Updated analysis of SWOG-directed intergroup study 0116: a phase III trial of adjuvant radiochemotherapy versus observation after curative gastric cancer resection

Gastric cancer-molecular and clinical dimensions

Gastric cancer imposes a considerable health burden around the globe despite its declining incidence. The disease is often diagnosed in advanced stages and is associated with a poor prognosis for patients. An in-depth understanding of the molecular underpinnings of gastric cancer has lagged behind many other cancers of similar incidence and morbidity, owing to our limited knowledge of germline susceptibility traits for risk and somatic drivers of progression (to identify novel therapeutic targets). A few germline (PLCE1) and somatic (ERBB2, ERBB3, PTEN, PI3K/AKT/mTOR, FGF, TP53, CDH1 and MET) alterations are emerging and some are being pursued clinically. Novel somatic gene targets (ARID1A, FAT4, MLL and KMT2C) have also been identified and are of interest. Variations in the therapeutic approaches dependent on geographical region are evident for localized gastric cancer-differences that are driven by preferences for the adjuvant strategies and the extent of surgery coupled with philosophical divides. However, greater uniformity in approach has been noted in the metastatic cancer setting, an incurable condition. Having realized only modest successes, momentum is building for carrying out more phase III comparative trials, with some using biomarker-based patient selection strategies. Overall, rapid progress in biotechnology is improving our molecular understanding and can help with new drug discovery. The future prospects are excellent for defining biomarker-based subsets of patients and application of specific therapeutics. However, many challenges remain to be tackled. Here, we review representative molecular and clinical dimensions of gastric cancer.

Evidence based radiation oncology with existing technology

AIM

To assess the real contribution of modern radiation therapy (RT) technology in the more common tumoral types in Central America, Caribbean and South America.

BACKGROUND

RT is an essential tool in the management of cancer. RT can be either palliative or of curative intent. In general, for palliative radiotherapy, major technologies are not needed.

MATERIALS AND METHODS

We analyzed the contribution of RT technology based on published evidence for breast, lung, gastric, gallbladder, colorectal, prostate and cervix cancer in terms of disease control, survival or toxicity with especial focus on Latin America.

RESULTS

Findings indicate that three dimensional conformal radiation therapy (3D RT) is the gold standard in most common type of cancer in the studied regions. Prostate cancer is probably the pathology that has more benefits when using new RT technology such as intensity modulated radiation therapy (IMRT) versus 3DRT in terms of toxicity and biochemical progression-free survival.

CONCLUSIONS

In light of the changes in technology, the ever-increasing access of developing countries to such technology, and its current coverage in Latin America, any efforts in this area should be aimed at improving the quality of the radiotherapy departments and centers that are already in place.

HER2 in resected gastric cancer: Is there prognostic value?

BACKGROUND AND OBJECTIVES

The role of HER2 in patients with early stage/resected gastric cancer is controversial. This study investigates the prevalence and prognostic value of HER2 in patients undergoing curative intent resection for gastric adenocarcinoma.

METHODS

HER2 status was evaluated in 111 patients with gastric adenocarcinoma treated surgically between 1/00 and 6/11 with tissue available for analysis. Immunohistochemistry (IHC) for HER2 was graded by two blinded pathologists. IHC was scored as 0+/1+: negative, 2+: equivocal, and 3+: positive. Fluorescence in situ hybridization (FISH) for HER2 was performed on equivocal (2+) samples, and in cases of pathologist disagreement.

RESULTS

HER2 expression as measured by IHC was negative in 61 (55%), equivocal in 37 (33.3%), and positive in 13 (11.7%) cases. FISH was positive in 8 of 37 samples tested, for a total of 21 HER2-positive cases (18.9%, 95% CI 11.6-26.2%). Patients with HER2-positive tumors were less likely to have signet ring cell features (23.8% vs. 53.9%, P = 0.008). HER2 status was not associated with tumor size, location, perineural or lymphovascular invasion, margin status, nodal metastasis, or stage (P > 0.05). HER2 status was not associated with OS (P = 0.385).

CONCLUSIONS

HER2 amplification/over-expression is present in patients with resected gastric adenocarcinoma, but is not associated with the presence of adverse prognostic factors. Our results suggest HER2 is not prognostic for patients with resected gastric adenocarcinoma.

Indirect comparison showed survival benefit from adjuvant chemoradiotherapy in completely resected gastric cancer with d2 lymphadenectomy

Background. Little data on directly comparing chemoradiotherapy with observation has yet been published in the setting of adjuvant therapy for resected gastric cancer who underwent D2 lymphadenectomy. The present indirect comparison aims to provide more evidence on comparing the two approaches. Methods. We conducted a systematic review of randomized controlled trials, extracted time-to-event data using Tierney methods (when not reported), and performed indirect comparison to obtain the relative hazards of adjuvant chemoradiotherapy to observation on overall and disease-free survival. Results. seven randomized controlled trials were identified. Three trials compared adjuvant chemoradiotherapy with adjuvant chemotherapy, and 4 trials compared adjuvant chemotherapy with observation. Using indirect comparison, the relative hazards of adjuvant chemoradiotherapy to observation were 0.43 (95% CI: 0.33-0.55) in disease-free survival and 0.52 (95% CI: 0.38-0.71) in overall survival for completely resected gastric cancer with D2 lymphadenectomy. Conclusions. Postoperative chemoradiotherapy can prolong survival and decrease recurrence in patients with resected gastric cancer who underwent D2 gastrectomy. Molecular biomarker might be a promising direction in the prediction of clinical outcome to postoperative chemoradiotherapy, which warranted further study.

