This is a reposting and updating of my "DCIS facts and misconceptions" thread. In setting up that thread, I wanted to share basic information about DCIS that I'd learned from my research and in my years on this board. I also wanted to provide links to reliable websites that have good general information about DCIS - there is a lot on the internet but much of it isn't vetted or reliable, or it may be just one person's (possibly biased) opinion. Lately my original thread has moved on to other important discussions and it's become a bit difficult to find the information and website links in among all the discussion. Therefore I WOULD REQUEST THAT THIS NEW THREAD BE LEFT AS A GENERAL DCIS INFORMATION THREAD, a place to discuss general information and general questions about DCIS.
***IF YOU HAVE QUESTIONS ABOUT YOUR OWN DIAGNOSIS, IT'S BEST TO START YOUR OWN THREAD IN THE DCIS FORUM.*** Every DCIS diagnosis is different. Some present little risk while others are much more concerning. If we start talking here about individual diagnoses and specific concerns, the discussion could misinform or misdirect someone who has a different type of DCIS diagnosis. That's why I'd like to keep this thread as a general information thread only.
A very important point about everything that follows: I'm not a doctor and I'm not an expert on DCIS. I'm just a former patient who happens to like digging through research. What's written here is what I've learned about DCIS in the 6 ½ years (updated: now 10 years!) since my diagnosis by weeding through research and from spending time on this board. I present this information not to tell anyone what to do but simply to help those who are newly diagnosed and have general questions about DCIS. My hope is that this information prompts those who are newly diagnosed to have better and more meaningful discussions with their doctors.
. **Okay, so what is DCIS? And what isn't DCIS?**
- DCIS is Stage 0 breast cancer - whatever the grade, whatever the size. DCIS is the earliest stage of breast cancer, with the best possible prognosis. DCIS is never invasive; there is no such thing as "invasive DCIS". DCIS can evolve to become invasive cancer but when that happens the diagnosis changes and becomes IDC and the stage changes to Stage I or higher.
- There is much debate these days as to whether DCIS is a cancer or a pre-cancer. What is agreed is that DCIS cells have most of the characteristics of cancer cells. The difference is that DCIS cells are contained within the milk ducts of the breast and do not have the capability to break through the ducts. Therefore DCIS cells cannot move into the open breast tissue, the lymph nodes or vascular system, or invade into the body - in other words, DCIS cannot metastasize. Most definitions of cancer include 3 criteria: 1) abnormal cells; 2) uncontrollable cell growth; and 3) the ability of the cells to move to a different location in the body and metastasize. Therefore it is because DCIS cannot metastasize that some medical experts choose to call DCIS a pre-cancer (DCIS does meet the first two criteria). Since DCIS doesn't fit the strict scientific/medical definition of cancer, there is some validity to that argument. And in fact the National Institute of Health (U.S.) no longer calls DCIS a "cancer". Instead, the NIH defines DCIS as "A noninvasive condition in which abnormal cells are found in the lining of a breast duct." That said, from the standpoint of understanding and treating DCIS, personally I believe the most appropriate definition of DCIS is that it is a "pre-invasive breast cancer". This is because while DCIS cells are not invasive in their current state, if DCIS cells remain in the breast, at any time one (or more) of those DCIS cells might undergo the biological change that gives the cell the ability to break through the milk duct and become an invasive cancer. When that happens, it's the very same cell that started as DCIS that has evolved to become an IDC cancer cell. 80% - 90% of IDC is believed to have evolved from DCIS. Therefore I feel that "pre-invasive breast cancer" is the best definition of DCIS because it explains the current state of the DCIS cell (non-invasive, by some definitions pre-cancer) while acknowledging the future potential to become an invasive breast cancer.
