European Journal of Cancer (2014) xxx, xxx– xxx
Available at www.sciencedirect.com
ScienceDirect journal homepage: www.ejcancer.com
Letter to the Editor
Measurement or estimation of glomerular filtration rate in seminoma patients: Quite another cup of tea Martin Fehr a,⇑, Tom Geldart b, Dirk Klingbiel c, Richard Cathomas d a
Medical Oncology and Haematology, Kantonsspital St. Gallen, Switzerland Medical Oncology, Poole and Royal Bournemouth Hospitals, UK c SAKK (Swiss Group for Clinical Cancer Research) Coordinating Centre Berne, Switzerland d Oncology/Haematology, Kantonsspital Graubu¨nden, Chur, Switzerland b
Received 11 April 2014; accepted 16 April 2014
Dear Editor, We read with interest the recent article of Shepherd et al. regarding the ‘performance of formulae based estimates of glomerular filtration rate (GFR) for carboplatin dosing in stage I seminoma’ [1]. Their analysis, based on a cohort of 115 patients highlights the problems associated with the use of formulae to estimate GFR (eGFR) in order to calculate carboplatin dose in the adjuvant treatment of patients with stage I seminoma. Although used by some oncologists, this practice is not based on prospective evidence as the pivotal MRC TE19/EORTC 30982 trial mandated radioisotopic measurement of GFR (or Creatinine Clearance from 24-h urine collection as a substitute) [2]. Independently, our group has recently reported the findings from a cohort of 426 patients with stage I seminoma treated with adjuvant carboplatin. Our conclusion is that no contemporary formula for eGFR based on serum creatinine (SCrea) can substitute for radioisotopic measurement of GFR with satisfactory accuracy [3]. Although Shepherd and co-authors have also acknowledged this, they conclude that dosing based on eGFR with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula might ‘predict an ⇑ Corresponding author: Tel.: +41 71 494 6269; fax: +41 714946325.
appropriate carboplatin dose in 86.4% of cases’ and ‘only 13.5% would have been underdosed’ [1]. In the treatment of stage I seminoma, adequate carboplatin dose is important. In the updated analysis of the MRC TE19/EORTC 30982 trial, dose-reduced patients had a 5-year relapse rate of 7.4% compared to 3.9% (p = 0.08) for patients with adequate carboplatin dose i.e. the rate of relapse almost doubled with only 10% dose reduction [4]. In both the cohorts of Shepherd et al. and Cathomas et al., the Cockroft–Gault formula appears to be associated with the lowest proportion of potentially clinically significant underdosing (6 10%); 4.5% and 18.1%, respectively. The proportion of potential underdosing by CKD-EPI (based on individual BSA) in relation to the Cockroft–Gault formula is substantially higher (2- to 3-fold) in both cohorts. A number of other analyses based on larger cohorts comparing various SCrea formulae for eGFR estimation and carboplatin dosing have been published recently with inconsistent conclusions [5–7]. In our opinion, it is reasonable to hypothesise that these differing results between cohorts may be substantially influenced by disparities in patient characteristics and changes in the methods used for SCrea measurement and calibration over time. In addition, cut-off limits defining accuracy and precision appear to be based mainly on
E-mail address: [email protected] (M. Fehr). http://dx.doi.org/10.1016/j.ejca.2014.04.028 0959-8049/Ó 2014 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Fehr M. et al., Measurement or estimation of glomerular filtration rate in seminoma patients: Quite another cup of tea, Eur J Cancer (2014), http://dx.doi.org/10.1016/j.ejca.2014.04.028
2
Letter to the Editor / European Journal of Cancer xxx (2014) xxx–xxx
arbitrary judgement rather than firm evidence and differ from paper to paper. In conclusion, the interpretation of differences between individual SCrea based eGFR formulae, judgement about accuracy and consequent recommendations for clinical use should be associated with extreme caution. On the basis of available data, we continue to advocate that radioisotope measurement of GFR remains a gold standard in the calculation of carboplatin dose in the adjuvant treatment of stage I seminoma.
