Women Diagnosed With Milder Form of Breast Cancer Live as Long as Other Women

Women over 50 years of age who have been treated for ductal carcinoma in situ (DCIS) are more likely to be alive ten years later than women in the general population. The findings are according to new research presented at the European Cancer Congress (ECCO) 2017.

Presented by Dr Lotte Elshof, research physician and epidemiologist at the Netherlands Cancer Institute, the findings showed that, the overall risk of dying from any other cause in women with DCIS is smaller. However, they do have a higher risk of dying from breast cancer.

Ductal Carcinoma in Situ

DCIS is non-invasive and differs from breast cancer. It originates in the milk ducts of the breast.

It does not lead to any signs or symptoms and 80% of the cases are detected through mammography.

If left untreated, it can progress into an invasive breast cancer, which can be life-threatening. Around 10-15% of the women with DCIS may develop breast cancer without treatment.

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It is usually treated with surgery or surgery combined with radiation therapy.

The risk of developing invasive breast cancer in the same breast, 10 years following treatment is approximately:

• 1% after mastectomy
• 10% after breast-conserving surgery alone
• 5% after breast-conserving surgery followed by radiotherapy

The number of women being diagnosed with DCIS is increasing, as it is being detected through breast screening programs.

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According to the American Cancer Society, about 60,000 cases of DCIS are diagnosed in the United States each year. This accounts for about 1 out of every 5 new breast cancer cases.

In the U.K, over 7,000 cases are diagnosed and over 2,300 in the Netherlands.

Study

The researcher team led by Dr Jelle Wesseling, a breast pathologist at the Netherlands Cancer Institute, studied data on almost 10,000 Dutch women who were diagnosed with DCIS between 1989 and 2004.

They tracked the patients for an average of 10 years and compared their death rates with the expected mortality in the general population.

They found that women over 50 years, who had been treated for DCIS had a 10% lower risk of dying from any cause compared to the general population.

Dr Lotte Elshof told the Congress, "Being diagnosed with DCIS can be extremely distressing, and research indicates that many women overestimate the risks involved and are confused about treatment. This study should provide reassurance that a diagnosis of DCIS does not raise the risk of dying."

"It might seem surprising that this group of women actually has a lower mortality rate than the general population. However, the vast majority would have been diagnosed via breast screening, which suggests they may be health-conscious and well enough to participate in screening."

The study shows that the risk of DCIS patients dying from breast cancer is

• 2.5% after 10 years
• 4% after 15 years

Though these rates are higher than in the general population, the rates were getting lower in women diagnosed with DCIS more recently.

Women diagnosed with DCIS had a lower risk of dying from diseases of the circulatory, respiratory and digestive systems and other cancers.

Conclusion

Further research with an increased study size is necessary to understand why some cases of DCIS progress into invasive cancer, while others do not.

Even after removal of the entire breast or after breast conserving therapy consisting of surgery, generally combined with radiation therapy, DCIS can progress into breast cancer. These treatments can have side-effects, on the heart as well.

This research provides reassurance for women diagnosed with DCIS in terms of longevity as well as in regards to the potential risks of side-effects.

Professor Philip Poortmans, President-elect of ECCO and head of the Radiation Oncology Department at Radboud University Medical Center (Nijmegen, The Netherlands), said, "However, we have to recognize that in one fifth of the patients who die, the cause is breast cancer, which is likely to result from progression of the DCIS they were diagnosed with. Therefore, we are eagerly waiting for the results of further research to identify the factors - including age, as clearly shown in this study - that contribute to the risk for recurrence and progression from DCIS for each individual patient."

"Remarkably, the increased risk of dying from breast cancer is completely offset by a lower risk of dying from other causes compared to women in the general population. This might be explained by the generally better health and socioeconomic status of women who regularly participate in breast cancer screening. This could also be tested in the on-going research." Poortmans added.

References

1. DCIS — Ductal Carcinoma In Situ - (http://www.breastcancer.org/symptoms/types/dcis)
2. Ductal carcinoma in situ (DCIS) - (http://www.mayoclinic.org/diseases-conditions/dcis/basics/definition/con-20031842)

Source-Medindia