Women Diagnosed with Schizophrenia Have Higher Breast Cancer Risk

JAMA Psychiatryrecently published a meta-analysis of 125 thousand women indicating higher breast cancer risk in women diagnosed with schizophrenia; screening should therefore not be forgotten during medical follow-up.

What Is Schizophrenia?

Schizophrenia is a chronic brain disorder affecting one in every 100 people, involving confusion between reality and imagination. It mostly begins in the 20s and continues lifelong. Research shows equal effects in men and women, but potentially earlier onset in men, with similar rates across ethnic groups. Increasingly understood, it is associated with chemical and structural brain changes and genes. Its complexity helps explain misconceptions: it does not mean split or multiple personality, and most patients are not dangerous. Most live with family, in group homes or independently. Active symptoms include delusions, hallucinations, difficulties with thinking and concentration, and low motivation. With treatment, people can often live near-normal lives. Even in infancy, an affected person has brain and genetic changes that will cause later schizophrenia. This close genetic association raises questions about links to cancer, another gene-related disease.

Uncertainty About Whether Schizophrenia Increases Cancer Risk

Assessing physical as well as mental health has become important. Patients may tend toward unhealthy lifestyles, leaving them vulnerable to metabolic disorders, diabetes and cardiovascular disease and other chronic illnesses. Cancer risk nevertheless remains uncertain. Despite smoking, alcohol and substance use, obesity and inactivity complicating health, epidemiological studies have inconsistent results. Many indicate the schizophrenia-cancer association cannot be explained by unhealthy-lifestyle risk factors. Other factors, including genetic mechanisms, may participate. Since schizophrenia is associated with lower risks of several cancers, including colorectal cancer, malignant melanoma and prostate cancer, its genetic factors have been hypothesized to protect against cancer. Its relationship with breast cancer remains uncertain, however.

In JAMA, this published study analyzed data from 1992 – 2016, covering 125760 people in 12 studies. It found schizophrenia increased women's breast cancer risk 1.3-fold. Because results varied widely, researchers nevertheless noted future studies might conclude schizophrenia does not increase breast cancer risk. Both diseases' genetic bases will remain subjects of research.

In conclusion, schizophrenia and breast cancer are both common diseases with genetic foundations. This research particularly indicates physicians should exercise greater care during follow-up. Patients should receive breast screening appropriate to age and risk factors, and women's physical needs should not be overlooked while psychiatric problems are treated.