The Difference Between Ductal Carcinoma In Situ (DCIS) and Invasive Breast Cancer

Ann Romney recently reported that she was being treated for ductal carcinoma in situ (DCIS). The headlines read that she was being treated for breast cancer, but Mrs. Romney was very clear in her statement that DCIS is technically a precancer because it is not invasive.
DCIS is often referred to as an early stage of breast cancer, but there is an important distinction. DCIS differs from invasive cancer in that it stays in the breast ducts. It is the capacity to spread, or metastasize, that makes invasive breast cancer dangerous. The concern with DCIS – a noninvasive cancer — is that it can transform to become invasive breast cancer.
Scientists believe that DCIS would not always progress to breast cancer. Once detected, though, it is removed surgically to eliminate the possibility that it would become cancer because no one can predict which women would have it transform and which would not.
DCIS is a serious condition that requires treatment, but many women face greater anxiety than they should because it is referred to as an early stage of breast cancer. The implication is that it is the first of an inevitable series of stages. Instead, it is a precancerous lesion that could undergo a transformation to become invasive. The distinction is important, but it is often lost.
Depending on how extensive the DCIS is and what its characteristics are, it may be removed with a lumpectomy or a mastectomy and may require radiation. The risk of recurrence is very low.
There are sometimes stories in the news about women with DCIS choosing to have both breasts removed to prevent the possibility of getting breast cancer. Having a bilateral prophylactic mastectomy for DCIS is more than is needed, though it might be considered when a woman has additional risk factors like a faulty BRCA gene or a very strong family history of breast cancer.
Mrs. Romney’s health care providers deserve credit for being clear about what her diagnosis meant. Too many women who are diagnosed with DCIS do not realize that it has important differences from invasive breast cancer. With proper treatment and attention to lifestyle factors that reduce breast cancer risk, future problems are unlikely.

Prophylactic Mastectomy: A Cautionary Tale

Hearing you're high risk for breast cancer is frightening. There is uncertainty as to what you should do about it -- and you desperately want to do something. But taking the most drastic step of having both breasts removed is not the right choice for many women. It wasn't for me.
I had no family history of breast cancer and would never have thought I was at risk until a routine mammogram showed a suspicious spot. A biopsy revealed that I had a precancerous condition that put me at high risk for getting breast cancer.
I thought my days were numbered. Adding to my concern was confusion about what this condition was and how it should be treated. Lobular carcinoma in situ (LCIS) is a cancer "in place" that has no potential for spreading outside the breast unless it undergoes a transformation. It is classified as a "Stage 0" breast cancer but is not a true cancer because it lacks the potential to metastasize, or spread.
Now there is more certainty about what women with LCIS should do, but when I was diagnosed almost twenty years ago, the medical community was evenly divided on what to recommend. Around half the doctors surveyed for a study at the time said they would carefully monitor women with LCIS with regular check-ups and mammograms. The other half said they would advise LCIS patients to have both breasts removed.
A double mastectomy for a precancerous condition seemed extreme -- since the treatment for a more threatening invasive cancer would have been a lumpectomy or a single mastectomy. LCIS indicates a potential for developing breast cancer in either breast, so to fully reduce the likelihood of breast cancer, both breasts have to be removed. But even with a double mastectomy, there is no guarantee you won't get breast cancer.
I considered the bilateral mastectomy, but followed the recommendation of my wise and progressive breast surgeon to have careful follow-up. Now most doctors favor this approach, and the women most likely to be grappling with the issue of having prophylactic bilateral mastectomy are those who have been diagnosed with a gene that causes susceptibility to breast cancer. Some are taking the initiative in deciding to have this surgery -- and in many cases, they are ignoring the recommendation of their doctors.
And why shouldn't they, you might ask. They are told their risk for getting breast cancer can be as high as 85%, and they are living with the uncertainty that breast cancer could strike at any time. Many have watched mothers or sisters struggle through surgery, radiation, and chemotherapy. They understandably want no part of that.
But there are reasons they should not rush into having this surgery.

• Some women with the gene will never get breast cancer. The risk of a woman with a susceptibility gene getting breast cancer at some point during her lifetime is 36% to 85%, as compared to a risk of 12.7% in the general population. The risk for women with the gene is often described as being "up to" 85%, but that number represents the worst case scenario.
• These estimates of risk are not etched in stone. They are likely to change as scientists learn more about how these genes lead to breast cancer, just as ideas about LCIS changed. One group has already reported that the risk may be lower than currently believed.
• Scientists are trying to learn why some women with the gene do not get breast cancer, and at some point, they may be able to predict who is at greatest risk and should consider prophylactic mastectomy.
• Women who get bilateral mastectomy can still get breast cancer. The surgery reduces risk by 90%, but does not eliminate it. Breast tissue is spread out in the chest, and some remains after mastectomy.
• There are less drastic ways to reduce breast cancer risk. Tamoxifen and Evista reduce breast cancer risk by around 50%. Some women can reduce their risk with a healthy lifestyle.
• The risk of getting breast cancer increases with age, even in women with a susceptibility gene unless they have close relatives who got breast cancer when young. For women whose mother or sister didn't get breast cancer until close to menopause, though, having breasts removed in their 30's -- as some women are doing -- may be premature.
• No surgery is free of risk, and further surgery may be necessary. Women having mastectomies can develop infections or have bad reactions to drugs, just as with any surgery. Implants need to be replaced periodically.

Of course, bilateral mastectomy may be the wisest choice for some women who have the gene, but it is too drastic a step for many others.