# What is DCIS (ductal carcinoma in situ)?

Source: https://oncologyistanbul.com/glossary/dcis

> The earliest, non-invasive form of breast cancer, confined to the milk ducts and not yet spread into surrounding tissue.

DCIS cells have not broken through the duct wall, so by definition they cannot yet spread to lymph nodes or elsewhere. It is highly treatable, usually with breast-conserving surgery, and is one of the situations where surgery-first is typical rather than neoadjuvant treatment.

## Related
- [Breast cancer treatment](https://oncologyistanbul.com/cancers/breast)

## Authoritative references
- [Wikipedia](https://en.wikipedia.org/wiki/Ductal_carcinoma_in_situ)
- [Wikidata](https://www.wikidata.org/wiki/Q337585)

Full glossary: https://oncologyistanbul.com/glossary