Pap Smear: Can It Detect Ovarian Cancer and STI?

Key takeaways:

• A pap smear isn't a reliable method for detecting STIs. However, it may detect STIs like human papillomavirus infection and trichomoniasis. 
• A pap smear is not designed for diagnosing or detecting ovarian cancer. But, it may occasionally detect ovarian cancer when it has spread to the cervix. 
• Ovarian cancer isn't easily detected on time because procedures like transvaginal ultrasound scans and CA-125 blood tests aren't very efficient for screening 
• An abnormal pap smear test result doesn't mean you have cervical cancer. It could mean you have an infection or precancerous disease of the cervix. 

A pap smear, also called pap test, is a test done to detect changes in the cervix, the neck of the uterus (womb). It is a screening procedure for cervical cancer. The test involves collecting cells from the cervix and viewing them under a microscope to detect any changes or abnormalities. 

It can detect cell changes that may potentially lead to cervical cancer, and it can also detect cervical cancer in rare instances.

Can pap smear be used to test for STIs?

A Pap smear test is not primarily used to check for sexually transmitted infections (STIs), but it can indicate an underlying infection if the results are unclear.

While it can detect human papillomavirus (HPV), which is the main cause of cervical cancer, trichomoniasis, herpes genitalis, candidiasis, and bacterial vaginosis, it's not a reliable method to detect other STIs. If an STI is suspected, additional tests are necessary for accurate diagnosis.

How doctors test for STI

Doctors test for STIs using different methods. These methods depend on your symptoms and a provisional diagnosis. Some of the tests used to detect STIs are:

• Blood tests: This will involve drawing your blood and sending it to the laboratory to test for STIs like syphilis, HIV, and herpes.
• Urine tests: Your healthcare provider may suggest collecting an uncontaminated sample of your urine and sending it to the laboratory to test for STIs like trichomoniasis and gonorrhea.
• Swab tests: The doctor uses a swab to collect a sample from your vagina, cervix, or tip of your urethra. Doctors use it to diagnose chlamydia, gonorrhea, herpes, and HPV.

Can a pap smear detect ovarian cancer?

A pap smear can detect ovarian cancer, but it is very rare. There is limited evidence that it can help in the early detection of ovarian cancer. However, if ovarian cancer spreads to the cervix, a pap smear may detect it. This usually happens in the advanced stage of the disease.

Tests for screening for ovarian cancer

There's no reliable screening test for ovarian cancer because the cancer does not have a precancerous stage, although more research is being done. However, some tests can be used to aid in the detection of ovarian cancer.

Doctors commonly use two tests when they suspect ovarian cancer. A combination of these tests, in addition to the menopausal status of the patient, is called the risk of malignancy index (RMI). 

The screening tests for ovarian cancer include the following.

Ultrasound scan

This may be a transvaginal or abdominal ultrasound scan. It is used to detect ovarian masses or abnormal ovarian growths. But it doesn’t show whether the mass is cancerous or harmless (benign). Most of the masses found while doing an ultrasound scan are benign.

Blood test

The body produces CA-125, a tumor marker, usually due to cancer cells or the body's response to cancer. Women with ovarian cancer usually have high levels of CA-125.

However, other conditions such as endometriosis and pelvic inflammatory diseases (PIDs) can cause an increase in CA-125, making this test unreliable. Also, CA-125 may not be high in women with early ovarian cancer.  

Other tests

Your doctor may request the following tests if your CA-125 levels are high, your ultrasound scan reveals ovarian masses, and your symptoms point toward ovarian cancer:

• Laparotomy: A large incision is made on the abdomen and the doctor looks at the ovaries and surrounding tissues. This is called exploratory laparotomy.
• Laparoscopy: A small incision is made on the abdomen, and the doctor uses a camera to examine the ovaries and surrounding structures.  
• Staging and biopsy: Your doctor may collect a sample of ovarian tissue and send it to the laboratory to check for cancer cells (biopsy). The surgery is also used to check the extent to which the cancer has spread (staging).

When should you get a Pap test?

You should get a pap test for the first time when you're 21 years old, whether you've had sex or not. If your pap test result is normal, your doctor may ask you to wait for three years before doing another pap test.

Do pap tests hurt?

Pap tests aren't supposed to hurt, but you may feel some discomfort during the procedure. If you experience painful penetrative sex, pap tests may hurt during the insertion of a speculum, an instrument used to keep the vagina open and visible during a pap test.

What an abnormal pap test means and the next step

An abnormal pap test is also known as a positive test. It means that some of the cells in the cervix appear different from normal cells. It doesn't necessarily mean that you have cervical cancer. An abnormal pap smear may include findings related to cancerous or non-cancerous tumors or lesions.

The next step to take after an abnormal pap test depends on your previous pap test results, your age, and previous treatment for pre-cancer or cervical cancer. Depending on these factors, your doctor may recommend any of the following tests:

• HPV test
• Combined HPV test and Pap test after one or three years.
• Colposcopy 
• Biopsy

You’ll be treated based on the results of these additional tests.