An impressive study published last week strongly suggests that when it comes to a certain kind of breast cancer, early, aggressive intervention has no effect on a patient’s survival 10 years later.
The research in JAMA Oncology reviewed the records of more than 100,000 women. After being diagnosed with ductal carcinoma in situ (DCIS), the women’s overall chances of dying were a little more than 3 in 100 over two decades. Survival rates for women who received treatment beyond a lumpectomy (to remove abnormal cells) were no different from those who had no additional interventions.
The results of the study were widely reported last week. One news source, the Washington Post, wrote, “The findings add to concerns that the ability to detect these lesions through mammograms may be leading to unnecessary mastectomies.”
We blogged about the common overtreatment of DCIS late last year, and the fact that because it’s found during a mammogram, which many women routinely have, diagnoses of DCIS have increased dramatically in recent years. Diagnosis is one thing, treatment is another, and the JAMA study shows that too often one automatically follows the other, which isn’t necessarily the best medicine.
Because DCIS is a noninvasive cancer (often referred to as Stage 0), the best treatment often is just a lumpectomy. When radiation follows that, the study showed, survival rates did not increase, although that procedure did reduce the likelihood that the cancer would recur. “Significantly,” according to The Post, “there was no difference in the survival rates between women with comparable tumors who had a mastectomy and those who had a less-invasive lumpectomy.”
But the fear factor continues to be a powerful motivator for overtreatment. Many women opt for breast removal to get rid of the perceived threat. As Steven Narod, a senior scientist at the Women’s College Research Institute in Toronto who led the JAMA study, told The Post, “That’s really what’s happening in the last 20 years in the U.S. We have created a culture of breast cancer awareness, and we’ve created a countercultural response of fear. When you do a mastectomy, you reduce the fear greatly.”
But you also disfigure people, waste money and resources, and overtreatment generally invites other problems, including infection and unnecessary worry, stress and exposure to radiation.
The study did identify certain patients for whom a more aggressive treatment for DCIS might be best because they have a higher risk of mortality – women diagnosed when they are younger than 35 and black women.
Some oncologists who reviewed the study cautioned that it had limitations. First, it didn’t compare cancer treatments against each other, but analyzed national cancer registry data from two decades. So analysis of individual patients’ treatments weren’t possible, and many physicians won’t change their clinical practice with such a broad-based review.
But for patients like Mary Lou Smith, the study reinforced her instincts. She was diagnosed with DCIS 30 years ago, then again eight years ago. Her doctors, according to The Post, advised her to have her breasts removed as the safest course of action. She declined, instead choosing to have the questionable tissue removed. That was not the typical treatment, and although Smith, now in her 60s, acknowledges her bias against aggressive treatment, she also told the paper that she understands why doctors recommend mastectomy, and why some women choose it.
“There’s a lot of uncertainty in cancer,” she said. “…So the more certainty we can have as patients, the more comfortable we’re going to be.”
Other research has found that although nearly 60,000 women annually undergo surgical treatment for Stage 0 cancers deemed to be a precursor to the full-blown disease, the number of invasive breast cancers (the deadliest) has not decreased. Some studies have indicated that even a lumpectomy might not be necessary for the mildest cases of DCIS, that surgically removing low-grade lesions didn’t increase survival compared with patients who did not have surgery.
The new study brings us around to a point regular readers of this blog will recognize: Screening is so advanced that tumors can be found even if they would never become threats to health. Technology doesn’t necessarily enable us to distinguish between what requires immediate attention and a range of treatment options from what doesn’t.
As The Post put it, “That has generated a polarizing debate about whether cancers are being overtreated and how to pull back.”