Senescence: permanent retirement
A stressed cell can stop dividing for good but stay alive. That protects against cancer in the short run, but retired cells leak inflammatory signals that help neighbouring tumours grow and resist treatment.
Diagram
Pick a product above a diagram to see the nodes it hits and the escape routes below the block. Hover or tap any node or arrow for what it is; every node opens its target, glossary entry or the pathway page. Violet boxes are druggable targets.
Retired workers who refuse to leave the office. They no longer do the job, but they shout, clutter the corridors, and sometimes hire back the very people who were fired.
What happens
In plain words, then the glossary entries the stage rests on. Chapter 1, The body's defences: Cancer is not the default.
A stressed cell can stop dividing for good but stay alive. That protects against cancer in the short run, but retired cells leak inflammatory signals that help neighbouring tumours grow and resist treatment.
Cellular senescence. Damaged cells can stop dividing permanently instead of dying. That protects against cancer at first, but senescent cells linger, secrete inflammatory signals, and after chemotherapy can help tumours relapse, so removing them (senolytics) is a new strategy.
The molecular players
The proteins and genes at this stage, with their role and how many products act on each. Listed players come from the atlas; drawn players sit as nodes in the diagrams above.
CDK4/6 is the engine that pushes a cell to copy its DNA. Blocking it alongside hormone therapy roughly doubled the time hormone-driven breast cancer stays controlled.
TP53 is the 'guardian of the genome', broken in half of all cancers. Fixing it directly has so far defeated every attempt, so drugs exploit what its loss makes cancers depend on.
Where medicines act
Products grouped by the node they hit, most advanced first, with the cancers an approved product is linked to. Pick one above the diagram to see it light up.
- AbemaciclibApprovedHR-positive / HER2-negative breast cancerHigh-risk early HR-positive breast cancerHR-positive metastatic breast cancer after CDK4/6 inhibitors
- PalbociclibApprovedHR-positive / HER2-negative breast cancerHER2-positive breast cancer
- DalpiciclibApprovedHR-positive / HER2-negative breast cancer
- RibociclibApprovedHR-positive / HER2-negative breast cancerHigh-risk early HR-positive breast cancer
- TrilaciclibApprovedSmall-cell lung cancer
- AtirmociclibPhase 3
- LerociclibPhase 3
- TQB3616Phase 3
- +1 more at CDK4/6 →
- SelinexorApprovedEndometrial cancerMultiple myelomaDiffuse large B-cell lymphoma
- OSE2101Phase 3
- KRT-232Phase 2
- EprenetapoptNegative
How tumours escape
Records tied to this stage that describe resistance, evasion or tolerance. The resistance atlas lists the routes class by class.
- preclinical evidenceAttack extrachromosomal DNA, the engine of oncogene amplification
Aggressive glioblastomas, sarcomas and gastric cancers keep amplified cancer genes such as EGFR, MYC, MDM2 and CDK4 on free-floating DNA circles (ecDNA) whose copy number rises and falls quickly, letting the tumour dial resistance up and down. Cells carrying ecDNA depend on CHK1, giving a first drug target.
- preclinical evidenceOne-two punch: clear senescent cells after chemotherapy
Chemotherapy leaves behind senescent cells that inflame tissues and help tumours relapse. A short course of senolytic drugs afterwards might reduce relapse and long-term side effects at once.
- speculativeresearchDetect tumours changing cell type from RNA in the blood
Some cancers escape treatment by changing into a different kind of cell that the drug no longer affects. Tumour RNA in blood could show this shift months before a biopsy would.
- 2024rctNATALEE: three years of ribociclib after surgery in a broad population of hormone-receptor-positive early breast cancerNew England Journal of Medicinechanged practice
- 2022reviewHallmarks of Cancer 2022: adding phenotypic plasticity, epigenetic reprogramming, microbiomes and senescent cellsCancer Discovery
Measured by
Biomarkers, tests and assays in the corpus that read this stage in a patient.
Open questions
What is not known at this stage: the atlas's own questions, the bottlenecks it bears on, and the ideas in the corpus that try to answer them.
- Should senescent cells be cleared after chemotherapy (the one-two punch), and with what?
- Do CDK4/6 inhibitors work mainly through senescence or arrest?
