Intrinsic and extrinsic flaws of the nomogram predicting bone-only metastasis in women with early breast cancer: An external validation study. (December 2016)

• Record Type: Journal Article
• Authors: Ouldamer, Lobna; Bendifallah, Sofiane; Chas, Marie; Boivin, Laura; Bedouet, Lea; Body, Gilles; Ballester, Marcos; Daraï, Emile
• Is Part Of: European journal of cancer. Volume 69(2016)
• Page Start: 102
• Page End: 109
• Publication Date: 2016-12
• Subjects: Bone metastases -- Breast cancer -- Molecular subtype -- Nomogram; Cancer -- Periodicals; Neoplasms -- Periodicals; Cancer -- Périodiques; Cancer; Tumors; Electronic journals; Periodicals; Electronic journals; 616.994
• DOI: 10.1016/j.ejca.2016.09.039
• Languages: English
• ISSNs: 0959-8049

Abstract

Abstract: Background: The recently developed MDACC nomogram purports to predict the risk of bone-only metastasis in women with early breast carcinoma based on five clinical and pathological characteristics. We set out to externally validate and assess its robustness using a tertiary breast cancer centre database. Methods: All consecutive women treated for early breast cancer in our centre between January 1989 and December 2013 and who had all the nomogram variables documented were eligible for analysis. Results: We identified 1255 eligible women for external validation analysis. The median follow-up was 54 months (range: 1–312) and time to initial metastasis 20 months (range: 1–80). The correspondence between the actual bone-only metastasis and the nomogram predictions implied poor calibration of the nomogram in the validation cohort, be it in the whole cohort or when stratified by breast cancer subtype. Conclusion: This external validation study of the MDACC nomogram showed limitations in its generalizability to a new and independent European patient population. Highlights: Nomogram to identify individuals at higher risk of bone-only metastasis in women with breast cancer. Low calibration using the nomogram both for the whole population and when stratified by breast cancer subtype. Late-onset bone metastasis is significantly higher in oestrogen receptor-positive women. The study showed limitations in the nomogram generalizability to a new and independent patient population.