Why Surgery Isn’t Always Necessary for This Form of Breast Cancer
Research suggests that thousands of women with DCIS may be receiving unnecessary treatment for breast cancer. A professor of radiation oncology shares her views.
How could breast cancer treatment be unnecessary?
The thought of a breast cancer diagnosis strikes a chill in the heart of every woman. It's important to know all the signs of breast cancer, including the symptoms or signs you'd never expect, and to get regular screenings. And if women are concerned, it's completely understandable that they may choose to opt for surgery, and perhaps further treatment, to try and ensure the cancer is eradicated. But for years, study after study has suggested that not all women with a diagnosis of ductal carcinoma in situ (DCIS) need aggressive treatment. DCIS is a precursor to breast cancer, but the dilemma is knowing which cases will develop into invasive cancer and which won't, warn researchers from the Mayo Clinic. About 1 in 5 new breast cancers will be DCIS, the American Cancer Society points out.
What is DCIS?
Breast cancer symptoms aren't limited to lumps—here are nine other breast cancer signs to watch for. And DCIS will often go unnoticed until a woman has a mammogram. Julia White, MD, professor of radiation oncology at Ohio State University Comprehensive Cancer Center in Columbus, explains exactly what DCIS is: "It's a cancer of the lining of the milk ducts," she says. "Smaller ducts empty into progressively larger ducts until they coalesce in the nipple for breastfeeding. DCIS creates abnormal cells internally within the duct, but it doesn't have the biological wherewithal to invade outside the duct. So the ducts become filled with abnormal cancer cells that leave behind cellular debris that calcifies." Like other forms of cancer, DCIS cells can vary in their aggressiveness. Tumors are graded 1-3, with 1 being the least aggressive type. DCIS is sometimes graded as zero because it's not invasive, Susan G. Komen explains.
How is it different from other cancer types?
There are some breast cancer symptoms that women ignore. Because DCIS can be hard to detect, it can be worrisome. But the National Breast Cancer Foundation points out that DCIS tends to be non-invasive, meaning that the abnormal cells are confined to the milk ducts and nowhere else. These cancer cells don't have the ability to "break through" into other areas of the breast and thus spread to the rest of the body.
What causes DCIS?
Taking simple measures to help prevent breast cancer is wise. And while the exact cause of DCIS isn't known, most doctors agree that there's likely to be a combination of factors that lead to DCIS occurring—family history, environmental influences, and lifestyle choices. For example, smoking, drinking excessive alcohol, and obesity are likely to make you more vulnerable to developing DCIS. “Your exposure to estrogen across your lifetime is known to affect DCIS risk,” says Sarah P Cate, MD a breast cancer surgeon at Mount Sinai Hospital in New York. “If you got your period early, entered menopause late and did not have children or had a child after age 30, your risk may be elevated."
What are the dangers of DCIS?
Breast cancer is scary, but there are also a lot of breast cancer myths women need to know about—and one of them is that DCIS is always dangerous. In the majority of cases—70 to 80 percent—DCIS isn't a problem because it's not invasive or the tumor is so slow-growing that it will never become a threat, Dr. Cate says. The trick is figuring out which DCIS cancers will progress and which ones will remain dormant or pose no threat—90 percent of dangerous breast tumors start in the ducts, she adds. “DCIS is non-invasive, which means it is extremely treatable."
Who is most likely to have DCIS?
DCIS rarely occurs before the age of 40; there's a significant spike in cases once women reach their 50s and 60s. Having a family history of breast cancer increases the likelihood, as does taking hormone replacement therapy for more than three to five years after menopause. Incidence also varies by race, with lower rates among Hispanic, Native American, and Alaskan Native women, the America Cancer Society reports.
How is DCIS diagnosed?
Before mammograms were common, DCIS was only diagnosed at an advanced stage. By this time, symptoms such as a palpable lump or blood-stained nipple discharge were often obvious. "Mammography is the only way to detect DCIS," adds Dr. Cate."Some women with DCIS may have a mass, but that is much less common."
How is DCIS treated?
Treatment for DCIS usually involves a surgical option, sometimes followed up with radiotherapy, Dr. Cate says. "New studies are examining the role that drugs which block or lower the effects of estrogen in the breast such tamoxifen or aromatase inhibitors can play in preventing the spread of DCIS—with or without surgery and radiation, she says. ”Women in the studies are followed closely and get mammograms every six months to see if that area is changing.”
Why are women being over-diagnosed and over-treated?
In past decades, doctors found DCIS at later, more progressed stages; surgery made sense because of the relatively high likelihood that the tumor would develop into an invasive cancer. Now, thanks to improved detection, most DCIS is caught at very early stages—before anyone can figure out whether it will be a problem. If doctors and patients opt for invasive surgery and radiation therapy (which has its own side effects) at this early stage, the harm of treatment may outweigh the risk of cancer. While most women and their doctors take the view that it's better to be safe than sorry, there's increasing evidence that waiting and monitoring the situation through active surveillance—getting mammograms twice a year—could prevent thousands of women from undergoing unnecessary treatment.
What are scientists doing about it?
There are several research projects underway to try and ascertain more precisely the best course of treatment for women with low-grade DCIS including COMET (Comparison of Operative to Monitoring and Endocrine Therapy), and also to see if it's possible to predict with more accuracy which kinds of DCIS will go on to become invasive. If doctors can identify aggressive tumors, they can tailor treatment more accurately to the women who truly need it, Cate says. "Until there are more definitive answers, it is better to be safe than sorry," Dr. Cate says. “Most breast cancers start as DCIS and the problem with not treating DCIS is that we don’t know which ones will spread and which won’t yet."
How can you lower your risk?
Avoiding cancer isn't always possible, but you can improve your odds by embracing a healthy lifestyle. The cause of DCIS is unclear, but since it can be a precursor to invasive breast cancer, the advice is to adopt healthy practices for lowering your risk of breast cancer, including:
- Not smoking
- Controlling your weight
- Staying physically active
- Limiting the dose and duration of hormone therapy
- Avoiding exposure to radiation and environmental pollution.
Advice for women concerned about DCIS
Dr. White's advice for women concerned about DCIS. "I believe in giving mammograms," she says."I think finding DCIS when it's small is better—you just have more options for your treatment." A conversation with your care providers can help you decide the best course—whether it's active surveillance (in which women forgo treatment and opt instead for mammograms twice a year), lumpectomy, or more aggressive forms of treatment.
- American Cancer Society:”Ductal Carcinoma In Situ (DCIS).”
- JAMA Surgery: “Survival Benefit of Breast Surgery for Low-Grade Ductal Carcinoma In SituA Population-Based Cohort Study.”
- Julia White, MD, professor of radiation oncology, Ohio State University Comprehensive Cancer Center, Columbus
- Susan G. Komen: “Treatment for DCIS.”
- National Breast Cancer Foundation: “Invasive Ductal Carcinoma (IDC).”
- Sarah P Cate, MD, breast cancer surgeon, Mount Sinai Hospital, New York City
- America Cancer Society: “Special Section: Breast Carcinoma In Situ.”