[2]
[3] [4]
[5]
Conflict of interest statement None declared. References [1] Shepherd STC, Gillen G, Morrison P, Forte C, Macpherson IR, White JD, et al. Performance of formulae based estimates of
[6]
[7]
glomerular filtration rate for carboplatin dosing in stage I seminoma. Eur J Cancer 2014;50:944–52. Oliver RTD, Mason MD, Mead GM, van der Maase H, Rustin GJS, Joffe JK, et al. Radiotherapy versus single-dose carboplatin in adjuvant treatment of stage I seminoma: a randomised trial. Lancet 2005;366:293–300. Cathomas R, Klingbiel D, Geldart TR, Mead GM, Ellis S, Wheater M et al. Ann Oncol 2014 Mar 25. [Epub ahead of print]. Oliver RTD, Mead GM, Rustin GJS, et al. Randomized trial of carboplatin versus radiotherapy for stage I seminoma: mature results on relapse and contralateral testis cancer rate in MRC TE19/EORTC 30982 Study. J Clin Oncol 2011;29:957–62. Ainsworth NL, Marshall A, Hatcher H, Whitehead L, Whitefield GA, Earl HM. Evaluation of glomerual filtration rate estimation by Cockroft–Gault, Jeliffe, Wright and Modification of Diet in Renal Disease (MDRD) formulae in oncology patients. Ann Oncol 2012;23:1845–53. Dooley MJ, Poole SG, Rischin D. A comparison of bedside renal function estimates and measured glomerual filtration rate (Tc99mDTPA) in cancer patients. Ann Oncol 2013;24:2746–52. Lauritsen J, Gundgaard MG, Mortensen MS, Oturai PS, FeltRasmussen B, Daugaard G. Reliability of estimated glomerular filtration rate in patients treated with platinum containing therapy. Int J Cancer 2014. http://dx.doi.org/10.1002/ijc.28816.
Please cite this article in press as: Fehr M. et al., Measurement or estimation of glomerular filtration rate in seminoma patients: Quite another cup of tea, Eur J Cancer (2014), http://dx.doi.org/10.1016/j.ejca.2014.04.028
Available at www.sciencedirect.com
ScienceDirect journal homepage: www.ejcancer.com
Letter to the Editor
Measurement or estimation of glomerular filtration rate in seminoma patients: Quite another cup of tea Martin Fehr a,⇑, Tom Geldart b, Dirk Klingbiel c, Richard Cathomas d a
Medical Oncology and Haematology, Kantonsspital St. Gallen, Switzerland Medical Oncology, Poole and Royal Bournemouth Hospitals, UK c SAKK (Swiss Group for Clinical Cancer Research) Coordinating Centre Berne, Switzerland d Oncology/Haematology, Kantonsspital Graubu¨nden, Chur, Switzerland b
Received 11 April 2014; accepted 16 April 2014
Dear Editor, We read with interest the recent article of Shepherd et al. regarding the ‘performance of formulae based estimates of glomerular filtration rate (GFR) for carboplatin dosing in stage I seminoma’ [1]. Their analysis, based on a cohort of 115 patients highlights the problems associated with the use of formulae to estimate GFR (eGFR) in order to calculate carboplatin dose in the adjuvant treatment of patients with stage I seminoma. Although used by some oncologists, this practice is not based on prospective evidence as the pivotal MRC TE19/EORTC 30982 trial mandated radioisotopic measurement of GFR (or Creatinine Clearance from 24-h urine collection as a substitute) [2]. Independently, our group has recently reported the findings from a cohort of 426 patients with stage I seminoma treated with adjuvant carboplatin. Our conclusion is that no contemporary formula for eGFR based on serum creatinine (SCrea) can substitute for radioisotopic measurement of GFR with satisfactory accuracy [3]. Although Shepherd and co-authors have also acknowledged this, they conclude that dosing based on eGFR with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula might ‘predict an ⇑ Corresponding author: Tel.: +41 71 494 6269; fax: +41 714946325.
