372P - Incidence of bone metastases and survival after a diagnosis of bone metastases (BM) in breast cancer patients

Date 29 September 2012
Event ESMO Congress 2012
Session Poster presentation I
Topics Breast Cancer, Metastatic
Presenter Lars Holmberg
Authors L. Holmberg1, M. Harries2, O. Agbaje1, H. Garmo3, S. Kabilan3, A. Taylor4, A. Purushotham5
  • 1Division Of Cancer Studies, Cancer Epidemiology Unit, Research Oncology, Kings College London School of Medicine, Guys Hospital, SE1 9RT - LONDON/UK
  • 2Department Of Medical Oncology, Guys and St Thomas’s Hospitals NHS Foundation Trust, Guys Hospital, SE1 9RT - London/UK
  • 3Division Of Cancer Studies, Cancer Epidemiology Unit, Research Oncology, King's College London School of Medicine, Guys Hospital, SE1 9RT - London/UK
  • 4Centre For Observational Research (oncology), Amgen Ltd., UB8 1DH - Uxbridge/UK
  • 5Division Of Cancer Studies, Research Oncology, Kings College London School of Medicine, Guys Hospital, SE1 9RT - LONDON/UK

Abstract

Objectives

To measure crude and cumulative incidence of BM and cumulative survival after diagnosis of BM. BM were grouped by (i) BM only (ii) BM followed by visceral metastases (iii) visceral metastases followed by BM.

Methods

Kaplan-Meier and Cox regression database analysis of women with breast cancer diagnosed 1975-2006 and treated at Guys Hospital London, whose details were prospectively updated regularly till end 2010.

Results

Of 7064 women, 1589 (22%) developed BM by end follow-up (mean 8.4 years); 2254 (32%) were diagnosed with breast cancer < 50 years, and 4810 (68%) ≥50 years; 735 (14.4%) were classified as grade I, 2303 (45.3%) grade II and 2049 (40.3%) grade III; 1530 (27.8%) were estrogen receptor (ER) –ve and 3982 (72.2%) ER +ve. Of all BM, 535 (33.7%) patients were in group i; 871 (54.8%) in group ii and 183 (11.5%) in group iii. Incidence of all BM within 0-3 years from breast cancer diagnosis was highest in 1980 (64/1000 person years) and lowest in 2006 (11/1000 person years), with the decline most pronounced in 1985-1990. Cumulative incidence of BM after 5 years follow up was highest in 1976-1982 (0.25 [95% CI 0.23-0.27]), falling to 0.22 (0.20-0.24) in 1983-1989, 0.18 (0.10-0.14) in 1990-1997 and 0.095 (0.08-0.12) in 1998-2006.Risk of BM was significantly influenced by: calendar period of breast cancer diagnosis, HR was 0.77 (0.68-0.86) 1983-1989, 0.46 (0.40-0.54) 1990-1997 and 0.33 (0.28-0.40) 1998-2006, all vs 1975-1982; tumour grade, HR 1.23 (1.08 - 1.40) grade 3 vs 1-2; nodal status, HR 1.88 (1.60-2.21) 1-3 nodes vs 0 nodes and 3.95 (3.36-4.64) 4+ nodes vs 0 nodes; and tumour size, HR 2.00 (1.75-2.29) 2-5 cm vs <2cm and HR 3.31 (2.73-4.01) 5+ cm vs <2cm. Amongst women with BM diagnosed within 10 years of breast cancer treatment, 25% were diagnosed within 1 year, 50% within 2.5 years and 75% within 4.7 years. Median survival after BM diagnosis was 2.3 years in group i compared with 0.96 years in group ii and 0.91 years in group iii.

Conclusion

Incidence of BM has decreased in recent years and risk of BM is significantly affected by clinical tumour characteristics. Women with bone only metastases survive longer with their disease. BM remain an important target for prevention, treatment and palliation in breast cancer.

Disclosure

A. Taylor: I own shares with Amgen and work at Amgen.

All other authors have declared no conflicts of interest.