- Nobody knows what % of DCIS will eventually evolve to become invasive cancer and nobody can predict which cases of DCIS will become invasive and over what period of time, despite what you may read from some 'experts' on the internet. Some studies of low grade DCIS not removed surgically have suggested that perhaps 20 % - 40% will become invasive over 5 to 10 years but other studies have shown that low grade DCIS, left untreated, can evolve to become invasive cancer even after 25 or 30 years. For those with high grade DCIS and DCIS with comedonecrosis, it is believed that the percentage that will become invasive is very high. However because these types of DCIS are almost always removed and treated, there is no way to know what percentage will become invasive if allowed to progress naturally. It is known that after treatment (i.e. when the DCIS is surgically removed), if there is a recurrence, in approx. 50% of cases the recurrence will not be found until the DCIS has progressed to become IDC. Currently there's a lot of research underway to better understand the biological factors that determine which cases of DCIS will evolve to become invasive and which are likely to remain DCIS (and therefore remain harmless). Unfortunately at this point in time medical science simply doesn't have the answer yet, but stay tuned.
- It is very common to have DCIS and IDC together. As explained above, most IDC evolves from DCIS. Therefore it's not unusual to find DCIS and IDC together in the same area of cancer. When that happens, the diagnosis, staging and treatment plan is based on the size and pathology of the invasive cancer. If you have any IDC in addition to DCIS, your diagnosis is NOT considered to be Stage 0 DCIS. The DCIS will need to be surgically removed but other than that, the rest of the treatment will focus on the invasive cancer. The DCIS will be adequately treated by whatever treatments are given to address the IDC.
- Until you have your final surgery, you don't know your final diagnosis and whether or not it is Stage 0 DCIS. A needle biopsy only retrieves a small number of samples therefore any diagnosis based on a needle biopsy is not a final diagnosis. Because DCIS and IDC are so often found together, it can happen that a needle biopsy shows only DCIS cells but IDC is also present in the area of cancer. Approximately 20% of women who are diagnosed with DCIS via a needle biopsy are ultimately found to have invasive cancer once all the surgery is done and the entire area with cancer is removed from the breast. Most of the women in this 20% have just one or a few microinvasions but approx. 5% are found to have larger areas of IDC and/or nodal involvement.
- "DCIS with a microinvasion" is a fairly common diagnosis. Although usually grouped in with DCIS, this diagnosis is actually a subset of IDC; DCIS with a microinvasion, called "DCIS-Mi", is Stage I - it is the earliest possible diagnosis of invasive cancer. By definition a microinvasion is an invasive tumor that is no larger than 1mm in size; it is called a T1mic tumor. An invasive tumor any larger than 1mm in size moves on to be a T1a tumor (or T1b, etc.) and the diagnosis is no longer DCIS-Mi but is IDC.
- If you have lymph node invasion, your diagnosis is not DCIS (with the exception noted below). DCIS cancer cells cannot travel to the nodes or move into the bloodstream. A DCIS cancer cell must evolve to become IDC before that can happen. It can sometimes (rarely) happen that a tiny amount of invasive cancer is hidden in the middle of an area of DCIS and isn't discovered when the breast tissue is analyzed; if this invasive cancer results in lymph node invasion, it might appear that the diagnosis is "DCIS with lymph node invasion" but it will be assumed that there was invasive cancer present but just not found. This is called an occult invasion.
- If isolated tumor cells (ITC) are found in your nodes, your diagnosis can still be DCIS. Isolated tumor cells are defined as single tumor cells or small cell clusters not greater than 0.2 mm. The area of invasion into the nodes is so tiny that those who have ITC are considered to be node negative. Therefore if the breast tumor is pure DCIS with no invasions present and if ITC are found, the diagnosis will remain Stage 0 DCIS. The assumption made in these cases is that the tiny number of cancer cells found in the lymph nodes were likely deposited there accidentally by a surgical instrument.
. **So you have DCIS... what does this mean and what's to come?**
- DCIS is heterogeneous disease; there are many different types of DCIS and many different diagnoses. A diagnosis of 3mm of grade 1 papillary DCIS is very different from a diagnosis of 7cm of grade 3 DCIS with comedonecrosis... and there are lots of variations in between. Different diagnoses present different risks. That's why even a small difference in diagnosis can lead to a different treatment recommendation for one person vs. another.
