From the Guidelines
There is no established direct genetic link between specific familial cancers and schizophrenia, but certain genetic syndromes such as Li-Fraumeni syndrome, associated with TP53 mutations, may increase the risk of various cancers and potentially have an indirect link to schizophrenia through shared genetic pathways. While both conditions can have genetic components, they generally involve different genetic pathways. Some research suggests potential overlaps in certain genetic variants between schizophrenia and cancer risk, particularly involving genes that regulate cell growth, apoptosis, and immune function. For example, disruptions in the DISC1 gene have been associated with schizophrenia and may influence cancer-related cellular processes 1. Additionally, the COMT gene, implicated in schizophrenia, may affect cancer susceptibility through its role in estrogen metabolism.
Patients with schizophrenia and their families should follow standard cancer screening guidelines appropriate for their age and risk factors. It's essential to consider the potential for increased cancer risk in individuals with a family history of cancer, especially if there's a known genetic predisposition. For instance, Li-Fraumeni syndrome, which is associated with an increased risk of breast cancer, osteosarcomas, soft-tissue sarcoma, brain tumors, adrenocortical carcinoma, and leukemia, may be relevant in this context 1.
Key points to consider include:
- Genetic predispositions and the associated genes that confer a high risk for breast cancer, such as BRCA1/2, TP53, PTEN, and others 1.
- The importance of a thorough family history evaluation to assess breast cancer risk, considering factors like the number of affected relatives, closeness of the relationship, and age at diagnosis 1.
- The role of genetic counseling and testing in identifying individuals at high risk of breast cancer, particularly those with a known genetic predisposition or a strong family history of the disease 1.
- The recommendation for annual breast MRI as an adjunct to mammogram and clinical breast examination (CBE) in women aged 25 years or older with a genetic predisposition for breast and ovarian cancer syndrome 1.
It's crucial to note that some environmental factors, like smoking, which is more prevalent in schizophrenia patients, can increase cancer risk independently of genetics. If you have both schizophrenia and a family history of cancer, discussing comprehensive screening plans with your healthcare providers is essential, as the relationship between these conditions remains an evolving area of research rather than a well-established clinical association.
From the Research
Familial Cancers Associated with Schizophrenia
- Breast cancer: Studies have found a genetic association between schizophrenia and an increased risk of breast cancer in women 2, 3.
- Ovarian cancer: There is evidence of a genetic link between schizophrenia and an increased risk of ovarian cancer 3.
- Colorectal cancer: Research suggests a causal relationship between genetic predisposition to schizophrenia and an increased risk of colorectal cancer 3.
- Lung cancer: Schizophrenia has been found to increase the risk of lung cancer 3.
- Thyroid cancer: A positive causal relationship has been discovered between schizophrenia and thyroid cancer 3.
- Colon cancer: Although not statistically significant, a small increased risk of colon cancer was associated with familial aggregation scores among parents of individuals with schizophrenia 4.
Cancer Sites with Reduced Risk
- Malignant neoplasm of the stomach: Schizophrenia has been found to reduce the risk of malignant neoplasm of the stomach 3.