Gastric cancer-molecular and clinical dimensions

Gastric cancer imposes a considerable health burden around the globe despite its declining incidence. The disease is often diagnosed in advanced stages and is associated with a poor prognosis for patients. An in-depth understanding of the molecular underpinnings of gastric cancer has lagged behind many other cancers of similar incidence and morbidity, owing to our limited knowledge of germline susceptibility traits for risk and somatic drivers of progression (to identify novel therapeutic targets). A few germline (PLCE1) and somatic (ERBB2, ERBB3, PTEN, PI3K/AKT/mTOR, FGF, TP53, CDH1 and MET) alterations are emerging and some are being pursued clinically. Novel somatic gene targets (ARID1A, FAT4, MLL and KMT2C) have also been identified and are of interest. Variations in the therapeutic approaches dependent on geographical region are evident for localized gastric cancer-differences that are driven by preferences for the adjuvant strategies and the extent of surgery coupled with philosophical divides. However, greater uniformity in approach has been noted in the metastatic cancer setting, an incurable condition. Having realized only modest successes, momentum is building for carrying out more phase III comparative trials, with some using biomarker-based patient selection strategies. Overall, rapid progress in biotechnology is improving our molecular understanding and can help with new drug discovery. The future prospects are excellent for defining biomarker-based subsets of patients and application of specific therapeutics. However, many challenges remain to be tackled. Here, we review representative molecular and clinical dimensions of gastric cancer.

Adjuvant therapy in gastric cancer: what is the optimal approach?

Gastric cancer confers a poor prognosis even when diagnosed as localized disease. Multimodality therapy improves the cure rate of patients with localized cancer. However, adjunctive therapeutic approaches differ in different regions of the world. This review focuses on the current standards and unresolved issues based on updated literature on therapy for localized gastric cancer. In the USA, the Intergroup 0116 trial established the use of postoperative chemoradiotherapy as a standard for patients who have surgery first for treatment of gastric cancer. In Europe, the MAGIC trial investigating perioperative chemotherapy demonstrated a survival benefit for gastric cancer patients. Finally, in Asia, the ACTS-GC and CLASSIC trials investigating postoperative chemotherapy established this as the standard of care after primary surgery that included D2 dissection. It is clear, however, that surgery alone is insufficient to achieve the highest possible cure rates.

Prognosis for gastric carcinomas with an insufficient number of examined negative lymph nodes

BACKGROUND

The optimal system for lymph node (LN) staging in gastric cancer is still a subject of debate. The aim of our study was to analyse the probability of error in negative LN (pN0) gastric carcinomas when a low number of LNs were harvested using a probabilistic model.

METHODS

Patients with gastric carcinoma who underwent R0 resection at three university hospitals between 2004 and 2009 were retrospectively included. A Bayesian model was used to analyse the probability of error for negative LNs (pN0) gastric carcinomas. Kaplan-Meier survival curves and the log-rank test were used to compare the overall and specific mortality of prognosis groups.

RESULTS

Of the 291 patients included, 123 were classified as pN0 (42%). A significant correlation was found between the extent of the LN dissection performed and the number of the LNs retrieved. According to the Bayesian model the carcinomas with 9 or fewer negative lymph nodes were considered to have a high risk (HR) of misclassification, whereas patients with 10-25 LNs analysed and those with more than 26 negative lymph nodes were considered to have a moderate risk (MR) and low risk (LR), respectively. The log-rank test showed a significant improvement in the disease-specific survival for the MR pN0 (p < 0.001) and LR pN0 (p < 0.04) but not for the HR pN0 patients compared to pN1 patients.

CONCLUSIONS

The proposed probabilistic model is clinically useful for differentiating the prognosis in pN0 gastric carcinomas when an insufficient number of negative lymph nodes are retrieved.

Perioperative therapy for locally advanced gastroesophageal cancer: current controversies and consensus of care

Gastroesophageal cancer (GEC) remains a challenging problem in oncology. Anatomically, GEC is comprised of distal gastric adenocarcinoma (GC), classically associated with Helicobacter Pylori, while proximal esophagogastric adenocarcinoma (EGJ AC) has increased significantly in incidence over the past years. Despite contrasting etiologies, histologies, and molecular phenotypes of distal and proximal GEC, in many cases perioperative (and metastatic) treatment strategies converge to similar approaches. For patients undergoing curative intent surgery, advances in perioperative chemotherapy and/or chemoradiotherapy, either before and/or after surgery, have demonstrated improved survivals compared to surgery alone. This review focuses on how the 'boundary' of the Z-line and/or the anatomical distinction of 'proximal' (EGJ) vs. 'distal' (GC) cancer has led to diverse inclusion/exclusion criteria for clinical trial enrollment, embodying various combinations of chemotherapy and radiation before and/or after surgery. Supporting evidence of each of these approaches consequently has led to a number of varying practices by geographical region and Institution/Physician, based on differing experience, preference, and clinical circumstance. Adequate direct comparison of these approaches is lacking currently, but data from a number of concerted efforts should be available in the next years to further direct best standards of care. Introduction of biologically targeted agents, namely anti-angiogenics and anti-HER family therapeutics are being evaluated to determine whether further therapeutic gains can be realized over classic cytotoxic chemotherapy alone (with/without radiotherapy). To date, novel molecularly targeted agents have yet to demonstrate benefit in this setting. In the following comprehensive review we will address the intricacies of perioperative treatment of locally advanced GEC, with focus on clinical trials supporting the diverse set of perioperative multidisciplinary approaches.

Adjuvant treatment for gastric cancer: chemotherapy versus radiation

Gastric cancer is among the leading causes of cancer death worldwide. Surgery is the only curative modality, but mortality remains high because a significant number of patients have recurrence after complete surgical resection. Chemotherapy, radiation, and chemoradiotherapy have all been studied in an attempt to reduce the risk for relapse and improve survival. There is no globally accepted standard of care for resectable gastric cancer, and treatment strategies vary across the world. Postoperative chemoradiation with 5-fluorouracil/leucovorin is most commonly practiced in the United States; however, recent clinical trials from Asia have shown benefit of adjuvant chemotherapy alone and have questioned the role of radiation. In this review, we examine the current literature on adjuvant treatment of gastric cancer and discuss the roles of radiation and chemotherapy, particularly in light of these new data and their applicability to the Western population. We highlight some of the ongoing and planned clinical trials in resectable gastric cancer and identify future directions as well as areas where further research is needed.

