ctDNA Testing for Newly Diagnosed Left Breast DCIS
No ctDNA tests are routinely recommended for newly diagnosed ductal carcinoma in situ (DCIS) of the breast as there is insufficient evidence supporting their clinical utility in this setting.
Current Guidelines for DCIS Evaluation
The standard diagnostic workup for DCIS focuses on traditional clinical and pathological assessment rather than molecular testing of circulating tumor DNA. According to established guidelines, the following evaluations are recommended:
Initial Assessment
- Complete history and physical examination of the breast 1
- Bilateral diagnostic mammography to define extent of disease 1
- Pathologic evaluation of the biopsy specimen 1
Pathologic Evaluation Should Include
- Nuclear grade of the lesion
- Presence or absence of necrosis
- Architectural patterns
- Extent (size) of DCIS
- Assessment of surgical margins 1
Biomarker Testing
- ER testing is recommended to determine potential benefit of endocrine therapies to reduce risk of future breast cancer 1
- PgR testing is considered optional 1
Why ctDNA Testing Is Not Indicated for DCIS
Lack of Evidence: Current guidelines do not recommend ctDNA testing for newly diagnosed DCIS 1
Limited Clinical Utility: ctDNA testing has demonstrated utility primarily in metastatic breast cancer settings, not in early-stage disease or DCIS 1
Biological Considerations: DCIS is a non-invasive condition confined within the milk ducts without direct access to the bloodstream, which limits the release of tumor DNA into circulation
Test Performance: Studies examining ctDNA in early breast cancer have shown limited sensitivity, particularly in non-invasive disease 2, 3
When ctDNA Testing May Be Considered
ctDNA testing might be considered in specific clinical scenarios:
Research Settings: Participation in clinical trials investigating the role of ctDNA in DCIS
Genetic Predisposition: If there is a strong family history or known genetic mutation (e.g., CHEK2 variant as mentioned in 1), genetic counseling and germline testing may be appropriate, but this differs from ctDNA testing
Progression to Invasive Disease: If there is evidence of microinvasion or progression to invasive breast cancer, ctDNA testing might be considered as part of the workup for invasive disease 2
Standard of Care for DCIS Management
Instead of ctDNA testing, management of DCIS should focus on:
Surgical Options: Breast-conserving surgery with radiation or mastectomy 1
Adjuvant Therapy: Consider tamoxifen or other endocrine therapy based on ER status to reduce risk of recurrence 1
Surveillance: Regular follow-up imaging and clinical examination
Conclusion
While ctDNA testing shows promise in advanced breast cancer for monitoring disease progression and treatment response 4, 3, there is currently insufficient evidence to support its routine use in newly diagnosed DCIS. Standard pathological assessment, including ER status determination, remains the cornerstone of DCIS evaluation and management.