How does antibody-based therapy help manage my cancer?

Question

Hello doctor,

I am 40 and currently on antibody-based treatment for cancer after a biopsy showed specific markers. The doctor said this drug targets cancer cells more than normal ones. My last blood test showed WBC 4,200 and mild fatigue. Still, I am confused about how it actually works inside the body.

How does an antibody treatment target cancer cells in a 40-year-old patient specifically?
How does it know which cells to attack and which to spare?
Does the expression level of the marker affect how well the treatment works?

I am worried whether low marker levels can reduce the benefit over time.

Kindly help.

Answer 1

Hello,

Welcome to icliniq.com.

I read your query and understood your concern.

It is understandable to have these questions, especially while going through treatment. Here is the detailed information:

Antibody-based therapies (also called targeted therapies) are designed to recognize specific markers or proteins that are present in higher amounts on cancer cells compared to normal cells, almost like a lock-and-key mechanism.

These antibodies attach to those markers and either block signals that help the cancer grow or flag the cancer cells so your immune system can recognize and destroy them. They do not target based on age, but rather on whether your tumor expresses that specific marker identified in your biopsy.

Normal cells are usually spared because they either do not have that marker or have it in much lower amounts, although some side effects can still occur. Regarding marker levels, yes, the amount of expression can influence how well the treatment works.

Higher expression often means a better response, while lower levels may reduce effectiveness over time, which is why doctors monitor response closely. Your WBC (white blood cell) count of 4,200 is slightly on the lower side but can be expected during treatment, and mild fatigue is also common.

The probable causes can be the presence of tumor-specific antigen or marker leading to initiation of targeted therapy; mild decrease in white blood cells and fatigue likely secondary to treatment effects.

Investigations to be done include

Regular complete blood counts.
Monitoring of tumor markers (if applicable).
Imaging studies (CT - computed tomography, MRI - magnetic resonance imaging, PET - positron emission tomography) to assess treatment response.
Periodic assessment of organ function, depending on the drug used.

We also need to rule out the following conditions:

Treatment-related fatigue versus anemia.
Leukopenia due to therapy versus underlying disease progression.
General cancer-related fatigue syndrome.

Probable diagnosis is malignancy with confirmed marker expression undergoing targeted monoclonal antibody therapy, with expected mild hematological side effects.

I would suggest this treatment plan:

Continue current targeted therapy under oncology supervision.
Monitor blood counts regularly.
Manage fatigue with adequate nutrition and rest.
Adjust treatment if significant side effects or reduced response occur.

Regular oncology follow-up is essential to track response and adjust therapy if needed. Early review is important if fatigue worsens or infections occur. Let me know if you have noticed any recent infections, fever, or further drop in energy levels.

I hope you are satisfied with my answer. For further queries, you can consult me at iCliniq.

Thank you.