Does my father’s dropped CEA mean his cancer is improving?

Question

Hello doctor,

I am writing about my father, who is 44 and was diagnosed with lung cancer about eight months ago.

He recently had a CT scan, and the report mentions a significant reduction in primary tumor size from 1.65 inches to 0.70 inches with decreased mediastinal lymphadenopathy. We do not fully understand what this means in practical terms for his treatment.

He has completed 4 cycles of carboplatin and pemetrexed so far. His oncologist mentioned that this is a major response on the scan, but we did not get a clear explanation of what that actually means.

His CEA levels have also dropped from 87 to 23 ng/mL. His pulmonologist seems cautiously positive, but no one is really explaining what to expect next.

At the same time, he has type 2 diabetes, and his HbA1c is 8.9 %. His endocrinologist mentioned that this is making steroid use during treatment more complicated.

Physically, he is extremely fatigued now, to the point where even walking to the bathroom requires him to stop and rest. That has been very concerning for us.

We are trying to understand a few things:

Does this kind of reduction on the CT scan mean the cancer is responding well to treatment?
Can a response like this ever make surgery an option?
What should we be asking his oncologist at the next visit to better understand his condition and next steps?

We feel like we are getting pieces of information from different doctors, but not a complete picture, and would really appreciate some clarity.

Please help.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I have read your query and can understand your concern.

The CT scan findings are actually encouraging. A reduction of the tumor from 1.65 inches to 0.70 inches, along with a decrease in mediastinal lymph nodes, means that the chemotherapy is working well.

In simple terms, the cancer burden has reduced significantly. When your oncologist mentions a major response, it usually refers to what we call a partial response, meaning the disease has shrunk but not completely disappeared. The fall in CEA (carcinoembryonic antigen) levels from previous values further supports that the treatment is effective.

At the same time, this does not mean the disease is completely cured. It means it is currently under good control. In many patients I have treated, this stage is where we either continue the same drugs or shift to maintenance therapy, depending on how the patient is tolerating treatment and how the disease behaves on follow-up scans.

Regarding surgery, it depends mainly on the stage at which the cancer was diagnosed initially. If there was mediastinal lymph node involvement from the beginning, surgery is usually not the first option, even after shrinkage.

However, in selected cases where the disease becomes limited and the patient is otherwise fit, the team may reconsider local treatments like surgery or radiation. This decision is always taken collectively by oncology, pulmonology, and thoracic surgery teams.

The fatigue you are describing is very significant and needs attention. Chemotherapy (a systemic cancer treatment using powerful drugs to kill fast-growing cancer cells throughout the body) itself can cause this, but in your father’s case, uncontrolled diabetes is likely adding to it.

An HbA1c (hemoglobin A1c) of 8.9 percent indicates poor sugar control, and steroids given with chemotherapy can worsen sugar control further. I have seen patients improve noticeably in strength once sugars are better controlled, so this part is very important and should not be ignored.

At your next visit, you should ask very directly

At what stage is the disease considered now, after the response?
What is the next plan?
Whether to continue chemotherapy or shift to maintenance?
Is any local treatment, like surgery or radiation, being considered?
And what is the overall goal going forward?
Also, ask clearly how to optimize his diabetes during treatment because that will directly affect his recovery and quality of life.

From my experience, asking the doctor to explain the plan for the next few months step by step usually brings much more clarity and helps families feel more in control.

Overall, this level of response is a good sign, but continued treatment and close follow-up are essential.

I hope this answers your query.

Please let me know if I can assist you further.

Thank you.