- There is no one single treatment option that is appropriate for all cases of DCIS. Based on current guidelines, treatment can range from a lumpectomy alone to surgery (lumpectomy or mastectomy with an SNB) with radiation and hormone therapy. The specifics of the diagnosis determines the treatment recommendation from the medical team. The decision on treatment is ultimately up to the patient, however. Each of us reacts to our diagnosis in our own way; our feelings, emotions and fears, as well as how we deal with risk and uncertainty, all need to be factored into our treatment decisions - it's much more than a medical decision. Some women choose to have more treatment than what's recommended by their doctors while other women decide to pass on treatments recommended by their doctors. There is no right or wrong so don't feel pressured or concerned because of what someone else did. Decide what's right for you and then don't look back.
- Those diagnosed with DCIS (or early stage invasive cancer) usually will not get a CT scan or PET scan. These scans are quite common among those who have more advanced BC. However because the risk of metastasis is virtually negligible with DCIS and is so low with early stage invasive cancer (such as DCIS-Mi), these scans are not considered necessary because it is so unlikely that they will find anything and because the scans themselves expose the patient to radiation (particularly PET scans).
- If you have pure DCIS, you will not need chemo. Chemo is a systemic treatment - it is given to address the risk that cancer cells may have moved into the body (i.e. distant recurrence/mets). Chemo is not given to treat cancer that is only in the breast and DCIS, by definition, is confined to the breast - that's why chemo isn't necessary. If it's found that you have a small amount of invasive cancer (a microinvasion or just slightly larger) along with your DCIS, according to current treatment guidelines you still likely won't be given chemo. This is because the risk of distant recurrence is considered to be too low to warrant such a toxic treatment. If however it's found that you have a larger amount of invasive cancer, then chemo might be required, depending on the size and pathology of the invasive cancer.
- If you have pure DCIS and are having a lumpectomy, you may benefit from the new Oncotype test for DCIS. The original Oncotype test was used to determine distant recurrence risk and the need for / benefit from chemo. Since chemo is not given for DCIS (see above), that version of the Oncotype test wasn't used on women who had pure DCIS. In December 2011 a new version of the Oncotype test was made available, specifically for women with DCIS. This Oncotype test provides an estimate of the 10-year risk of an invasive recurrence after lumpectomy surgery; test results may be helpful in determining whether or not to have radiation after surgery. Note however that all the patients in the trial had low or intermediate grade DCIS that was ≤2.5 cm in size or high-grade DCIS that was ≤1 cm. The other criteria in the trial was that surgical margins had to be 3mm or greater. Therefore this test may not be worthwhile for those who have larger areas of DCIS or smaller margins, cases where it's more clear that radiation can provide a significant reduction in recurrence risk. Note as well that the Oncotype for DCIS is new and doesn't yet have a lot of testing behind it. Even Genomic Health, the company that sells/markets the Oncotype tests, says that the test provides "additional information" that doctors and patients can use in addition to "the traditional measurements such as margin width, tumor size and tumor grade". Given the cost of the test (approx. $4000), this may put into question the value of the Oncotype test for current DCIS patients, at least until more testing is done on the test itself.
- At this time, based on current medical knowledge, there is no relevance to HER2 status for those who have pure DCIS. While HER2+ invasive breast cancer is known to be very aggressive, there is little understanding of what HER2+ status means for those with DCIS. Several small studies have been undertaken to determine how HER2+ DCIS differs from HER2- DCIS; the results of some of the studies have shown that HER2+ DCIS might be more aggressive but the results of other studies have shown the opposite. The most recent study, in 2013, actually suggested that HER2+ DCIS might be less likely to recur as invasive cancer. So there's no clear answer yet. There also are no special/different treatments for those who have HER2+ DCIS, although several clinical trials currently underway. What is known is that a large percentage of DCIS is HER2+ (a much higher percentage than for IDC) which may suggest that as DCIS evolves to become invasive, in some cases HER2 overexpression might decrease, with the cancer changing from being HER2+ (as DCIS) to HER2- (as IDC). HER2+ DCIS is an evolving area, so stay tuned. But for now, don't worry if your DCIS wasn't tested for HER2 status - some doctors/hospitals do this testing, others don't. And DON'T WORRY IF YOUR DCIS IS HER2+. That doesn't necessarily mean that your DCIS is more aggressive - nobody knows.
