Prognostic factors and Survival Rates for Ductal Carcinoma in Situ (DCIS)

A diagnosis of ductal carcinoma in situ (DCIS) is always good news for the breast cancer patient.

The prognosis for DCIS is always very, very good, regardless of the exact nature of the type of breast cancer and the treatment method used.

There will always be ongoing research and speculation as to the most risky types of DCIS, or those most likely to either progress or recur as something worrisome. However, regardless of specific characteristics and treatment choices, the overall survival rates for ductal carcinoma in situ is close to 100%.

This post has been recently up-dated with all the latest facts and figures for a diagnosis of DCIS. We have created a brand new page all about Ductal Carcinoma In-Situ, Factors for DCIS. Check it out! Other posts that may be of interest include Survival Rates for Breast Cancer and Survival Rates for Breast Cancer based on Stage.

What is Ductal Carcinoma In-Situ (DCIS)?

For an in-depth look at Ductal Carcinoma visit our latest post.

Basically, ductal carcinoma in-situ is a very early form of breast cancer, whereby cancer cells, of various grades, are present in the milk ducts of the breasts.

The reason ductal cancer is named ‘in-situ’ at this early phase, is that the abnormal cells have not yet spread outside of the milk ducts. This explains the reason for the very good prognosis for this type of breast cancer.

That’s good news, then.

The bad news is, ‘nothing lasts forever’ and the good news is, ‘nothing lasts forever’.

Very profound Moose!

Factors at Diagnosis that affect Prognosis for Ductal Carcinoma in Situ

Many people used to think that Ductal Carcinoma In-Situ was a precursor for invasive breast cancer or a ‘pre-cancerous’ condition. However, researchers have struggled for many years to work out which ductal carcinomas in-situ develop into invasive breast cancer and why.

Indeed, not all of these early changes progress to a more invasive, problematic cancer. The high survival rates of 98% to 99% for Ductal Carcinoma In-Situ, in 2010 reflect the effectiveness of treatment.

At present, there does not seem to be one
definitive prognostic marker. Indeed, it is difficult to find research on one single factor alone, such as age, or tumor grade, because they are all inter-linked.

This clearly shows that each individual case is different and outcome and prognosis is based upon many factors.

However, research suggests that 5 main factors of DCIS on diagnosis seem to predict a less favourable outcome. These include:-

(i) Younger age at Diagnosis
(ii)Tumor Grade
(iii)Presence of Necrosis
(iv)Positive Margins
(v)Large Tumor size or clinically palpable at diagnosis

So what does all that mean, Doc?

Well, let’s take a closer look …

(i) Younger age at Diagnosis of DCIS

A medical study published in 2015 set out to estimate the 10 and 20-year mortality rate after an initial diagnosis of ductal carcinoma in-situ.

The statistics were taken from the Surveillance, Epidemiology and End Results (SEER) from 108,196 women diagnosed with DCIS between the years of 1988 to 2011.

survival rates for ductal carcinoma in situ

The study found that the average age of diagnosis for DCIS was 53.8 years. In general the overall breast cancer death rate over a 20 year period was only 3.3%.

However, the mortality rate at 20 years increased to 7.8% in women who were diagnosed with DCIS before the age of 35 years old.

A further 2014 research study concluded that after 10 years the rates of local recurrence after breast conservative therapy and radiotherapy were as follows:-

Women over 50 years at diagnosis: 11% recurrence rate
For women between 45 and 50 years: 15% recurrence rate
Women under 45 years: 25% recurrence rate

We can see from the above figures that the younger the age at diagnosis, the higher the percentage likelihood of recurrence.

However, this is often because younger women present with a higher grade tumor and are not as rigorously followed up by mammogram screening.

Don’t forget, that if you are a younger woman reading this following a diagnosis of DCIS, that age at diagnosis is NOT the only factor on outcome.

The ‘sojourn time’ for early breast tumor development is faster in younger women

Breast tumors in younger women do seem to progress faster than with older women, particularly in the pre-clinical phases (before clinical symptoms).

This is sometimes called the ‘sojourn time‘. The sojourn time is the difference in time between abnormalities found on mammogram and the time it takes for them to be clinically detectable, (when the breast cancer tumor has grown to a palpable lump).

Sojourn time sometimes formally defined as, the mean duration of pre-clinical disease, has been consistently shown to be longer for older women and for slower-growing breast tumors.

I’m confused, Doc. If early DCIS is treated how do we know the sejourn time?

No Moose, specialists estimate the mean (or average) sejourn time to assess factors such as frequency of mammography for different ages.

(ii) and (iii) Tumor Grade and Necrosis at Diagnosis of DCIS

There are 3 grades of Ductal Carcinoma In-Situ (DCIS). If you have been diagnosed with DCIS you will be able to find the Grade on your Pathology Report.

