The goal of this clinical research study is to find out if combining a standard blood test (CA-125) that checks for ovarian cancer with other blood tests that check for related tumor markers may be helpful in the early detection of ovarian cancer in women who are at low risk. Tumor markers are substances in the blood that may be related to ovarian cancer.

Up to 8,000 women will take part in this multicenter study.

Currently, there is no effective screening to detect ovarian cancer at its earliest stage in low risk women. CA-125 is an FDA approved blood test that may show the presence of ovarian cancer. Researchers have found other blood tests that detect ovarian cancers that may be missed by CA125 testing. Results of blood tests are combined into a Risk of Ovarian Cancer-2 (ROCA2) score to decide whether you need to return for additional bloodwork and/or an ultrasound.

If you are eligible to take part in this research study:

You will have blood (about 3-4 tablespoons) drawn for testing of tumor markers that can detect ovarian cancer.

You will be asked to complete a questionnaire about your medical and family history. It should take about 20-30 minutes to complete.

You will be asked to complete a questionnaire about your symptoms. It should take about 10-15 minutes to complete.

Depending on your CA-125 level you will receive 1 of 3 recommendations:

You will have blood (about 3-4 tablespoons) drawn for testing of tumor markers in 1 year.

You will have blood (about 3-4 tablespoons) drawn for testing of tumor markers in 3 months, OR You will have blood (about 3-4 tablespoons) drawn for testing of tumor markers, and you will have a transvaginal ultrasound (to look at your ovaries and fallopian tubes) in 6 weeks +/- 2 weeks.

An ultrasound test uses sound waves to check the position, size, and shape of the ovaries. During a transvaginal ultrasound, a small probe will be placed in your vagina and used to create and measure sound waves.

Based on the results of the transvaginal ultrasound (if you receive one):

You and the study doctor will discuss options for further treatment or standard cancer management, OR You will have blood (about 3-4 tablespoons) drawn for testing of tumor markers in 3 months.

When you return for your next yearly visit:

You will be asked to complete the questionnaire about your symptoms. You will be asked to complete a follow-up visit survey so that any updates to your personal and family medical history can be recorded. It should take about 10 minutes to complete.

Your blood draw results will be sent to you by letter or e-mail so that you will know when to return for a visit.

If you miss a visit, the study staff may try to contact you by telephone, e-mail, or letter. Visit reminders may also be sent to you by letter or e-mail.

If you are unable to return for visits after 3 years, you will be taken off study. You may continue to take part in this study unless you no longer qualify for the study or you no longer would like to take part in this study.

If you develop ovarian or non-ovarian cancer on this study, researchers will no longer collect blood draws, transvaginal ultrasounds, or questionnaires from you. However, the study team will continue to collect updates in your medical record. This includes slides that will be reviewed from cases of ovarian or non-ovarian cancer that are collected as part of your standard of care.

Inclusion Criteria:

1. Female, >/= 50 years old or less than 75 years old.
2. Postmenopausal (>/= 12 months amenorrhea).
3. Have at least one ovary.
4. Cancer-free and have not received any chemotherapy or radiation therapy for >/=12 months prior to enrolling on this study.
5. Willingness to return for CA 125 blood tests annually or earlier if indicated.
6. Willingness to return to undergo transvaginal ultrasound if indicated.
7. Women need to provide the name of a gynecologist or qualified healthcare professional willing to provide appropriate follow-up care if indicated

Exclusion Criteria:

1. Female: Less than 50 years old or older than 75 years at the time of enrollment.
2. Psychiatric or psychological or other conditions which prevent a fully informed consent.
3. Prior removal of both ovaries.
4. Active non-ovarian malignancy.
5. Women who have a history of non-ovarian malignancy will be eligible if they have no persistent or recurrent disease and have not received treatment for >12 months. If they are on SERMS (i.e. tamoxifen or aromatase inhibitors) they will not be excluded. Women maybe undergoing or have had treatment <12 months prior to study entry for basal cell carcinoma only.
6. High risk for ovarian cancer due to familial predisposition as defined by the following: a. Known mutation in BRCA1 of BRCA2. b. Two 1st or 2nd degree relatives of same lineage who have: two ovarian cancers; one ovarian cancer & one pre-menopausal breast cancer; two pre-menopausal breast cancers; one pre-menopausal & one post-menopausal breast cancer. (These conditions can also be met using the patient and one 1st or 2nd degree female relative.) c. Ashkenazi Jewish descent with one 1st degree or two 2nd degree relatives with pre-menopausal breast or ovarian cancer or participant has had pre-menopausal breast cancer. d. 1st or 2nd degree male relative with breast cancer diagnosed at any age. (First degree relative defined as children, siblings and parents. Second degree relative defined as half-siblings, aunts, uncles, nieces, nephews, grandparents, and grandchildren.)
7. Hereditary Nonpolyposis Colorectal Cancer (HNPCC)/Lynch Syndrome: known genetic mutation, presumed HNPCC carrier, Amsterdam criteria.