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. 1999 Apr;79(11-12):1752–1760. doi: 10.1038/sj.bjc.6690279

Modelling the effects of standard prognostic factors in node-positive breast cancer

W Sauerbrei 1, P Royston 2, H Bojar 3, C Schmoor 1, M Schumacher 1; the German Breast Cancer Study Group (GBSG)1
PMCID: PMC2362813  PMID: 10206288

Abstract

Prognostic models that predict the clinical course of a breast cancer patient are important in oncology. We propose an approach to constructing such models based on fractional polynomials in which useful transformations of the continuous factors are determined. The idea may be applied with all types of regression model, including Cox regression, the method of choice for survival-time data. We analyse a prospective study of node-positive breast cancer. Seven standard prognostic factors – age, menopausal status, tumour size, tumour grade, number of positive lymph nodes, progesterone and oestrogen receptor concentrations – were investigated in 686 patients, of whom 299 had an event for recurrence-free survival and 171 died. We determine a final model with transformations of prognostic factors and compare it with the more traditional approaches using categorized variables or assuming a straight line relationship. We conclude that analysis using fractional polynomials can extract important prognostic information which the traditional approaches may miss. © 1999 Cancer Research Campaign

Keywords: breast cancer, prognostic factors, regression modelling, variable transformation, fractional polynomials

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Altman D. G., Lausen B., Sauerbrei W., Schumacher M. Dangers of using "optimal" cutpoints in the evaluation of prognostic factors. J Natl Cancer Inst. 1994 Jun 1;86(11):829–835. doi: 10.1093/jnci/86.11.829. [DOI] [PubMed] [Google Scholar]
  2. Balslev I., Axelsson C. K., Zedeler K., Rasmussen B. B., Carstensen B., Mouridsen H. T. The Nottingham Prognostic Index applied to 9,149 patients from the studies of the Danish Breast Cancer Cooperative Group (DBCG). Breast Cancer Res Treat. 1994;32(3):281–290. doi: 10.1007/BF00666005. [DOI] [PubMed] [Google Scholar]
  3. Chung M., Chang H. R., Bland K. I., Wanebo H. J. Younger women with breast carcinoma have a poorer prognosis than older women. Cancer. 1996 Jan 1;77(1):97–103. doi: 10.1002/(SICI)1097-0142(19960101)77:1<97::AID-CNCR16>3.0.CO;2-3. [DOI] [PubMed] [Google Scholar]
  4. Collett K., Hartveit F., Skjaerven R., Maehle B. O. Prognostic role of oestrogen and progesterone receptors in patients with breast cancer: relation to age and lymph node status. J Clin Pathol. 1996 Nov;49(11):920–925. doi: 10.1136/jcp.49.11.920. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Crowe J. P., Jr, Gordon N. H., Shenk R. R., Zollinger R. M., Jr, Brumberg D. J., Shuck J. M. Age does not predict breast cancer outcome. Arch Surg. 1994 May;129(5):483–488. doi: 10.1001/archsurg.1994.01420290029004. [DOI] [PubMed] [Google Scholar]
  6. Elston C. W., Ellis I. O. Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up. Histopathology. 1991 Nov;19(5):403–410. doi: 10.1111/j.1365-2559.1991.tb00229.x. [DOI] [PubMed] [Google Scholar]
  7. Galea M. H., Blamey R. W., Elston C. E., Ellis I. O. The Nottingham Prognostic Index in primary breast cancer. Breast Cancer Res Treat. 1992;22(3):207–219. doi: 10.1007/BF01840834. [DOI] [PubMed] [Google Scholar]
  8. Palta M., Amini S. B. Consideration of covariates and stratification in sample size determination for survival time studies. J Chronic Dis. 1985;38(9):801–809. doi: 10.1016/0021-9681(85)90123-7. [DOI] [PubMed] [Google Scholar]
  9. Pichon M. F., Broet P., Magdelenat H., Delarue J. C., Spyratos F., Basuyau J. P., Saez S., Rallet A., Courriere P., Millon R. Prognostic value of steroid receptors after long-term follow-up of 2257 operable breast cancers. Br J Cancer. 1996 Jun;73(12):1545–1551. doi: 10.1038/bjc.1996.291. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Sauerbrei W., Hübner K., Schmoor C., Schumacher M. Validation of existing and development of new prognostic classification schemes in node negative breast cancer. German Breast Cancer Study Group. Breast Cancer Res Treat. 1997 Jan;42(2):149–163. doi: 10.1023/a:1005733404976. [DOI] [PubMed] [Google Scholar]
  11. Schmoor C., Olschewski M., Schumacher M. Randomized and non-randomized patients in clinical trials: experiences with comprehensive cohort studies. Stat Med. 1996 Feb 15;15(3):263–271. doi: 10.1002/(SICI)1097-0258(19960215)15:3<263::AID-SIM165>3.0.CO;2-K. [DOI] [PubMed] [Google Scholar]
  12. Schmoor C., Schumacher M. Effects of covariate omission and categorization when analysing randomized trials with the Cox model. 1997 Jan 15-Feb 15Stat Med. 16(1-3):225–237. doi: 10.1002/(sici)1097-0258(19970215)16:3<225::aid-sim482>3.0.co;2-c. [DOI] [PubMed] [Google Scholar]
  13. Schumacher M., Bastert G., Bojar H., Hübner K., Olschewski M., Sauerbrei W., Schmoor C., Beyerle C., Neumann R. L., Rauschecker H. F. Randomized 2 x 2 trial evaluating hormonal treatment and the duration of chemotherapy in node-positive breast cancer patients. German Breast Cancer Study Group. J Clin Oncol. 1994 Oct;12(10):2086–2093. doi: 10.1200/JCO.1994.12.10.2086. [DOI] [PubMed] [Google Scholar]
  14. Schumacher M., Schmoor C., Sauerbrei W., Schauer A., Ummenhofer L., Gatzemeier W., Rauschecker H. The prognostic effect of histological tumor grade in node-negative breast cancer patients. Breast Cancer Res Treat. 1993;25(3):235–245. doi: 10.1007/BF00689838. [DOI] [PubMed] [Google Scholar]
  15. Simon R., Altman D. G. Statistical aspects of prognostic factor studies in oncology. Br J Cancer. 1994 Jun;69(6):979–985. doi: 10.1038/bjc.1994.192. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Walker R. A., Lees E., Webb M. B., Dearing S. J. Breast carcinomas occurring in young women (< 35 years) are different. Br J Cancer. 1996 Dec;74(11):1796–1800. doi: 10.1038/bjc.1996.632. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. de la Rochefordiere A., Asselain B., Campana F., Scholl S. M., Fenton J., Vilcoq J. R., Durand J. C., Pouillart P., Magdelenat H., Fourquet A. Age as prognostic factor in premenopausal breast carcinoma. Lancet. 1993 Apr 24;341(8852):1039–1043. doi: 10.1016/0140-6736(93)92407-k. [DOI] [PubMed] [Google Scholar]

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