Progression — growth or spread of cancer

Disease progression is a standardised clinical term denoting an objective increase in the size of existing tumours or the appearance of new malignant lesions. In solid tumours, it is formalised through frameworks such as the Response Evaluation Criteria in Solid Tumors (RECIST), typically defined as at least a 20% increase in the sum of tumour diameters.

Progression reflects the biological evolution of cancer, often driven by acquired resistance mechanisms where tumour cells adapt to therapeutic pressure. Progression can occur locally within the primary organ, regionally in draining lymph nodes, or distantly as metastatic disease affecting other organs.

Recognising progression protects patients from enduring the side effects of therapies that have ceased providing benefit. Once progression is confirmed, your medical team will discuss next steps, which may include switching to second-line therapies, trying alternative drug classes, or adjusting radiation plans.

Documenting progression also initiates practical conversations about symptom management. Proactively adjusting care helps address emerging physical discomfort early, safeguards functional independence, and ensures that ongoing interventions match your current goals and overall physical reserves.

Progression is confirmed through surveillance imaging such as CT, MRI, or PET-CT scans, often assessed using RECIST criteria. It may also be suspected when tumour markers (e.g., PSA, CA-125, CEA) rise steadily, or when novel resistance mutations appear on liquid biopsy.

Disease progression can occur across all cancer types, including solid malignancies such as lung, colorectal, breast, and renal cell cancers, as well as haematological malignancies like multiple myeloma and lymphoma, where it manifests through marrow involvement or organ enlargement.

Documented progression typically leads to discontinuing the current regimen and initiating next-line therapies, such as switching from chemotherapy to immunotherapy. If progression is oligometastatic (only one or two new spots), focused local treatments like stereotactic radiotherapy may be combined with ongoing systemic drugs.