Impact of adjuvant therapy on locally advanced adenocarcinoma of the stomach

Postoperative chemo-radiotherapy versus chemotherapy for resected gastric cancer: a systematic review and meta-analysis

INTRODUCTION

This study conducted a systematic review and meta-analysis (direct and indirect) of published randomised controlled trials (RCTs) to compare the effects of postoperative chemo-radiotherapy (ChRT) with chemotherapy (Ch) on overall and disease-free survival (DFS) for patients with resectable gastric cancer.

METHODS

We searched MEDLINE and CENTRAL from the date of inception and annual meeting proceedings of American Society of Clinical Oncology and American Society for Radiation Oncology from 1999 to November 2012 for RCTs comparing postoperative ChRT with Ch, postoperative ChRT with surgery alone and postoperative Ch with surgery alone. The primary outcome was overall survival (OS); secondary outcomes included DFS and toxicity. Hazard ratios (HRs), confidence intervals (CIs) and P values (P) were estimated with fixed effects models using Revman 5.1.

RESULTS

We found six trials comparing postoperative ChRT with Ch (n = 1171). Meta-analysis of direct comparison trials showed that postoperative ChRT significantly improved both OS (HR 0.80, 95% CI 0.65-0.98, P = 0.03) and DFS (HR 0.76, 95% CI 0.63-0.91, P = 0.003) when compared with Ch. There were no significant differences in toxicity between the two groups.

CONCLUSIONS

This study suggests a survival benefit of postoperative ChRT over Ch in patients with resected gastric cancer.

The impact of radiotherapy on survival in resectable gastric carcinoma: a meta-analysis of literature data

BACKGROUND

The benefit of external radiotherapy for gastric carcinoma has been extensively studied, but data on survival are still equivocal.

OBJECTIVE

To assess the effectiveness of surgery combined with preoperative radiotherapy or postoperative chemoradiotherapy in the reduction of all-cause mortality in patients with resectable gastric carcinoma.

METHODS

Computerised bibliographic searches of MEDLINE and CANCERLIT (1970-2006) were supplemented with hand searches of reference lists.

STUDY SELECTION

Studies were included if they were randomised controlled trials (RCTs) comparing mortality of surgery combined with preoperative radiotherapy or postoperative chemoradiotherapy to surgery alone, and if they included patients with histologically-proven gastric adenocarcinoma without metastases. Nine eligible RCTs, 4 of preoperative radiotherapy (832 patients) and 5 of postoperative chemoradiotherapy (869 patients), were identified and included in the meta-analysis.

DATA EXTRACTION

Data on study populations, interventions, and outcomes were extracted from each RCT according to the intention to treat method by three independent observers and combined using the DerSimonian and Laird method.

RESULTS

Surgery combined with preoperative radiotherapy compared to surgery alone significantly reduced the 3-year (OR 0.57; 95% CI 0.43-0.76: p=0.0001) and 5-year (OR 0.62; 95% CI 0.46-0.84; p=0.002) mortality rate. A significant reduction of the 5-year (OR 0.45; 95% CI 0.32-0.64; p<0.00001) mortality rate was observed when surgery followed by chemoradiotherapy was compared to surgery alone.

CONCLUSIONS

In patients with resectable gastric carcinoma, adjuvant radiotherapy significantly reduces 3-year and 5-year all-cause mortality, but the magnitude of the benefit is relatively small. Available evidence is inadequate to determine whether postoperative chemoradiotherapy is superior to preoperative radiotherapy.

Results of adjuvant radiochemotherapy for gastric adenocarcinoma in Slovenia

AIMS

To analyze the results of postoperative concomitant radiochemotherapy with 5-florouracil (5-FU) and leucovorin (LV) in patients with gastric carcinoma treated in a single institution.

METHODS

During 2001-2004, 123 patients with the mean age of 60 years, were treated for adenocarcinoma of the stomach, stage Ib-IV, with postoperative concomitant radiochemotherapy. Radical (R0) and non-radical (R1) resection of the tumor was performed in 107 and 16 patients, respectively. Adjuvant treatment consisted of five cycles of five-day chemotherapy with 5-FU (425 mg/m(2)) and LV (20 mg/m(2)) and concomitant radiotherapy with the total dose of 45 Gy.

