Despite a decade of progress in targeted cancer therapies and immunotherapy, a significant portion of patients still experience disease progression even when receiving guideline-concordant treatment. This persistent gap between therapeutic promise and clinical reality has reignited debate over whether oncology’s narrow focus on tumor biology alone is sufficient to guide effective care. Evidence increasingly shows that treatment success depends not just on the tumor’s characteristics but on the patient’s immune status and dynamic tumor activity — factors that remain inconsistently integrated into routine practice.
Research over the past decade consistently demonstrates that the interaction between tumor cells and the immune system — often described as the Cancer-Immunity Cycle — is central to disease trajectory and therapeutic response. As Chen and Mellman outlined in Nature in 2017, effective treatment response is only possible when the immune system is functionally active. Further, Galon et al. Showed in Science in 2006 that the density and activity of tumor-infiltrating lymphocytes significantly influence prognosis and treatment response, although Fridman et al. Emphasized in Nature Reviews Cancer in 2012 that the tumor microenvironment acts as a key modulator of therapeutic efficacy.
Parallel advances have highlighted the clinical value of circulating tumor cells (CTCs), which serve as dynamic biomarkers of disease activity. Cristofanilli et al. Established in the New England Journal of Medicine in 2004 that CTC counts in peripheral blood correlate with overall survival, offering a real-time, cellular-level view of disease progression that imaging alone cannot provide. Despite this, routine integration of functional immune assessments and CTC monitoring remains limited in clinical workflows.
For more on this story, see Targeted Oncology: Optimizing Targeted Therapies and Treatment.
Experts argue this omission is particularly consequential for immunotherapies such as dendritic cell treatments and CAR-T cell therapy, whose success hinges on the patient’s immunological baseline. As noted in recent analyses, the effectiveness of these approaches is not guaranteed by tumor targeting alone; rather, it depends on whether the patient’s immune system is capable of mounting a response. Without preconditioning or functional immune analysis, the potential of such therapies often goes unrealized.
This has led to a growing call for a broader diagnostic framework that combines functional immune analysis, longitudinal CTC tracking, and adaptive treatment adjustments — especially within personalized immunotherapy strategies. Proponents suggest that integrating these elements could significantly improve treatment outcomes by ensuring therapies are only administered when systemic conditions allow them to work.
The central question in oncology is shifting from “Which treatment is indicated?” to “Under what systemic conditions can a treatment actually exert its effect?” This reframing challenges existing routines but opens a path toward more precise, individualized care — one that treats the patient as a whole biological system, not just a tumor to be targeted.
This follows our earlier report, Latest Advances in HER2-Positive Breast Cancer Treatment.
Why do some patients not respond to guideline-recommended cancer therapies?
Despite correct tumor targeting, many patients fail to respond because their immune system is not functionally capable of mounting an effective response, a factor often overlooked in treatment planning.
How can circulating tumor cells improve cancer monitoring?
CTCs provide a real-time, cellular-level assessment of disease activity in the blood, correlating with survival and offering continuous tracking that imaging cannot match.
What change could improve immunotherapy effectiveness in clinical practice?
Combining functional immune analysis with longitudinal CTC monitoring and adaptive treatment adjustment could ensure immunotherapies are given only when the patient’s immune system is primed to respond.