Efficacy of Adjuvant Chemotherapy after Surgery when Considered over all Cancer Types: A Synthesis of Meta-Analyses
- 177 Downloads
Despite a large number of clinical trials having been conducted to assess the efficacy of adjuvant chemotherapy after surgery for various cancers, whether it is best to use this treatment remains a generally contentious issue for many common cancers. The purpose of this study was to ascertain whether any general conclusions can be drawn about the efficacy or inefficacy of this treatment within different cancer classifications.
Meta-analyses of randomized, controlled trials (RCTs) of adjuvant chemotherapy after surgery were synthesized over as many types of cancer as possible. Data sources were Medline, Embase, and the Cochrane library. Eligible meta-analyses were meta-analyses of RCTs for any type of cancer that compared surgery followed by adjuvant chemotherapy with surgery followed by no adjuvant chemotherapy.
The literature search found 25 meta-analyses for 15 cancer types that satisfied the criteria necessary for detailed analysis within this study. The estimates of relative risk for all cause mortality were reported as being less than one (indicating adjuvant chemotherapy is beneficial) by all meta-analyses apart from a meta-analysis for colorectal cancer metastasized to the liver. Moreover, 15 of these meta-analyses also reported that the 95 % confidence interval for this relative risk is less than one (indicating statistical significance at the 5 % level).
The results for all cancer types included in this study except for cancer metastasized to the liver can be thought of as supporting each other through the idea of there being a common treatment effect or at least a common range of effect across all (or most) of these cancer types. For example, with regard to cancer types where the evidence in favor of adjuvant chemotherapy after surgery is only moderately strong, the results of this study may encourage more clinicians to regard the use of this treatment as standard practice.
KeywordsRelative Risk Adjuvant Chemotherapy Cancer Type Colorectal Liver Metastasis Metastatic Cancer
This work was supported by the Engineering and Physical Sciences Research Council of the UK through the MATCH Programme (Grant GR/S29874/01). RJB was also partially funded by PROMEP (El Programa de Mejoramiento del Profesorado) of Mexico.
- 1.Weissman DE, von Gunten CF. Fast Fact and Concept #99. Chemotherapy: response and survival data. 2nd edn. November 2007. End-of-Life/Palliative Education Resource Center (www.eperc.mcw.edu).
- 5.Noguchi S, Koyama H, Uchino J, Abe R, Miura S, Sugimachi K, et al. Postoperative adjuvant therapy with tamoxifen, tegafur plus uracil, or both in women with node-negative breast cancer: a pooled analysis of six randomized controlled trials. J Clin Oncol. 2005;23(10):2172–84.PubMedCrossRefGoogle Scholar
- 12.Malthaner RA, Wong RK, Rumble RB, Zuraw L. Neoadjuvant or adjuvant therapy for resectable esophageal cancer: a systematic review and meta-analysis. BMC Med. 2004;2(35).Google Scholar
- 18.Stewart L, Burdett S, Glioma Meta-analysis Trialists (GMT) Group. Chemotherapy for high-grade glioma. Cochrane Database Syst Rev. 2002;(3):CD003913.Google Scholar
- 21.Nelson R, Freels S. Hepatic artery adjuvant chemotherapy for patients having resection or ablation of colorectal cancer metastatic to the liver. Cochrane Database Syst Rev. 2006;(4):CD003770.Google Scholar
- 23.Portier G, Elias D, Bouche O, Rougier P, Bosset J-F, Saric J, et al. Multicenter randomized trial of adjuvant fluorouracil and folinic acid compared with surgery alone after resection of colorectal liver metastases: FFCD ACHBTH AURC 9002 trial. J Clin Oncol. 2006;24(31):4976–82.PubMedCrossRefGoogle Scholar