Trends in overall survival in Swedish patients withprimary metastatic breast cancer – 1994 to 2014

Sammanfattning: Introduction Each year approximately 7600 individuals are diagnosed with breast cancer in Sweden, someof which with primary metastatic breast cancer (PMBC). Several new drugs for treatingmetastatic breast cancer have been introduced during the last three decades, many of whichclaims to prolong survival. Aim The aim of this study was to determine if the median overall survival (OS) had improved from1994 to 2014 in patients with PMBC in the healthcare region of Uppsala/Örebro. Material and methods Between 1994 and 2014, 871 patients were diagnosed with PMBC in the healthcare region ofUppsala/Örebro, 168 in 1994-1999, 362 in 2000-2006 and 341 in 2007-2014. The patientcharacteristics were compared with Chi2 test and the Kaplan-Meier method was used tocalculate the median survival for each group. Univariate and multivariate analyses were usedto calculate factors affecting survival. Results The estimated median OS was 12.1 months in 1994-1999, 22.0 months in 2000-2006 and 19.7months in 2007-2014. There was a statistically significant difference in median OS between1994-1999 and 2000-2006, and between 1994-1999 and 2007-2014, but no significantdifference was seen between 2000-2006 and 2007-2014. Increasing age had a negative impacton survival, whereas estrogen receptor-positivity and Grade I-II correlated with prolongedsurvival. Women who had undergone surgery of the breast tumor had longer survival thanthose who had not had surgery. Conclusion The median OS in patients with PMBC have improved from 1994-1999 to 2000-2014. Nodifference was seen between 2000-2006 and 2007-2014.