Is there a risk of developing breast cancer for women with endometriosis?

Breast cancer risk and Endometriosis: A survey

Key Points

Highlights:

• Does endometriosis increase the risk of breast cancer development?

Key Results:

• Several studies that were included in the survey either concluded in a positive (direct) or negative (null or inverse) association between breast cancer and endometriosis.
• 11 studies of varying study designs found that there is a positive association between breast cancer and endometriosis while 11 studies concluded that there is a negative or null association between the two.
• A comprehensive conclusion regarding the risk of developing breast cancer for women with endometriosis continues to be the subject of ongoing research.

What’s done here?

• The study aims to conduct a survey of available published epidemiological data that show an association between endometriosis and risk of breast cancer and to critically evaluate the strength of this relationship.

Limitations:

• Inherent variations in study design and weaknesses present in each study must be kept in mind while reading the survey.

Lay Summary

Understanding the interplay between the development of breast cancer and the presence of endometriosis and vice versa is complex since many risk factors including hormone or genetic variations and medical treatments have a role in each disease process. Thus, parsing out different epidemiological studies with varying results and research methods may yield a clearer picture on the correct association of breast cancer with endometriosis.

After pooling studies that concluded in either a positive (direct) or negative (null or inverse) association between breast cancer and endometriosis, several conclusions were made. From the survey conducted for this study, four retrospective cohort studies, 4 case-control studies, and 3 case-cohort studies demonstrated a notable risk of developing breast cancer among women with endometriosis. However, 5 case-control studies, one prospective cohort study, 1 case-cohort study, and one cross-sectional study found a negative association between endometriosis and breast cancer. Additionally, one prospective cohort study, 1 case-cohort study, and 1 case-control study support a null association between breast cancer and endometriosis.

Conclusions cannot be made from the studies included in this survey due to the inherent variations in study design and weaknesses present in each study. Additionally, limitations of each study including selection, detection, and recall bias hinder the data evaluation process. Additional large and well-designed studies are needed to provide evidence-based data regarding the association of breast cancer development in women with endometriosis.