Percentage of DCIS Cases That Upgrade to Stage 4 Invasive Cancer at Definitive Surgery
The percentage of DCIS cases diagnosed on initial biopsy that are found to be stage 4 invasive cancer at definitive surgery is effectively 0%. While DCIS can be upgraded to invasive cancer at surgery, these are almost exclusively early-stage invasive cancers, not metastatic disease.
Upgrade Rates from DCIS to Invasive Cancer
DCIS diagnosed on initial biopsy may be upgraded to invasive cancer at definitive surgery, but the rates vary:
- Approximately 20-25% of patients diagnosed with pure DCIS on initial biopsy will have invasive breast cancer identified when the entire lesion is removed 1
- In a study of 587 women with initial core needle biopsy diagnosis of DCIS, 38% (220 patients) were found to have invasive disease on final pathology 2
- Another study found that among 206 biopsy-confirmed DCIS lesions, 24.3% were upgraded to microinvasive ductal carcinoma and 21.4% to invasive ductal carcinoma (total upgrade rate of 45.7%) 3
Risk Factors for Upgrade to Invasive Cancer
Several factors predict a higher likelihood of finding invasive cancer at definitive surgery:
- Clinical examination findings: Presence of a palpable mass (odds ratio 5.09) 2
- Imaging findings: Mammographic mass (odds ratio 7.37) 2, MRI detection as mass or non-mass enhancement 3
- Biological markers: Negative progesterone receptor status and high Ki-67 levels 3
- Loss of NES1 gene expression: Associated with 40% incidence of invasive carcinoma at definitive surgery 4
Nodal Involvement in DCIS Upgraded to Invasive Cancer
When DCIS is upgraded to invasive cancer, the risk of nodal involvement is present but limited:
- Axillary nodal metastases were found in 13% (35 of 269) of patients who had axillary nodal staging and were upgraded to invasive cancer 2
- All patients with nodal metastases had invasive carcinoma on final pathology 2
Implications for Management
The risk of finding invasive cancer at definitive surgery has important implications for surgical planning:
- Sentinel lymph node biopsy (SLNB) should be considered in patients with DCIS who are undergoing mastectomy, as mastectomy precludes future SLNB if invasive disease is subsequently discovered 1
- SLNB should also be considered for patients with DCIS who have a high risk of harboring invasive cancer, particularly those with a palpable mass or tumor size ≥2.0 cm on MRI 5
Key Points to Remember
- While upgrade from DCIS to invasive cancer occurs in 20-45% of cases, these are almost exclusively early-stage invasive cancers
- Stage 4 (metastatic) disease is exceedingly rare in patients initially diagnosed with DCIS
- MRI contrast enhancement patterns can help exclude the presence of invasion with high negative predictive value (98.5%) 6
- Careful assessment of clinical and radiologic risk factors can help identify patients at higher risk for harboring invasive disease
In conclusion, while a significant percentage of DCIS cases may be upgraded to invasive cancer at definitive surgery, the upgrade to stage 4 metastatic disease is essentially non-existent in this population.