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PubMed This is a summary of 15 peer-reviewed journal articles Updated
Oncology

Predicting the Future: Advanced Risk Stratification and the Demicco Score

At a Glance

The modified Demicco score estimates how likely a solitary fibrous tumor is to spread using age, tumor size, mitotic activity, and necrosis. It guides follow-up but cannot predict one person’s outcome, and low-risk tumors can recur years later.

Because Solitary Fibrous Tumor (SFT) is a disease with a risk of late recurrence, doctors use specialized tools to predict how the tumor might behave over many years. In the past, these tumors were simply labeled “benign” or “malignant,” but we now know that even tumors that look “benign” under a microscope can occasionally spread [1][2].

To provide a more accurate picture, experts use risk-stratification tools like the modified Demicco model, which combines several factors to estimate the likelihood of the tumor spreading to other parts of the body (metastasis) [3][4].

The Four Variables of the Demicco Score

The modified Demicco score uses four specific pieces of information from your pathology report and medical record to calculate your risk [3]:

  1. Patient Age: Your age at the time of diagnosis (e.g., under or over 55).
  2. Tumor Size: The largest measurement of the tumor (in centimeters).
  3. Mitotic Activity: A count of how many cells are actively dividing (mitoses) in a specific area of tissue.
  4. Tumor Necrosis: The presence of “dead” tumor tissue, which can indicate that a tumor is growing faster than its blood supply can support [5].

Understanding Your Risk Category

By adding points for these four variables, the model places patients into one of three categories. These are cohort-derived estimates that predict metastasis risk at a population level—they do not guarantee your individual outcome or replace site-specific clinical judgment [6].

Risk Category Meaning of the Score Estimated Metastasis Risk (Cohort Examples)
Low Risk Most SFTs fall into this group. These tumors are generally smaller and slow-growing [3]. Low risk (though not zero), with 10-year metastasis risk generally reported under 5% in specific cohorts [3].
Intermediate Risk These tumors may have higher mitotic counts or larger sizes [3]. Roughly 10-20% risk of spreading within 10 years [3].
High Risk These tumors often show significant necrosis and high mitotic activity [3]. Roughly 70-75% risk of spreading within 5-10 years [3].

Beyond the Score: Evolving Research

While the Demicco score is the standard, emerging research looks at the tumor’s DNA to provide more detail [6]. These findings are investigational and are not a universally validated replacement for standard scoring.

  • TERT-Promoter Mutations: These genetic changes may be found in older patients and larger tumors [7]. Some studies suggest an intermediate-risk tumor with a TERT mutation may behave more aggressively, but testing is not universal [8][5].
  • TP53 Mutations: Mutations in the TP53 gene are sometimes linked to dedifferentiation—the process where an SFT turns into a high-grade sarcoma [9][10].
  • Dedifferentiation: This is a histologic diagnosis that may make standard scoring less informative. If your pathology report mentions dedifferentiation, it indicates a significantly higher risk of the tumor returning or spreading, requiring an integrated expert review rather than relying strictly on the Demicco model [10].

Important Limitations

It is vital to remember that the Demicco score is a tool for prediction, not a guarantee.

  • Late Recurrence: Even “low-risk” tumors have been known to return or spread 10 to 15 years after the initial surgery [11][12]. “Low risk” does not mean “no risk.”
  • Tumor Location: The Demicco model was originally designed for tumors outside the brain. For tumors inside the central nervous system (CNS) or eye (orbit), the model may be less accurate, and doctors often use site-specific grading systems [13][14].
  • Individualized Monitoring: Because SFT can be unpredictable, many experts recommend extended or lifelong surveillance. However, your specific plan must be individualized based on your risk, site, and treatment history rather than a one-size-fits-all approach [15][11].

Common questions in this guide

What is the modified Demicco score for solitary fibrous tumor?
The modified Demicco score is a clinical and pathology-based tool that estimates how likely a solitary fibrous tumor is to spread to other parts of the body. It uses age at diagnosis, tumor size, mitotic activity, and tumor necrosis, and provides a population-based estimate rather than a guarantee about one person’s outcome.
What information is needed to calculate my SFT Demicco score?
Your care team uses your age at diagnosis, the tumor’s largest measurement, its mitotic count, and whether necrosis is present. These details are usually found in your medical record and pathology report.
Can a low-risk SFT come back or spread years later?
Yes. Low risk means the estimated chance is lower, not that the chance is zero; solitary fibrous tumors can recur or spread 10 to 15 years after surgery. Your doctor may recommend extended or lifelong surveillance based on your individual risk and treatment history.
Can TERT or TP53 results change my SFT risk assessment?
They may add important context, but these genetic findings are not a universally validated replacement for the Demicco score. A TERT-promoter mutation may suggest more aggressive behavior in some intermediate-risk tumors, while TP53 changes can be associated with dedifferentiation, which may require expert review.
Is the Demicco score accurate for an SFT in the brain or eye?
The Demicco model was originally designed mainly for tumors outside the brain and may be less accurate for tumors in the central nervous system or orbit. Doctors may use a site-specific grading or risk model for these locations.
How often will I need follow-up scans after SFT treatment?
There is no single imaging schedule for everyone with SFT. Follow-up depends on your risk category, tumor location, treatment history, and medical team’s judgment, and monitoring may need to continue for many years.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What is my total score and risk category (low, intermediate, or high) according to the modified Demicco model?
  2. 2.Based on my risk score, how often will I need follow-up imaging, and for how many years?
  3. 3.Does my pathology report mention a TERT-promoter or TP53 mutation, and how does that change your view of my 'intermediate' or 'low' risk score?
  4. 4.Was there any evidence of 'necrosis' or 'dedifferentiation' in the tissue samples?
  5. 5.If my tumor is in the brain (CNS) or eye (orbit), are you using a site-specific risk model instead of the standard Demicco score?

