Cancer is one of the most feared diagnoses; but the reputed unpredictability is almost the scariest part. Cancer is a group of diseases formed by abnormal cells. Scientists work relentlessly to prevent and find a cure against malignant neoplasm, which is just another term for cancer. There are two factors that should be taken into account, controllable and uncontrollable causes.
Controllable factors are lifestyle risks; such as smoking, eating charred or grilled food, or alcohol consumption. Uncontrollable factors are depending on age and genetics; e.g. gender, ethnicity and genes.
Genetics is the passing-on of physical characteristics from one generation to the next. A gene is the basic physical and functional unit of heredity and contributes to each individual’s unique physical features and body mechanism. Therefore, some gene mutations create the risk of hereditary cancers. Most common female hereditary cancers are, for example; ovarian cancer, endometrial cancer and colon cancer.
There are several forms of gene mutation, the most commonly found are;
- BRCA – increasing the risk of breast cancer to 50-60% (risk rate in women without BRCA mutation is usually at 10%) and increasing the risk of ovarian cancer to 20-40% (risk rate in women without BRCA mutation is usually at 1 -1.5 %)
- MMR (Mismatch Repair) – increases the risk of colon cancer to 40-60% and endometrial cancer to 40-60% (risk rate in women without MMR mutation is usually at 1.7 % for these two types) and increases the risk of ovarian cancer to 10%
In order to verify a gene mutation, genetic testing is required by taking a blood sample or doing a biopsy. It takes about 12 weeks to receive the results.
Genetic testing is recommended for women
- who have more than one person diagnosed with ovarian cancer, colon cancer, gastrointestinal cancer, prostate cancer or genitourinary cancer in their family
- diagnosed with cancer age below 50 years
- where cancer was found in multiple organs e.g. colon cancer and ovarian cancer, endometrial cancer and colon cancer
- where cancer was found in different spots in the same organ e.g. both sides of the ovary
- diagnosed with high grade epithelial ovarian cancer, fallopian tube cancer and peritoneal cancer
If gene mutation is detected during the test, the physician will be able to develop a suitable plan to prevent, early detect or treat cancers effectively. More targeted screening can be undertaken; such as mammograms, abdomen ultrasound, blood tests or colonoscopy. In some cases, drastic intervention such as surgery can be discussed to eliminate risks.
Result should also be communicated to other direct family members to determine their predisposition and minimize their risks.
If the test shows no evidence of gene mutation, it does not mean there is no risk of cancer since other risk factors may still remain.
Assoc. Prof. Dr. Tarinee Manchana
Gynecologic Oncology Specialist
Faculty of Medicine, Chulalongkorn University
and Gynecology Centre, BNH Hospital