How does tumor genome testing help in breast cancer care?

Question

Hello doctor,

I was recently diagnosed with breast cancer, and my oncologist mentioned that genetic testing of my tumor might help determine the most appropriate treatment plan. My grandmother and aunt both had breast cancer, so there is concern about a possible hereditary component to this diagnosis.

I would like to understand all available treatment options and ensure that the most targeted therapy is chosen for my specific type of cancer. There is also concern about whether this information could affect my children’s future health risks. How does cancer genome testing work, and how can it help guide treatment decisions?

Kindly advise.

Answer 1

Hello,

Welcome to icliniq.com.

I understand your concern.

I am truly sorry to hear about the diagnosis of breast cancer. Understandably, this situation can feel overwhelming for both the patient and the family, especially when there is a history of breast cancer in close relatives.

Feeling worried and stressed in such circumstances is normal. However, it is important to note that breast cancer is no longer as difficult to treat as it once was. At present, several effective treatment options are available, and continuous advances in research and new therapies are improving outcomes and offering greater hope.

Two main types of genetic tests can be performed on the tumor to guide treatment decisions:

Oncotype DX (Oncotype diagnostic test):- This test analyzes the activity of more than twenty genes in the tumor deoxyribonucleic acid (DNA). It helps determine how aggressive the tumor is, the likelihood of recurrence or spread, and whether chemotherapy is likely to be beneficial after surgery. Since the cancer is in an early stage, the Oncotype DX test can be particularly useful in deciding whether chemotherapy is necessary.
BRCA (Breast cancer gene) test:- This test determines whether the breast cancer is hereditary in nature. A positive BRCA result can help in selecting appropriate targeted therapies if the cancer recurs, spreads, or becomes more aggressive. This information is also important for female children. If the BRCA test result is positive, screening for daughters is usually advised once they reach 25 years of age. If they also test positive, preventive and risk-reducing strategies can be planned early, based on individual risk assessment.

As the cancer is in an early stage, the first step in treatment is usually surgery. During surgery, the tumor and any involved lymph nodes are removed. The tissue sample is then sent for histopathological examination, which provides detailed information such as:

Tumor size.
Number of lymph nodes involved.
Hormone receptor status, including ER (estrogen receptor) and PR (progesterone receptor) positivity.

Based on the tumor size, lymph node involvement, hormone receptor status, and genetic test results, the need for chemotherapy is assessed. If chemotherapy is required, all medications, expected side effects, and safe management strategies are explained in detail.

Most chemotherapy-related side effects are temporary and reversible, and recovery usually occurs after completion of treatment. Before deciding on the next steps, it is advisable to consider genomic tests.

I would suggest the following measures:

Surgery may be considered.

If chemotherapy is not required, the next step is to evaluate the need for radiotherapy, which may be given to the breast or the axillary (underarm) region. Guidance is provided regarding possible side effects and their management.
The final component of treatment is hormonal therapy. If the tumor is hormone receptor–positive, hormonal treatment is prescribed for a minimum of five years and, in some cases, up to ten years. This therapy significantly reduces the risk of cancer recurrence or spread. Any side effects experienced during hormonal therapy are monitored and managed appropriately.

I hope this explanation is clear and reassuring. There is no need to fear the treatment journey, as support and guidance are provided at every step. Breast cancer is now much more manageable and treatable than in the past.

Thank you.