RESULTS

The treatment was completed according to the protocol in 101 patients. Stomatitis, dysphagia, and nausea and vomiting of grade three occurred in 32, 27, and 23 patients, respectively. The median follow-up time of 87 survivors was 30.4 months (range 17.4-58.3 months). At two years, locoregional control (LRC), disease-free survival (DFS), disease-specific survival (DSS) and overall survival (OS) rates were 86%, 65%, 74%, and 73%, respectively. In the multivariate analysis, the initial Hb level was identified as independent prognostic factor for all survival four endpoints, the involvement of whole stomach with cancer for LRC, the total dose of 5-FU per five-day cycle for DFS, and pT stage for DSS.

CONCLUSIONS

In operable gastric carcinoma, postoperative concomitant radiochemotherapy with 5-FU and LV is feasible and its toxicity acceptable. Its potential to improve the treatment outcome compared to the surgery alone is yet to be tested in well designed prospective randomized studies.

Adjuvant and neoadjuvant therapy for gastric cancer

Although the incidence of gastric cancer is decreasing, it remains a significant source of cancer-related mortality. Surgery remains the best chance for cure from gastric cancer. Adjuvant and neoadjuvant therapy have played increasing roles in attempting to reduce the disease-specific mortality and prolong survival. In this article, the authors review the literature and summarize the salient points regarding the roles of adjuvant and neoadjuvant therapy for gastric cancer.

Optimal locoregional treatment in gastric cancer

Worldwide, gastric cancer is one of the leading causes of cancer-related death. The mainstay of curative treatment is radical surgery. But even with optimal surgical resection, the prognosis remains modest in the Western world. Numerous attempts have been undertaken to improve clinical outcome. More extensive lymph node dissection, adjuvant radiotherapy and adjuvant chemotherapy did not result in a survival benefit in randomized trials. Only postoperative chemoradiotherapy has proven to be valuable in prospective randomized trials. Questions are to be answered about optimization of surgery, radiotherapy and chemotherapy, and fine tuning of the three modalities. One of the key issues that should be addressed is whether pre- or postoperative chemoradiotherapy will benefit survival or locoregional control in the case of optimal surgery with an "over-D1" lymphadenectomy and without splenectomy. In this article the most relevant literature on locoregional treatment in operable gastric cancer will be reviewed and future strategies will be discussed.

Patterns of failure in gastric carcinoma after D2 gastrectomy and chemoradiotherapy: a radiation oncologist's view

The risk of locoregional recurrence in resected gastric adenocarcinoma is high, but the benefit of adjuvant treatment remains controversial. In particular, after extended lymph node dissection, the role of radiotherapy is questionable. Since 1995, we started a clinical protocol of adjuvant chemoradiotherapy after D2 gastrectomy and analysed the patterns of failure for 291 patients. Adjuvant chemotherapy consisted of five cycles of fluorouracil and leucovorin, and concurrent radiotherapy was given with 4500 cGy from the second cycle of chemotherapy. With a median follow-up of 48 months, 114 patients (39%) showed any type of failure, and the local and regional failures were seen in 7% (20 out of 291) and 12% (35 out of 291), respectively. When the recurrent site was analysed with respect to the radiation field, in-field recurrence was 16% and represented 35% of all recurrences. Our results suggest that adjuvant chemoradiotherapy has a potential effect on reducing locoregional recurrence. Moreover, low locoregional recurrence rates could give a clue as to which subset of patients could be helped by radiotherapy after D2 gastrectomy. However, in order to draw a conclusion on the role of adjuvant radiotherapy, a randomised study is needed.

