Approximately 14,000 women die each year of ovarian cancer in the United States.
The average risk of getting ovarian cancer in your lifetime is about 1.4%, but if you have a family history or genetic mutation that predisposes to ovarian cancer, the risk can be as high as 40%.
Most women know that ovarian cancer can be silent until it is advanced to Stage 3-4.
The symptoms are vague and can be confused with gastrointestinal dysfunction, such as vague abdominal pain, indigestion, early satiety, and rectal pressure. The treatment of ovarian cancer involves extensive surgical removal of the uterus, tubes and ovaries, the omentum (fat that surrounds the intestines), lymph node dissections, and often removal of the peritoneal surfaces.
This is often followed (or can be preceded) by chemotherapy. Typically the cancer will recur within several years, and results in additional surgeries or rounds of chemotherapy.
The five year survival rates as reported by the American Cancer Society are 28% for Stage 3, and only 19% for Stage 4. If we could find ovarian cancer in earlier stages we could improve survival. We know that survival for Stage 1 tumors (confined to the ovary) is 78%, and if the tumor is confined to the pelvic organs, Stage 2, the survival is 61%. So how do we find the tumors earlier, when survival would be improved? Do yearly ultrasounds find the cancer earlier, and save lives.
Menopause Care Updates, published this month by the North American Menopause Society, reported on a study that addressed whether yearly ultrasound screening of women would change the stage at diagnosis and disease-specific survival. In total, 46,000 women were screened at the University of Kentucky from 1987-2017. The women who were screened had no symptoms and were over the age of 50, or over the age of 25 with a family history of ovarian cancer.
If a woman had an abnormal ultrasound, the study was repeated in 4-6 weeks to see if the abnormal finding was persistent. If it was, she underwent additional testing with a CA125, tumor morphology evaluation (looking at the size and complexity of the tumor), and Doppler flow evaluation which evaluated the blood flow to the tumor. A total of 699 women, or 1.5% were taken to the operating room for a surgical procedure. Of these women who had surgery, 71, or approximately 10% were malignant.
The disease free survival was assessed for these women who were screened, vs. women who wer not screened and whose cancers were detected clinically. Not surprisingly, the proportion of Stage 1 tumors was significantly higher in the women screened that those not screened. Disease specific survival at 5, 10 and 20 years was 86%, 68%, and 65% in those who were screened, vs. 45%, 31%, and 19% in those who were not screened.
On initial glance, this data is impressive, but when the experts looked at the data, things were not as clear. First, the incidence of ovarian cancer in the study group was much higher than expected. This could be explained by the study group including those at higher risk of ovarian cancer, those with a family history of ovarian cancer (23%) or a strong family history of breast cancer (43%).
Genetic carrier testing was not performed on these patients.
The rate of ovarian cancer in the study population was 271/100,000 patients screened, vs. only 11/100,000 in the control group. This disparity indicated that the group that was screened was a high-risk group, and clearly benefited from increased screening.
Other issues that need to be considered with widespread screening is the cost that is involved with annual additional testing. Another consideration is the risks of surgery in those 90% of patients found to have abnormal ultrasounds that do not have cancer. These patients would not have had surgery if they had not been screened this carefully, and some would experience side effects of the surgery which could be serious or life-threatening.
The final recommendations from this study was not to do routine ultrasound screening on patients at average risk of ovarian cancer. This is also the recommendation of US Preventive Task Force.
So this means that physicians should not recommend an ultrasound routinely, yearly, on patients at average risk of ovarian cancer. But,…..
Often patients come to the office complaining of vague symptoms of pain, rectal pressure, bladder pressure, abdominal distention, early satiety, or a change in bowel function. We must always consider ovarian cancer in a differential diagnosis, and order an ultrasound when indicated to rule-out ovarian pathology.
Even more important, as physicians, we should always consider a family history of breast, ovarian, pancreatic, uterine and colon cancer which can be related to genetic mutations that increase the risk of ovarian cancer. Genetic testing should be offered to patients at increased risk of cancer, as genetic mutations that increase the risk of cancer can be managed with increased surveillance and preventive surgery. Women with BRCA mutations have an increased risk of ovarian cancer, and should strongly consider risk-reducing removal of the ovaries and fallopian tubes after childbearing which drastically decreases their risk.
Marilyn Jerome, MD
Foxhall Ob-Gyn Associates
American Cancer Society
Menopause Care Updates, December 2018. North American Menopause Society, commentary by Mindy S. Christianson, MD