- Checking the lymph nodes, i.e. a sentinel node biopsy, is not required for those who have pure DCIS. However women who have high grade DCIS have a reasonable risk that some invasive cancer might be found in the final pathology; because of this, sometimes an SNB will be recommended (note that it is current practice to check the nodes if any amount of invasive cancer is found). An SNB is really not necessary when someone is having an lumpectomy, because an SNB can always be done later if any invasive cancer is found, but is more important for women having a mastectomy because an SNB cannot effectively be done after a mastectomy. Current treatment guidelines suggest that women with DCIS who have a low risk that invasive cancer may be found (i.e. those who appear to have a small amount of lower grade DCIS), do not require an SNB even if they are having a mastectomy. Current treatment guidelines also do not suggest having an SNB for anyone with DCIS having a lumpectomy or on the prophylactic side for anyone with DCIS who is having a BMX.
NEW! For women having a MX for low-risk DCIS who are looking to avoid node removal, a new option may be to identify the sentinel node(s) prior to the MX surgery, mark the node(s) with blue dye or a titanium marker, and then proceed with the MX surgery, without actually doing the SNB and removing any nodes. If any invasive cancer is found in the post-surgical pathology work, at that point another operation can be scheduled to remove the highlighted nodes to check for cancer. Although the procedure was specifically developed to address the risks faced by women having prophylactic mastectomies, women with low-risk DCIS (i.e. cases where it's unlikely that invasive will be found in the MX pathology) might benefit as well. Because this procedure is so new, it's unlikely that many doctors are doing it yet, but it's certainly worth the discussion with your breast surgeon.
- Lymphedema is possible, even after an SNB. Approx. 3% - 7% of women who have SNBs develop lymphedema (and this may be under-reported). Lymphedema can develop anytime in your life after you have nodes removed and once it develops, you will have lymphedema for life. This is an important consideration for anyone having an SNB for DCIS (particularly lower grade DCIS). Note that the fewer the number of nodes removed, the lower the risk that you may develop lymphedema - but there is always a risk.
- The number of nodes removed during an SNB varies by individual based on our lymphatic systems. Sometimes only one node is removed, sometimes as many as 4 or 5 nodes will be removed. Prior to the SNB procedure, isotopes and/or dye is injected into the breast. The isotopes/dye flow towards the nodes. The nodes that "light up" are the ones that are removed. The flow of the isotopes/dye into the nodes is meant to simulate how cancer cells from the breast would flow into the nodes. For this reason, if only one node lights up, only one node needs to be removed but if several nodes light up, all should be removed.
- Recurrence risk after a lumpectomy for DCIS is based on your personal pathology and can't be known until after surgery. Don't assume that what your risk will be the same as anyone else's. The key factors that go into the determination of recurrence risk are size of the surgical margins, size of the tumor/area of DCIS, grade of tumor, presence (or lack of presence) of comedonecrosis, hormone status and age of patient at time of diagnosis. Someone who is older who has a small, low grade DCIS tumor and good surgical margins might have a recurrence risk that is as low as 3% - 4% (even without radiaton) whereas someone who is younger who has a larger, high grade tumor and poor surgical margins could have a recurrence rate that is as high as 60% (prior to radiation). Because the size of the margins and the size of the tumor aren't known until after surgery, it's impossible to know for sure what your recurrence risk will be until after the final pathology report is available, although many doctors speculate or estimate. Don't let your doctor give you "averages" when it comes to recurrence risk; insist on knowing your specific risk level.
