Stage 1 Ovarian Cancer

What is stage 1 ovarian cancer?

Stage 1 ovarian cancer is a malignant neoplasm that begins in the ovaries and has not reached adjacent lymph nodes or spread to other parts of the system. It is also known as early-stage ovarian cancer. [¹]

Recent studies suggest that ovarian cancer can begin in the fallopian tube or peritoneum; therefore, updated definitions of stage 1 ovarian cancer include these two parts of the female anatomy. [²]

What are the subtypes of stage 1 ovarian cancer?

Subtypes of stage 1 ovarian cancer are classified based on the cells where it originates. The most common is epithelial ovarian cancer which originates in the epithelial cells outside the ovaries. 85 - 90% of all stage 1 ovarian cancers are epithelial, with 70 - 80% being high-grade serous ovarian carcinomas (HGSOC). [³][⁴][⁵] . Other types of epithelial ovarian cancers include:

Endometrioid carcinoma (10%)
Mucinous carcinoma (6%)
Clear cell carcinoma (6%)

The remaining types of malignant stage 1 ovarian cancer are mentioned below.

Germ-cell ovarian cancer originates in the ovaries' ova-producing cells and only accounts for 3 - 5% of all malignant ovarian cancers. The most common subtypes are immature teratomas, mixed germ-cell, dysgerminomas, and choriocarcinoma [³] [⁶]
Sex cord-stromal ovarian cancer begins in the tissue cells holding the ovary together that produce the hormones progesterone and estrogen. These account for 1% of all malignant ovarian cancers. The most common types include granulosa-cell, Sertoli-Leydig cell, and granulosa-theca tumors. [³] [⁷]

Stage 1 ovarian cancer staging and diagnosis

Ovarian cancer staging

The TNM system is used to describe and classify cancers, including ovarian cancer, where:

T (tumor) describes the location and size of the ovarian tumor
N (nodes) indicates whether or not it has spread to nearby lymph nodes
M (metastasis) describes if and how far ovarian cancer has spread from its origin

Within this staging, ovarian cancer cells have grades that are defined as follows:

Low grade: Ovarian cancer cells appear and are organized like normal cells within the tumor to be well differentiated. A low-grade ovarian mass tends to grow slowly.
High grade: Ovarian cancer cells appear abnormal, have no normal structure, and are undifferentiated or poorly differentiated. High-grade ovarian masses grow rapidly and spread quickly.

How common is stage 1 ovarian cancer?

Stage 1 ovarian cancer is rare, affecting 1 in every 10,000 women in the US, making up only 1% of all new cancer cases in the country. In 2022, an estimated 19,880 women in the US were diagnosed with ovarian cancer, with a majority of cases in non-Hispanic white women. [¹¹][¹²]

Furthermore, stage 1 ovarian cancer is most frequently diagnosed in women between the ages of 55 and 64, with the median age of diagnosis at 63. [¹²]

How is stage 1 ovarian cancer diagnosed?

Stage 1 ovarian cancer is hard to diagnose; less than 20% of cases are found during this early stage. [13] This low diagnosis rate is because symptoms and signs during this stage are basically nonexistent, and it is only when the cancerous cell spreads that detection is possible.

The most common diagnostic methods include a pelvic exam, genetic testing, diagnostic imaging, laparoscopy, colonoscopy, and biopsy.

Pelvic Exam

In a pelvic exam, a doctor palpates the pelvis while inserting two gloved, lubricated fingers into the vagina to feel the shape, size, and consistency of the ovaries and uterus. In the early stage, ovarian growths are very difficult to feel.

Genetic Testing

A family history of ovarian cancer increases the risk of developing ovarian cancer. Genetic testing is advised to check for gene mutations such as BRCA1, BRCA2, MSI, NTRK, and MMR mutations. [¹⁴] Once a genetic link has been established, doctors recommend routine ovarian cancer screening, including a pelvic exam, CA-125 blood test, and transvaginal ultrasound.

Lab Tests

Blood tests specifically designed to detect stage 1 ovarian cancer are also limited and still under research. The most commonly used for epithelial cell ovarian cancer is a CA-125 blood test.

CA-125 blood tests measure CA-125, a protein in the blood. Research has shown many women with ovarian cancer have more CA-125 in their blood. Additionally, this protein has been seen to go down as treatment progress, making a potential marker to gauge the effectiveness of treatment.

