Although women diagnosed with advanced breast cancer general do not have as good a prognosis as women diagnosed in earlier disease stages, significant improvements have been made. The introduction of new chemotherapy drugs in the last decade has resulted in longer survival times for these women, the findings of a new study suggest.
As reported in the current issue of the journal Cancer, Dr. Stephen Chia, from the University of British Columbia in Vancouver, and colleagues assessed the outcomes of 2,150 women who were treated for metastatic breast cancer, cancer that has spread from the breast to other areas of the body.
The women were separated into four groups according to when new drugs for metastatic breast cancer became available in British Columbia: January 1991 to December 1992, the starting point; January 1994 to December 1995, when paclitaxel and vinorelbine were made available; January 1997 to December 1998, when the aromatase inhibitors and docetaxel were released; and July 1999 to June 2001, when trastuzumab and capecitabine hit the market.
All of the patients had similar characteristics, although women treated later in the decade were more likely to have estrogen receptor-positive cancer, receive follow-up therapy after the initial chemotherapy, and have a longer time between diagnosis and metastasis.
The average survival periods for patients first treated from 1991 to 1992 and from 1994 to 1995 were similar, at 438 and 450 days, respectively. The survival periods for those treated from 1997 to 1998 and 1999 to 2001 were significantly longer by comparison: 564 and 667 days, respectively.
Further analysis of the data confirmed that treatment during the late 1990s was associated with significantly longer survival periods than treatment during the early 1990s.
This population-based study of a large group of women recently diagnosed with metastatic breast cancer “is the first to our knowledge that demonstrates a significant improvement in survival over time,” Chia’s team concludes.
“This improvement in survival appeared to be caused by the availability and use of newer, more effective systemic agents for the treatment of metastatic breast cancer.”
