Low rate of mortality from breast cancer after DCIS diagnosis

Research published this week estimates that the risk of dying from early stage breast cancer within 20 years of diagnosis is very low (3.3%).

Breast Cancer Mammogram

About one fifth of breast cancers detected through routine mammograms are at an early stage; some cells in ducts within the breast have become cancerous, but have not yet started spreading into the surrounding tissue.

This is known as ductal carcinoma in situ breast (DCIS) or stage zero cancer. Such cancers can be easily removed surgically. However, some women can subsequently develop a second breast cancer after having a DCIS breast cancer removed and this may (in a low proportion of patients) be invasive and ultimately fatal.

Steven Narod MD and colleagues analysed data in the Surveillance, Epidemiology and End Results (SEER) 18 registries database to see if they could identify factors predictive of mortality after a DCIS diagnosis.

The study included data from 108,196 women diagnosed with DCIS between 1988 and 2011. The average age at diagnosis was 54 years and the women had follow-up data covering an average of 7.5 years.

The analysis found the risk of dying from breast cancer within 10 years of DCIS diagnosis to be 1.1%. Although low, this is still 1.8 times higher than the breast cancer mortality rate in the general population.

At 20 years after a DCIS diagnosis, the overall mortality rate was 3.3%. This rate more than doubled among women who developed DCIS before the age of 35 years and for black women.

Although, it is generally considered that an invasive recurrence on the same side (ipsilateral) as the DCIS is associated with a greater risk of dying from breast cancer, this study showed that preventing an ipsilateral invasive recurrence did not prevent death from breast cancer.

Although radiotherapy reduced the risk of ipsilateral invasive recurrence, it did not reduce the risk of dying from breast cancer within 10 years of DCIS diagnosis.

Interestingly, patients undergoing single mastectomy had a higher breast cancer 10-year mortality rate than those undergoing radiotherapy, despite having a lower risk of ipsilateral invasive recurrence. Thus, more aggressive treatment of DCIS does not necessarily reduce breast cancer mortality.

The authors concluded:

Some cases of DCIS have an inherent potential for distant metastatic spread. It is therefore appropriate to consider these as de facto breast cancers and not as pre-invasive markers predictive of a subsequent invasive cancer"

In a related editorial, Laura Esserman, and Christina Yaud commented "If we want the future to be better for women with DCIS, we have to be committed to testing new approaches to care."

Sources:

Comments

  1. Zsuzsanna Suba Zsuzsanna Suba Hungary says:

    The low but consistent incidence rate of invasive breast cancer deriving from ductal in situ carcinoma (DCIS) justifies that the usual surgical and adjuvant therapy of high grade DCIS is not always capable of ensuring a tumor-free life, while low grade DCIS is perhaps superfluously over treated.
    Appropriate estrogen receptor (ER)-signaling is the chief safeguard of genomic stability in strong interplay with DNA-controlling and repairing systems, such as BRCA-genes and their protein products [http://goo.gl/EsB1bK]. Detection of DCIS by mammographic screening may be regarded as an early marker of disturbed hormonal, metabolic and DNA-stabilizer equilibrium, since the female breast is exquisitely sensitive to the defects of estrogen signaling [http://goo.gl/xRh4wL]. The stronger the defect of cellular estrogen surveillance, the higher is the probability of DCIS development with high-risk characteristics.
    Among young cases with active ovarian estrogen synthesis, the relatively higher risk of poorly differentiated DCIS may be attributed to the low incidence rate of more successfully suppressed ER-positive cancers rather than an excessive inclination to ER-negative tumors. Moreover, among dark-skinned American women, the higher risk of developing poorly differentiated DCIS and the higher breast cancer mortality rate as compared with white women are associated with estrogen deficiency and further hormonal defects. These endocrine disturbances may be explained by the incongruence between their excessive pigmentation and the poor light and sunshine exposure of North-America.
    [http://dx.doi.org/10.2174/157489212801820048].
    In women, during aging, progressive weakening of estrogen signaling and the associated gene stabilizer mechanisms are dangerous systemic processes [http://goo.gl/yiYszF], despite any usual, aggressive treatment of DCIS. In patients having increased risk of invasive breast cancer, natural estrogen substitution is the optimal risk-reducing therapy aiming the stabilization of gene regulatory processes and the apoptotic death of accidentally initiated tumor cells [http://dx.doi.org/10.2147/dddt.s89536]. By contrast, antiestrogen treatment against tumor recurrence may be risky, being effective only in such genetically proficient women who are capable of strong, counteractive upregulation of estrogen signaling. Tumor growth may be provoked by de novo or acquired antiestrogen resistance being associated with the missing capacity of patients for the extreme upregulation of estrogen signaling or with the exhaustion of defensive counteractions by excessive antiestrogen administration [http://dx.doi.org/10.2147/dddt.s89536].      
    In conclusion, in cases of DCIS which have been diagnosed, the most important preventive strategy against invasive breast cancer development is to combine lumpectomy with strict control and maintenance of estrogen signaling over a whole lifetime.
    Zsuzsanna Suba

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News-Medical.Net.
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