Today we know that cancer is not only a disease of somatic cells, but it also affects the immune system; our body, through its defense mechanisms, has the ability to recognize and eliminate abnormal cells before they turn into tumors. However, when cancer manages to escape this surveillance, the immune system becomes trapped in an unequal battle: exhausted, confused, or directly suppressed by the tumor itself.
In the face of this threat, traditional medicine has responded for years with three main tools: surgery, chemotherapy, and radiotherapy. These strategies have saved countless lives, but they have also shown their limits.
For decades, the goal was to eliminate the tumor at all costs, without fully considering the impact these treatments could have on the body’s natural defenses. Today, science proposes a deeper vision: it is not enough to destroy cancer, we must also reactivate immunity.
To achieve this, it is necessary to understand how conventional treatments affect the immune system. In this analysis, there are good aspects, others that are bad, and some that are definitely ugly.
The good: when traditional treatments support the immune system
Despite their aggressive reputation, chemotherapy and radiotherapy can have beneficial effects on the immune system if applied in a controlled manner. When the tumor mass and the toxins produced by cancer (such as excess lactic acid) are strategically reduced, the immune system regains part of its ability to act. In these cases, the treatment can facilitate the immune response and help the body regain control.
Some drugs can even induce immunogenic cell death, a process in which tumor cells die releasing danger signals that activate the body’s natural defenses. These signals function as a biological alarm that alerts dendritic cells and T lymphocytes, allowing the immune system to learn to recognize the enemy and attack it with greater precision.
Figure 1. Traditional treatments can both destroy cancer and reshape the immune landscape. Depending on dose and context, they may trigger immune activation or suppression, highlighting the need for approaches that integrate tumor control with immune preservation.
Another promising approach is metronomic chemotherapy, which consists of administering low and frequent doses instead of high and spaced ones. This type of treatment reduces toxicity, protects defenses, and can transform the tumor microenvironment into one more favorable for immunotherapy. It also inhibits angiogenesis (the formation of new blood vessels that feed the tumor) and limits the expansion of immunosuppressive cells.
Altogether, this turns chemotherapy into a strategic ally, not just a weapon of destruction.
The bad: when treatment weakens the most important ally
Despite the above, in most cases, traditional treatments severely damage the immune system.
High-dose chemotherapy does not distinguish between malignant and healthy cells, destroying lymphocytes, hematopoietic stem cells, intestinal cells, and many others essential for the body’s regeneration. The result is a collapsed immune system, right at the moment when it is most needed.
A weakened immune system not only leaves the body more exposed to infections but also reduces its ability to control cancer in the long term. Moreover, this exhaustion can interfere with the effectiveness of subsequent therapies, such as immunotherapy, which depend on a functional immune system to generate lasting results.
Radiotherapy also presents this double-edged sword: while it can eliminate localized tumors, it damages surrounding tissues and generates chronic inflammation. In the long term, this alters the balance of the tumor environment, promotes fibrosis, and, in some cases, even facilitates mutations that could lead to relapse.
That is why it is essential to understand that the key is not only to destroy the tumor but to preserve the integrity of the immune system, which is the body’s most powerful defense.
The ugly: when the medical system resists change
Beyond biological effects, there is another obstacle: the resistance of the medical system to change. Despite evidence showing the limitations of traditional treatments, many hospitals and professionals continue to apply them as the first option, almost automatically.
This resistance does not always stem from a lack of will, but from a medical and economic structure that has relied on these methods for decades. Doctors were trained to attack cancer with chemotherapy or radiation, not to strengthen the patient’s immunity.
And although immunotherapy has proven to be a revolutionary advance, its implementation requires a new way of thinking, one where the biology of the immune system takes priority over the indiscriminate destruction of the tumor.
More and more people are seeking treatments that not only destroy cancer but also rebuild their health and vital energy. This search is driving interest in more precise, less toxic, and more integrative therapies, such as intratumoral immunotherapy, which activates defenses directly within the tumor.
A new balance: combining the best of both worlds
The future of cancer treatment is not about discarding the old, but about integrating it intelligently. Conventional treatments can play an important role if applied with strategy and immunological awareness.
For example, a low dose of chemotherapy or a short course of radiation can reduce tumor size and prepare the ground for immunotherapy to act more effectively.
In some cases, localized radiation can trigger a phenomenon known as the abscopal effect, where local tumor damage causes an immune response throughout the body.
This demonstrates that when used correctly, the combination of therapies can have a synergistic effect, rather than a competitive one.
Intratumoral immunotherapy represents this paradigm shift: a way to turn the tumor into an immunological training ground.Instead of weakening the body, it strengthens it. Instead of suppressing, it awakens. And by doing so, it offers a more lasting and human hope, the possibility that the body itself learns to defend itself.
Main Reference:
Williams, J. R. (2019). The Immunotherapy Revolution: The Best New Hope for Saving Cancer Patients’ Lives. Williams Cancer Institute Press.
