Historically, DCIS was understood to be a precursor to invasive ductal carcinoma and was treated aggressively with mastectomy. Beginning in the 1970's evidence supporting the efficacy of breast sparing wide local excision (lumpectomy) shifted treatment away from mastectomy.
Today we know that the progression from low grade (low risk) to higher grade (higher risk) lesions is not linear. Some lesions never progress to invasive ductal carcinoma. The DCIS treatment paradigm is likely to shift again based upon new data published by Narod et al. Their findings indicate that:
These data have rekindled the controversy over the optimum treatment of DCIS. Proponents of aggressive therapy credit surgical excision of DCIS lesions for the trend of decreasing breast cancer mortality, depicted in the chart to the right. Proponents of less aggressive therapy believe that technology has compelled the identification and excision of smaller and smaller DCIS lesions which present little or no risk of mortality. They counsel patients to wait and see if their small low grade lesions will progress to higher grade lesions with greater risk before initiating treatment. The new paradigm reserves initial aggressive therapy for DCIS lesions in women younger than 35-40 years, black women and women with genetic mutations that predispose to invasive breast cancer.
DCIS Management Options
DCIS management is determined by: lesion size, focal vs multifocal, histological grade, estrogen receptor status, presence of microinvasion, patient age and preference. Historically, DCIS was treated with simple mastectomy. The goal of mastectomy is to reduce the risk of invasive carcinoma and post surgical recurrence by the removing the majority of breast tissue including the entire DCIS lesion. The local-regional control rates of DCIS by mastectomy are reported as 96%-100%.•
Immediate post mastectomy reconstructive surgery is an option for many women. Modern skin sparing and nipple preserving mastectomy options can offer improved aesthetic outcomes. Nipple preserving procedures may even preserve sensation. (Patient rights to breast reconstruction following mastectomy can be found at the following website,Women's Health and Cancer Rights Act of 1998 )
While the simple mastectomy cure rate for DCIS is high, it may be more aggressive therapy than some women want or require. Today, breast conserving surgery (lumpectomy) combined with post operative whole breast radiation therapy offers long term survival statistics similar to mastectomy. The addition of adjuvant endocrine therapy has been demonstrated to reduce the risk of local recurrence and the development of new contralateral and ipsilateral breast cancers but does not increase the long term survival rate.•
In general, larger breasts may achieve a better cosmetic effect from breast conserving techniques. The percentage of breast volume excised may be an important determinant of cosmesis and patient satisfaction after breast-conserving surgery.• Smaller breasts may achieve a better cosmetic effect from mastectomy with reconstruction.
Selecting mastectomy over breast conserving surgery:•
Breast Conserving Surgery (BCS): DCIS Recommendations:•
There are surgeons whose practice specialty is breast surgery. A woman is more likely to find such a surgeon in a major medical center. It may be important to consult with a Board Certified Plastic Surgeon who specializes in breast surgery and reconstruction.
Lumpectomy is a (BCS) that intends to surgically remove all disease, suspicious calcifications and at least 2mm of surrounding healthy tissue. If clear margins are not obtained on the initial lumpectomy, re-excision of any positive margins is required. Re-excision rates vary widely depending on multiple factors including the lesion size and the means used to identify lesion perimeters.
Lumpectomy in conjunction with radiation therapy has been shown to reduce local recurrence of DCIS when the mass is about 4cm in diameter or less. Lumpectomy is usually performed in the outpatient setting using local anesthesia. If the breast is large, position of the mass requires extensive manipulation or sentinel node biopsy is anticipated, general anesthesia may be required.
Several studies have shown that only 1-2% of women with DCIS will die of breast cancer regardless of whether they were treated with lumpectomy or mastectomy. Therefore, mastectomy is usually reserved for cases where repeated lumpectomy fail to produce clear margins, where there are diffuse malignant appearing microcalcifications or when the breast is small and resection would result on significant deformity.
Radiation therapy involves the delivery of high energy rays to the treatment site. These rays disrupt vascular endothelium in the treatment field resulting in decreased tissue vascularity. The reduced vascularity deprives microinvasive lesions and invasive breast cancer the environment needed for efficient cellular reproduction.*
Endocrine therapy may be recommended to prevent the recurrence of estrogen (+) lesions.
- Selective Estrogen Receptor Modulators (SERMs) including tamoxifen and raloxifene act like estrogens in some tissues, but block estrogen action in others. Estrogens act through estrogen receptors (ERs) to mediate nuclear transcription. In females, estrogens play a key role in reproduction and induce beneficial effects on the skeletal, cardiovascular, and central nervous systems.•
The SERMs tamoxifen and raloxifene both exhibit estrogen receptor (ER) antagonist activity in breast and agonist activity in bone, but only tamoxifen manifests agonist activity in the uterus. Common anti-estrogen side effects include: fatigue, hot flashes, night sweats, vaginal discharge, and mood swings.
- Tamoxifen has been shown in a randomized controlled study to reduce the recurrence of invasive breast cancer but it increase the risk of:
- Raloxifene does not increase the risk of endometrial cancers but has toxic effects similar to tamoxifen.
- The mortality rate of women receiving or not receiving SERMS post breast cancer diagnosis is the same (Cuzick, Powles, Veronesi, 2003).
- Aromatase inhibitors such as anastrozole and exemestane are also frequently prescribed to postmenopausal women to reduce the recurrence of breast cancer. A recent study of 4560 postmenopausal women at moderate risk for developing breast cancer because of previous cancer or DCIS diagnoses was conducted. The women were given exemestane, an aromatase inhibitor, or a placebo. At the 35 month follow up, 11 invasive breast cancers were detected in those given exemestane and in 32 of those given placebo, with a 65% relative reduction in the annual incidence of invasive breast cancer. There were no significant differences between the two groups in the incidence of other cancers or treatment related deaths (Gross et al, 2011).
- Bisphosphonates continue to be a controversial chemoprevention treatment. Conflicting study results range from no overall survival benefit to significant benefits for patients with low estrogen levels.
This content will be reviewed or retired by 12/2019