appropriate carboplatin dose in 86.4% of cases’ and ‘only 13.5% would have been underdosed’ [1]. In the treatment of stage I seminoma, adequate carboplatin dose is important. In the updated analysis of the MRC TE19/EORTC 30982 trial, dose-reduced patients had a 5-year relapse rate of 7.4% compared to 3.9% (p = 0.08) for patients with adequate carboplatin dose i.e. the rate of relapse almost doubled with only 10% dose reduction [4]. In both the cohorts of Shepherd et al. and Cathomas et al., the Cockroft–Gault formula appears to be associated with the lowest proportion of potentially clinically significant underdosing (6 10%); 4.5% and 18.1%, respectively. The proportion of potential underdosing by CKD-EPI (based on individual BSA) in relation to the Cockroft–Gault formula is substantially higher (2- to 3-fold) in both cohorts. A number of other analyses based on larger cohorts comparing various SCrea formulae for eGFR estimation and carboplatin dosing have been published recently with inconsistent conclusions [5–7]. In our opinion, it is reasonable to hypothesise that these differing results between cohorts may be substantially influenced by disparities in patient characteristics and changes in the methods used for SCrea measurement and calibration over time. In addition, cut-off limits defining accuracy and precision appear to be based mainly on
E-mail address: [email protected] (M. Fehr). http://dx.doi.org/10.1016/j.ejca.2014.04.028 0959-8049/Ó 2014 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Fehr M. et al., Measurement or estimation of glomerular filtration rate in seminoma patients: Quite another cup of tea, Eur J Cancer (2014), http://dx.doi.org/10.1016/j.ejca.2014.04.028
2
Letter to the Editor / European Journal of Cancer xxx (2014) xxx–xxx
arbitrary judgement rather than firm evidence and differ from paper to paper. In conclusion, the interpretation of differences between individual SCrea based eGFR formulae, judgement about accuracy and consequent recommendations for clinical use should be associated with extreme caution. On the basis of available data, we continue to advocate that radioisotope measurement of GFR remains a gold standard in the calculation of carboplatin dose in the adjuvant treatment of stage I seminoma.
[2]
[3] [4]
[5]
Conflict of interest statement None declared. References [1] Shepherd STC, Gillen G, Morrison P, Forte C, Macpherson IR, White JD, et al. Performance of formulae based estimates of
[6]
[7]
glomerular filtration rate for carboplatin dosing in stage I seminoma. Eur J Cancer 2014;50:944–52. Oliver RTD, Mason MD, Mead GM, van der Maase H, Rustin GJS, Joffe JK, et al. Radiotherapy versus single-dose carboplatin in adjuvant treatment of stage I seminoma: a randomised trial. Lancet 2005;366:293–300. Cathomas R, Klingbiel D, Geldart TR, Mead GM, Ellis S, Wheater M et al. Ann Oncol 2014 Mar 25. [Epub ahead of print]. Oliver RTD, Mead GM, Rustin GJS, et al. Randomized trial of carboplatin versus radiotherapy for stage I seminoma: mature results on relapse and contralateral testis cancer rate in MRC TE19/EORTC 30982 Study. J Clin Oncol 2011;29:957–62. Ainsworth NL, Marshall A, Hatcher H, Whitehead L, Whitefield GA, Earl HM. Evaluation of glomerual filtration rate estimation by Cockroft–Gault, Jeliffe, Wright and Modification of Diet in Renal Disease (MDRD) formulae in oncology patients. Ann Oncol 2012;23:1845–53. Dooley MJ, Poole SG, Rischin D. A comparison of bedside renal function estimates and measured glomerual filtration rate (Tc99mDTPA) in cancer patients. Ann Oncol 2013;24:2746–52. Lauritsen J, Gundgaard MG, Mortensen MS, Oturai PS, FeltRasmussen B, Daugaard G. Reliability of estimated glomerular filtration rate in patients treated with platinum containing therapy. Int J Cancer 2014. http://dx.doi.org/10.1002/ijc.28816.
Please cite this article in press as: Fehr M. et al., Measurement or estimation of glomerular filtration rate in seminoma patients: Quite another cup of tea, Eur J Cancer (2014), http://dx.doi.org/10.1016/j.ejca.2014.04.028
