ESOPHAGEAL CANCER
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Historical control bias: adjuvant chemotherapy in esophageal cancer.
Bhansali MS; Patil PK; Badwe RA; Havaldar R; Desai PB.
Dis Esophagus, 10(1):51-4 1997 Jan.This article emphasizes that the studies that determined the efficacy of chemotherapy in patients with esophageal cancer by comparing survival rates of chemotherapy-treated patients with those of historical controls, contained bias that could have compromised the validity of the studies' results. The authors show how historical controls cannot be used to investigate the efficacy of a treatment. To demonstrate the point, they evaluated survival in patients with esophageal cancer treated with adjuvant chemotherapy and compared them with those of historical controls and contemporary controls. While comparison with historical controls demonstrated a survival advantage for patients treated with chemotherapy, comparison with contemporary controls showed no beneficial effect on survival associated with chemotherapy.
Chemotherapy for carcinoma of the esophagus: a comparison of evidence from meta-analyses of randomized trials and of historical control studies.
Bhansali MS, Vaidya JS, Bhatt RG, Patil PK, Badwe RA, Desai PB.
Ann Oncol 1996 Apr;7(4):355-9.This study analyzed the results of published randomized trials and of studies that used historical controls to determine the effects of cisplatin-based chemotherapy on survival in patients with esophageal cancer. Analysis of studies in which survival rates of patients treated with chemotherapy were compared to those of historical controls showed a survival advantage associated with chemotherapy use. On the other hand, analysis of randomized trials in which survival of chemotherapy-treated patients were compared to those of contemporary controls revealed that patients treated with chemotherapy fared no better in terms of survival, than those who did not receive the treatment. These data indicate that use of historical controls introduce bias that compromise the validity of the study conclusions.
Pre-operative radiotherapy prolongs survival in operable esophageal carcinoma: a randomized, multicenter study of pre-operative radiotherapy and chemotherapy
The second Scandinavian trial in esophageal cancer.
Nygaard K; et al.
World J Surg, 16(6):1104-9; discussion 1110 1992 Nov-Dec.The results of this study show that patients with esophageal cancer who receive chemotherapy before undergoing surgery fare no better, in term of survival, than those who receive surgery only. On the other hand, survival rates seemed to be improved in patients who received radiation therapy, compared to those who did not.
Bleomycin/cis-platin as neoadjuvant chemotherapy before radical radiotherapy in localized, inoperable carcinoma of the esophagus.
A prospective randomized multicentre study: the second Scandinavian trial in esophageal cancer.
Hatlevoll R; et al.
Radiother Oncol, 24(2):114-6 1992 Jun.The results of this study show that survival rates in patients with advanced esophageal cancer who received chemotherapy before radiotherapy were no better than those of patients who received radiation therapy only.
Chemotherapy followed by surgery compared with surgery alone for localized esophageal cancer.
Kelsen DP; et al.
N Engl J Med, 339(27):1979-84 1998 Dec 31.The results of this large, randomized trial show that chemotherapy does not prolong survival in patients with early esophageal cancer. The trial was conducted on 440 patients who were randomized to receive chemotherapy before and after surgery, or surgery alone. During a 6-year follow-up, no significant differences in terms of survival were observed between the two groups. Average survival was 14.9 months in patients who underwent adjuvant chemotherapy, and 16.1 months in patients who received surgery only.
A randomized study of radiotherapy alone versus radiotherapy plus 5-fluorouracil and platinum in patients with inoperable, locally advanced squamous cancer of the esophagus.
Slabber CF; Nel JS; Schoeman L; Burger W; Falkson G; Falkson CI.
Am J Clin Oncol, 21(5):462-5 1998 Oct.The results of this study show that the addition of chemotherapy to radiation therapy does not improve survival in patients with inoperable esophageal cancer.
Neoadjuvant chemoradiotherapy for esophageal cancer: is it worthwhile?
Tamim WZ; Davidson RS; Quinlan RM; O'Shea MA; Orr RK; Swanson RS.