Low Grade DCIS: This may also be called Nuclear Grade 1 or ‘low mitotic rate’. These cancer cells look very similar to normal breast cells and are less likely to recur after surgery.
Moderate Grade DCIS: This grade is also called Nuclear Grade 2 or ‘intermediate mitotic rate’. This grade of DCIS tends to fall between low grade and high grade.
High Grade DCIS: May also be referred to as Nuclear Grade 3 or ‘high mitotic rate’. In this case, the cancer cells look more abnormal and tend to be fast-growing and more likely to recur after surgery.

1.Low Grade DCIS 2. Moderate Grade DCIS 3. High Grade DCIS

A Brazilian medical study examined 403 cases of Ductal Carcinoma In-Situ between the years of 2003 to 2008.

This study found that a solid morphology was the most common feature found in 42.2% of the cases. Furthermore, high-grade DCIS was also common and discovered in 72.7% of patients.

A subtype of DCIS, comedo necrosis, associated with necrosis (cell death) was present in just over half of the cases (55%). In addition, this feature was more common in solid tumors.

Both high-grade DCIS and comedo necrosis were identified more often in younger patients.

In conclusion, this study found high-grade DCIS to be associated with progression to invasive breast cancer.

Oh, this all sounds very complicated!

You will be able to find the grade and subtype of your DCIS on your pathology report.

Don’t forget the overall survival rate for DCIS is excellent.

Positive Margins

The surgical margin is the rim of normal tissue that is taken away along with the breast cancer during surgery.

The aim of surgery is to remove all cancer cells together with a normal section of tissue.

After surgery, the pathology report will classify the margins as follows:-

Clear (Negative margins or clean margins): No cancer cells are found at the edge of the surrounding tissue removed.
Close: Cancer cells are close to the edge of the removed tissue.
Positive: Despite surgery, the cancer cells are present at the edge of the removed tissue.

Well, I never knew that. I thought ‘positive margins’ were something from high school Math.

Tumor Margins and Prognostic Factors: Latest Recommendations

Over the years, positive margins following surgery for DCIS have been associated with local recurrence of breast cancer. However, some cases of DCIS will not recur or progress to invasive ductal cancer.

This poses a dilemma for the surgeon with small, positive margins being associated with recurrence on one hand. However, on the other hand, DCIS patients may also be having unnecessary large resections with poor cosmetic outcomes. The optimal or best margin width for DCIS has caused a lot of controversy over the years.

One large 2016 meta-analysis examined 7,883 women with DCIS treated with breast-conserving therapy and radiation to the whole breast. The above study found that negative margins half the incidence of recurrence of cancer in the same breast.

Furthermore, the research suggests an optimal margin of 2mm.

Interestingly, it was also found that wider margins do not significantly decrease the recurrence of breast cancer. Finally, the study concluded that negative margins of less than 2mm are not an indication for mastectomy alone.

Treatment plays a role for those patients with DCIS. The chances of DCIS recurring for those with positive margins was 35% when treated with breast conserving surgery alone. This figure dropped to 20% when radiation was added to the treatment for positive margins.

(v)Tumor Size or Clinical features on diagnosis

Tumor size, as a single prognostic factor in DCIS, has remained controversial amongst medical experts.

Whilst many cases of DCIS are diagnosed by mammography and are not palpable on diagnosis some present as a clinical, palpable mass (or breast lump).

Narod, following a 2014 medical study, asserts that:-

Tumour size and palpability are risk factors for breast cancer recurrence and mortality.

One small, 2006 medical study concluded that higher rates of invasive caner were detected according to tumor size. Progression to invasive cancer occurred in 10% of DCIS patients with a tumor size between 2.5 to 3.5 cms, 57% for tumor size 3.6 to 4.5 cms and 71% for tumors between 4.5 and 6 cms.

This study concluded that tumors over 2.5 cms have a higher risk of progressing to invasive cancers. However, the study stresses the correlating importance of axillary node involvement.

The controversy over tumor size and prognosis in DCIS cases highlight the many, multi-linked factors when attempting to predict outcomes. Remember, Each case is individual.

Other factors that may affect Survival Rates for Ductal Carcinoma in Situ

Hormone Replacement Therapy and Age of Menarche

There has been extensive research in the past regarding the connection between women taking hormone replacement therapy (HRT) after menopause and invasive breast cancer.

However, there are very few studies that have examined the risk of HRT associated with Ductal Carcinoma In-Situ. A 2012 study examined 1,179 post-menopausal women with Carcinoma-In-Situ.

The study found no association between DCIS and use of Hormone Replacement Therapy (including estrogen alone and estrogen and progesterone combined therapy). Furthermore, there was no association with current use of HRT or the duration of use of these hormones.

However, the study concludes that larger clinical trials are needed to truly assess if there are any associations between HRT and DCIS.

