Citing Nationwide Variations in DCIS Therapy, Researchers Call for Standards

While it's agreed that the incidence of ductal carcinoma in situ (DCIS) is rising in the United States due to the popularization of breast cancer screening, there is a disagreement about treatment, which varies widely across the country, according to a new study of some 25,206 patients. The authors found that therapy ranges from aggressive surgical treatment (mastectomy, axillary dissection) to undertreatment (failure to use radiation), with many variations in between.Figure: Lead author Nancy N. Baxter, MD, PhD: “According to our study, many patients underwent aggressive surgical treatment for DCIS, yet other patients appeared to have been undertreated, with no radiation therapy after lumpectomy for almost half of them, even in many patients with adverse risk factors. We believe that heightened awareness and establishment of standard treatment recommendations could improve DCIS treatment.”“There are no standard treatment recommendations,” said the team, led by Nancy N. Baxter, MD, PhD, Professor of Surgery at the University of Minnesota Medical School. She and her colleagues point out in the study, published in the March 17 issue of the Journal of the National Cancer Institute (2004;96:443–448), that this confuses surgeons as well as patients seeking the best management strategy. “It is difficult to write guidelines for DCIS treatment,” she said. “For example, the disease is variable—some women have large tumors, others, multifocal tumors. In some women the tumors may have an aggressive appearance, in others not. Patient preferences also vary.” “Thus, there are controversies in DCIS treatment, which makes it hard to come to consensus, which is the basis for guidelines.” She added, however, that some groups have been able to make recommendations to practitioners, pointing specifically to the Cancer Care Ontario Practice Guidelines Initiative sponsored by Cancer Care Ontario and the Ontario Ministry of Health and Long-Trem Care Program in Evidence-Based Care (www.cancercare.on.ca/pdf/sumry1_10.pdf). (Also see article on page 10 about the National Comprehensive Cancer Network's new DCIS guidelines). Until guidelines are developed, Dr. Baxter said in an interview, women diagnosed with DCIS who have any reservations about their care should consider second opinions. Dr. Baxter emphasizes that DCIS is a precursor of invasive cancer, justifying complete surgical removal. “We know that although the cancerous cells are contained entirely within the breast ducts, some patients with DCIS, particularly those with comedo lesions, will have a higher rate of recurrence—and if [these lesions] do recur it may be as invasive breast cancer,” she stated. “The main problem is that it is difficult to predict who will have a recurrence and who an excellent outcome.” 15% of All Breast Cancers Once uncommon, DCIS now accounts for approximately 15% of all breast cancers diagnosed in the US; in 2003 an estimated 56,000 new cases were reported. Results To evaluate the current treatment of DCIS, particularly the use of surgery and radiation therapy, Dr. Baxter and her colleagues used the NCI's Surveillance, Epidemiology, and End Results (SEER) database. They looked at the records of 25,206 women diagnosed with DCIS between 1992 and 1999, and found the following: ▪ The number of cases of DCIS increased 73% over the eight years of the study. ▪ The rate of mastectomy decreased from 43% to 28% from 1992 to 1999. However, due to the increase in the diagnosis of DCIS, the age-adjusted incidence of mastectomy for DCIS in the population remained the same (7.8 per 100,000 women in 1992 and 1999), the researchers reported. ▪ Almost half the patients undergoing lumpectomy did not receive radiation therapy (55% in 1992 and 46% in 1999), but as many as 33% of those with comedo histology received none in 1999—“surprising, since by then it was strongly recommended for such patients,” Dr. Baxter noted. ▪ In contrast, as the study years passed patients were less likely to have axillary dissection. Yet its rate remained high—30% in DCIS patients with mastectomy in 1999—even though it is not generally recommended for treating DCIS, she said. Figure: Monica Morrow, MD, says she sees a serious disconnect between patients and their surgeons regarding DCIS treatment. “For the present, understanding who makes treatment decisions and why is likely to do more to improve the care of women with DCIS than any treatment guidelines.”“Our findings revealed significant variations in treatment—notably, while many patients underwent aggressive surgery for DCIS, others similarly diagnosed were undertreated, with almost half having no radiation therapy after lumpectomy even when adverse risk factors were present.” Dr. Baxter's coauthors were Beth A. Virnig, Sara B. Durham, and Todd M. Tuttle. Regional Variations Large Regional variations in treatment were large, the study found. For example, 74% of Connecticut women with DCIS received breast-conserving therapy compared with only 55% of Utah patients. The researchers added that variations identified in the study—particularly those based on geographic location—suggest that at least some reflect individual and institutional practice patterns. “These differences may be reduced by the development of treatment standards,” Dr. Baxter reiterated. Editorial by Monica Morrow In an accompanying editorial, Monica Morrow, MD, Professor of Surgery at Northwestern University and Director of the Breast Cancer Center at Northwestern Memorial Hospital, said she sees a serious disconnect between patients and their surgeons regarding treatment. She cited the confusion that prevails among women diagnosed with DCIS regarding both the nature of the disease and the information they receive on how to treat it. “With [so little] understanding, rational decision-making regarding therapy is difficult,” she said, noting that in one study, for example, “no correlation between the patient's preferences and the surgeon's treatment recommendations was observed.” In contrast, other studies show that women who perceive they have participated in decision-making are more satisfied with the outcome of care, regardless of the treatment, Dr. Morrow said. “The ability to predict which women with DCIS will develop invasive cancer will ultimately solve the dilemma of [how best to treat] DCIS. For the present, understanding who makes treatment decisions and why is likely to do more to improve the care of women with DCIS than any treatment guidelines.” Another breast cancer expert, Patrick Borgen, MD, Chief of the Breast Surgery Service at Memorial Sloan-Kettering Cancer Center, said in an interview that he found the Baxter et al study “impressive,” adding, “it's hard to argue that 25,000 DCIS patients from across the country are less than representative.” “It's a fascinating time capsule showing the dynamic evolution in the diagnosis and treatment of breast cancer as a whole over an eight-year period,” he said. “It is a valuable reminder that for 70 years—1900 to 1970—radical mastectomy was virtually the only treatment for breast cancer. Surgeons wanted to keep on doing what they had been trained to do and didn't welcome change.” “While it took more than 20 years for breast-conservation therapy to be generally accepted, once change got underway, there was no slowing it down,” he said. “The Baxter study dramatically shows this in the data on the spread of mammography and the decline in mastectomy and axillary dissection.” Spread to Lymph Nodes Rare Dr. Borgen said he believes the axillary dissection data reflect a decade-long realization that the spread of disease to the lymph notes is actually very rare. “Over the last five years [since the study was completed], abandonment of the procedure accelerated, so that by today, probably no more than five to eight percent of surgeons use axillary dissection,” he said. “Some researchers call DCIS a pre-cancerous condition, but that is wrong. It is cancer—just remove some cells and study them. They clearly are cancer cells. And if you leave them alone they will become invasive.”

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