Anyone else with IDC end up with DCIS years later??

I'm not sure what she's saying. If nothing could grow there after radiation, then radiation would be a 100% cure for local cancers.

Hi JeanQ:

I'm sorry to hear this, but glad to hear it was not invasive.

I am not sure what the surgeon is getting at either, so please don't hesitate to discuss it with your oncologist. To expand on what ksusan said, I would think that the normal cells lining the ducts can continue to "grow" in the years following a course of radiation, as part of normal cell turnover. In addition, in practice, it may be difficult to distinguish between recurrent disease versus new disease. While the DCIS may be recurrent disease, given the four years since initial diagnosis, it seems at least formally possible that some normal cells or perhaps some pre-existing atypical cells may have undergone additional changes leading to a new diagnosis of ER-PR- DCIS.

Unfortunately, as ksusan noted, whole-breast irradiation is not 100%. In this regard, with DCIS:

Solin (2015): http://jco.ascopubs.org/content/early/2015/09/14/JCO.2015.60.8588.abstract

"Five randomized clinical trials have consistently demonstrated that adding radiation treatment after surgical excision for patients with DCIS reduces the risk of local recurrence in the ipsilateral breast by approximately half. (8-16) The Early Breast Cancer Trialists' Collaborative Trial Group (EBCTCG) meta-analysis combined data from four of the randomized trials of radiation treatment after surgical excision.(17) Two randomized clinical trials have demonstrated that adding tamoxifen reduces the risk of all breast cancer events (ipsilateral plus contralateral) for hormone receptor–positive DCIS tumors.(9,10,14,18,19)."

Thus, following a diagnosis of pure DCIS, whole-breast radiation therapy may achieve a local, same-breast relative risk reduction benefit of ~ 50%. However, the potential actual or absolute risk reduction benefit for an individual will depend upon the magnitude of their personal risk without radiation, which may vary in view of factors such as grade and margin size. For example, if a person's estimated 10-year risk of ipsilateral (same) in-breast recurrence was estimated to be about 15%, then their potential risk reduction benefit following radiation would be about 0.50 x 15 % = 7.5 %. This would leave a residual ipsilateral 10-year recurrence risk following radiation of about 7.5% (15% - 7.5% = 7.5%). Recurrences may be DCIS or invasive disease, with approximately half being invasive.

With a diagnosis of invasive disease, "[a]fter breast-conserving surgery, radiotherapy to the conserved breast [also approximately] halves the rate at which the disease recurs":

EBCTCG (2011): http://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(11)61629-2.pdf

With a diagnosis of hormone receeptor-positive DCIS or IDC, while endocrine therapy can confer additional benefit, endocrine therapy would not be effective on recurrent or new disease that was ER- PR- (DCIS or IDC).

The above is for information only. Anyone considering radiation therapy should consult with a Radiation Oncologist to ensure receipt of accurate, current, case-specific, expert professional medical advice.

BarredOwl

I had IDC four years ago, with LX and chemo and radiation, and had a local recurrence (exact same spot) 8 months ago, this time TN IDC with a larger area of grade 3 DCIS with necrosis. Chemo, no rads (for the reason you pointed out above), and now a UMX. I had radiation boosts to the area, and still - a recurrence. All it took was a couple of TN cells to survive chemo and rads and then set up camp and start dividing again.

I've always wondered if local recurrence was less common than metastatic, as I don't often hear much about it, although my MO seems to support this thinking. The literature on recurrence almost always describes mets. I'm curious to hear what others have to say, too.