Questions For You

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References

References (15)
  1. 1

    Lessons Learned From an Untreated "Benign" Thoracic Tumor.

    Scrimgeour LA, Grada Z, Aswad BI, Ng T

    The Annals of thoracic surgery 2017; (103(2)):e135-e137 doi:10.1016/j.athoracsur.2016.07.006.

    PMID: 28109372
  2. 2

    Comparison of published risk models for prediction of outcome in patients with extrameningeal solitary fibrous tumour.

    Demicco EG, Griffin AM, Gladdy RA, et al.

    Histopathology 2019; (75(5)):723-737 doi:10.1111/his.13940.

    PMID: 31206727
  3. 3

    Risk assessment in solitary fibrous tumors: validation and refinement of a risk stratification model.

    Demicco EG, Wagner MJ, Maki RG, et al.

    Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2017; (30(10)):1433-1442 doi:10.1038/modpathol.2017.54.

    PMID: 28731041
  4. 4

    Prognostic usefulness of a modified risk model for solitary fibrous tumor that includes the Ki-67 labeling index.

    Sugita S, Segawa K, Kikuchi N, et al.

    World journal of surgical oncology 2022; (20(1)):29 doi:10.1186/s12957-022-02497-2.

    PMID: 35105348
  5. 5

    Solitary Fibrous Tumor: Integration of Clinical, Morphologic, Immunohistochemical and Molecular Findings in Risk Stratification and Classification May Better Predict Patient outcome.

    Machado I, Nieto Morales MG, Cruz J, et al.

    International journal of molecular sciences 2021; (22(17)) doi:10.3390/ijms22179423.

    PMID: 34502329
  6. 6

    Prognostic analysis of extrameningeal solitary fibrous tumor using the modified Demicco model: a clinicopathologic study of 111 Chinese cases.

    Yao CC, Zhou J, Li X, et al.

    Frontiers in oncology 2023; (13()):1272090 doi:10.3389/fonc.2023.1272090.

    PMID: 38239634
  7. 7

    TERT promoter mutations and prognosis in solitary fibrous tumor.

    Bahrami A, Lee S, Schaefer IM, et al.

    Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2016; (29(12)):1511-1522 doi:10.1038/modpathol.2016.126.

    PMID: 27562490
  8. 8

    TERT promoter mutations in solitary fibrous tumour.

    Demicco EG, Wani K, Ingram D, et al.

    Histopathology 2018; (73(5)):843-851 doi:10.1111/his.13703.

    PMID: 29985536
  9. 9

    Spectrum and Clinical Impact of Secondary Genetic Alterations in Translocation-Associated Sarcomas.

    Chang HY, Tap W, Slotkin E, et al.

    JCO precision oncology 2025; (9()):e2500603 doi:10.1200/PO-25-00603.

    PMID: 41166676
  10. 10

    Clinicopathological review of solitary fibrous tumors: dedifferentiation is a major cause of patient death.

    Yamada Y, Kohashi K, Kinoshita I, et al.

    Virchows Archiv : an international journal of pathology 2019; (475(4)):467-477 doi:10.1007/s00428-019-02622-9.

    PMID: 31392468
  11. 11

    Central nervous system solitary fibrous tumors: Case series in accordance with the WHO 2021 reclassification. Framework for patient surveillance.

    Matthijs V, Beckers R, Broecke CV, et al.

    Acta neurochirurgica 2024; (166(1)):414 doi:10.1007/s00701-024-06304-7.

    PMID: 39417883
  12. 12

    Evaluation of NAB2-STAT6 Fusion Variants and Other Molecular Alterations as Prognostic Biomarkers in a Case Series of 83 Solitary Fibrous Tumors.

    Salguero-Aranda C, Martínez-Reguera P, Marcilla D, et al.

    Cancers 2021; (13(20)) doi:10.3390/cancers13205237.

    PMID: 34680383
  13. 13

    Solitary fibrous tumor of thoracic cavity, extra-thoracic sites and central nervous system: Clinicopathologic features and association with local recurrence and metastasis.

    Alexiev BA, Finkelman BS, Streich L, et al.

    Pathology, research and practice 2021; (224()):153531 doi:10.1016/j.prp.2021.153531.

    PMID: 34171600
  14. 14

    Pathological Features and Clinical Course in Patients With Recurrent or Malignant Orbital Solitary Fibrous Tumor/Hemangiopericytoma.

    Sagiv O, Bell D, Guo Y, et al.

    Ophthalmic plastic and reconstructive surgery 2019; (35(2)):148-154 doi:10.1097/IOP.0000000000001189.

    PMID: 30371551
  15. 15

    Surveillance for metastatic hemangiopericytoma-solitary fibrous tumors-systematic literature review on incidence, predictors and diagnosis of extra-cranial disease.

    Ratneswaren T, Hogg FRA, Gallagher MJ, Ashkan K

    Journal of neuro-oncology 2018; (138(3)):447-467 doi:10.1007/s11060-018-2836-2.

    PMID: 29551003

This page explains the modified Demicco score for informational purposes only and does not constitute medical advice. Your pathology and oncology team should interpret your individual risk and surveillance plan.

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