- being tested at scaleMolecular-class-directed adjuvant therapy in endometrial cancer
Give adjuvant treatment by the tumour's molecular class rather than by stage and grade: nothing for POLE-mutated, immunotherapy for MMRd, chemotherapy plus targeted agents for p53-abnormal, hormones for NSMP.
- early clinicalresearchA biomarker-directed trial of vitamin D after surgery for digestive tract cancers
A Japanese trial found vitamin D supplements did not help everyone after digestive cancer surgery, but appeared to help a subgroup identified by a tumour marker. That subgroup deserves its own trial.
- early clinicalindustryAn open-science consortium on the undruggable drivers, open until a candidate
Companies and public funders would pool money and scientists to crack the hardest cancer proteins, such as MYC and mutant p53, sharing everything openly until there is a real drug candidate, then competing on the final product.
- early clinicalCDK4-selective inhibitors as the new first-line backbone
If a CDK4-only drug matches CDK4/6 inhibitors on efficacy with less neutropenia, continuous dosing and better adherence could translate into longer control.
- early clinicalresearchExtend p53 reactivation beyond the Y220C mutation
One faulty version of the p53 guardian protein can now be repaired by a drug that plugs a hole in it. Systematically hunting for similar holes in other faulty versions could help far more patients.
- early clinicalHER2 ADCs as standard for HER2-positive serous endometrial cancer
Serous endometrial cancers often overproduce HER2. Enhertu already works in them; testing HER2 in every p53-abnormal tumour and using the ADC earlier could change outcomes for the worst subtype.
- early clinicalIntercept cancer at the field stage
Whole regions of tissue carry cancer mutations long before a tumour exists. Detecting and treating the field, not the tumour, could prevent cancers rather than cure them.
- early clinicalIs aneuploidy itself a druggable vulnerability?
Most cancers have the wrong number of chromosomes; normal cells do not. If that difference creates a specific weakness, a drug against it would spare normal tissue by definition.
- early clinicalpolicyStop routine endoscopies for non-dysplastic Barrett's oesophagus
People with Barrett's oesophagus without dysplasia have endoscopies every few years, but the BOSS trial found no survival benefit. Redirecting effort to those with dysplasia would save harm and cost.
- early clinicalresearchWhole-body MRI plus blood DNA surveillance for people with Li-Fraumeni syndrome
People with an inherited TP53 mutation face a near-certain lifetime cancer risk. Yearly whole-body MRI catches cancers early; adding blood DNA tests may catch them earlier still.
9 more ideas are linked to this stage's pathways, targets and terms; see the rankings →
Key evidence
Papers in the corpus tied to this stage's pathways, targets and terms, newest first.
- 2024rctNATALEE: three years of ribociclib after surgery in a broad population of hormone-receptor-positive early breast cancerNew England Journal of Medicinechanged practice
- 2022reviewHallmarks of Cancer 2022: adding phenotypic plasticity, epigenetic reprogramming, microbiomes and senescent cellsCancer Discovery
- 2022reviewSenescence and cancer - role and therapeutic opportunitiesNature Reviews Clinical Oncology
- 2020rctmonarchE: two years of abemaciclib after surgery in high-risk, hormone-receptor-positive early breast cancerJournal of Clinical Oncologychanged practice
- 2015basicMartincorena: normal sun-exposed skin is a patchwork of cancer-mutation clonesScience
- 2013reviewCancer genome landscapes: about 140 driver genes, and each tumour needs only a handfulScience
- 2000reviewThe Hallmarks of Cancer: six capabilities every tumour must acquireCell
- 2000reviewVogelstein, Lane and Levine 2000: surfing the p53 networkNature
- 1999reviewSherr and Roberts 1999: CDK inhibitors as regulators of the G1 phaseGenes and Development
- 1997reviewLevine 1997: p53, the cellular gatekeeper for growth and divisionCell
- 1993basicEl-Deiry 1993: WAF1, the gene through which p53 stops cell divisionCell
- 1991reviewHollstein 1991: p53 mutations in human cancersScience
src/data/mechanics-atlas.ts). Players, medicines, escape routes, tests, ideas and papers are resolved from the knowledge graph at build time through the stage's pathways, targets and terms, so every item here has its own page and sources. Where a section is missing, the corpus has no record tied to the stage yet. Nothing here is medical advice; see about and methodology. Stage 1.5 of 56.