Is Cancer in Your Genes? Understanding Hereditary Cancers

When Cancer Runs in Families
Many patients ask this question often in quiet fear, but with hope in their eyes, “Doctor, my mother had breast cancer. Does that mean I will get it too?”
It is a valid and an important question. While most cancers happen because of random DNA changes or lifestyle factors, about 5–10% of all cancers are hereditary meaning they are caused by genetic mutations passed down through families.

Having a genetic mutation does not mean you will definitely develop cancer, it simply means the cancer risk is higher, and that knowledge gives you power: the power to screen early, make lifestyle changes, and take preventive steps.

Common Types of Hereditary Cancers

Some cancers are more likely to be inherited due to specific gene mutations. Knowing about them helps doctors guide your screening and care.

What are BRCA1 and BRCA2 Genes
BRCA1 and BRCA2 are the genes that help repair damaged DNA and protect cells from cancer. When these genes mutate, this protection weakens, raising the risk of Hereditary cancers. Each person has two copies of these genes, one inherited from each parent. Those who inherit a harmful (mutated) gene are at increased risk of different cancers, such as, breast and ovarian cancer, and some other cancers.

People who have inherited a harmful/ mutated BRCA1 or BRCA2 gene are at increased risk of developing cancers at a younger age as compared to those who do not have the mutated gene.

Most people, who inherit a harmful BRCA1 or BRCA2 gene from one parent, have a normal second copy of the gene that is inherited from the other parent. This second copy of the normal gene, is generally enough to protect the cells from developing cancer. But this normal gene can also get mutated in a person’s lifetime and develop cancer.

What cancers are linked to harmful BRCA1 or BRCA2 gene?

1. Breast and Ovarian Cancer are linked to BRCA1 and BRCA2 gene mutations. Besides the risk of breast and ovarian cancers, risks of prostate, and pancreatic cancer also increases.

2. Colorectal Cancer – Often caused by Lynch Syndrome (HNPCC) or Familial Adenomatous Polyposis (FAP). BRCA1 mutation may also raise
the risk of uterine and stomach cancers.

3. Prostate Cancer – Can be hereditary, particularly with BRCA2 or HOXB13 mutations.

4. Melanoma (Skin Cancer) – Linked with CDKN2A or BAP1 gene mutations, especially when multiple family members are affected.

5.Pancreatic and Stomach Cancer – May be connected to mutations in BRCA2, CDH1, or PALB2 genes.

6.Kidney and Thyroid Cancer – Certain genetic syndromes like Von Hippel–Lindau and Multiple Endocrine Neoplasia (MEN2) also raise the risk.

One can suspect a hereditary cancer risk if several relatives have had the same or related types of cancer, if cancer appeared in the family at a younger age (under 50), or if any family member was diagnosed with multiple cancers.

A known genetic mutation, such as BRCA or Lynch syndrome, in the family is also a strong indicator. Recognizing these patterns helps your oncologist recommend the right genetic testing, preventive screenings, lifestyle changes, and personalized care plans to reduce risk and ensure early detection.