Prognostic significance of the number of examined lymph nodes in node-negative gastric adenocarcinoma

AIM

In this study, we investigated the prognostic significance of the number of examined lymph nodes in node-negative gastric adenocarcinoma (GC).

PATIENTS AND METHODS

A total of 1194 node-positive and 1030 node-negative GC patients undergoing potentially curative gastrectomy was enrolled in this study. Patients were stratified into 3 groups according to the number of examined lymph nodes: group 1, ≤ 15; group 2, 16-25; group 3, >25.

RESULTS

Patients with node-negative GC had significantly favorable survival compared with those with node-positive. Among patients with node-negative T2-T4 disease, the percentage of locoregional relapse was higher in those with <25 examined lymph nodes than in those with ≥ 25 examined lymph nodes. The number of examined lymph nodes affected the overall survival rates for patients with node-negative T2-T4 GC but not for patients with T1 lesions. Tumor size, tumor location, the number of examined lymph nodes, T status, and the presence of perineural invasion were significant prognostic factors as determined by multivariate analysis in node-negative GC.

CONCLUSIONS

No survival benefit of examining ≥ 15 lymph nodes was noted for patients with node-negative T1 GC. Extensive lymphadenectomy in patients with node-negative T2-T4 lesions in whom the number of examined lymph nodes was >25 had favorable survival.

Radiotherapy for gastric cancer: a systematic review and meta-analysis

There have been many trials trying to prove the benefit of radiotherapy for gastric cancer; however, the results were either inclusive or controversial. The purpose of the study was to elucidate the effect of radiotherapy on gastric cancer delivered as perioperative or palliative treatment. We conducted systematic searches for trials exploring the effect of radiotherapy on gastric cancer. In the subgroup of patients receiving preoperative radiotherapy for gastric cancer, a significant benefit was found on 10-year overall survival with a hazard ratio (HR) of 0.75 (95% confidence interval (CI), 0.61 to 0.91); however, the benefit on 5-year overall survival was not proven (HR, 0.68; 95%CI, 0.45 to 1.01). There are also no significant differences in resection rate and radical resection rate between group of patients receiving radiotherapy and control group with a relative risk (RR) of 1.06 (95%CI, 0.99 to 1.13) and 1.12 (95%CI 0.93 to 1.36), respectively. In the subgroup of patients receiving postoperative radiotherapy for gastric cancer, survival benefits were found on 3- and 5-year progression-free survival with HR of 0.69 (95%CI, 0.53 to 0.90) and HR of 0.70 (95%CI, 0.61 to 0.80), respectively. Survival benefits of adjuvant radiotherapy on 3- and 5-year progression-free survival were also found; nonetheless, there was no evidence of significant difference in 3-year overall survival (HR, 0.70; 95%CI, 0.61 to 1.01). The effect of radiotherapy on 5-year overall survival was also quite controversial. In short, gastric cancer patients could benefit from radiotherapy both in the form of preoperative radiotherapy and postoperative radiotherapy.

Postoperative chemoradiotherapy versus postoperative chemotherapy for completely resected gastric cancer with D2 Lymphadenectomy: a meta-analysis

Background

Both chemoradiotherapy and chemotherapy are used in postoperative adjuvant therapy for resected gastric cancer. However, it is controversial whether chemoradiotherapy or chemotherapy is the optimal strategy for patients with gastric cancer after D2 lymphadenectomy. The present meta-analysis aims to provide more evidence on the relative benefits of adjuvant therapies in this setting.

Methods

We conducted a systematic review of randomized controlled trials, extracted time-to-event data using Tierney methods (when not reported), and performed meta-analysis to obtain the relative hazards of adjuvant chemoradiotherapy to chemotherapy on efficacy and toxicities.

Results

A total of 895 patients from 3 randomized controlled trials were identified for this meta-analysis. All patients were from Asian countries. Our results showed that postoperative chemoradiotherapy significantly improved locoregional recurrence-free survival [LRRFS: hazard ratio (HR) = 0.53, 95% CI = 0.32–0.87, p = 0.01] and disease-free survival (DFS: HR = 0.72, 95% CI = 0.59–0.89, p = 0.002); however, the improvement of distant metastasis recurrence-free survival (DMRFS: HR = 0.86; 95% CI = 0.66–1.11, p = 0.25) and overall survival (OS: HR = 0.79, 95% CI = 0.61–1.03, p = 0.08) were non-significant. The main grade 3 or 4 toxicities were equivalent between the two groups.

Conclusion

In non-selected Asian patients with resected gastric cancer who underwent D2 lymphadenectomy, postoperative chemoradiotherapy improved LRRFS and DFS but might not improve OS compared to postoperative chemotherapy.

(Neo)-adjuvant chemo(-radio) therapy for adenocarcinomas of the gastroesophageal junction and the stomach in the West

Worldwide, the treatment of adenocarcinomas of the gastroesophageal junction and stomach has changed over the past decades. It is no longer surgery alone. Nowadays, most patients undergo surgery plus pre- and/or postoperative therapies. However, there are still marked differences in surgical procedures between the East and the West which might influence the surgical prognosis and thereby also the choice of perioperative treatment strategies. In the East, with its more extended surgical procedures, including standard D2 dissections, the current treatment philosophy is primary surgery followed by adjuvant chemotherapy. Neoadjuvant approaches are restricted to really advanced tumors, and perioperative chemoradiation is not routinely used (at least to date). This clearly differs from treatment strategies currently recommended in Western countries. In Europe and North America, pre- plus postoperative chemotherapy has become the recommended treatment for locally more advanced tumors, and preoperative chemoradiation is increasingly administered to patients with adenocarcinomas of the gastroesophageal junction (Siewert type I/II). However, the role of postoperative chemotherapy (despite its increasing use) is still under discussion in the West (especially Europe) and not generally recommended/accepted as a standard treatment. Postoperative chemoradiation, which is one standard treatment in North America, is only regarded as a treatment option for patients after 'inadequate surgery' (i.e. <D2 dissection) in many European countries.

Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial

BACKGROUND

Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease.

PATIENTS AND METHODS

Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone.

RESULTS

HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation.

CONCLUSION

Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS.

CLINICAL TRIAL

INT-0116/SWOG9008 phase III.

New and emerging combination therapies for esophageal cancer

Esophageal cancer comprises two different histological forms - squamous cell carcinoma (SCC) and adenocarcinoma (AC). While the incidence of AC has increased steeply in Western countries during the last few years, the incidence of SCC is fairly stable. Both forms differ in pathogenesis and response to chemotherapy and radiation therapy. Plenty of studies have evaluated new chemotherapy combination regimens in the neoadjuvant, adjuvant, and palliative setting. In addition, new radiation and chemoradiation protocols have been investigated. Finally, molecular-targeted therapy has been included in several new randomized prospective trials. Therefore, this review presents new data on this topic and critically discusses promising approaches towards a more effective treatment in a disease with a grim prognosis.

D2 lymphadenectomy with surgical ex vivo dissection into node stations for gastric adenocarcinoma can be performed safely in Western patients and ensures optimal staging

BACKGROUND

The AJCC recommends examination of >16 nodes to stage gastric adenocarcinoma. D2 lymphadenectomy (LAD) followed by surgical ex vivo dissection (SEVD) into nodal stations is standard at many high-volume Asian centers, but potential increases in morbidity and mortality have slowed adoption of D2 LAD in some Western centers.

METHODS

A total of 331 patients with gastric adenocarcinoma who underwent surgical resection at one Western institution from 1995 to 2010 were examined.

RESULTS

Median age of patients was 69 years old, 65% were male, and 84% were white. D1 LAD was performed in 285 patients (86%) and D2 LAD in 46 patients (14%), with SEVD being performed in 17 patients (37%) in the D2 group. D2 LAD with or without SEVD was performed much more commonly between 2006 and 2010. For the D1, D2 without SEVD, and D2 with SEVD groups, the median number of examined nodes and percentage with >16 examined nodes were 16 and 51%, 27 and 93%, and 40 and 100%, respectively. Major complications occurred in 16% of the D1 group and 17% of the D2 group (p>0.05), and 30-day mortality was 3% for the D1 group and 0% for the D2 group. D2 LAD was a positive prognostic factor for overall survival on univariate (p=0.027) and multivariate analyses (p=0.005), but there were several possible confounding variables.

CONCLUSIONS

D2 LAD at our Western institution was performed with low morbidity and no mortality. Optimal staging occurred after D2 LAD combined with SEVD, where a median of 40 nodes were examined and all patients had >16 examined nodes.

Perioperative chemotherapy for resectable gastroesophageal cancer: a single-center experience

BACKGROUNDS

Multimodal treatment for locally advanced gastric cancer has been reported to improve disease-free survival when compared to surgery alone. We aimed to clarify the efficacy and safety of perioperative chemotherapy for locally advanced gastric cancer patients treated in daily clinical practice.

METHODS

Patients diagnosed with locally advanced gastric cancer were treated with perioperative chemotherapy and surgery. The primary end point was the complete resection (R0) rate. Secondary end points were disease-free survival (DFS), overall survival (OS), toxicity, radiological response rate, pathological response rate and downstaging rate. We also looked for prognostic and predictive factors for DFS, OS, pathological complete response and the R0 rate.

RESULTS

Forty patients were found eligible for this retrospective analysis. At diagnosis, 52.5% of patients were classified as stage II and 47.5% were stage III. Forty percent of patients completed three preoperative cycles and three postoperative cycles. A tolerable toxicity related to chemotherapy was found. Thirty-nine patients underwent surgery: 80% reached a complete resection (R0), down-staging was detected in 57.5% and 17.5% had a pathologically complete response. The median time of disease-free survival was 34.05 months (95%CI 25.6-42.4), and the median time of overall survival was 39.01 months (95%CI 30.8-47.1). We found that the presence of comorbidities were independent predictive factors for the pathologic response, while the chemotherapy schedule and the clinical response could independently predict a complete resection.

CONCLUSIONS

Our results support that perioperative chemotherapy for locally advanced gastric cancer can be safely delivered in daily clinical practice, obtaining an improvement of the pathologic response and the complete resection of gastric cancer.

Modern oncological approaches to gastric adenocarcinoma

Gastric cancer (GC) is a major health burden throughout the world, especially in certain endemic regions. GC is commonly diagnosed at an advanced stage because of the lack of early detection strategies and is usually associated with a dismal outcome. For patients with localized GC (LGC), surgery is the best cure: cure rates are highly associated with the surgical pathology stage. Adjunctive therapies improve the cure rates by about an additional 10%. Therefore, a multimodality approach is highly recommended for all patients with LGC. This article highlights some of the therapeutic advances made against GC and features important ongoing trials.

Therapy for locally advanced adenocarcinoma of the gastroesophageal junction: optimizing outcome

Adenocarcinoma of the distal esophagus and gastroesophageal junction has been rapidly increasing in incidence in Western nations over the past several decades. Although in the past, a similar management strategy has been used for adenocarcinoma and squamous cell carcinoma, without distinguishing by location or pathology, there is now greater motivation to optimize therapeutic strategies for adenocarcinoma in general and by specific location within the esophagus, with the goal of improving outcome. Siewert recognized the need to classify tumors based on anatomic location and proposed a classification scheme for distal esophageal and gastroesophageal junction neoplasms to guide therapy and allow more meaningful study. Although the available randomized data relevant to adenocarcinoma patients often include a mix of the 2 histologies and the various anatomical locations bundled together, these data suggest that a variety of surgical approaches are appropriate and that neoadjuvant therapy improves survival for patients with locally advanced disease. Although definitive evidence is lacking, neoadjuvant chemoradiation appears superior to neoadjuvant chemotherapy alone for improving resectability, maintaining locoregional control, and maximizing survival. There is a need to identify more effective approaches to identifying optimal systemic regimens for individual patients that may be combined with local therapy to further improve outcome.

