A phase II trial of concurrent 3D-CRT/IMRT and oxaliplatin, 5-fluorouracil and leucovorin (FOLFOX) in gastric cancer patients with R0 gastrectomy and D2 lymph node dissection

Efficacy and safety of intensity-modulated radiation therapy versus three-dimensional conformal radiation treatment for patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND

Radiation or radiochemotherapy is a common adjuvant therapy for gastric cancer. Intensity-modulated radiation therapy (IMRT) has been demonstrated to provide better dose conformity, allowing dose escalation and/or reduction of normal tissue exposure compared with three-dimensional conformal radiation treatment (3D-CRT). However, the efficacy of IMRT and 3D-CRT in gastric cancer remains controversial. This study aimed to compare the efficacy and safety of IMRT with those of 3D-CRT in treating patients with gastric cancer through conducting a meta-analysis of 3-year survival rates [overall survival (OS) and disease-free survival (DFS)], local control rates, and toxic event rates.

METHODS

Embase, PubMed, the Cochrane Library, and clinical trial databases were searched to identify the clinical trials of IMRT versus 3D-CRT for treating patients with gastric cancer. The obtained data of survival and safety were analyzed using the Stata 14.0 software.

RESULTS

A total of 9 controlled clinical studies, including 516 patients with gastric cancer, met the inclusion criteria and were included in this meta-analysis. The results of the meta-analysis showed that the 3-year OS rate was slightly higher in the IMRT group than in the 3D-CRT group, without any statistical significance. The 3-year local control rate was significantly higher in the IMRT group than in the 3D-CRT group. No significant difference in the 3-year DFS rate was found between the IMRT and 3D-CRT groups. Grade 2-4 toxicities were similar between the IMRT and 3D-CRT groups.

CONCLUSION

The findings suggested that IMRT might be superior to 3D-CRT in treating patients with gastric cancer in terms of local control rates without increasing toxicity.

The prognostic value of lymph node ratio for local advanced gastric cancer patients with adjuvant chemoradiotherapy after D2 gastrectomy

This study aimed to find the prognostic factors of local advanced gastric cancer patients with adjuvant concurrent chemoradiotherapy after radical D2 gastrectomy, and explore the prognostic value of lymph node ratio (LNR).We retrospectively analyzed 164 gastric cancer patients enrolled in West China Hospital from 2006 to 2013, who underwent D2 radical gastrectomy and adjuvant chemoradiotherapy. With univariate analysis and the Cox regression model, we evaluated the association of LNR and other clinical pathological characteristics with overall survival (OS) and relapse-free survival (RFS) of patients.Of 164 gastric cancer patients, the median age at diagnosis was 60 (IQR 51-66), with 121 males (73.78%) and 43 females (26.22%). The median follow-up time was 41.5 months. One-year and 3-year OS rate of the whole cohort was 97.6% and 88.4%, with 1-year RFS rate of 90.2% and 3-year RFS rate of 76.8%, respectively. In the univariate analysis, we found that age >60years (P = .025), TNM stage III (P = .014), LNR >0.25 (P = .006) and radiation dose <45Gy (P = .048) predicted worse OS. Further multivariate analysis indicated that age >60y (HR 2.375, 95% CI 1.100-5.128; P = .028), TNM stage III (HR 7.692, 95% CI 1.009-58.824; P = .049) and LNR >0.25 (HR 2.439, 95% CI 1.075-5.525; P = .033) were independent prognostic factors for unfavorable OS. The COX analysis showed that related prognostic factors of worse RFS were TNM stage III (HR 3.802, 95% CI 1.506-9.615; P = .049) and LNR >0.25 (HR 2.326, 95% CI 1.332-4.065; P = .003).LNR can be used as an important prognostic indicator for gastric cancer patients with D2 resection and adjuvant chemoradiotherapy, and LNR more than 0.25 indicates poor prognosis.

