-gastrectomy alone or D2-gastrectomy plus adjuvant chemoradiotherapy (INT-0116 protocol) at the Hospital A. C. Camargo from September 1998 to December 2008. Statistical analysis were performed using multiple conventional methods, such as c-statistic, adjusted Cox's regression and stratified survival analysis.

RESULTS

Our analysis involved 128 patients. According to c-statistic, the N-Ratio (i.e., as a continuous variable) presented "area under ROC curve" (AUC) of 0.713, while the number of metastatic nodes presented AUC of 0.705. After categorization, the cut-offs provide by Marchet et al. displayed the highest discriminating power - AUC value of 0.702. This N-Ratio categorization was confirmed as an independent predictor of survival using multivariate analyses. There also was a trend of better survival by adding of adjuvant chemoradiotherapy only for patients with milder degrees of lymphatic spread - 5-year survival of 23.1% vs 66.9%, respectively (HR = 0.426, 95% CI 0.150-1.202; P = 0.092).

CONCLUSIONS

This study confirms the N-Ratio as a tool to improve the lymph node metastasis staging in gastric cancer and suggests the cut-offs provided by Marchet et al. as the best way for its categorization after a D2-gastrectomy. In these settings, the N-Ratio appears a useful tool to select patients for adjuvant chemoradiotherapy, and the benefit of adding this type of adjuvancy to D2-gastrectomy is suggested to be limited to patients with milder degrees of lymphatic spread (i.e., NR2, 10%-25%).

Impact of external-beam radiation therapy on outcomes among patients with resected gastric cancer: a multi-institutional analysis

BACKGROUND

Use of perioperative chemotherapy (CTx) alone versus chemoradiation therapy (cXRT) in the treatment of resectable gastric cancer remains varied. We sought to define the utilization and effect of CTx alone versus cXRT on patients having undergone curative-intent resection for gastric cancer.

METHODS

Using the multi-institutional US Gastric Cancer Collaborative database, we identified 505 gastric cancer patients between 2000 and 2012 who received perioperative therapy in addition to curative-intent resection. The impact of perioperative therapy on survival was analyzed by the use of propensity-score matching of clinicopathologic factors among patients who received CTx alone versus cXRT.

RESULTS

Median patient age was 62 years, and most patients were male (58.2 %). Most patients had a T3 (38.7 %) or T4 (36.8 %) lesion and lymph node metastasis (73.4 %). A total of 211 (42.8 %) patients received perioperative CTx alone, whereas the remaining 294 (58.2 %) patients received cXRT. Factors associated with receipt of cXRT were younger age (odds ratio, 1.93) and lymph node metastasis (odds ratio, 4.02; both P < 0.05). At a median follow-up of 28 months, the median overall survival (OS) was 33.4 months, and the 5-year OS was 36.7 %. Factors associated with worse overall survival included large tumor size [hazard ratio (HR), 1.83], T3 (HR 2.96) or T4 (HR 4.02) tumors, and lymph node metastasis (HR 1.57; all P < 0.05). In contrast, receipt of cXRT was associated with improved long-term OS (CTx alone, 20.9 months; cXRT, 46.7 months; HR 0.51; P < 0.001).

CONCLUSIONS

cXRT was utilized in 58 % of patients undergoing curative-intent resection for gastric cancer. With propensity score-matched analysis, cXRT was an independent factor associated with improved recurrence-free survival and OS.

Is postoperative adjuvant chemoradiotherapy efficacious and safe for gastric cancer patients with D2 lymphadenectomy? A meta-analysis of the literature

BACKGROUND

Adjuvant chemoradiotherapy (CRT) for patients with gastric cancer after D2 lymphadenectomy remains controversial. The objective of the present meta-analysis was to analyze efficacy and safety of postoperative CRT and establish a consensus on whether it is suitable for the patients.

METHODS

We searched PubMed, Ovid, Cochrane, and Web of Science. Statistical analysis was carried out by STATA version 12.0 software. The quality of evidence was assessed by Jadad and the Newcastle-Ottawa quality assessment scale.

RESULTS

Six studies involving 2135 patients were included for the meta-analysis. The results showed that, compared with non-CRT, postoperative adjuvant CRT was associated with a significant improvement in 5-year overall survival (OS) (HR = 0.79, 95% CI 0.68-0.92, P = 0.002) and 5-year relapse-free survival (RFS) (HR = 0.81, 95% CI 0.70-0.93, P = 0.004). However, there were no differences in distant metastasis (RR = 0.93, 95% CI 0.82-1.06, P = 0.304) and treatment-related toxicity between the two groups.

CONCLUSIONS

From the results of our study, postoperative adjuvant CRT may be associated with longer 5-year OS and 5-year RFS in patients with D2 lymphadenectomy, but might not improve 5-year disease-free survival compared to non-CRT. Methodologically high-quality comparative studies are needed for further evaluation.

Mixture and non-mixture cure fraction models based on the generalized modified Weibull distribution with an application to gastric cancer data

The cure fraction models are usually used to model lifetime time data with long-term survivors. In the present article, we introduce a Bayesian analysis of the four-parameter generalized modified Weibull (GMW) distribution in presence of cure fraction, censored data and covariates. In order to include the proportion of "cured" patients, mixture and non-mixture formulation models are considered. To demonstrate the ability of using this model in the analysis of real data, we consider an application to data from patients with gastric adenocarcinoma. Inferences are obtained by using MCMC (Markov Chain Monte Carlo) methods.