However, not everyone with ovarian cancer has elevated CA-125 levels, and such a blood test is not always reliable. [¹⁵] Other medical conditions, such as pelvic inflammatory disease and endometriosis, can cause levels of CA-125 to rise. However, if someone without any underlying conditions has an abnormal amount of CA-125, doctors will recommend further investigation.

No blood screening tests are recommended for germ cell or stromal ovarian cancers. Preliminary research results suggest checking the levels of certain biomarkers, such as the blood protein alpha-fetoprotein (AFP) or human chorionic gonadotropin (HCG) for some types of germ cell cancers, as cases have been noted with elevated levels.

Diagnostic Imaging

TVUS (transvaginal ultrasound) is a diagnostic method where an ultrasound wand is inserted into the vagina and used to look at the ovaries, fallopian tubes, and uterus. This tool can locate masses or lesions and tell if they are solid or fluid-filled cysts. However, it cannot tell if a mass is benign or malignant.

CT scans, MRIs, x-rays, and PET scans are generally not done during stage 1 ovarian cancer because they cannot pick up small ovarian masses.

Biopsy

A biopsy is the only definitive method of identifying cancerous ovarian growth. It involves taking a sample from the ovaries. However, this procedure risks the undue spread of cancerous cells and is normally reserved for later stages.

If fluid builds up in the abdomen, known as ascites, a sample can be used to diagnose stage 1 ovarian cancer. Performed via a procedure known as a paracentesis, the abdominal wall is pierced with a needle under local anesthesia.

Laparoscopy

A laparoscopy may be done to view the outer surface of the ovaries, fallopian tubes, and uterus to see if a mass has ruptured. It involves inserting a thin, tubed camera into the small incision in the lower abdomen, which doctors manipulate to view the internal organs. Additionally, a biopsy can also be done during a laparoscopy.

Stage 1 ovarian cancer symptoms

Symptoms of stage 1 ovarian cancer do not present in the beginning. When do present, they include the following:

Abdominal or pelvic pain or swelling
Bloating
Difficulty eating
Upset stomach
Indigestion
Reduced appetite
Fatigue
Painful sexual intercourse
Menstrual cycle irregularities
Vaginal discharge
Frequent urination
Bladder sensitivity resulting in a constant urge to urinate

It is important to note that many of these symptoms are similar to other medical conditions and illnesses, but they will vary from normal and be persistent. Patients must be aware and acknowledge symptoms that continue for extended periods and consult a gynecologist.

Stage 1 ovarian cancer treatment

Treatment plans for stage 1 ovarian cancer involve a multidisciplinary team of oncological gynecologists, pathologists, radiologists, surgeons, and counselors. Each case needs to be assessed individually, taking several factors into account, such as the type of stage 1 ovarian cancer, its grade, available options, adverse effects of interventions, and the patient’s health and preferences, such as the ability to have children after treatment.

Primary stage 1 ovarian cancer treatment

Common treatment plans for stage 1 ovarian cancer include surgery with adjuvant chemotherapy. [¹¹]

Surgery

For most stage 1 ovarian cancer cases that are confined to one or both ovaries, doctors may recommend one or more of the following procedures:

Unilateral salpingo-oophorectomy: Only one ovary and its connecting fallopian tube are removed. This option allows patients to become pregnant in the future.

Bilateral salpingo-oophorectomy: Both ovaries and fallopian tubes are removed. Patients can no longer become pregnant and will go into early menopause as the body can no longer produce sex hormones.

Hysterectomy: The uterus and surrounding tissue is removed. This is recommended if stage 1 ovarian cancer is high-grade.

Partial hysterectomy only removes the uterus
A total hysterectomy removes the uterus and cervix

Adjuvant Chemotherapy

Chemotherapy is given after surgery to destroy any remaining cancerous ovarian cells. Medication is administered intravenously or via an abdominal port, known as intraperitoneal chemotherapy. Treatment runs for six cycles, where drugs are given once every three weeks for a total of 5 – 6 months of treatment.

Another approach that may be used is dose-dense adjuvant chemotherapy, where medication is given weekly. Research has not established whether this method is more effective than 3-week doses and depends greatly on a patient’s drug tolerance. [¹⁶]

Other types of treatment for stage 1 ovarian cancer

Other therapies, such as radiation therapy, target therapy, and immunotherapy, may also be recommended but are generally less common in the early stages.

