Presymptomatic screening and treatment of adnexal lesions to protect against ovarian cancer is ineffective, according to a study published in the October issue of Radiology.
“Regrettably, although effective screening for ovarian cancer is highly desirable, there is currently no convincing evidence that it can reduce mortality among average-risk women,” authors Perry J. Pickhardt, MD, and Meghan E. Hanson, MD, of the University of Wisconsin School of Public Health and Medicine in Madison, concluded.
The authors reviewed 2,869 consecutive CT colonography exams of post-menopausal women for incidental adnexal mass findings, or indeterminate lumps in tissue around the uterus. One hundred eighteen lesions classified as indeterminate and potentially or probably important (C-RADS E3 or E4) findings were discovered, accounting for 4.1 percent of the sample. The average maximal diameter of the lesions was 4.1 cm.
Standard clinical guidelines urge further workup of any E3 or E4 masses. Eighty women (68 percent of the positive adnexal lesion cohort) underwent cross-sectional pelvic imaging or surgical resection of the masses.
None of the patients that followed up with either surgery or further imaging was diagnosed with ovarian cancer.
Cystadenomas and cystadenofibromas were the most common pathological findings, occurring in a total of 14 patients. After 3.5 years of follow-up, the study found that none of the non-surgically resected lesions had presented any negative consequences to patients.
With a mean follow-up time of 27 months, four women in the study were diagnosed with ovarian cancer. Two were diagnosed as mucinous cystadenocarcinoma, one was diagnosed with papillary serous carcinoma and one with poorly differentiated adenocarcinoma. All four patients, however, had presented negative (adnexal mass free) CT findings at the start of the study.
In reviewing previous studies that likewise found that presymptomatic screening of women for ovarian cancer was ineffective, the authors wrote. “Our findings further support this unfortunate situation, as many indeterminate adnexal masses were identified in this screening cohort, yet no presymptomatic ovarian cancers were diagnosed. Furthermore, a negative finding at CT was not protective against subsequent development of ovarian cancer, with all four cases occurring within this cohort.”
The authors noted that ovarian cancer is the leading cause of gynecologic cancer-related deaths in the U.S., killing 14,600 women in 2009. The authors hypothesized that ovarian cancer results in such a high rate of death (14,600 out of 21,550 diagnoses in 2009) in part because of the aggressiveness with which ovarian cancer spreads.
Moreover, because so many post-menopausal women present with adnexal masses and yet so few of them are malignant, the authors suggested that incidental adnexal lesion findings be treated less aggressively, and that suspected ovarian cancer workups should be based on stronger risks factors than those associated with adnexal masses.
“On the basis of our findings, more refined risk factor assessment with better identification of women at higher risk and perhaps less aggressive management of low-risk cases would appear to be warranted.”
The authors noted that their findings might not be directly applicable to diagnostic contrast-enhanced CT, since their study utilized low-dose CT, although their research did agree with previous, contrast-enhanced studies. They also pointed out that some patients that chose not to follow-up their lesion findings (38 in total) could have sought care at a different hospital.
The authors concluded by saying that because of the aggressiveness of ovarian cancer and its lack of association with incidental adnexal lesion discoveries, “The window for presymptomatic (ovarian) cancer detection may be too narrow for screening of the general population.”