Simple ovarian cysts are very common in women and do not require additional ultrasound observation or surgical removal, according to a new study in which more than 72,000 women and over 119 years old hip ultrasound exam.
A study of collaboration between UC San Francisco and Kaiser Permanente Washington found that simple cysts were normal, very commonly occurring women before and after menopause, and were not associated with a higher risk of ovarian cancer. As a result, if they are not symptomatic, simple cysts can safely be ignored, researchers discovered.
In contrast, complex cysts or solid ovarian masses are much less common, but they are associated with a significantly higher risk of developing malignant cancers. These masses should be used or surgically removed.
Paper published November 12, 2018 JAMA Internal Medicine, suggests changing the way simple cysts are usually monitored and sometimes treated.
"There is a lot of unnecessary medical supervision that goes on for simple cysts," said responsible author Rebecca Smith-Bindman, UCSF Professor at the Department of Radiology and Biomedical Imaging. She is also a professor in the Department of Epidemiology and Biostatistics, and in obstetric, gynecological, and reproductive medicine, as well as a member of Philip R. Lee's Institute for Health Policy Studies.
"Simple cysts are almost universally benign, but given the fear that they could attract a cancer precursor, they are often observed and diverted to gynecologists and oncologists," she said. "Our study found that asymptomatic simple cysts of any size should be considered normal for women of all ages and ignored."
Ovarian cancer is the fifth largest cause of cancer deaths among women in the United States, of which 22,000 new cases and 14,000 deaths are diagnosed annually.
The use of transvaginal pelvic ultrasound increased over the last two decades has led to frequent ovarian mass determinations. Although most of these masses are benign, researchers and professional guidelines have, however, suggested continuous moni- toring of simple cysts due to the poor prognosis of ovarian cancer as well as concerns about the risk of small cancer that is beneficial.
This is the first study to quantitatively determine the risk of ovarian cancer in a large, unexplored population based on ultrasound characteristics of the ovarian mass, including simple cysts. The authors sought to clarify the properties that could be predicted with great certainty whether the ovary mass is benign and does not require supervision.
The study looked at 72,093 women who had a pelvic ultrasound through Kaiser Permanente Washington in January 1997 and December 2008. Approximately 75 percent were less than 50 years old.
During the study, 118 778 ultrasound examinations were performed on women. Of the 54,452 women under the age of 50, researchers estimate that about 24% (12,957 women) were diagnosed with a simple cyst and no one had cancer during control. Of the 17,641 women aged 50 and older, approximately 13 percent (2349 women) were diagnosed with simple cyst and only one was diagnosed with cancer.
In the statistical analysis of women with a simple cyst, regardless of the size of the cyst, the cancer was approximately zero. The study found 210 cases of ovarian cancer, almost all were observed in women with a complex cystic mass.
Ultrasound accurately predicted the probability of cancer, which greatly increased the odds for women with a complex cystic or solid ovarian mass, the authors write. They estimate that, within three years, 6.5 percent postmenopausal women with such masses will be diagnosed with ovarian cancer. In contrast, women with simple ovarian cysts were not associated with a higher risk of cancer than those with normal ovaries. The authors acknowledged the limitations, among which women with an earlier cancer history were not included in the study.
"One of the reasons for the observation of simple cysts is that imaging may be inaccurate and can pass complexity," said Smits-Bindman, a member of the UCSF Helen Diller Family Center for Comprehensive Cancer. "Our data were not supported. Cysts that are interpreted as simple, even very large, are not cancer-related.
"I understand why women and doctors do not want to properly diagnose ovarian cancer," she said. "Ovarian cancer is a devastating disease, but ovarian cancer does not cause simple cysts, and after simple imaging cysts, early detection of ovarian cancer has not improved."
Authors: Co-authors are Liina Poder, Associate Professor of Radiology and Biomedical Imaging, UCSF; and Eric Johnson, MS and Diana L. Miglioretti, Kaiser Permanente Doctor of the Washington Institute for Health Research. Dr. Miglioretti is also a professor at Davis, California.
Funding: The research was supported by the National Cancer Institute grant R21CA131698 and K24CA125036.
Disclosure: Are not.
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