What Happens When a Cancer Treatment Stops Working?

A cancer treatment is no longer effective and the disease continues to progress — for patients and their families, this can mark a significant turning point. The most important question is then not only: “What is the next treatment?” but first: What do we know about the disease today that we did not know at the time of the previous treatment decision?

Cancer is not a static disease. A tumor can consist of different cell populations that may behave differently over time. Under treatment, sensitive cells may be suppressed while resistant populations remain and continue to grow — becoming visible, for example, as renewed tumor growth or new metastases. Findings from the initial diagnosis therefore do not necessarily reflect the disease in full at a later stage.

This means that the situation needs to be reassessed.

A New Assessment After Disease Progression

When disease progression occurs, it may be appropriate to review the basis of the previous treatment decision — depending on the type of cancer, the treatments already received, and the current clinical situation. This includes updated imaging and laboratory results, pathology findings, as well as previous therapies and the response to them.

In advanced cancers, additional genomic testing may also be relevant — particularly when biomarkers are known that may influence the choice of an approved therapy. If several biomarkers are linked to approved treatments, multigene testing can provide an efficient and tissue-sparing way to investigate them.

A renewed analysis of the tumor may also provide additional information — either through a repeat biopsy or, in certain situations, through a liquid biopsy, in which circulating tumor DNA (ctDNA) in the blood is analyzed. The European Society for Medical Oncology (ESMO) considers validated and sufficiently sensitive ctDNA tests in advanced cancers a potential tool for identifying therapeutically relevant alterations.

However, treatment selection does not depend solely on whether a molecular alteration is identified. What matters is the significance of that alteration for the specific tumor type and how strong the scientific evidence is that a treatment directed against it can reasonably be expected to provide clinical benefit.

The Precision Oncology Approach

This is where precision oncology comes in. Rather than selecting treatment solely on the basis of the original cancer diagnosis, the biological characteristics of the tumor, potential biomarkers, and the course of the disease to date are incorporated into the decision-making process.

Molecular findings are not considered in isolation. They are evaluated together with the tumor type, previous treatments, the patient’s current health status, and the available scientific evidence.

Depending on the individual findings, this may lead to different treatment strategies. These can include established subsequent-line therapies as well as targeted treatments or immunotherapies, provided that relevant biomarkers, clinical data, and the individual situation support their use. In selected cases, combinations of different therapeutic approaches may also be considered.

In medically justified individual situations, the off-label use of an already approved medication may also be evaluated if the available evidence and the individual benefit-risk profile support such an approach.

The Hallwang Clinic Approach

These principles also guide the care of patients with advanced or previously heavily treated cancers at the Hallwang Clinic.

Even before a possible admission, the medical team reviews the available records, including histopathology findings, current imaging, previous treatments, laboratory results, and any existing molecular analyses. Where medically appropriate, additional diagnostics may provide further information for subsequent treatment planning.

Learn more here about how individualized treatment planning works at the Hallwang Clinic.

The objective is to assess, on the basis of the tumor’s current characteristics, the previous course of the disease, and the available scientific evidence, which treatment options may be medically appropriate in the individual case.

Do you have questions about your current situation or would you like a second medical opinion? Contact our medical team for an individualized review of your medical records.