Results of chemoirradiation after curative resection of locally advanced gastric cancer

To evaluate the results of post-operative chemoirradiation for gastric carcinoma. The records of 58 patients who underwent resection for gastric carcinoma were retrospectively reviewed. Forty-six patients had complete resection without any residual disease but with high-risk factors of relapse. Twelve patients had microscopic residual disease. Doses of irradiation ranged from 45 to 54 Gy with a median dose of 49 Gy in 1.8 Gy fractions. Fifty-three of the patients received 5-fluorouracil-based concomitant chemoradiotherapy, and all of them received chemotherapy after the completion of radiotherapy. The median survival of the entire group of patients was 21 months. The 30th month disease-free and overall survival after surgery was 32 and 45%, respectively. The median survival time and 30th month survival rate was 23 months and 54% in patients with no residual disease, and 15 months and 18% for those with residual disease, respectively (p = 0.049). A statistically significant correlation was detected between residual disease and survival and between high-grade tumour and survival (p < 0.05 for each). Patients with both nodal involvement and direct tumour extension beyond the gastric wall have a high risk of locoregional failure, and adjuvant chemoradiotherapy reduces local failure and improves survival.

Combined-modality therapy for gastric cancer

Gastric cancer has a poor prognosis. It is often diagnosed at an advanced stage, and potentially curative treatments often can not be exercised. Even when a curative surgical resection is possible, only a minority of patients survive beyond 5 years, and locoregional failures are frequent among patients undergoing curative resections. Recently, the use of postoperative adjuvant chemoradiotherapy has yielded some notable benefits. Earlier studies have shown survival benefits in patients undergoing chemoradiotherapy for locally advanced unresectable gastric cancer. The recently reported Intergroup 0116 trial compared surgery alone with surgery plus postoperative chemotherapy plus chemoradiotherapy. Superior overall and disease-free survival rates among patients given combined-modality postoperative therapy were observed. These results established a new standard of care for patients following resection of gastric carcinoma. Preoperative combined-modality chemoradiotherapy may improve resectability, and is under investigation at the University of Texas M. D. Anderson Cancer Center. The development of novel radioenhancers and the selection of therapy on the basis of molecular determinants of response may result in much-needed advances in this field.

Intraoperative radiotherapy in the multimodality approach to gastric cancer

It is difficult to conclude a clear benefit from the addition of IORT to the multimodality treatment of gastric cancer based on the studies available. Only three prospective randomized trials have been published and each varies in the approach of combining adjuvant and neoadjuvant chemotherapy and EBRT with IORT. With a complex degree of confounding factors in these and other retrospective series, it also remains difficult to identify a decrease in local recurrence rates, or an improvement in overall patient survival rates attributable to the use of IORT. Several series, however, have identified patient subsets--specifically, patients who have advanced disease with serosal extension or node-positive disease--who may be more likely to benefit from the addition of IORT to gastric resection. Finally, there is no evidence in prospective or retrospective series that there is an increased patient risk or inferior outcome caused by the addition of IORT. Limited evidence of a possible benefit in advanced disease and no evidence of a disadvantage to the use of IORT have promoted continued use and investigation in the multimodality treatment of an aggressive disease. Continued efforts in prospective randomized trials should be promoted to further delineate the efficacy of IORT and EBRT in the treatment of gastric cancer, especially in light of recently published data [30], where concurrent chemotherapy has been reported to increase survival rates in high-risk patients.

Introducing the Intergroup 0116 Protocol of Adjuvant Chemo-radiotherapy in Gastric Cancer into Clinical Practice

AIMS

The results of techniques from a well-conducted clinical trial are often difficult to reproduce when implemented in community oncology practice. The U.S. Intergroup 0116 protocol of adjuvant chemo-radiotherapy in gastric cancer presented in mid-2000 produced a survival advantage over surgery alone. The current study aims to determine the adherence with protocol design and delivery of radiation therapy (radiotherapy) in the initial 20 patients managed with the Intergroup 0116 protocol at The National University Hospital, Singapore.