Adjuvant IMRT/XELOX radiochemotherapy improves long-term overall- and disease-free survival in advanced gastric cancer

PURPOSE

In a retrospective analysis, adjuvant intensity-modulated radiation therapy (IMRT) combined with modern chemotherapy improved advanced gastric cancer survival rates compared to a combination of three-dimensional conformal radiation therapy (3D-CRT) and conventional chemotherapy. We report on the long-term outcomes of two consecutive patient cohorts that were treated with either IMRT and intensive chemotherapy, or 3D-CRT and conventional chemotherapy.

PATIENTS AND METHODS

Between 2001 and 2008, 65 consecutive gastric cancer patients received either 3D-CRT (n = 27) or IMRT (n = 38) following tumor resection. Chemotherapy comprised predominantly 5-fluorouracil/folinic acid (5-FU/FA) in the earlier cohort and capecitabine plus oxaliplatin (XELOX) in the latter. The primary endpoints were overall survival (OS) and disease-free survival (DFS).

RESULTS

Median OS times were 18 and 43 months in the 3D-CRT and IMRT groups, respectively (p = 0.0602). Actuarial 5-year OS rates were 26 and 47  %, respectively. Within the IMRT group, XELOX gave better results than 5-FU/FA in terms of OS, but this difference was not statistically significant. The primary cause of death in both groups was distant metastasis. Median DFS times were 14 and 35 months in the 3D-CRT and IMRT groups, respectively (p = 0.0693). Actuarial 5-year DFS rates were 22 and 44  %, respectively. Among patients receiving 5-FU/FA, DFS tended to be better in the IMRT group, but this was not statistically significant. A similar analysis for the XELOX group was not possible as 3D-CRT was almost never used to treat these patients. No late toxicity exceeding grade 3 or secondary tumors were observed.

CONCLUSION

After a median follow-up period of over 5 years, OS and DFS were improved in the IMRT/XELOX treated patients compared to the 3D-CRT/5-FU/FA group. Long-term observation revealed no clinical indications of therapy-induced secondary tumors or renal toxicity.

Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial

BACKGROUND

Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease.

PATIENTS AND METHODS

Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone.

RESULTS

HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation.

CONCLUSION

Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS.

CLINICAL TRIAL

INT-0116/SWOG9008 phase III.

Who benefits from adjuvant radiation therapy for gastric cancer? A meta-analysis

PURPOSE

Large randomized trials have demonstrated significant survival benefits with the use of adjuvant chemotherapy or chemoradiation therapy for gastric cancer. The importance of adjuvant radiation therapy (RT) remains unclear. We performed an up-to-date meta-analysis of randomized trials testing the use of RT for resectable gastric cancer.

METHODS AND MATERIALS

We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for randomized trials testing adjuvant (including neoadjuvant) RT for resectable gastric cancer. Hazard ratios describing the impact of adjuvant RT on overall survival (OS) and disease-free survival (DFS) were extracted directly from the original studies or calculated from survival curves. Pooled estimates were obtained using the inverse variance method. Subgroup analyses were performed to determine whether the efficacy of RT varies with chemotherapy use, RT timing, geographic region, type of nodal dissection performed, or lymph node status.

RESULTS

Thirteen studies met all inclusion criteria and were used for this analysis. Adjuvant RT was associated with a significant improvement in both OS (HR = 0.78, 95% CI: 0.70-0.86, P<.001) and DFS (HR = 0.71, 95% CI: 0.63-0.80, P<.001). In the 5 studies that tested adjuvant chemoradiation therapy against adjuvant chemotherapy, similar effects were seen for OS (HR = 0.83, 95% CI: 0.67-1.03, P=.087) and DFS (HR = 0.77, 95% CI: 0.91-0.65, P=.002). Available data did not reveal any subgroup of patients that does not benefit from adjuvant RT.

CONCLUSION

In randomized trials for resectable gastric cancer, adjuvant RT provides an approximately 20% improvement in both DFS and OS. Available data do not reveal a subgroup of patients that does not benefit from adjuvant RT. Further study is required to optimize the implementation of adjuvant RT for gastric cancer with regard to patient selection and integration with systemic therapy.

Surgical treatment results of intestinal and diffuse type gastric cancer. Implications for a differentiated therapeutic approach?

AIM

To study the outcome of patients who were surgically treated for primary gastric cancer with specific attention to differences in treatment results for intestinal and diffuse type tumours.

METHODS

All patients who underwent a potentially curative gastric resection between 1995 and 2011 in our institute were included. Patient, tumour and treatment characteristics were obtained retrospectively. Binary logistic and Cox regression models were used for multivariate analysis.

RESULTS

A consecutive series of 132 patients was included. Median follow-up was 53 months. There were no significant differences between patients with intestinal (N = 62) versus diffuse type (N = 70) gastric cancer with regard to the proportion of patients who underwent (neo)adjuvant treatment. Postoperative mortality was 2%. Pathological T- and N-stage were significantly more advanced for patients with diffuse type tumours. There was a significant difference in the percentage of microscopically irradical resections (2% versus 24%, p < 0.001) and median overall survival (129 versus 17 months, p < 0.001) between patients with intestinal type tumours and those with diffuse type tumours. On multivariate analysis, diffuse type histology was the only factor significantly associated with an R1 resection. In a multivariate Cox regression model, diffuse type histology was a significant adverse prognostic factor for overall survival.

