What Causes a Durable Cancer Remission?

Cancer relapse is unfortunately all too common in patients who were told their disease was eradicated. We’ve all heard of the patient who receives a clear diagnosis, only to be stricken with cancer yet again.

Why is it that the cancer came back?

Why didn’t the remission last?

This is exactly what scientists are trying to figure out and recently it seems that they may have found the reason behind a mechanism that creates a “durable remission.”

The key appears not to lie in chemotherapy, radiation or even a new drug, but in the power of our own immune system. While the aforementioned therapies may help in fighting off a tumor, it seems that when the immune system is responsible for the death of the last tumor cell, there are better results because memory lymphocytes are formed. 

What Are Memory Lymphocytes?

Memory lymphocytes are one of the subtypes of immune cells that support immune function. The two main types of lymphocytes are B-lymphocytes and T-lymphocytes. B-lymphocytes help make anti bodies and T-lymphocytes help kill tumor cells and control immune responses. Both, however, leave a “memory” of the antigens they have encountered in the form of “memory lymphocytes”So, throughout our lifetime if our bodies encounter the same pathogen again, the memory lymphocytes are able to mount a rapid defense.

But How Does The Body Use Memory Lymphocytes For Remission?

The way that memory lymphocytes are created for tumors is when an effector response clears out tumor from a tissue.  The effector response then goes back, introduces lymphocytes one tumor cell after another.  When they eat the last tumor cell, the majority of these cells will delete themselves or just rest down.

But a small percentage of lymphocytes will become dedicated to the tissue where the tumor was, and become memory lymphocytes….and  that’s exactly how durable remissions occur.

The dedicated cells will remain tumor-specific T cells and tumor-specific antibody-producing B cells, and they will rest and survive in that tissue.

Early data has shown that these cells are still alive 10 years later, living  in the same tissue! No other cells other than dendritic cells are expected to live for that long, and this may be why tumors don’t come back.

When the immune system, rather than chemotherapy or radiation, is responsible for the death of the very last tumor cell, a very specific process occurs.

The immune effector response puts a percentage of the effector lymphocytes in a suspended animation state as sentinel cells that are resting in the tissue where the tumor was. If any malignant stem cells try to reestablish business as a tumor, they will be destroyed by T cells or B cells.