Some Good News About DCIS and Worrisome Mammograms

Health Tips / Some Good News About DCIS and Worrisome Mammograms

I’ve lost track of the number of women who’ve told me something like this: “My mammogram experience was horrible. They called me back with this get-in-here-right-away sense of urgency. I was terrified. They took lots of pictures, talked about calcifications. I had one biopsy, then had to return for another. The suspense was horrible.”

And after the biopsy…

“I was told I had DCIS (ductal carcinoma in situ) and that it’s really not the same as breast cancer, but it needed to be removed anyway because having DCIS increased my risk for regular breast cancer. I had the lumpectomy, then radiation. One doctor suggested chemotherapy, another recommended removing both breasts. I said no, but now I go back every few months for a recheck. And I think about this all the time.”

It’s helpful to know a few things about DCIS. First, it’s not the same as the invasive breast cancer that’s the second leading cause of US cancer deaths among women (after lung cancer). Invasive means it can invade (spread to) other tissues in the body.

“In situ” is Latin for “in place,” meaning the cancer cells have not spread to nearby healthy breast cells. Yes, it would be clearer if they’d dropped the “in situ” and simply referred to it as non-invasive. 

You might be surprised to learn that DCIS is a relatively new condition. Since it’s virtually never felt as a breast lump (it’s too tiny), doctors became aware of it only with an increase in screening mammograms. Physicians saw calcium clumps, most of them completely benign and of no significance. Other calcifications contained cancer cells apparently trapped inside a milk duct.

The big question was how to judge the significance of these cancer cells and what the future held for a woman with DCIS. When doctors first started seeing DCIS on mammograms, it was regarded as an early stage of cancer and treated very aggressively. This meant surgery (lumpectomy or mastectomy) and radiation therapy and possibly taking hormone-blocking agents (more on these below).

Some doctors suggested bilateral mastectomy (surgical removal of both breasts) and others chemotherapy, the latter quickly discounted because by definition there was no evidence of cancer spread.

Some reassuring good news appears

The good news about worrisome mammograms and DCIS was published this week in JAMA Oncology, which reported on an immense 20-year study that tracked what actually happened to 100,000 women diagnosed with DCIS. The top take-aways about breast calcifications and DCIS are:

  • By far the majority of breast calcifications are harmless, benign, and do not require a biopsy. By having access to your previous mammograms, a radiologist can determine if the calcifications are stable and can simply make a note about them for future mammograms. This is called watchful waiting and it’s a perfectly reasonable recommendation.
  • First-time (or changing) calcifications might represent DCIS, the answer determined by a breast biopsy. However, don’t let anyone tell you that DCIS is the same as invasive breast cancer or that it will definitely lead to invasive breast cancer. This is simply not correct.
  • Among the 100,000 women diagnosed with DCIS, the death rate from invasive breast cancer was 3.3%. This is the same death rate from invasive breast cancer as in women without DCIS.
  • Women with DCIS can be divided in two groups:

High risk (20%) Women who are black or under age 35 or who have a specific hormone receptor cell type.

Low risk (80%) Everyone else. Essential to underscore here that 80% of women with DCIS are in the low-risk group.

DCIS therapies for the 80% low-risk group

This depends on the cell type (whether hormone receptors are positive or negative). Treatment can range from endocrine therapy (such as taking the estrogen blocker tamoxifen) to simple lifestyle changes (exercise, diet, alcohol reduction, avoiding post-menopause hormone replacement therapy). The study found that more aggressive treatments, including lumpectomy and radiation, conferred absolutely no long-term survival advantage.

DCIS therapies for the 20% high-risk group

Lumpectomy/mastectomy/radiation/hormones unfortunately did not reduce the chances of dying of invasive breast cancer after ten years. Regardless what course of therapy is undertaken, the high-risk group remains twice as susceptible to ultimately dying of invasive breast cancer as the general population (7.8% vs. 3.3%). But being high-risk DCIS doesn’t mean you’ll die of invasive breast cancer—it just means that you’re at greater risk than the general population.

I think the fear-mongering about breast calcifications and DCIS, especially over the past few years, is inexcusable. Even before this study was published, oncologists knew that the majority of women with DCIS were not on an inexorable road to a fatal invasive breast cancer. Nevertheless, women have told me that their doctors urgently wanted to schedule them for a lumpectomy and that radiation treatments were scheduled as they were leaving the hospital.

The future with DCIS

What will likely now occur as the result of this review of 100,000 women with DCIS:

  • If you’re a low-risk or average-risk woman having a mammogram and some new clumps of calcium are seen, your doctor may recommend a few months of watchful waiting or an ultrasound-guided biopsy.
  • If you’re low-risk or average-risk and found to have DCIS, you’ll be advised about healthful lifestyle changes and, depending on your hormone receptor type, be offered hormone-blocking medications.
  • If you’re a low-risk or average-risk woman with DCIS and you’re offered lumpectomy and radiation, get a second opinion.
  • If you’re a high-risk woman (under 35 or black or receptor-positive) who has DCIS, you’ll be offered a more aggressive program, likely lumpectomy followed by radiation. This program has been shown to reduce the recurrence of DCIS but not–repeat not–to affect your risk of fatal invasive breast cancer. You’ll still remain at twice the risk of the general population. A perfectly reasonable question: if you’re high risk, is any treatment justified? The answer is yes because it has also been shown that a very tiny percentage of DCIS in high-risk women can change to actual invasive breast cancer. Thus, if you’re in this group you’re better off having the lumpectomy. Just remember that no matter what choice you make, you’re at a higher risk for breast cancer than the general population. If something more drastic than lumpectomy and radiation is offered (such as mastectomy), do get a second opinion.

In general, if a doctor is frightening you about the DCIS possibilities, always get a second or even third opinion. I don’t think fear serves any useful health purpose.

Be well,
David Edelberg, MD