CONCLUSIONS

Striking differences were found between patients with diffuse type tumours and those with intestinal type tumours. These differences call for a differentiated approach in the potentially curative treatment of these two tumour types.

Publicly funded clinical trials and the future of cancer care

Publicly sponsored trials, conducted primarily by cooperative groups sponsored by the National Cancer Institute, and commercially sponsored trials are necessary to create new knowledge, improve the care of oncology patients, and develop new drugs and devices. Commercial sponsors launch clinical trials that will result in drug approval, label extension, expansion of market share, and an increase in shareholder value. Conversely, publicly sponsored trials seek to optimize therapy for a particular disease, create new knowledge, and improve public health; these trials can also result in label extension of a drug and even in initial drug approval. Publicly sponsored trials may combine and/or compare drugs developed by different commercial sponsors, develop multimodality therapies (e.g., the combination of chemotherapy and radiation), or develop novel treatment schedules or routes of drug administration (e.g., intraperitoneal chemotherapy). Publicly sponsored trials are more likely to focus on therapies for rare diseases and to study survivorship and quality of life; these areas may not be a priority for commercial entities. Screening and prevention strategies have been developed almost exclusively by the public sector given the large sample size and long follow-up period needed to complete the trial and, therefore, the lack of short-term commercial gain. Finally, given the public nature of the funding, clinical investigators are expected to publish their results even if the outcomes are unfavorable for the investigational therapy. With the ongoing reorganization of the cooperative groups to form a national clinical trials network, opportunities exist to create a robust platform for biomarker discovery and validation through the expanded collection of well-annotated biospecimens obtained from clinical trial participants. Thus, publicly funded trials are vital to developing and refining new cancer treatments and disseminating results to the medical community and the general public.

Postoperative chemoradiotherapy combined with epirubicin-based triplet chemotherapy for locally advanced adenocarcinoma of the stomach or gastroesophageal junction

Background

Due to low tolerance to chemotherapy, the maximum number of cycles of postoperative adjuvant chemotherapy is 4 in adjuvant gastric clinical trials. The aim of this study is to retrospectively evaluate the safety and efficacy of adjuvant epirubicin-based triplet chemotherapy and radiotherapy in the treatment of resected locally advanced stomach or gastroesophageal junction adenocarcinoma.

Methodology/Principal Findings

From January 2004 to July 2008, ninety-seven consecutive gastric or gastroesophageal junction adenocarcinoma patients in stages T3–4/N+ were treated with postoperative radiotherapy and chemotherapy. The recommended treatment plan was radical resection followed by 1–2 cycles of adjuvant chemotherapy (ACT), postoperative chemoradiotherapy (CRT), and, finally, 4–5 cycles of ACT. The patients were classified into two groups depending on the number of cycles of ACT: group 1 received 4–6 cycles (n = 59), and group 2 received 0–3 cycles (n = 38). The detailed grouping is as follows: RT alone, 2; RT and CT, 18; concurrent RTCT and CT, 41; and CRT, 36. Of the 97 patients, 77 patients received concurrent therapy (CRT, (5-fluorouracil or capecitabine), and 20 received radiotherapy alone because of patient refusal (n = 15) or treatment toxicity (n = 5). After a median follow-up of 44 months, the 3-year disease free survival(DFS) and overall survival (OS) were 66.5% and 69.5% for group 1 and 45.5% and 50% for group 2, respectively (p = 0.005 and p = 0.024). Multivariate analysis revealed that 4–6 cycles of ACT, lymphovascular invasion, or peritoneal metastasis were independent prognostic factors for disease-free survival or overall survival (p<0.05).

Conclusions/Significance

This study demonstrates that concurrent chemoradiation with adjuvant epirubicin-based triplet chemotherapy is feasible and tolerable for gastric or gastroesophageal junction carcinoma patients. Patients can benefit from more cycles of ACT.

Comparison of two different adjuvant treatment modalities for pN3 gastric cancer patients after D2 lymph node dissection: can we avoid radiotherapy in a subgroup of patients?

Adjuvant chemoradiotherapy (CRT) is the standard of care for gastric cancer patients in the USA. However, in countries where D2 lymph node dissection is performed, the effect of radiotherapy on locoregional recurrence is controversial. The aim of this study is to compare the outcomes in pN3 gastric cancer patients following two adjuvant treatment modalities: chemotherapy (CT) and CRT after D2 lymph node dissection. Between 2005 and 2009, 71 gastric cancer patients who underwent D2 lymph node dissection and had pTanyN3M0 stage (according to AJCC 6th edition) were identified. Fifty-three patients were treated with CT and 18 patients received CRT. CRT consisted of bolus fluorouracil (FU) 425 mg/m(2) and leucovorin 20 mg/m(2) before, after, and during radiotherapy. For the CT arm, treatment protocols consisted of combination therapies involving FU and cisplatin as the backbone. Median overall survival (OS) and disease-free survival (DFS) rates for all patients were 26.3 months (15-37.7 months) and 12.5 months (8-17.1 months). Median OS in CT arm was 26.8 months and it was 34.2 months for CRT arm (p = 0.74). DFS rates did not differ statistically either (p = 0.56, 12.5 and 15.2 months for CT and CRT, respectively). Locoregional recurrence rates were also similar (p = 0.63). Only metastatic/dissected lymph node ratio (≥0.75) was identified as a prognostic factor in both univariate and multivariate analyses for DFS. Comparison of CT versus CRT for N3 stage gastric cancer patients with D2 lymph node dissection did not reveal any statistically significant difference in survival rates and locoregional recurrence.

Postoperative chemoradiotherapy in high risk locally advanced gastric cancer

Purpose

To evaluate treatment outcome of patients with high risk locally advanced gastric cancer after postoperative chemoradiotherapy.

