Retrospective data indicate that de novo MBC, premenopausal status, estrogen receptor (ER)-positive status, HER2-positive disease, and fewer metastatic sites are significantly associated with long-term MBC survival (defined as ≥5 years) among women diagnosed with MBC.[186]Klar N, Rosenzweig M, Diergaarde B, et al. Features associated with long-term survival in patients with metastatic breast cancer. Clin Breast Cancer. 2019 Aug;19(4):304-10.
http://www.ncbi.nlm.nih.gov/pubmed/30827763?tool=bestpractice.com
[187]Leone JP, Leone J, Vallejo CT, et al. Factors associated with short- and long-term survival in metastatic HER2+ breast cancer. J Clin Oncol. 2022 40:16_suppl, 1047 [Epub ahead of print].
https://ascopubs.org/doi/abs/10.1200/JCO.2022.40.16_suppl.1047
One patient cohort reported improved overall survival over the study period (2010 to 2018), with a considerable proportion of patients alive at 8 years.[187]Leone JP, Leone J, Vallejo CT, et al. Factors associated with short- and long-term survival in metastatic HER2+ breast cancer. J Clin Oncol. 2022 40:16_suppl, 1047 [Epub ahead of print].
https://ascopubs.org/doi/abs/10.1200/JCO.2022.40.16_suppl.1047
An earlier study, employing back-calculation methods, estimated an increase in 5-year relative survival rate among women diagnosed with de novo MBC (at age 15-49 years) from 18% between 1992-1994 to 36% between 2005-2012.[188]Mariotto AB, Etzioni R, Hurlbert M, et al. Estimation of the number of women living with metastatic breast cancer in the United States. Cancer Epidemiol Biomarkers Prev. 2017 Jun;26(6):809-15.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5833304
http://www.ncbi.nlm.nih.gov/pubmed/28522448?tool=bestpractice.com
Improved survival in these studies coincides with significant therapeutic advances for HER2-positive MBC.
The median overall survival of patients with MBC is 2-3 years.[189]Valachis A, Carlqvist P, Ma Y, et al. Overall survival of patients with metastatic breast cancer in Sweden: a nationwide study. Br J Cancer. 2022 Sep;127(4):720-5.
https://www.nature.com/articles/s41416-022-01845-z
http://www.ncbi.nlm.nih.gov/pubmed/35597870?tool=bestpractice.com
[190]Gomes I, Aguiar P, Miranda A, et al. Overall survival of patients with locoregional and metastatic breast cancer: is the influence of baseline characteristics the same? Anticancer Res. 2019 Sep;39(9):5135-42.
https://ar.iiarjournals.org/content/39/9/5135.long
http://www.ncbi.nlm.nih.gov/pubmed/31519625?tool=bestpractice.com
[191]Zeichner SB, Herna S, Mani A, et al. Survival of patients with de-novo metastatic breast cancer: analysis of data from a large breast cancer-specific private practice, a university-based cancer center and review of the literature. Breast Cancer Res Treat. 2015 Oct;153(3):617-24.
http://www.ncbi.nlm.nih.gov/pubmed/26358708?tool=bestpractice.com
In the US, 5-year relative survival rate for women with de novo MBC is 31% (data from 2013 to 2019).[8]National Cancer Institute. Cancer stat facts: female breast cancer [internet publication].
https://seer.cancer.gov/statfacts/html/breast.html