Breast carcinoma in situ is a heterogeneous group of neoplastic lesions confined to the breast ducts (ductal carcinoma in situ [DCIS]). The diagnosis of DCIS increased dramatically following the introduction of screening. It represents 25% of all new diagnosed breast cancers.
The goal of therapy for DCIS is to prevent the development of invasive breast cancer.
Therapeutic approaches include surgery, radiation therapy, and adjuvant endocrine therapy.
The options for treatment of these patients are breast-conserving therapy (BCT) or mastectomy.
Local treatment for DCIS is usually based on breast-conserving therapy followed by adjuvant radiation therapy. (RT). Radiation therapy may be reasonably omitted in a select population of patients with low-risk disease.
Mastectomy can be considered in some cases.
BCT for DCIS offers a low rate of recurrence with minimal complications.
Mastectomy is curative for most patients with DCIS, with only 1 to 2 percent of disease recurrence. The causes of recurrence are inadequate margins, incomplete removal of breast tissue or an unrecognized invasive carcinoma during the surgery. When breast reconstruction is needed it is normally performed immediately.
Sentinel lymph node biopsy (SLNB) is indicated in some women that require a mastectomy
The lymphatic drainage pattern is changed after performing a mastectomy so at a later date it is impossible to perform an SLNB if needed (for example if invasive cancer is found unexpectedly in the specimen).
As patients who require a mastectomy are those with a higher likelihood of having an invasive cancer they should routinely undergo SLNB.
Criteria for BCT
1. Histologically negative margins can be achieved with a lumpectomy. Negative margins are defined by tumor-filled ducts separated by a measurable distance from the inked surface (ie, 2 mm). It is recognized that it may not be possible to achieve these margin widths, particularly with DCIS close to the skin or muscle.
2. Multifocal disease is not a contraindication for BCT unless it is a multicentric disease which means involving two or more quadrants.
3. Cosmetically acceptable resection
If patients do not meet BCT criteria, a mastectomy is indicated..
Breast-conserving therapy (BCT)
· BCT refers to a lumpectomy to remove the tumor with negative surgical margins. It is usually followed by radiotherapy to treat any residual disease.
· Core biopsy, needle, wire, reflector, or seed localization under mammographic guidance prior to surgical excision may ensure complete resection.
· RDT is the standard for patients treated with BCT, though it may be reasonable to omit it in selected patients.
· Complete tissue examination.
· Exclude invasive carcinoma.
· Evaluate the distance of the resection margins.
· Check for contiguous or multifocal distribution.
· The goal when treating DCIS is to prevent the development of an invasive breast cancer.
· BCT and mastectomy have similar cancer-specific survival rates.
· Local treatment for DCIS is usually based on breast-conserving therapy followed by adjuvant radiation therapy. (RT)
· Complete tissue examination is important when BCT is performed to exclude invasive carcinoma.
· With appropriate treatment the prognosis is excellent.