Materials and Methods

Between May 2003 and May 2012, thirteen patients who underwent postoperative chemoradiotherapy for gastric cancer with resection margin involvement or adjacent structure invasion were retrospectively analyzed. Concurrent chemotherapy was administered in 10 patients. Median dose of radiation was 50.4 Gy (range, 45 to 55.8 Gy).

Results

The median follow-up duration for surviving patients was 48 months (range, 5 to 108 months). The 5-year overall survival rate was 42% and the 5-year disease-free survival rate was 28%. Major pattern of failure was peritoneal seeding with 46%. Locoregional recurrence was reported in only one patient. Grade 2 or higher gastrointestinal toxicity occurred in 54% of the patients. However, there was only one patient with higher than grade 3 toxicity.

Conclusion

Despite reported suggested role of adjuvant radiotherapy with combination chemotherapy in gastric cancer, only very small portion of the patients underwent the treatment. Results from this study show that postoperative chemoradiotherapy provided excellent locoregional control with acceptable and manageable treatment related toxicity in patients with high risk locally advanced gastric cancer. Thus, postoperative chemoradiotherapy may improve treatment result in terms of locoregional control in these high risk patients. However, as these findings are based on small series, validation with larger cohort is suggested.

Postoperative adjuvant radiotherapy for patients with gastric adenocarcinoma

In gastric adenocarcinoma, high rates of loco-regional recurrences have been reported even after complete resection, and various studies have been tried to find the role of postoperative adjuvant therapy. Among them, Intergroup 0116 trial was a landmark trial, and demonstrated the definite survival benefit in adjuvant chemoradiotherapy, compared with surgery alone. However, the INT 0116 trial had major limitation for global acceptance of the INT 0116 regimen as an adjuvant treatment modality because of the limited lymph node dissection. Lately, several randomized studies that were performed to patients with D2-dissected gastric cancer were published. This review summarizes the data about patterns of failure after surgical resection and the earlier prospective studies, including INT 0116 study. Author will introduce the latest studies, including ARTIST trial and discuss whether external beam radiotherapy should be applied to patients receiving extended lymph node dissection and adjuvant chemotherapy.

The role of perioperative radiotherapy in gastric cancer

Gastric cancer is one of the most common neoplasms and a main cause of cancer-related mortality worldwide. Surgery remains the mainstay for cure and is considered for all patients with potentially curable disease. However, despite the fact that surgery alone usually leads to favorable outcomes in early stage disease, late diagnosis usually means a poor prognosis. In these settings, multimodal therapy has become the established treatment for locally advanced tumors, while the high risk of locoregional relapse has favored the inclusion of radiotherapy in the comprehensive therapeutic strategy. We provide a critical, non-systematic review of gastric cancer and discuss the role of perioperative radiation therapy in its treatment.

Radiotherapy for tumors of the stomach and gastroesophageal junction--a review of its role in multimodal therapy

There is broad consensus on surgical resection being the backbone of curative therapy of gastric- and gastroesophageal junction carcinoma. Nevertheless, details on therapeutic approaches in addition to surgery, such as chemotherapy, radiotherapy or radiochemotherapy are discussed controversially; especially whether external beam radiotherapy should be applied in addition to chemotherapy and surgery is debated in both entities and differs widely between regions and centers. Early landmark trials such as the Intergroup-0116 and the MAGIC trial must be interpreted in the context of potentially insufficient lymph node resection. Despite shortcomings of both trials, benefits on overall survival by radiochemotherapy and adjuvant chemotherapy were confirmed in populations of D2-resected gastric cancer patients by Asian trials.

Recent results on junctional carcinoma patients strongly suggest a survival benefit of neoadjuvant radiochemotherapy in curatively resectable patients. An effect of chemotherapy in the perioperative setting as given in the MAGIC study has been confirmed by the ACCORD07 trial for junctional carcinomas; however both the studies by Stahl et al. and the excellent outcome in the CROSS trial as compared to all other therapeutic approaches indicate a superiority of neoadjuvant radiochemotherapy as compared to perioperative chemotherapy in junctional carcinoma patients. Surgery alone without neoadjuvant or perioperative therapy is considered suboptimal in patients with locally advanced disease.

In gastric carcinoma patients, perioperative chemotherapy has not been compared to adjuvant radiochemotherapy in a randomized setting. Nevertheless, the results of the recently published ARTIST trial and the Chinese data by Zhu and coworkers, indicate a superiority of adjuvant radiochemotherapy as compared to adjuvant chemotherapy in terms of disease free survival in Asian patients with advanced gastric carcinoma. The ongoing CRITICS trial is supposed to provide reliable conclusions about which therapy should be preferred in Western patients with gastric carcinoma. If radiotherapy is performed, modern approaches such as intensity-modulated radiotherapy and image guidance should be applied, as these methods reduce dose to organs at risk and provide a more homogenous coverage of planning target volumes.

Intraoperative radiotherapy for the treatment of resectable locally advanced gastric adenocarcinoma: topography of locoregional recurrences and long-term outcomes

INTRODUCTION

To report feasibility, tolerance, anatomical sites of upper abdominal locoregional recurrence and long-term outcome of gastric cancer patients treated with surgery and a component of intraoperative electron beam radiotherapy (IORT).

MATERIALS AND METHODS

From January 1995 to December 2010, 32 patients with primary gastric adenocarcinoma treated with curative resection (R0) [total gastrectomy (n = 9; 28 %), subtotal (n = 23; 72 %) and D2 lymphadenectomy in all patients] and apparent disease confined to locoregional area [Stage: II (n = 15; 47 %), III (n = 17; 53 %)] were treated with a component of IORT (IORT applicator size 5-9 cm in diameter, dose 10-15 Gy, beam energy 6-5 MeV) over the celiac axis and peripancreatic nodal areas. Sixteen (50 %) patients also received adjuvant treatment (external beam radiotherapy n = 6, chemoradiation n = 9, chemotherapy alone n = 1).

