Sep 17, 2010 10:22AM Beesie wrote:
What we know is that the overall long-term survival rate for DCIS is about 98%. That seems to be the average of all the studies I've read.... a few studies have the number at as low as 95% but most say 98% - 99%.
What we also know is that women who have pure DCIS have a 100% survival rate, if they don't have a recurrence. By definition, pure DCIS cannot move outside of the breast and breast cancer in the breast is never fatal.
The logical conclusion therefore is that only women who have pure DCIS who then have a recurrence will succumb to breast cancer. Or in other words, the 2% of women with DCIS who eventually do die of the disease must have had a recurrence. And the recurrence must have been IDC, not DCIS.
Based on this, the way I look at it is that the objective of DCIS treatment is to minimize the risk of recurrence to an 'acceptable' level. Recurrence risk will never be 0% - that's impossible, no matter what surgery or treatment we have. So there will always be some level of risk. But now we get to the tricky part. What is an 'acceptable' level of recurrence risk? And what is acceptable as a treatment to get to the lowest possible risk level? This depends entirely on the individual.
Some of us are more risk averse than others. A 10% recurrence risk might be just fine for some women but other women might not be comfortable with a recurrence risk at that level.
It's also true that some of us are willing to do things to reduce our risk that others wouldn't consider. Every treatment comes with it's own risks and side effects, so we have to balance the risks/side effects of the treatments with the benefits we get in terms of BC recurrence risk reduction. Some women would remove both their breasts to avoid taking Tamoxifen. Other women would gladly take Tamoxifen if it means that they can keep their breasts.
The last - and possibly most important factor - that plays into recurrence risk decisions is the diagnosis itself. Someone who had a small amount of low grade DCIS will likely have a low recurrence risk (4% - 5%) after a lumpectomy alone. For these individuals, with such a low risk, the benefit from other treatments is low. Because of this, some women in this position choose to take no other treatments. Other women choose to have mastectomies or to have radiation and take Tamoxifen; these two actions can reduce their risk to about 1% - 2%. For the first group of women, these treatments are 'over-treatment' but to the second group of women, these treatments are 'necessary'.
Then there are women who have large amounts of high grade DCIS. After a lumpectomy alone, their recurrence risk could be as high as 40% - 50%. For these women, some additional treatment is necessary. But what treatment? Individual preferences and individual risk profiles really come into play here. Some women will choose to have a mastectomy, to get their risk to 1% - 2%. Other women will consider that to be too drastic and unnecessary, and will instead have radiation and take Tamoxifen, and will live with a recurrence risk of 10% - 12%.
It's all in how we look at recurrence risk, and how we assess it as compared to other risks and side effects (the risks from radiation, a life without breasts, etc.). In the end though, none of us can avoid have some level of recurrence risk.