- Radiation is usually recommended after a lumpectomy for DCIS but in some cases radiation may provide little benefit and might not be necessary. How much benefit you will get from radiation, in terms of a reduction in recurrence risk, all depends on what your risk was to begin with. Generally it's believed that radiation reduces recurrence by approx. 50%. However if your recurrence risk is only 4% to begin with, your recurrence risk reduction will be only 2% (50% of 4%). On the other hand, if your recurrence risk after surgery alone is 60%, your recurrence risk reduction from radiation will be 30% (50% of 60%). The Van Nuys Prognostic Index (VNPI), developed specifically for DCIS, is commonly used to determine recurrence risk and whether or not radiation should be recommended. The VNPI calculates a 'score' based on margin size, tumor size, and tumor grade/aggressiveness. A low score corresponds with a very low recurrence risk. Therefore women with a low VNPI score may be able to forgo radiation with little risk. Another tool available for those with DCIS who are unsure about whether or not to have radiation after a lumpectomy is the new Oncotype test (see above for more information).
- Tamoxifen is usually recommended to those who have ER+ DCIS (except for those who've had a bilateral mastectomy) however the benefit from Tamoxifen varies by individual so it's best to assess your risk & benefit before deciding whether or not Tamoxifen is for you. As with radiation, how much benefit you get from Tamoxifen depends on what your risk was to begin with. Tamoxifen provides 3 benefits: 1) It reduces the risk of local recurrence by approx. 45%. For those who have a high risk of recurrence following a lumpectomy, this benefit can be quite significant. However for those with a low risk of recurrence after a lumpectomy and those who've had a mastectomy, this benefit might be quite low. 2) It reduces the risk of the development of a new breast cancer in either breast. If you've had a bilateral mastectomy, your risk to get a new BC is only 1% - 2% over your lifetime, so the benefit from Tamoxifen is minimal. But if you still have one or both breasts, your risk is higher and the benefit is greater. However it's important to remember that your risk to develop a new BC spans your entire lifetime whereas Tamoxifen, even if taken for the full 5 years, will provide risk reduction only for approx. 10 - 15 years. If you are 50 and your lifetime risk to develop a new BC (over 40 years to age 90) is 20%, this means your risk over the next 15 years is probably around 7%. Tamoxifen can reduce this risk by approx. 45%, taking it down to 4%. As a result, your lifetime risk would go from 20% to 17%. 3) It reduces the risk of a distant recurrence. This benefit isn't a factor for women who have DCIS, since by definition DCIS cannot move beyond the breast and develop into a distant recurrence (mets). The net of all this is that taking or not taking Tamoxifen is your choice, based on how you feel about your risk level and the benefits you'll get from Tamoxifen. Some women will get a significant risk reduction benefit from Tamoxifen whereas other women will get minimal benefit.
UPDATED - Tamoxifen is currently the only endocrine therapy approved for women who've had DCIS. For women with invasive cancer, while Tamoxifen is given to pre-menopausal women, post-menopausal women often are prescribed an Aromatase Inhibitor (either Arimidex or Aromasin or Femara). Aromatase Inhibitors (AIs) are not yet approved for women who've had DCIS. Recent studies have however shown that the AIs may be more effective than Tamoxifen at reducing recurrence. Based on this, and in anticipation of the approval of AIs for women with DCIS, the 2016 NCCN Guidelines now indicate that post-menopausal women with DCIS may choose to take either Tamoxifen or an AI. The guidelines note that there may be some advantage for aromatase inhibitor therapy in patients <60 years old or those who have concerns about thromboembolism.
- For those who have pure DCIS, the recurrence rate after a mastectomy is generally in the range of 1% - 2%. There have been many studies over many years that have confirmed this recurrence rate after a mastectomy. In recent years a couple of studies have shown however that for those who have negative or very small surgical margins after a mastectomy (1mm or smaller), the recurrence rate might be higher. This is why it's becoming more common for women who have mastectomies for DCIS to also get radiation, if they have close surgical margins. So don't assume that if you have a mastectomy for DCIS, you will not require radiation. Radiation might still be recommended.