Arch Surg, 133(7):722-6 1998 Jul.The role of adjuvant chemotherapy in patients with esophageal cancer is still under debate. Chemotherapy is commonly given to patients with esophageal cancer prior to surgery. Its administration has been shown to cause significant disability but no survival advantage in this type of patients. This study evaluated survival and quality of life in 51 patients receiving chemotherapy before undergoing surgery. Average survival time was 16.3 months, not significantly different from the reported survival of patients who received surgery alone. Of note, these patients spent 20% of their survival time (3.3 months) undergoing treatment and experiencing treatment-related side effects.
High dose chemoradiotherapy followed by esophagectomy for adenocarcinoma of the esophagus and gastroesophageal junction:
Results of a phase II study of the Eastern Cooperative Oncology Group.
Keller SM; et al.
Cancer, 83(9):1908-16 1998 Nov 1.The results of this study show that high dose radiotherapy and chemotherapy prior to surgery in patients with stage I and stage II esophageal cancer is associated with excess morbidity and mortality. In particular, among 46 patients enrolled in the study, there were 8 treatment-related deaths. Average survival in patients who survived treatment was 16.6 months.
Preoperative radiotherapy in esophageal carcinoma: a meta-analysis using individual patient data
Oesophageal Cancer Collaborative Group
Arnott SJ; et al.
Int J Radiat Oncol Biol Phys, 41(3):579-83 1998 Jun 1.Since there is no conclusive evidence demonstrating a survival advantage in patients with early esophageal cancer treated with radiation therapy before surgery, this study was conducted to determine the effects of radiation treatment on survival in this type of patients. Published and unpublished trials conducted on more than a thousand patients were evaluated. No clear survival advantage could be demonstrated in patients with esophageal cancer treated with radiation therapy over those who did not receive it.
Low dose preoperative radiotherapy for carcinoma of the oesophagus: results of a randomized clinical trial.
Arnott SJ; et al.
Radiother Oncol, 24(2):108-13 1992 Jun.The results of this study show that radiation therapy given before surgery does not prolong survival in patients with esophageal cancer. One-hundred-and-seventy-six patients were randomized to receive pre-operative radiotherapy or surgery alone. No differences in survival rates were observed between the two groups.
The quality of swallowing for patients with operable esophageal carcinoma: a randomized trial comparing surgery with radiotherapy.
Badwe RA, et al.
Cancer 1999 Feb 15;85(4):763-8.The results of this study show that patients with esophageal cancer who are treated with surgery fare significantly better than those treated with radiation therapy. The study was conducted on 99 patients with operable esophageal cancer who were randomized to receive radiation therapy only or surgery only. Patients treated with surgery were 2.7 times more likely to be alive 1 year after treatment, compared to those treated with radiation therapy. Furthermore, those who underwent surgery were twice as likely to experience improvement in swallowing, compared to those who received radiotherapy.
Chemoradiotherapy followed by surgery compared with surgery alone in squamous-cell cancer of the esophagus.
Bosset JF, et al.
N Engl J Med 1997 Jul 17;337(3):161-7.
The results of this study show that administration of preoperative chemo- and radiotherapy does not prolong survival in patients with esophageal cancer. The study was conducted on 282 patients randomized to undergo treatment with either surgery alone or with chemotherapy and radiotherapy prior to surgery. Average survival was 18.6 months in both groups. Although patients undergoing chemo- and radiotherapy had longer disease-free survival (but not longer survival), this treatment was associated with higher rates of deaths following surgery.
Carcinoma of the esophagus. Part 2: Adjuvant therapy.
Minsky BD.
Oncology (Huntingt) 1999 Oct;13(10):1415-27.This article highlights that treatment consisting of radiation therapy or chemotherapy given before or after surgery does not improve survival in patients with esophageal cancer. The effects of a combined approach where both chemo- and radiotherapy are administered before surgery are still under investigations
Squamous carcinoma of the oesophagus. Surgery alone or combined with perioperative radiotherapy?
Purkiss SF, Huddy PE.
Eur J Surg Oncol 1994 Feb;20(1):21-4.The results of this study show that radiation treatment given before and after surgery in patients with esophageal cancer is not associated with prolonged survival, compared to surgery alone.