MATERIALS AND METHODS

A formal quality assurance audit was performed on clinical features, radiotherapy treatment charts and simulation films of the first 20 patients treated with the Intergroup 0116 protocol from July 2000 to September 2001. Specific details were audited for their consistency with described protocol in domains of eligibility criteria, radiotherapy prescription, target volume coverage and adherence to dose-limiting normal tissue tolerances. Compliance and toxicity with the protocol was assessed by audit of delivered radiotherapy dose, treatment interruptions, inpatient admissions and weight loss during radiotherapy.

RESULTS

The 20 audited patients were appropriately selected on the basis of eligibility criteria of Intergroup 0116 protocol. There was only one minor variation of radiotherapy target volume coverage resulting from marginal coverage of the porta hepatis region. Adherence to the protocol was satisfactory, with 19 patients completing the radiotherapy protocol as planned and only one major variation in treatment delivery resulting from gastrointestinal toxicity. One major and one minor variation in normal tissue-dose constraints occurred on the heart and spinal cord, respectively. Compliance with treatment delivery was good, with only one patient failing to complete the prescribed radiotherapy dose owing to toxicity, although seven patients required treatment interruption.

CONCLUSION

This audit showed good compliance with radiotherapy design and delivery. A formal medical quality assurance audit may provide a useful tool to assess complex new protocols introduced into routine departmental practice.

Curative treatment of gastric cancer: towards a multidisciplinary approach?

Despite marked decreases in incidence over the last century, particularly in developed countries, gastric cancer is still the second-most common tumor worldwide. Surgery remains the gold standard for the cure of locoregional disease. However, in most countries, the diagnosis is made at an advanced stage, and the 5-year survival for surgically resectable disease stays far below 50%. The efficacy of chemotherapy and/or radiation therapy in addition to surgery has been actively studied over the last 30 years. Unfortunately, with few exceptions, most studies of adjuvant therapy in gastric cancer have given deceiving results. The purpose of this review is to address the reasons for our failure to objectivate an improvement in the cure of gastric cancer with adjuvant treatment in most trials, and to consider potential solutions. The low efficacy of chemotherapy regimens available up to now may have hampered our progress. In addition, many previous studies suffered limitations of design or methodology (e.g. low accrual, inadequate disease stage selection, inadequate surgical treatment) that may have obscured a treatment effect. Furthermore, the reduced treatment tolerance of post-gastrectomy patients, perhaps due to their poor nutritional status, results in decreased or delayed adjuvant systemic therapy, with potential adverse consequences in its efficacy. Among potential solutions, the arrival of new drugs, taxanes and topoisomerase I inhibitors in particular, which have shown encouraging results in metastatic disease, may increase the impact of chemotherapy in a multidisciplinary treatment approach. Pre-treatment with chemotherapy and/or radiation therapy prior to surgery may also be advantageous, averting the problems associated with post-surgical treatment. Such an approach has been shown to be feasible in phase II studies, and is relatively well tolerated by patients. Several carefully designed randomized phase III trials are underway to answer this question.

Postoperative adjuvant chemoradiation in completely resected locally advanced gastric cancer

BACKGROUND

The 5-year survival of patients with completely resected node-positive gastric cancer ranges from 15% to 25%. We explored the feasibility of a chemoradiation regime consisting of concomitant hyperfractionated radiotherapy and 5-fluorouracil protracted venous infusion (5-FU PVI).

MATERIALS AND METHODS

Forty patients received a total or partial gastrectomy operation and D2 nodal resection for Stage III gastric cancer; they were then irradiated by linac with 6-15-MV photons. The target included the gastric bed, the anastomosis, stumps, and regional nodes. A total dose of 55 Gy was given in 50 fractions using 1.1 Gy b.i.d. All patients received a concomitant 200 mg/m2/day 5-FU PVI. Patients were examined during the follow-up period as programmed. Toxicity was recorded according to RTOG criteria.

RESULTS

After a median follow-up of 75.6 months (range: 22-136 months), 24 (60%) patients had died, and 16 (40%) were alive and free of disease. The 5-year actuarial incidence of relapse was 39%, 22%, and 2% for distant metastases, out-field peritoneal seeding, and in-field local regional recurrences, respectively. The 5-year actuarial cause-specific survival was 43%. Three patients survived more than 11 years. Acute > or = Grade 3 toxicity consisted of hematologic (22.5%) and gastrointestinal toxicity (nausea and vomiting 22.5%, diarrhea 2.8%, and abdominal pain 2.6%). No late toxicity was observed.

