Over the past decade immunotherapy — treatments that rally the patient’s own immune system to attack tumours — has moved from promise to practice, producing complete remissions in some previously incurable cancers. In a recent clinical programme at Memorial Sloan Kettering Cancer Center, 71‑year‑old Maureen Sideris received 45‑minute infusions of the checkpoint inhibitor dostarlimab every three weeks and, after four months, her oesophageal tumour vanished without surgery, chemotherapy or radiation; her principal treatment toxicity was adrenal insufficiency causing fatigue. That result sits alongside 2022 and 2024 trials that showed dramatic tumour regressions in rectal cancer and an expanded cohort of 117 patients with varied tumour types sharing a particular genetic signature. Researchers say these findings mark an inflection point: durable, sometimes curative responses are now achievable for subsets of patients, even as most cancers remain resistant.
Key takeaways
- The 2018 Nobel Prize recognised the science behind immune checkpoint inhibitors, which are now used across many tumour types.
- CAR T‑cell therapies, effective mainly in blood cancers, and checkpoint inhibitors are the leading immunotherapy platforms today, but each has limits.
- Overall response rates to current immunotherapies typically fall in the 20–40% range, leaving a majority of patients without benefit.
- In MSK’s expanded study of tumours with a specific genetic profile, 103 patients completed treatment and 84 experienced complete disappearance of their tumours; only two required subsequent surgery.
- Only about 5% of tumours carry the genetic features that predict a surgery‑free response to the particular checkpoint strategy studied, underscoring the need for broader approaches.
- Adverse events can range from mild (rashes, diarrhoea, fatigue) to rare but serious organ inflammation (liver, heart, kidneys), per the US National Cancer Institute.
- Multimodal tactics — combining immunotherapy with radiation, ultrasound, microbiome modulation or low‑cost drugs such as statins — are under study to increase the proportion of responders.
Background
Concepts of immune surveillance date back nearly a century, but only in recent decades have tools matured that reliably harness the immune system against cancer. Two major clinical successes have emerged: CAR T‑cell therapies, which reprogramme a patient’s T cells in the lab to target tumour antigens, and immune checkpoint inhibitors, drugs that disable inhibitory brakes on T cells so they can attack tumours. The checkpoint approach earned its pioneers the Nobel Prize in 2018 and has since been approved across multiple cancer types.
Despite those advances, important gaps remain. CAR T therapies have shown outstanding results in certain blood cancers but have struggled to penetrate solid tumours, which account for more than 90% of new cancer diagnoses. Checkpoint inhibitors can provoke a wide array of immune‑related side effects because they reduce the immune system’s built‑in restraints; and, crucially, no current immunotherapy benefits every patient — response rates commonly hover between 20% and 40% depending on cancer type and biomarker profile.
Main event
The clinical examples attracting attention include patients treated with checkpoint blockade at Memorial Sloan Kettering. Maureen Sideris, treated there for oesophageal cancer with dostarlimab, received 45‑minute infusions every three weeks and experienced complete tumour disappearance within four months. Her experience — tumour eradication without surgery, chemo or radiation — highlights the potential for immune drugs to provide organ‑preserving, life‑saving outcomes.
MSK’s investigators initially reported exceptional responses in small 2022 and 2024 rectal cancer studies among tumours with a mismatch‑repair‑deficient or hypermutated genetic profile. They then opened an expanded cohort enrolling 117 patients with oesophageal, bladder, stomach and other tumours that shared the same predictive signature. Of the 103 patients who finished the planned course, 84 had complete responses and only two later needed surgery, a striking rate of organ‑sparing remissions in that selected group.
Other centres have produced similar, though smaller, signals using different checkpoint agents. MD Anderson researchers reported outcomes consistent with the idea that specific genetic or immunological tumour features can predict unusually robust responses. Meanwhile, investigators are testing combinations — adding radiation or ultrasound to make tumours more immunogenic, and exploring how diet, microbiome changes and widely available drugs such as statins might amplify benefit.
Analysis & implications
These results shift the conversation from incremental improvement to rethinking standard practice for some patients. Where surgery, chemotherapy or radiotherapy have been the default curative tools, immunotherapy now offers a pathway to organ preservation and lower long‑term morbidity in genetically selected cases. If validated in larger, randomized studies, this could reduce life‑altering surgeries such as rectal, bladder or stomach removals for a subset of patients.
