High dose external beam radiation therapy with or without concomitant chemotherapy for esophageal carcinoma

WITHDRAWN. Combined chemotherapy and radiotherapy (without surgery) compared with radiotherapy alone in localized carcinoma of the esophagus

BACKGROUND

Esophageal carcinoma can be managed primarily with either a surgical or non-surgical radiotherapeutic approach. Combination chemotherapy (CT) and radiotherapy (RT) has been incorporated into clinical practice and applied increasingly, especially in North America.

OBJECTIVES

To evaluate combined CT and RT (CTRT) versus RT alone in patients with localized esophageal carcinoma. Outcomes included overall survival, cause-specific survival, local recurrence, dysphagia relief, quality of life, acute and chronic toxicities.

SEARCH STRATEGY

The Cochrane strategy for identifying randomized trials was combined with relevant MeSH headings. The Cochrane Library, MEDLINE, CancerLIT and EMBASE were last searched in April 2005. References from relevant articles and personal files were included.

SELECTION CRITERIA

Randomized controlled trials in patients with localized esophageal cancer comparing RT alone with combined CTRT were included. Studies comparing non-chemotherapy agents such as pure radiotherapy sensitisers, immunostimulants, planned esophagectomy, were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data independently. Trial quality was assessed using the Jadad scale and Detsky checklist. Sensitivity analyses were planned to examine the effect of concomitant versus sequential treatment, study quality, radiotherapy dose, and whether the drug regimen contained cisplatin or 5-fluorouracil were performed.

MAIN RESULTS

Nineteen randomized trials were included, with eleven concomitant and eight sequential RTCT studies. Concomitant RTCT provided significant reduction in mortality with a harms ratio (HR) of 0.73 (95% confidence interval (CI) 0.64 to 0.84). Using an estimated mortality rate for the control group of 62% at year one and 83% at year two, the absolute survival benefit for RTCT was 9% (95% CI 5 to 12%) and 4% (95% CI 3 to 6%]) respectively. There was an absolute reduction of local recurrence rate of 12% (95% CI 3 to 22%), number needed to treat (NNT) of 9, when the local recurrence rate for the RT alone arm was 68%. This was associated with a significant risk of severe and life-threatening toxicities (number needed to harm (NNH)of 6). Sensitivity analyses did not identify any factors that interacted with the results. The results from sequential RTCT studies showed no significant benefit in survival or local control but significant toxicities.

AUTHORS' CONCLUSIONS

Based on the available data, when a non-operative approach is selected then concomitant RTCT is superior to RT alone for patients with localized esophageal cancer but with significant toxicities. In patients who are in good general condition, and the risk benefit has been thoroughly discussed with the patient, concomitant RTCT should be considered for the management of esophageal cancer compared with radiotherapy alone.

Combined chemotherapy and radiotherapy (without surgery) compared with radiotherapy alone in localized carcinoma of the esophagus

BACKGROUND

Esophageal carcinoma can be managed primarily with either a surgical or non-surgical radiotherapeutic approach. Combination chemotherapy (CT) and radiotherapy (RT) has been incorporated into clinical practice and applied increasingly, especially in North America.

OBJECTIVES

To evaluate combined CT and RT (CTRT) versus RT alone in patients with localized esophageal carcinoma. Outcomes included overall survival, cause-specific survival, local recurrence, dysphagia relief, quality of life, acute and chronic toxicities.

SEARCH STRATEGY

The Cochrane strategy for identifying randomized trials was combined with relevant MeSH headings. The Cochrane Library, MEDLINE, CancerLIT and EMBASE were last searched in April 2005. References from relevant articles and personal files were included.

SELECTION CRITERIA

Randomized controlled trials in patients with localized esophageal cancer comparing RT alone with combined CTRT were included. Studies comparing non-chemotherapy agents such as pure radiotherapy sensitisers, immunostimulants, planned esophagectomy, were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data independently. Trial quality was assessed using the Jadad scale and Detsky checklist. Sensitivity analyses were planned to examine the effect of concomitant versus sequential treatment, study quality, radiotherapy dose, and whether the drug regimen contained cisplatin or 5-fluorouracil were performed.

MAIN RESULTS

Nineteen randomized trials were included, with eleven concomitant and eight sequential RTCT studies. Concomitant RTCT provided significant reduction in mortality with a harms ratio (HR) of 0.73 (95% confidence interval (CI) 0.64 to 0.84). Using an estimated mortality rate for the control group of 62% at year one and 83% at year two, the absolute survival benefit for RTCT was 9% (95% CI 5 to 12%) and 4% (95% CI 3 to 6%]) respectively. There was an absolute reduction of local recurrence rate of 12% (95% CI 3 to 22%), number needed to treat (NNT) of 9, when the local recurrence rate for the RT alone arm was 68%. This was associated with a significant risk of severe and life-threatening toxicities (number needed to harm (NNH)of 6). Sensitivity analyses did not identify any factors that interacted with the results. The results from sequential RTCT studies showed no significant benefit in survival or local control but significant toxicities.

AUTHORS' CONCLUSIONS

Based on the available data, when a non-operative approach is selected then concomitant RTCT is superior to RT alone for patients with localized esophageal cancer but with significant toxicities. In patients who are in good general condition, and the risk benefit has been thoroughly discussed with the patient, concomitant RTCT should be considered for the management of esophageal cancer compared with radiotherapy alone.

