Breast cancer treatments are improving and prognoses more positive overall, but, even at this advanced stage of the high-tech “war on cancer,” early diagnosis and staging are still of the essence. 

And that holds true regardless of patient age and tumor biology.

So conclude Sepideh Saadatmand, MD, of Erasmus University Medical Centre in Rotterdam, the Netherlands, and colleagues in an observational study published Oct. 6 in The BMJ.

Drawing on data from the Netherlands Cancer Registry, the researchers compared overall survival of 173,797 female breast cancer patients from two time windows.

They found that tumors diagnosed from 2006 to 2012 were smaller, more often lymph node negative and more often low grade than those diagnosed between 1999 and 2005.

Meanwhile, the cohort in the more recent window had higher relative survival rates and overall survival rates for all tumor and nodal stages. This effect was especially notable in women over 75.  

At five years’ follow-up, overall relative survival of patients improved from 91 percent in the earlier group to 96 percent in the later.

In univariable and multivariable analyses, both tumor stage and lymph node status had a statistically significant influence on overall survival in both cohorts.

“The importance of early detection is dual—with increasing tumor size, lymph node positivity also increases,” write the authors before stressing that surgery remains crucial and conservative surgery tends to be best.

Saadatmand and colleagues point out that their data are “of special importance for research trials that often use prognosis per tumor stage as primary outcomes. Tumor size and nodal status still had a significant and major influence independent of tumor biology in the current era of more conservative surgery and the new, more effective, and widely applied systemic (neo-)adjuvant therapies.”

In an accompanying editorial, Harold Burstein, MD, and Ines Vaz-Luis, MD, of Dana Farber Cancer Institute in Boston, state that, despite its observational nature, the Netherlands study offers “powerful takeaway lessons” thanks to its extensive, population-based data.

They write, “A challenge ahead is to help other societies build models of screening and treatment that foster the access and success of the Dutch experience.”