- If you have a mastectomy, you will lose all feeling in your breast. If you have a skin sparing mastectomy, you may regain some feeling on your skin but this is not the same as having feeling in your breast. Think of what you would feel if you had a baseball inserted under a layer of your skin - the only feeling you'd have is a surface feeling. While all the natural breast sensation is gone once the breast tissue is removed and the nerves are cut, there have been studies that show that a percentage of women develop phantom feelings that seem like real breast sensation. Those types of phantom sensations can be pleasant however with a mastectomy there is also a risk that you may develop real or phantom pains. While not often discussed this way, from a physical standpoint a mastectomy is similar to an amputation and it comes with all the possible side effects of any amputation. And a reconstructed breast cannot develop real sensations. This is not to discourage anyone who is thinking about having a mastectomy in order to lower recurrence risk; this is just to lay out the facts. Note that there are new reconstruction techniques that may result in more natural feeling being regained however at this time these methods of reconstruction are not widely available.
- DCIS cancer cells, if moved out of the milk duct, will not become invasive and start to spread. DCIS cancer cells are pre-invasive. They have most of the characteristics of invasive cancer cells but based on current scientific understanding, they require one final molecular change to the myoepithelial layer of the cell to become invasive cancer. What this means is that if you have a biopsy or surgery that releases some DCIS cancer cells into the open breast tissue, you don't have to worry that these cells will become invasive cancer. As DCIS cancer cells they will not be able to thrive and grow and multiply in the open breast tissue.
- DCIS cannot recur in the contralateral (opposite) breast so a diagnosis of DCIS does not put you at risk of a "recurrence" in the other breast. It is in fact very unusual for any breast cancer to recur in the other breast. For breast cancer to recur in any location outside of the originating breast, what happens is that some invasive (not DCIS) cancer cells leave the breast, either through the lymphatic system or through the bloodstream, and then settle elsewhere in the body. When the breast cancer cells take hold somewhere other than the breast, this is considered metastasis (i.e. mets). Some of the more common places that breast cancer cells move to are the bones or the liver. It is very unusual for cancer cells to move from one breast through the lymphatic system or bloodstream and then land in the other breast. This just doesn't happen very often. So even invasive cancer rarely recurs in the contralateral breast. As for DCIS, DCIS cancer cells are confined to the milk ducts; they cannot move into the lymphatic system or the bloodstream. While DCIS can spread out and fill the ductal system of the originating breast, DCIS cancer cells will remain within that breast.
- A diagnosis of DCIS, like any diagnosis of breast cancer, increases the future risk that you might be diagnosed with a new primary breast cancer, in either breast. While DCIS cannot recur in the contralateral breast, any diagnosis of breast cancer, even DCIS, is believed to increase the future risk that you might be diagnosed again. This second diagnosis is not a recurrence, but is a new primary breast cancer, unrelated to your first diagnosis. How much your risk goes up vs. the average women (who hasn't been diagnosed with BC) depends on your personal health history, your family history of breast cancer, and your age. So it is important to talk to your oncologist to understand your risk of being diagnosed again - it is different for each of us and it might be higher than you expect or it also could be lower than you expect. Understanding your risk in this area can impact your decisions on hormone therapy and whether or not to have a mastectomy or bilateral mastectomy.
That's it for now! I will include a list of website links with good information about DCIS in a follow-up post in this thread.
If anything is confusing or isn't clear, please ask. Or if there are topics about DCIS that haven't been covered and you think should be included, please ask (it will give me an excuse to do more research!). Questions are very welcome.
However as requested at the beginning, LET'S PLEASE KEEP THIS THREAD FOCUSED ON GENERAL INFORMATION ABOUT DCIS, RATHER THAN GETTING INTO THE SPECIFICS OF INDIVIDUAL DIAGNOSES AND DECISIONS. Those discussions are better served in their own threads, where they can get the focus and attention they deserve. Thank you!
Edited to expand/clarify the discussion on whether DCIS is a cancer or pre-cancer.
Edited to update the information about the use of Aromatase Inhibitors.
“No power so effectually robs the mind of all its powers of acting and reasoning as fear.” Edmund Burke
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