In addition, the age of menarche has not been shown, so far, to be associated with DCIS incidence. Indeed, it is more likely (3.7 times) for women over 60 to develop DCIS.

When I asked for a smoking hot body, menopause was not quite what I had in mind!

Some cases of DCIS will progress towards invasive breast cancer if left untreated

There is a general consensus that DCIS may represent a transitional stage between the normal breast tissue and invasive breast carcinoma.

However, it is still largely unknown which types of DCIS are ‘non-progressing‘ towards invasive breast cancer if left untreated.

One recent study estimated that only between 100 to 270 cases of DCIS per 100000 will not progress to invasive breast cancer if left untreated.

A medical study from the United Kingdom examined 84 breast cancer screening units. This large research study looked at DCIS diagnoses between the years of 2003 and 2007 for women aged 50 to 64 years.

Data from over 5,243,658 was analyzed. The average frequency of DCIS detected was 1.60 per 1000 women. The study found that for every 3 cases of DCIS detected on screening there was one less case of invasive cancer in the next 3 years.

What does this mean Doc?

Well, that large study seems to indicate that 1 in 3 Ductal Carcinomas In-Situ will progress to invasive cancer over a 3 year period, if left untreated.

Treatment options for DCIS: lumpectomy or mastectomy

In most cases, the first line of treatment when DCIS is diagnosed is some form of breast surgery.

There are two basic surgical approaches for DCIS treatment:-

Breast Conserving Surgery (also known as a lumpectomy)
Mastectomy (or breast removal)

Lumpectomy is usually adequate if the area of breast abnormality is very small or only one abnormality is found on a mammogram.

Also, lumpectomy is usually recommended if the DCIS is of a less aggressive type such as non-comedo DCIS.

Lumpectomy is most effective for DCIS patients with small, low-grade DCIS which is easily identifiable on mammogram. In some cases the amount of DCIS is so small that the first exploratory biopsy is enough to remove all of the carcinoma and a subsequent lumpectomy is not required.

But, which treatment is best for DCIS Doc?

That is a really good question, Moose.
There are pros and cons for both options …

Lumpectomy Versus Mastectomy: Prognosis for DCIS

The survival rate following mastectomy for DCIS is reported to be 98% to 99%. That represents a 1% to 2% rate of local recurrence.

Medical studies of excision of DCIS reported a 20% to 44% local recurrence rate over a 10 year period.

For women who underwent breast conserving therapy and radiation there was a 10% to 15% rate of local recurrence.

However, the increased local recurrence risk following breast conservation surgery did NOT affect breast cancer-specific survival when compared with patients who underwent mastectomy for DCIS.

Both groups of patients had a 99% long term breast cancer specific survival.

The gold standard of treatment for DCIS at the moment is wide local excision (lumpectomy) with radiotherapy. According to one 2012 medical study, surgery and radiation therapy is superior to just surgery regarding recurrence rates. However, neither of these approaches affect overall survival rates.

So, how do women with DCIS know which surgical treatment is best for them?

The best approach is to discuss your individual case and all the options with your whole medical team. Pre-surgery counselling can also be very useful.

The use of triple therapy (lumpectomy, radiation, tamoxifen) Does it have a role in DCIS.

It has been suggested, in the past, that triple therapy (lumpectomy, radiation and Tamoxifen) for DCIS reduces the risk of local recurrence of invasive breast cancer by 8% to 9%..

Despite some medical studies suggesting that there is a role for anti-hormonal therapy for DCIS a recent 2016 medical review questions this opinion.

Tjalma, from the above study, suggests that treatment with an anti-hormonal therapy, such as Tamoxifen or Anastrozole, for women with DCIS increased morbidity but did not reduce mortality.

A 2014 review of the use of Tamoxifen, as opposed to no additional treatment in DCIS patients, showed a reduction in the risk of new DCIS events in the same and opposite breast.

There was also a signigicant reduction in breast cancers in the opposite breast. However, there was no significant reduction in invasive breast cancers in the affected breast after Tamoxifen use.

Tjalma argues that the decision to give hormone therapy is ‘questionable’ because it has no effect on mortality and does have significant side effects that can affect the quality of life.

What are the side effects of Tamoxifen therapy, Doc?

Risk of blood clots, stroke,
endometrial and uterine cancers, bone loss and depression.

Wow! That’s quite a list!

In Conclusion

As we have seen in this post, there are many inter-linking prognostic factors for DCIS. As I have constantly stressed, the overall prognosis for DCIS is excellent and each case is individual.

When we look at overall survival rates for breast cancer, the improvements over the last ten years have been outstanding.

However, although treatment options at the moment for DCIS appear to have no impact on overall survival rates, as research continues treatment and knowledge can only improve. On the other hand, there is also an important need for evidence-based guidelines to prevent over-treatment for DCIS in all women.