CONCLUSION

This regime of concomitant 5-FU PVI and hyperfractionated radiotherapy was well tolerated and resulted in successful locoregional control and satisfactory survival.

Gastric surgical adjuvant radiotherapy consensus report: rationale and treatment implementation

PURPOSE

Radiation therapy has recently emerged as a pivotal modality in the management of completely resected, high-risk gastric cancer. The recently published results of the Intergroup 0116 Gastric Surgical Adjuvant Trial randomized high-risk (T3,4 and/or node positive), completely resected gastric or gastroesophageal adenocarcinomas to receive either observation alone or radiochemotherapy after complete resection. Radiochemotherapy produced significant improvements in relapse-free (p < 0.0001) and overall survival (p = 0.01). Radiation oncologists must now clearly comprehend the principles governing the rationale supporting this therapy to apply it to those afflicted with this disease. This paper represents a consensus report reviewing data supporting radiotherapy, important clinical and anatomic issues related to radiotherapy, and details of the practical application of radiation therapy to commonly occurring clinical presentations. Supportive therapy during and after radiochemotherapy is also discussed.

[Target volume in radiotherapy of gastric adenocarcinoma]

The spread of gastric adenocarcinoma may follow three main patterns: hematogenic, lymphatic and intraperitoneal. A GTV should be considered in preoperative or exclusive radiation therapy. After non-radical surgery, a "residual GTV" will be defined with the help of the surgeon. The CTV encompasses three intricated volumes. a) A "tumor bed" volume. After radical surgery, local recurrences appear as frequent as distant metastases. The risk depends upon the depth of parietal invasion and the nodal status. Parietal infiltration may extend beyond macroscopic limits of the tumor, especially in "linitis plastica". Therefore this volume will include: the tumor and the remaining stomach or their "bed of resection", a part of the transverse colon, the duodenum, the pancreas and the truncus of the portal vein. In postoperative RT, this CTV also includes the jejuno-gastric or jejuno-esophageal anastomosis. b) A peritoneal volume. For practical purposes, two degrees of spread must be considered: (1) contiguous microscopic extension from deeply invasive T3 and T4 tumors, that remain amenable to local sterilization with doses of 45-50 Gy, delivered in a CTV including the peritoneal cavity at the level of the gastric bed, and under the parietal incision; (2) true "peritoneal carcinomatosis", with widespread seeds, where chemotherapy (systemic or intraperitoneal) is more appropriate. c) A lymphatic volume including the lymph node groups 1 to 16 of the Japanese classification. This volume must encompass the hepatic pedicle and the splenic hilum. In proximal tumors, it is possible to restrict the lower part of the CTV to the lymphatic volume, and therefore to avoid irradiation of large intestinal and renal volumes. In distal and proximal tumors, involvement of resection margins is of poor prognosis--a radiation boost must be delivered at this level. The CTV in tumors of the cardia should encompass the lower part of the thoracic esophagus and the corresponding posterior mediastinum. In tumors invading the distal esophagus, a more complete coverage of mediastinal lymph nodes should be considered, especially in patients in good general condition. In tumors of the gastric fundus, most of the left hemidiaphragm should be included, as well as the spleen and its hilum (or their resection bed). In proximal tumors without involvement of the lesser curvature, a full coverage of the hepatic pedicle is not necessary. In contrast, for distal tumors, the hepatic pedicle and the hepatoduodenal ligament should be included whereas the splenic area could be spared.

CONCLUSION

Planning the treatment of gastric cancer remains difficult; target volumes must be customized by experienced radiation oncologists according to tumoral and clinical situation.

Results of irradiation or chemoirradiation following resection of gastric adenocarcinoma

PURPOSE

To evaluate the results of postoperative irradiation +/- chemotherapy for carcinoma of the stomach and gastroesophageal junction.