Multiple Management Modalities in Esophageal Cancer: Combined Modality Management Approaches

The overall success rate nationally in treating esophageal carcinomas remains poor, with over 90% of patients succumbing to the disease. In part I of this two-part series, we explored epidemiology, presentation and progression, work-up, and surgical approaches. In part II, we explore the promising suggestions of integrating chemotherapy and radiation therapy into the multimodal management of esophageal cancers. Alternative approaches to resection alone have been sought because of the overall poor survival rates of esophageal cancer patients, with failures occurring both local-regionally and distantly. Concomitant chemotherapy and radiation therapy (XRT) have been shown, by randomized trial, to be more effective than XRT alone in treating unresectable esophageal cancers and also have shown promise as a neoadjuvant treatment when combined with surgery in the multimodal treatment of this disease. Various studies have also addressed issues such as preoperative chemotherapy, radiation dose escalation, chemotherapy/XRT as a definitive treatment versus use as a surgical adjuvant, and alternative chemotherapy regimens. There are suggestions of some progress, but this remains a difficult problem area in which management is continuing to evolve.

Combined chemotherapy and radiotherapy (without surgery) compared with radiotherapy alone in localized carcinoma of the esophagus

BACKGROUND

Esophageal carcinoma can be managed primarily with either a surgical or radiotherapeutic (non surgical) approach. Strategies to improve the outcome of either modality alone include the use of combined modalities. Combination chemotherapy radiotherapy is one approach that has been explored over the years with increasing application in clinical practice especially in North America.

OBJECTIVES

To evaluate the effectiveness of combined chemotherapy and radiotherapy versus radiotherapy alone in the outcome of patients with localized esophageal carcinoma. Outcomes of interest include overall survival, cause specific survival, local recurrence, dysphagia relief, quality of life, acute and chronic toxicities.

SEARCH STRATEGY

The Cochrane strategy for identifying randomized trials was combined with MeSH headings including esophageal neoplasms, radiotherapy, chemotherapy combined modality, drug therapy combination. MEDLINE, CancerLIT and EMBASE were searched using this strategy. In addition, the Cochrane library was also searched. References from relevant articles and personal files were included.

SELECTION CRITERIA

Randomized controlled trials in patients with localized esophageal cancer, with one arm employing radiotherapy alone, and one arm employing combination radiotherapy chemotherapy were included. Studies comparing non chemotherapy agents such as pure radiotherapy sensitisers, immunostimulants, planned esophagectomy, were excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent reviewers, and the trial quality was assessed using both the Jadad scoring and Detsky checklist. Sensitivity analysis was planned to explore sources of heterogeneity where heterogeneity existed. The factors hypothesized a priori included combination versus sequential treatment, quality of study, biological effective radiotherapy dose (i.e. Radiotherapy dose) cisplatin versus non cisplatin containing trials, and 5FU versus non 5FU containing trials. Odds Ratio (OR) and 95% confidence limits were used to assess the significance of the difference between the treatment arms. Absolute risk difference and number needed to treat (NNT) were used to express the magnitude of difference where appropriate.

MAIN RESULTS

Thirteen randomized trials were included in the analysis. There were eight concomitant and five sequential radiotherapy and chemotherapy (RTCT) studies. The studies were analyzed separately due to observed heterogeneity across all the studies and biological considerations. Concomitant RTCT provided significant overall reduction in mortality at 1 and 2 years. The mortality in the control arms was 62% and 83% respectively. Combined RTCT provided an absolute reduction of mortality by 7% (95% CI 1-15%) and 7% (95% CI 0-15%) respectively. Expressed as NNT, this is 12 and 12 respectively. At longer follow up, the results were heterogeneous, cautioning against pooling of the data. There was a reduction in the overall local recurrence rate. The local recurrence rate for the control arms was in the order of 68%. Combined RTCT provided an absolute reduction of local recurrence rate of 12% (95% CI 3-22%) with a NNT of 9. There was significant increase of severe and life threatening toxicities with a NNH of 6, with this approach. The sensitivity analysis did not identify any factor that interacted with the results, or subgroup in which the benefit appear to be limited to. The results from the sequential RTCT studies were heterogeneous and could not be pooled. Factors hypothesized a priori did not identify any single source that could account for a significant component of the heterogeneity. Examining the results individually, there was no data to support clinical benefit. This approach was also accompanied by significant toxicities.

REVIEWER'S CONCLUSIONS

When a non-operative approach is selected, then concomitant RTCT is superior to the RT alone. This approach is accompanied by significant toxicities. In patients who are in good general condition, and the risk benefit has been thoroughly discussed with the patient, co thoroughly discussed with the patient, concomitant RTCT should be considered for the management of esophageal cancer compared with radiotherapy alone.

Biology of esophageal cancer and the role of combined modality therapy

1. The biology of esophageal cancer involves multifactorial environmental and genetic events. 2. The understanding of the clinical significance of molecular markers is rapidly evolving. 3. Combined-modality approaches should still include surgery in good performance status (ECOG scale < or = 2) patients. 4. Neoadjuvant chemoradiation is probably better than surgical resection alone for patients with potentially curable disease, but only validation of this approach by CALGB-9781 can justify this as a new "proven" standard-of-care in the United States. 5. A pathologic complete response to neoadjuvant therapy is the strongest predictor of long-term survival. 6. 5-FU, by either short course or protracted continuous infusion, comprises the backbone of combination chemotherapy in combined-modality design. 7. Radiation therapy should be given at standard 1.8 to 2 Gy/fraction without a scheduled break. 8. Only by enrolling sufficient numbers of patients in prospective clinical trials will clinicians be able to further define the optimal sequencing and actual necessity of each individual component of combined-modality therapy.