Women who have been diagnosed with breast cancer based on breast tissue biopsies should consider getting a second medical opinion. Findings of a new study have revealed that biopsy specialists often misdiagnose breast tissue, and this could pose a problem in terms of giving the patient the appropriate treatment.
For the new study published in the Journal of the American Medical Association (JAMA) on March 17, Joann Elmore from the University of Washington School of Medicine in Seattle, together with colleagues, asked 115 pathologists to examine 240 breast biopsy specimens, after which their diagnoses were compared with those of three internationally recognized pathologists who had already seen the same slides.
Although the pathologists identified invasive breast cancer well, they had difficulty identifying whether or not abnormal cells in the tissue samples could increase a woman's risks of developing cancer in the future, which means that some women may be undertreated and some may be treated too aggressively.
About half the time, pathologists involved in the study were able to correctly diagnose abnormal precancerous cells - instances that in essence are no better than a coin toss, said Elmore. Treating this condition often involves frequent monitoring and medication.
The pathologists were not able to catch 4 percent of invasive breast cancer cases, 13 percent of ductal carcinoma in situ (DCIS) cases and 35 percent of atypia. Pathologists also misdiagnosed atypia to be a more serious condition 17 percent of the time.
"In this study of pathologists, in which diagnostic interpretation was based on a single breast biopsy slide, overall agreement between the individual pathologists' interpretations and the expert consensus-derived reference diagnoses was 75.3%, with the highest level of concordance for invasive carcinoma and lower levels of concordance for DCIS and atypia," the researchers wrote in their study.
Completely healthy women were likewise misdiagnosed to either have increased breast cancer risks or invasive breast cancer 13 percent of the time, suggesting that women who were diagnosed with DCIS or atypia could be reassured that their condition may not be an invasive cancer and that they do not have to rush for treatment. It also means women should get a second opinion once they are diagnosed to have abnormal pre-cancer or DCIS.
"Women with DCIS are receiving the same kind of treatment that women with early invasive breast cancer are receiving," Elmore said. "Because women receive such intensive treatment for DCIS, it's important we get this diagnosis right."