METHODS AND MATERIALS

The records of 63 patients who underwent resection for stomach cancer were retrospectively reviewed. Twenty-five patients had complete resection with no residual disease but with high-risk factors for relapse. Twenty-eight had microscopic residual and 10 had gross residual disease. Doses of irradiation ranged from 39.6 to 59.4 Gy with a median dose of 50.4 Gy in 1.8 Gy fractions. Fifty-three of the 63 (84%) patients received 5-fluorouracil (5-FU)-based chemotherapy.

RESULTS

The median duration of survival was 19.3 months for patients with no residual disease, 16.7 months for those with microscopic residual disease, and 9.2 months for those with gross residual disease (p = 0.01). The amount of residual disease also significantly impacted locoregional control (p = 0.04). Patients with linitis plastica did significantly worse in terms of survival, locoregional control, and distant control than those without linitis plastica. The use of 4 or more irradiation fields was associated with a significant decrease in the rate of Grade 4 or 5 toxicity when compared to the patients treated with 2 fields (p = 0.05).

CONCLUSIONS

There was a significant association between survival and extent of residual disease after resection as well as the presence of linitis plastica. Distant failures are common and effective systemic therapy will be necessary to improve outcome. The toxicity of combined modality treatment appears to be reduced by using greater than 2 irradiation fields.

Response to neoadjuvant chemotherapy best predicts survival after curative resection of gastric cancer

OBJECTIVE

In Western populations, long-term survival rates after curative resection of gastric cancer remain extremely poor. The lack of effective adjuvant therapy has prompted the evaluation of neoadjuvant approaches. Since 1988, we have conducted three separate phase II trials using neoadjuvant chemotherapy to treat patients with potentially resectable gastric cancer. The present study was conducted to evaluate whether response to neoadjuvant chemotherapy is predictive of survival in patients with resectable gastric cancer.

METHODS

Eighty-three patients with pathologically confirmed gastric adenocarcinoma were treated with neoadjuvant chemotherapy before planned surgical resection. Response was assessed by upper gastrointestinal series, endoscopy, computed tomography scan, and pathologic examination.

RESULTS

For the three phase II trials, clinical response rates ranged from 24% to 38%. Three patients (4%) had a complete pathologic response. Sixty-one patients (73%) underwent a curative resection. Median follow-up was 26 months. Univariate analysis revealed T stage, number of positive nodes, and response to chemotherapy to be significant predictors of overall survival. However, on multivariate analysis, response to chemotherapy was found to be the only independent prognostic factor.

CONCLUSIONS

Response to neoadjuvant chemotherapy is the single most important predictor of overall survival after neoadjuvant chemotherapy for gastric cancer. These findings support further evaluation of neoadjuvant approaches in the treatment of this disease.

Patterns of failure and long-term results in high-risk resected gastric cancer treated with postoperative radiotherapy with or without intraoperative electron boost

BACKGROUND

To evaluate the possible role of adjuvant radiotherapy in the management of high-risk resected gastric carcinoma.

METHODS

From 1982 to 1993, 62 patients surgically resected of a primary gastric cancer with adverse pathological features (serosal and/or regional lymph node involvement) were treated with postoperative radiotherapy with (Group I) or without (Group II) intraoperative electron boost to the surgical bed and coeliac axis (IORT).

RESULTS

After a median follow-up of 75.6 months (range 4-120+) for IORT patients and 91.2 months (range 6-149+) for non-IORT patients, overall relapse rates for Group I and Group II patients were 44.5% and 48.6% and local-regional relapse rates were 11.1% and 20%, respectively. Actuarial survival rates projected at the maximum follow-up were 41% and 38% in Groups I and II, respectively.

CONCLUSIONS

This retrospective analysis suggests a beneficial effect of adjuvant external radiotherapy in promoting local-regional control in high-risk resected gastric cancer.