RESULTS

With a median follow-up time of 40 months (range, 2-60), locoregional recurrence was observed in five (16 %) patients (4 nodal in hepatic hilum and 1 anastomotic). Only pN1 patients developed locoregional relapse. No recurrence was observed in the IORT-treated target volume (celiac trunk and peripancreatic nodes). Overall survival at 5 years was 54.6 % (95 % CI: 48.57-60.58). Postoperative mortality was 6 % (n = 2) and postoperative complications 19 % (n = 6).

CONCLUSIONS

It is feasible to integrate IORT as a component of radiotherapy in combined modality therapy of gastric cancer. Local control is high in the radiation boosted area, but marginal regional extension (in particular, involving the hepatic hilum) might be considered as part of the anatomic IORT target volume at risk in pN+ patients.

A randomized, controlled, multicenter study comparing intensity-modulated radiotherapy plus concurrent chemotherapy with chemotherapy alone in gastric cancer patients with D2 resection

BACKGROUND AND PURPOSE

The role of postoperative chemoradiotherapy in the treatment of patients with gastric cancer with D2 lymph node curative dissection is not well established. In this study, we compared postoperative intensity-modulated radiotherapy plus chemotherapy (IMRT-C) with chemotherapy-only in this patient population.

MATERIALS AND METHODS

We randomly assigned patients with D2 lymph node dissection in gastric cancer to IMRT-C or chemotherapy-only groups. The adjuvant IMRT-C consisted of 400 mg of fluorouracil per square meter of body-surface area per day plus 20mg of leucovorin per square meter of body-surface area per day for 5 days, followed by 45 Gy of IMRT for 5 weeks, with fluorouracil and leucovorin on the first 4 and the last 3 days of radiotherapy. Two 5-day cycles of fluorouracil and leucovorin were given 4 weeks after the completion of IMRT. Chemotherapy-only group was given the same chemotherapy regimens as IMRT-C group.

RESULTS

The median overall survival (OS) in the chemotherapy-only group was 48 months, as compared with 58 months in the IMRT-C group; the hazard ratio for death was 1.24 (95% confidence interval, 0.94-1.65; P=0.122). IMRT-C was associated with increases in the median duration of recurrence-free survival (RFS) (36 months vs. 50 months), the hazard ratio for recurrence was 1.35 (95% confidence interval, 1.03-1.78; P=0.029). COX multivariate regression analysis showed that lymph node metastasis and TNM stage were both the independent prognostic factors. Rates of all grade adverse events were similar in the two treatment groups.

CONCLUSIONS

IMRT-C improved RFS, but did not significantly improve OS among patients with D2 lymph node dissection in gastric cancer. Using IMRT plus chemotherapy was feasible and well tolerated in patients with gastric cancer after D2 resection.

Gastrointestinal lymphomas: Morphology, immunophenotype and molecular features

Primary gastrointestinal lymphoma comprises 10-15% of all non-Hodgkin lymphomas and encompasses 30-40% of the total extranodal lymphomas. Approximately 60-75% of cases occur in the stomach, and then the small bowel, ileum, cecum, colon and rectum. Lymphoid neoplasms may consist of mature B, T and less commonly extranodal NK/T cells. Of these, the two most frequently encountered histologic subtypes are extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), where Helicobacter pylori infection is implicated in a number of cases, and diffuse large B cell lymphoma. Several B cell lymphomas are associated with chromosomal aberrations. Enteropathy-associated T cell lymphoma, type I in particular, usually arises in a background of celiac disease. T cell gene rearrangement confirms clonality. NK/T cell neoplasms are invariably associated with Epstein-Barr virus infection and are often aggressive; thus, differentiation from a benign NK-cell enteropathy is paramount. Although incidence of other hematopoietic malignancies in the gastrointestinal tract such as plasma cell myeloma associated with amyloidosis, plasmablastic lymphoma, Hodgkin disease, histiocytic sarcoma and mast cell sarcoma is extremely rare, these entities have been documented, with the latter two demonstrating aggressive clinical behavior. Endoscopic ultrasonography is an important adjunct in disease staging and follow-up. Conservative antibiotic treatment of stage I MALT lymphomas with associated Helicobacter pylori infection achieves good clinical outcome with high remission rate. Chemotherapy, radiation and rarely surgery are reserved for advanced diseases or cases resistant to conservative therapy and those not associated with Helicobacter pylori infection.

Who profits from neoadjuvant radiochemotherapy for locally advanced esophageal carcinoma?

BACKGROUND

Patients suffering from locally advanced esophageal carcinoma are generally treated using multimodal therapies. This prospective, non-randomized trial was performed to evaluate the survival benefit of neoadjuvant radiochemotherapy prior to surgery in comparison with surgery only.

PATIENTS & METHODS

Histopathological outcomes and survival were compared between 61 patients who underwent neoadjuvant radiochemotherapy and 64 comparable control patients who had been under-staged. After neoadjuvant therapy, tumor regression was assessed using the method described by Mandard in 1994. Survival curves for the two groups were estimated using the Kaplan-Meier method, and compared with the log-rank test.

RESULTS

Median and 3-year recurrence-free survival for the entire group were 26 months and 39.7%, respectively. The median and 3-year overall survival reached 34 months and 48.1%. Patients who showed complete response to neoadjuvant therapy had significantly improved survival (35 months) compared to patients with residual tumor cells (28 months), patients with tumors unresponsive to radiochemotherapy (22 months), or patients who received surgery only (control group, 29 months). Patients with nodal-negative carcinomas showed significantly longer survival after surgery only and after neoadjuvant therapy compared to patients with lymph node-positive cancers.

CONCLUSIONS

Complete response after neoadjuvant radiochemotherapy is associated with significantly improved survival. Negative nodal status is a major determinant of outcomes following primary operation or neoadjuvant treatment.