Breast cancer remains one of the most prevalent types of cancer, but a new study in Canada shows that recurrence rates have at least been halved since the 1980s, thanks to early detection and improved treatment options.
Published in the Journal of Clinical Oncology, the study examined data on 7,178 women who underwent treatment for early to moderately advanced breast cancers from 1986 to 1992 and 2004 to 2008. Cancer characteristics were matched from each period, including the presence of a protein called HER2 and the status of estrogen receptors.
HER2 deserves attention because it is a component that drives the growth of cancer cells; not to mention that tumors with HER2 have the tendency to be much more aggressive than those without the protein.
Medication developed in the 1990s started targeting HER2-positive tumors. Together with the detection of cancers in their early stages, targeted therapies were able to improve overall survival rates for cancer because they allowed drugs to work better at fighting cancer.
In the study, it was shown that the overall risk of breast cancer recurring in women in the second group was 50 percent lower compared to the earlier group, for every year after they are declared cancer-free.
Cases involving HER2-positive cancers also showed the most reductions in risk of recurrence. For instance, a woman with a recurrence risk of 23 percent for the first period only has to deal with a nine percent recurrence risk on the second period.
According to BC Cancer Agency's Dr. Karen Gelmon, the study's lead author, analyzing data on breast cancer patients in Canada not only provided reassurance that survival rates are improving but also gave researchers valuable data to use in their studies.
"It showed we were doing better, but the peaks are still there," she added.
Researchers were not able to show how recurrence rates were improving but they believe it is most likely due to technologies that improved screening procedures, which ultimately improved early detection rates. There was also the fact that advancements in technology translated to advancements in treatment, allowing for more comprehensive and targeted approaches that make it possible to combat specific types of cancer.
The study titled "Comparison of Breast Cancer Recurrence and Outcome Patterns Between Patients Treated From 1986 to 1992 and From 2004 to 2008," was carried out by Yvonne Zheng, Caroline H. Speers, Scott K. Tyldesley, and Rachel J.D. Cossetti, alongside Gelmon.