Clinical calculator summary
CTS5 Late Recurrence Calculator
Clinical calculator summary
CTS5 Late Recurrence Calculator
CTS5 is a clinicopathologic score estimating late distant recurrence risk from years 5 to 10 in ER-positive early breast cancer after 5 years of endocrine therapy.
Evidence-based context for fast calculator use
- Purpose:
- Support extended endocrine therapy risk discussion
- Population:
- Patients with ER-positive early breast cancer who are distant recurrence-free after 5 years of endocrine therapy
- Factors:
- Age, Tumor size, Tumor grade, Positive lymph nodes
- Reference:
- Dowsett et al., J Clin Oncol 2018
CTS5 Late Breast Cancer Recurrence
Clinical Context & Background
CTS5 = 0.438 x node group + 0.988 x (0.093 x size - 0.001 x size^2 + 0.375 x grade + 0.017 x age). Tumor size is capped at 30 mm; node group maps 0, 1, 2-3, 4-9, >9 positive nodes to 0-4.Reference Data
| CTS5 Score | 5-10 Year Late Distant Recurrence Category |
|---|---|
| < 3.13 | Low risk (<5%) |
| 3.13 - 3.86 | Intermediate risk (5-10%) |
| > 3.86 | High risk (>10%) |
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
When To Use
- Use CTS5 Late Breast Cancer Recurrence when cTS5 estimates 5-10 year late distant recurrence risk category after 5 years of endocrine therapy in ER-positive early breast cancer.
- Confirm that the patient, diagnosis, disease phase, and available inputs match the cited model before calculation.
How To Interpret
- Interpret the displayed result using the calculator-specific formula and reference table, spanning < 3.13 through > 3.86.
- A boundary result should prompt input verification and clinical review rather than false precision.
What To Do Next
- Integrate the result with invasive versus in-situ status, stage, receptor biology, treatment timing, genomic testing, comorbidity, and patient goals.
- Document the inputs, result, timing, and clinical context so the assessment can be reproduced.
Limitations
- Do not interchange screening-risk, DCIS, invasive prognosis, genomic, and post-neoadjuvant tools.
- The result supports clinician judgment and does not independently determine treatment.
Validated Population
patients undergoing breast cancer risk, staging, pathology, recurrence, or treatment-benefit assessment
How to apply this result
For a representative case, verify Age at diagnosis, Invasive tumor size, Tumor grade, calculate the result, and confirm that its classification matches the highlighted reference band before continuing the disease-specific pathway.
Related Tools
Frequently Asked Questions
Does CTS5 predict benefit from extended endocrine therapy?
CTS5 estimates late distant recurrence risk. It does not directly predict benefit from extended endocrine therapy, so treatment decisions should also consider toxicity, menopausal status, bone health, genomic assays when available, and patient preference.
When should CTS5 be used?
CTS5 is intended for ER-positive early breast cancer patients who have completed 5 years of endocrine therapy without distant recurrence, especially in postmenopausal populations where the model is most established.
Evidence-based oncology decision support. Verify with clinical guidelines.