Why Do Only Some Cancer Patients Respond to Immunotherapy Treatments?

The Mechanism of Immunotherapy

Immunotherapy, such as drugs like PD1 Ketruda, targets specific proteins expressed by cancer cells. These drugs aim to bolster the immune system's ability to recognize and attack cancer cells. Yet, there are instances where these treatments fail to work, leading to a significant challenge for medical practitioners and researchers.

Why Some Cancers Ignore Immunotherapy

Several underlying factors can lead to the ineffectiveness of immunotherapy. Physicians are still struggling to create treatments for certain types of cancer that do not respond to these interventions. The success of immunotherapy often depends on the patient's immune response, as the treatment utilizes the patient's immune cells to fight cancer.

The Factors Hindering Immunotherapy Efficacy

T-cell Exhaustion

T-cells are critical in mounting an effective immune response against cancer. If the T-cells are insufficient or not reactive enough, they may fail to trigger a meaningful immune response. This can lead to the ineffectiveness of immunotherapy.

Microbiomes

The human microbiome, which consists of bacteria and other microorganisms, plays a crucial role in boosting the immune system. Variations in the bacterial flora can impede the activation of an effective immune response by immunotherapy medications. These fluctuations can significantly impact treatment outcomes.

Cancer Mutations

For immunotherapy to work effectively, certain proteins called antigens must be present on the surface of tumor cells. If these antigens are not present in sufficient quantities or if the cancer has mutated to produce fewer of these surface antigens, the immune system may struggle to detect and attack the cancer cells.

Why Cancer Immunotherapy Works for Some and Not All

Each person's response to cancer immunotherapy can vary widely, much like how different individuals may react to the same medications in different ways. For example, Ibuprofen may provide relief to one person without any side effects while causing drowsiness in another. Similarly, while someone may be allergic to penicillin, another person might not show any adverse reaction.

This variability is akin to the randomness observed in human development and health. Two people with seemingly identical conditions might respond differently to the same treatment. Personal factors such as genetics, lifestyle, and environmental influences can all play a role in determining the effectiveness of cancer immunotherapy.

Personal Anecdote: A Tale of Similar Diagnoses and Outcomes

As a case in point, I was diagnosed with Stage IB adenocarcinoma confined to the head of my pancreas. Following a modified Whipple procedure and relatively mild chemotherapy, I am now approaching the five-year mark since my diagnosis. In contrast, an acquaintance of mine in Norway with an almost identical diagnosis and treatment regime saw a recurrence within a year and survived it for only five months.

This stark difference in outcomes underscores the unique variability in individual responses to cancer treatments. What works for one individual may not work for another, emphasizing the need for personalized approaches to cancer care.

Despite the challenges, research in the field of immunotherapy continues to advance. Scientists and medical practitioners are working tirelessly to understand which immunotherapy is best for each specific type of cancer, paving the way for more effective and personalized treatments in the future.