However, the gains are uneven. The MSK expansion depended on a molecular signature present in roughly 5% of tumours; the remaining 95% still require new strategies. That reality creates acute research priorities: broaden the spectrum of targetable tumour features, reduce toxicity, and make effective treatments affordable and scalable. CAR T approaches, for instance, must be adapted to penetrate solid‑tumour microenvironments, and checkpoint strategies must become safer for wider use.
Economics and access pose parallel challenges. Many immunotherapies are costly to manufacture and deliver. Even when clinical benefit is clear, uneven global access and payer decisions will determine whether breakthroughs translate into population‑level survival gains. Policymakers, providers and industry will need to align on pricing, trial diversity and infrastructure so that effective immunotherapies do not remain available only to a privileged few.
Comparison & data
| Approach | Primary target | Typical response | Key limitation |
|---|---|---|---|
| CAR T‑cell therapy | Engineered T cells vs blood cancer antigens | High in certain leukemias/lymphomas | Poor penetration of solid tumours; complex manufacturing |
| Checkpoint inhibitors | PD‑1/PD‑L1, CTLA‑4 pathways | 20–40% overall; higher in biomarker‑positive tumours | Immune‑related adverse events; variable efficacy |
| Dostarlimab (MSK cohort) | PD‑1 blockade in genetically selected tumours | 84 complete responses of 103 completers in expanded cohort | Applicable to ~5% of tumours with that signature |
| Cancer vaccines (personalised) | Patient‑specific tumour antigens | Promising early signals (e.g., small kidney and melanoma studies) | Early‑phase data; logistical complexity |
The table summarises broad performance and limitations. While checkpoint drugs offer a widely applicable mechanism, their benefit concentrates in tumours with specific molecular or immunological profiles. CAR T is a proven paradigm in hematologic malignancies but needs evolution to treat the solid‑tumour majority. Personalised vaccines and combination regimens aim to expand the fraction of patients who achieve durable remissions.
Reactions & quotes
Clinicians and patients have responded with a mix of awe and cautious optimism, stressing both the human impact and the need for rigorous follow‑up.
“It’s unbelievable — almost like science fiction,”
Maureen Sideris, patient (Memorial Sloan Kettering trial participant)
Sideris’ remark underscores the contrast between decades of invasive treatments and the possibility of non‑surgical cures for some patients. Clinician reactions emphasise both emotional weight and scientific significance.
“People are living, and living with good quality lives,”
Jennifer Wargo, surgical oncology & immunotherapy researcher, MD Anderson
Wargo highlights that successful immunotherapy can produce durable survival with preserved function. Other experts stress that the current breakthroughs are biomarker‑driven and that broader applicability will require additional discovery and validation.
“We have to move from Medieval times to modern times,”
Luis Diaz, head of solid tumour oncology, Memorial Sloan Kettering
Diaz framed the clinical aim: reduce reliance on mutilating surgery where immune‑based cures are possible, while acknowledging that most tumours still lack predictive features for such outcomes.
Unconfirmed
- Whether inexpensive statins reliably boost immunotherapy efficacy remains under investigation and is not yet proven in randomized phase III trials.
- Early‑day dosing improving outcomes has shown signal in limited studies but needs larger validation before changing scheduling practices.
- Claims that chemotherapy and radiation will be obsolete within ten years are speculative and depend on broadening effective options well beyond the ~5% of tumours currently highlighted by MSK’s genetic‑signature results.
Bottom line
Immunotherapy has entered a new phase in which, for carefully selected patients, it can deliver durable remissions and even apparent cures without surgery or conventional cytotoxic treatments. The MSK experience with dostarlimab in tumours carrying a predictive genetic signature provides one of the clearest examples: rapid, complete responses and the prospect of organ preservation for a meaningful minority of patients.
That said, most cancers do not yet carry the molecular features that predict such dramatic benefit. The path forward is to expand the population that can be helped — through combination therapies, vaccine strategies, microbiome and metabolic modulation, and better biomarkers — while keeping safety, cost and access at the centre of clinical and policy discussions. If those barriers are addressed, immunotherapy could reshape cancer care over the coming decade; until then, the progress is transformative for some and aspirational for many.
Sources
- BBC Future — feature on emerging immunotherapy results (media)
- Memorial Sloan Kettering Cancer Center — institutional news and clinical trial descriptions (clinical/academic)
- MD Anderson Cancer Center — oncology research summaries (academic/clinical)
- Dana‑Farber Cancer Institute — research and personalised vaccine studies (academic/clinical)
- US National Cancer Institute — overview of immunotherapy and side effects (official/educational)