Regulatory T-cell density and cytotoxic T lymphocyte density are associated with complete response to neoadjuvant paclitaxel and carboplatin chemoradiotherapy in gastric cancer

Regulatory T-cell density and cytotoxic T lymphocyte density are crucial in regulating antitumor immune responses. Tumor infiltration has marked therapeutic effects in gastric carcinoma, and there is evidence that chemoradiotherapy (CRT) exhibits an immune-mediated component. In the present study, the density of CD4⁺ and CD8⁺ cells were evaluated in post-CRT surgical samples from 68 patients with gastric cancer using immunohistochemistry. The associations between T-cell density, cytotoxic T lymphocyte density and clinical survival rate were also analyzed. Cytotoxic T lymphocyte density was associated with gastric carcinoma regression grade and regulatory T-cell density was also associated with gastric carcinoma regression grade. Of the patients who had a pathologic complete response, 84 and 76% were found to have a high CD3⁺ and CD4⁺ cell density, which was significantly different to patients who had a low CD3⁺ and CD4⁺ cell density. High cytotoxic T lymphocyte density was also associated with improved survival rates of patients with gastric cancer. In conclusion, these outcomes indicated that regulatory T-cell density and cytotoxic T lymphocyte density in the tumor microenvironment were associated with the response to neoadjuvant CRT and may represent a therapeutic target for gastric cancer.

Between evidence and new perspectives on the current state of the multimodal approach to gastric cancer: Is there still a role for radiation therapy?

In patients affected by gastric cancer (GC), especially those in advanced stage, the multidisciplinary approach of treatment is fundamental to obtain a good disease control and quality of life. Although many chemotherapeutics in combination to radiotherapy are adopted in the peri- or postoperative setting, the most optimal timing, regimens and doses remains controversial. In the era of radical surgery performed with D2-lymphadenectomy, the role of radiation therapy remains to be better defined. Categories of patients, who could benefit more from an intensified local treatment rather than more toxic systemic therapy, are still under investigation. Evidence and recent updates of the randomized trials, meta-analysis and prospective trials show that the postoperative radiotherapy plays a fundamental role in reducing the loco-regional recurrence and in turn the disease-free survival in operable advanced GC patients, also after a well performed D2 surgery. Therapeutic decisions should be taken considering the individual patients, but the multimodal approach is necessary to guarantee a longer survival and a good quality of life. Ongoing randomized trials could better define the timing and the combination of radiotherapy and systemic therapy.

Adjuvant chemoradiation for gastric carcinoma: State of the art and perspectives

An estimated 990,000 new cases of gastric cancer are diagnosed worldwide each year. Surgical excision, the only chance for prolonged survival, is feasible in about 20% of cases. Even after surgery, the median survival is limited to 12 to 20 months due to the frequency of locoregional and/or metastatic recurrences. This led to clinical trials associating surgery with neoadjuvant or adjuvant treatments to improve tumor control and patient survival. The most studied modalities are perioperative chemotherapy and adjuvant chemoradiotherapy. To date, evidence has shown a survival benefit for postoperative chemoradiotherapy and for perioperative chemotherapy. Phase III trials are ongoing to compare these two modalities. The aim of this review is to synthesize current knowledge about adjuvant chemoradiotherapy in the management of gastric adenocarcinoma, and to consider its prospects by integrating modern radiotherapy techniques.

[Role of postoperative chemoradiotherapy in the therapeutic management of adenocarcinomas of the stomach and oesogastric junction]

The available data in the literature show that for gastric adenocarcinoma or gastroesophageal junction adenocarcinoma, postoperative chemoradiotherapy improves disease-free survival after surgery with D0 or D1 lymph node dissection (and perhaps D2) as well as in case of positive node or R1 resection. With the publications of perioperative chemotherapy trials, the role of postoperative radiotherapy in the therapeutic arsenal of gastric adenocarcinoma or gastroesophageal junction adenocarcinoma becomes difficult to define. Postoperative radiotherapy is indicated in case of R1 resection.