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Letters to the Editor

Response to "Disparities in the Use of Chemotherapy and Monoclonal Antibody Therapy for Elderly Advanced Colorectal Cancer Patients in the Community Oncology Setting"

^aDepartment of Oncology, Western Hospital, Footscray, Australia; ^bBioGrid Australia, Parkville, Australia; ^cDepartment of Oncology, Royal Melbourne Hospital, Parkville, Australia

Correspondence: Maggie Moore, M.B.B.S., Oncology Department, Western Hospital, Gordon Street, Footscray, Victoria 3011, Australia. Telephone: 613-8345-6333; Fax: 613-8345-6445; e-mail: maggie.moore{at}wh.org.au

Received October 7, 2008; accepted for publication November 24, 2008; first published online in THE ONCOLOGIST Express on January 6, 2009.

Disclosures

Maggie Moore: None; Suzanne Kosmider: None; Kathryn Field: None; Jayesh Desai: None; Lionel Lim: None; Frances Barnett: None; Peter Gibbs: None

The content of this article has been reviewed by independent peer reviewers to ensure that it is balanced, objective, and free from commercial bias. No financial relationships relevant to the content of this article have been disclosed by the authors, planners, independent peer reviewers, or staff managers.

McKibbin et al. [1] recently highlighted age-related differences in treatment patterns for metastatic colorectal cancer in community practice. Although the authors acknowledge some of the limitations of their article, the absence of data regarding the chemotherapy dose, the failure to consider patient influences on treatment received, and apparent biases in the analysis and interpretation may compromise the value of this research.

Information regarding chemotherapy dosing is fundamental to understanding the relationship between treatment and outcome; however, it was not provided in this study. Many oncologists routinely initiate treatment at lower doses in older patients [2], which may be one explanation for the differences in outcome observed. Consistent with this was the unexpected finding that younger patients treated with oxaliplatin and 5-fluorouracil experienced a higher rate of chemotherapy-specific adverse events such as neutropenia or neuropathy.

The authors' assertion that "the approach to the treatment of elderly patients appears to differ significantly from that of younger patients," implies that the observed differences relate to the practice of the treating clinician. However, older patients may have different treatment objectives than younger patients [3] and may be more likely to decline a recommended treatment option [4]. It seems possible that many of the elderly patients reviewed by McKibbin et al. [1] may have elected for single-agent treatment upfront, even if doublet chemotherapy was recommended.

The authors' use of the word "disparity" in the title of their article implies that older patients received inferior treatment. They state that initial doublet therapy is associated with superior response rates and progression-free survival, which is not disputed; however, in two prospective randomized trials, there was no overall survival advantage for this approach over single-agent therapy [5, 6]. The authors have not referenced these studies despite acknowledging that "the receipt of initial doublet therapy did not significantly reduce the hazard for mortality."

The decision by McKibbin et al. [1] to measure survival outcomes from the initiation of chemotherapy rather than from the diagnosis of metastatic disease may explain some of the observed survival difference, if an initial "watch and wait" approach was more commonly adopted in older patients. When we looked at our own data prospectively collected at four hospitals in Melbourne, Australia, between January 2004 and May 2007, we found that 17 of 71 (24%) patients aged 65 years had treatment initiated >3 months after diagnosis, compared with 5 of 66 (8%) patients aged <65 (p = .01). In this limited number of patients, we found no impact of age on overall survival, measured from the date of diagnosis (Fig. 1).

View larger version (10K): [in this window] [in a new window]   Figure 1. Kaplan–Meier analysis of overall survival since time of diagnosis for 137 patients with advanced colorectal cancer treated at four hospitals in Melbourne, Australia. Hazard ratio, 0.98; 95% confidence interval, 0.61–1.58.

	AUTHOR CONTRIBUTIONS

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Conception/design: Maggie Moore, Peter Gibbs

Provision of study materials: Suzanne Kosmider, Kathryn Field, Jayesh Desai, Lionel Lim, Frances Barnett, Peter Gibbs

Collection/assembly of data: Maggie Moore, Suzanne Kosmider, Kathryn Field, Jayesh Desai, Lionel Lim, Frances Barnett, Peter Gibbs

Data analysis: Maggie Moore, Suzanne Kosmider, Kathryn Field, Peter Gibbs

Manuscript writing: Maggie Moore, Peter Gibbs

Final approval of manuscript: Maggie Moore, Suzanne Kosmider, Kathryn Field, Jayesh Desai, Lionel Lim, Frances Barnett, Peter Gibbs

	ACKNOWLEDGMENT

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The authors thank BioGrid Australia for assistance with data collection and statistical analysis.

	REFERENCES

Top Author Contributions References

 

1. McKibbin T, Frei CR, Greene RE et al. Disparities in the use of chemotherapy and monoclonal antibody therapy for elderly advanced colorectal cancer patients in the community oncology setting. The Oncologist 2008;13:876–885.[Abstract/Free Full Text]
2. Field KM, Kosmider S, Jefford M et al. Chemotherapy dosing strategies in the obese, elderly and thin patient: Results of a nationwide survey. J Oncol Pract 2008;4:108–113.[Abstract/Free Full Text]
3. Yellen SB, Cella DF, Leslie WT. Age and clinical decision making in oncology patients. J Natl Cancer Inst 1994;86:1766–1770.[Abstract/Free Full Text]
4. Field KM, Kosmider S, Desai J et al. Re: Residual treatment disparities after oncology referral for rectal cancer. J Natl Cancer Inst 2008;100:1739.[Free Full Text]
5. Koopman M, Antonini NF, Douma J et al. Sequential versus combination chemotherapy with capecitabine, irinotecan, and oxaliplatin in advanced colorectal cancer (CAIRO): A phase III randomised controlled trial. Lancet 2007;370:135–142.[CrossRef][Medline]
6. Seymour MT, Maughan TS, Ledermann JA et al. Different strategies of sequential and combination chemotherapy for patients with poor prognosis advanced colorectal cancer (MRC FOCUS): A randomised controlled trial. Lancet 2007;370:143–152.[CrossRef][Medline]

This Article Full Text (PDF) All Versions of this Article: theoncologist.2008-0222v1 14/1/104    most recent eLetters: Submit a response to this article Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services E-mail this article link to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Reprints/Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Moore, M. Articles by Gibbs, P. Search for Related Content PubMed Articles by Moore, M. Articles by Gibbs, P.