Is Cancer Hereditary?

Is Cancer Hereditary?

What is hereditary? The characteristic of a disease, determined by genetic factors that are passed on from parents to their offspring.

So is cancer hereditary? Cancer is a disease caused due to change or alteration in genes also called mutations or genetic mutations. These genetic mutations can be acquired mutations or inherited mutations. Acquired mutations are the type of mutations that occurs during the lifetime, due to environmental factors, exposure to any carcinogenic agents leading a disease. Inherited mutations are the type of mutations that leads to disease due to we inherit the mutated genes from our parents.

Genes are a part of DNA that is compactly coiled in a structure known as a chromosome. Every individual has 46 chromosomes, where each parent shares a set of 23 chromosomes each making up 46 chromosomes. Each chromosome is said to scatter about 25000 genes, which are the functional units of DNA. Defining that an individual share about >50% of the same genetic profile of that of our parents. In order to answer the question that is cancer hereditary? a lot of testings and analysis is required.

Is Cancer Hereditary? 

Although not all individuals with such hereditary mutations would develop cancer but are at risk of developing cancer. And the individuals who do not develop cancer but have these hereditary mutations are considered carriers and they pass on these mutations to the next generation. And hence cancer is considered as hereditary, though not all the generations may develop cancer. Thus the hereditary mutations are passed down to generation to generations and it is not predictive that who in the family may develop cancer.

Hence the family history of cancer puts up an individual into a high risk of developing cancer. And it is being observed that about 5% to 10% of all cancers are due to an inherited genetic mutation. An individual at birth only inherits these genetic mutations, although may acquire the disease in the progressing years of life.

Not all cancers are hereditary cancer; there are few cancers such as breast cancer, ovarian cancer, prostate cancer, colorectal cancers which are considered to be more prevalent cancers running within the families. And these types of cancers within the family are defined as family cancer syndromes. Few of which are enlisted below:

Hereditary Breast and Ovarian Cancer (HBOC) syndrome

• Family history of breast and/or ovarian cancer.

Lynch syndrome is also known as hereditary non-polyposis colorectal cancer

• Family history of colorectal cancer.

Li-Fraumeni syndrome

• Family history of one or more of the following different cancers such as leukemia, cancer of adrenal cortex, breast cancer, brain (central nervous system) cancers, sarcomas such as osteosarcoma and soft tissue sarcomas and breast cancer.

The strong family history may increase the risk of cancer, for an individual. Family members with multiple types of cancer running down in the family are suggestive to undergo genetic counseling and/or met a health care professional. As the genetic counselor can provide guidance over cancer running within your family and over what genetic test and how it can help you to know about your risk of developing cancer.

The genetic test enables an individual to recognize his own individual risk of developing cancer. Tests provided by Myriad Genetics, Myriad myRisk, and Myriad BRCAnalysis are the two tests available for genetic profiling for both healthy individuals and cancer patients.

Is Cancer Hereditary? Myriad myRisk gives your risk of 8 common hereditary cancers. And Myriad BRCAnalysis answers your risk of breast, ovarian, pancreatic and prostate cancer.

References:

• National Cancer Institute. Physician Data Query (PDQ). Cancer Genetics Overview. 2016. 
• National Cancer Institute. Genetic Testing for Hereditary Cancer Syndromes. 2013. 

BY- Divya Jindam