Radiation dose-response of human tumors

PURPOSE

The dose of radiation that locally controls human tumors treated electively or for gross disease is rarely well defined. These doses can be useful in understanding the dose requirements of novel therapies featuring inhomogeneous dosimetry and in an adjuvant setting. The goal of this study was to compute the dose of radiation that locally controls 50% (TCD50) of tumors in human subjects.

METHODS AND MATERIALS

Logit regression was used with data collected from single institutions or from combinations of local control data accumulated from several institutions treating the same disease.

RESULTS

90 dose response curves were calculated; 62 of macroscopic tumor therapy, 28 of elective therapy with surgery for primary control. The mean and median TCD50 for gross disease were 50.0 and 51.9 Gy, respectively. The mean and median TCD50 for microscopic disease control were 39.3 and 37.9 Gy, respectively. At the TCD50, an additional dose of 1 Gy controlled an additional 2.5% (median) additional patients with macroscopic disease and 4.2% (median) additional patients with microscopic disease. For both macro- and microscopic disease, an increase of 1% of dose at the TCD50 increased control rates approximately 1% (median) or 2-3% (mean). A predominance of dose response curves had shallow slopes accounting for the discrepancy between mean and median values.

CONCLUSION

Doses to control microscopic disease are approximately 12 Gy less than that required to control macroscopic disease, and are about 79% of the dose required to control macroscopic disease. The percentage increase in cures expected for a 1% increase in dose is similar for macroscopic microscopic disease, with a median value of approximately 1%/% and a mean of approximately 2.7%/%.

Treatment of adenocarcinoma of the stomach with resection, intraoperative radiotherapy, and adjuvant external beam radiation: a phase II study from Radiation Therapy Oncology Group 85-04

BACKGROUND

Fewer than 10% of patients presenting with adenocarcinoma of the stomach in the United States can expect to be cured. These discouraging results have led to trials of various adjuvant therapies. Some studies suggest a role for radiation in improving regional control. Radiation doses, however, are limited by the tolerance of abdominal organs.

METHODS

Between 1985 and 1989, the Radiation Therapy Oncology Group conducted a phase II study to determine the feasibility of using intraoperative radiotherapy (IORT) in the treatment of adenocarcinoma of the stomach. Forty-three patients were entered into the study. Patients underwent maximal surgical resection (subtotal or total gastrectomy and regional node dissection) and IORT doses of 12.5-16.5 Gy were delivered in 27 patients. Adjuvant external beam radiation was given to 23 of the 27 patients with total doses ranging from 24 to 50 Gy.

RESULTS

Two-year actuarial survival in the 27 patients receiving IORT was 47% and median survival was 19.3 months. Disease-free survival was 27%. Fifteen percent failed locally only, 26% with distant metastases only and 22% with both. Acute postoperative complications occurred in 14% with one fatality. Severe late complications occurred in 7% with one fatality.

CONCLUSIONS

Intraoperative radiotherapy combined with surgical resection and postoperative radiotherapy appears to be feasible without excessive morbidity in a multiinstitutional study. Its ultimate value requires further study.

The role of radiation therapy in the management of gastric cancer

Gastric cancer continues to be one of the most important gastrointestinal cancers. Despite improved surgery and resection rates of 30%-60% still most of the patients die of loco-regional recurrence or distant metastasis. The role of adjuvant and palliative treatment of gastric cancer has world-wide been assessed in uncontrolled and prospective studies. Many of those were insufficient with respect to the number of patients and inclusion of prognostic factors as stratification criteria. Furthermore, the radiation oncologist would have preferred if these studies had looked at loco-regional tumor control instead of response rates or overall survival. A comprehensive overview of the currently available data for radiation therapy in adjuvant and palliative treatment schedules of gastric cancer is given and the limits of these studies are critically discussed. Until now, there is no clear evidence of improved overall survival from the addition of radiation therapy. However, the data suggest radiation therapy might be an effective measure to reduce loco-regional recurrence rates and similarly increase the recurrence-free survival. For the next future, optimally designed phase III trials with sufficient numbers of patients should be initiated to assess the definite value of radiation therapy for gastric cancer.