My father, 67, has lung cancer. Why is it still incurable?

Question

Hello doctor,

My father was just diagnosed with lung cancer last week, and our whole family is in shock. He is 67 and has never smoked a day in his life, but the CT scan showed a 1.25-inch mass in his right upper lobe, and the biopsy confirmed adenocarcinoma.

We have been reading everything we can find online, and one question keeps bothering all of us: why does cancer remain incurable despite decades of research? We understand that treatments like Pembrolizumab and Carboplatin have improved survival rates, but why cannot they eliminate the disease completely?

His oncologist mentioned something about tumor heterogeneity and resistance mechanisms, but we did not fully understand. His PD-L1 expression came back at 60 percent, and the EGFR mutation was negative. We have also read that lung cancer cells somehow keep adapting to every treatment given to them.

Is it because the cancer keeps changing its genetic makeup, or is it something related to how the immune system responds? We feel so helpless seeing him go through this and just want to understand what we are actually fighting. Any clarity would mean so much to our family right now.

Please advise.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

Thank you so much for sharing your concern with me.

I can truly understand how difficult and overwhelming this situation must be for you and your family. It is very natural to ask why, despite so many years of research, cancer cannot always be completely cured.

The main reason is that cancer is not made up of identical cells. Even within the same tumor, there are different types of cancer cells. Some respond well to treatment, while a few may naturally survive. These surviving cells can grow again later, which is why the disease may not be fully eliminated.

Cancer cells also have the ability to adapt over time. When we give treatment, most of the cancer may shrink, but a small portion can change and become resistant. This is not something anyone is doing wrong; it is simply how cancer behaves biologically.

Regarding the immune system, treatments like Pembrolizumab help the body recognize and attack cancer cells. Your father’s PD-L1 level of 60 percent is actually encouraging, as it suggests a better chance of response to such therapy. However, even then, some cancer cells can escape the immune system and continue to grow.

So the challenge is that while treatment can control the disease very well, cancer can keep changing and adapting, which makes complete and permanent elimination difficult in some cases.

Hope I have addressed all of your queries and concerns. Do follow up whenever needed.

Thank you.