Targeted therapy

Target therapy may be advised for patients with a genetic component to their stage 1 ovarian cancer to suppress the specific genes or proteins contributing to cancer's growth. Doctors will run a panel of tests to determine which target drug therapy is best suited.

Target therapy has also been suggested as a maintained treatment to reduce the chances of recurrences in patients who have gone into partial or total remission. [¹⁷]

Immunotherapy

Immunotherapy enhances the body’s immune system's ability to attack cancerous ovarian cells via immune checkpoint inhibitors that prevent cancer cells from deactivating the immune response. This treatment is recommended for patients unsuitable for surgery or with an MSI or MMR genetic mutation. [¹⁸]

Radiation Therapy

Radiation therapy is not a first-line treatment for stage 1 ovarian cancer. It usually follows patients who have localized clear-cell ovarian cancer after chemotherapy.

Can stage 1 ovarian cancer be cured?

The answer to “can stage 1 ovarian cancer be cured” depends on several factors, such as the subtype of ovarian cancer, its location, tumor size, the presence of any genetic mutations, and the patient’s overall health and comorbidities. If caught early, epithelial ovarian cancer can be completely eliminated for most patients after surgery and chemotherapy.

Prognosis: Stage 1 ovarian cancer survival rate

With treatment, the prognosis for stage 1 ovarian cancer depends on several factors, such as the patient’s age and specifics of the cancer subtype and grade. Furthermore, the prognosis for stage 1 ovarian cancer is generally much better than in later stages.

Prognosis deals with two metrics: survival and quality of life. Survival looks at the five-year survival rate, which reflects the percentage of patients alive five years after their initial diagnosis. Quality of life is concerned with the ability of the patient to continue to live a healthy and enjoyable life. It looks at their health condition and the burden of the medical interventions they are going through. For a general prognosis chart of ovarian cancers, including stage 1 cancer, refer to [¹²].

Stage 1 ovarian cancer survival rate

The 5-year survival rate for people with all types of stage 1 ovarian cancer is 93% in the US. [¹⁹] However, this is an average, and survival rates vary from case to case. For example, the survival rate for a woman younger than 60 with low-grade epithelial ovarian cancer is higher than a woman older than 65 with the same type of cancer.

Stage 1 ovarian cancer prognosis and survival rates have slowly increased over the past few decades thanks to advancements in treatment options, better detection methods, and lifestyle changes such as the common use of birth control pills.

Stage 1 ovarian cancer recurrence rate

The recurrence rate of stage 1 ovarian cancer is approximately 10%. The chances of ovarian cancer return increase in cases of high-grade growth. [²⁰]

Stage 1 ovarian cancer growth rate

How fast does ovarian cancer grow? This depends on the subtype and grade. High-grade ovarian cancers grow rapidly, reaching advanced stages within the year of initial diagnosis. For other subtypes, it is harder to give a definitive growth rate because they are rare and often diagnosed in later stages

Lifestyle changes for managing and preventing ovarian cancer

Evidence suggests that making certain lifestyle changes can reduce the risk of developing ovarian cancer and potentially improve the prognosis for those already diagnosed.

Oral contraceptives

Research findings have shown that women who take birth control pills for three or more years are 30 – 50% less likely to develop ovarian cancer. This decrease may last up to 30 years after the pills have been stopped. IUDs have also been linked to contributing to decreasing the risk of ovarian cancer. [²¹]

Pregnancy and breastfeeding

Women who have a full-term pregnancy or breastfeed have a lower risk of developing ovarian cancer. [²²]

Preventative surgical procedures

Women who have undergone tubal ligation or a previous hysterectomy are at a lower risk of developing ovarian cancer. Preventative surgical procedures are often advised for women with a family history of ovarian cancer and the aforementioned genetic mutations. Such a procedure can substantially lower their chances of ovarian cancer. [²³]

If these procedures are performed after natural menopause, there is an estimated 40 – 70% risk reduction, especially for women with BRCA2 mutations. [²⁴]

Conclusion

Takeaway

Stage 1 ovarian cancer is an extremely rare type of cancer, with only 1.1% of women ever being diagnosed in their lifetime. [¹²] It has many subtypes and grades with varying prognoses. However, it should not be left untreated because the most common ones have the potential to grow and spread rapidly, drastically reducing the long-term rate of survival.

The prognosis of stage 1 ovarian cancer is promising, which is why early detection is vital. While the treatment approach is highly individualized, it is commonly surgery and chemotherapy.