Obstetrics and Gynecology/Ovarian Neoplasia

Epidemiology

With respect to general ovarian neoplasms, 30% of postemenopausal women with adenexal masses have malignant disease, compared to 7% in pre-menopausal women.

The vast majority of young women who present with adenexal masses have functional ovarian cysts.
Dermoid cysts and serous cystadenomas are tied with respect to the incidence of tumor etiology in reproductive age women.

The median age of diagnosis for ovarian cancer in Canada is 56 years of age.
50% of ovarian masses in women over 50 years of age are malignant.
75% of women are diagnosed at stage III cancer because of delayed presentation of ovarian cancer symptoms.
1/70 women will develop ovarian cancer in their lifetimes.
Ovarian cancer is the leading cause of gynecological death in North America.
Ovarian cancer is the 5th most common malignancy in North America
90% of all ovarian cancers are epithelial ovarian cancers, 80% of which are serous papillary carcinomas.
10-15% of all ovarian cancers are hereditary in origin.

Possible etiologies of the adenexal mass:

Gastrointestinal tract: bowel cancer, constipation, bowel abscess
Urinary tract: full bladder
Obstetrical/Gynecological: pregnancy, hydrosalpinx, tubal cancer, fibroids, ovarian cancer

Functional ovarian cysts arise from ovulatory failure, growth, and rupture of the graffian follicle.
Endometriomas arise from cyclic bleeding of ectopic endometrium.
Dermoid cysts arise from oocytes.

Epithelial ovarian tumors arise from the peritoneal coverings of the ovaries.

Risk factors:

Nulliparity
Early menarche
Late menopause
Age over 40
Family history of breast, colorectal, or ovarian cancer
BRCA 1 or 2 mutations
Oral contraceptive use, hysterosalpingectomy, breast feeding, and tubal ligation are protective factors.

Women may present with

Pelvic and abdominal ultrasound
- Benign disease will usually present as a mass <8cm in size, cystic in consistency, and unilateral
- Malignant disease will typically present as a mass >8cm in size, solid and cystic in consistency, and bilaterally. Furthermore, ascites, omental lesions, and enlarged lymph nodes may be visualized: all of which suggest a malignant etiology.
CT scanning (MRI rarely used for this purpose)
Ca-125 measurement (if required equipment)
CBC + differential: if anemic, thorough workup should be completed for a gastrointestinal pathology.
Creatinine

Laparotomy and biopsy. Laparotomy is performed according to the following guidelines
- Cancer without evidence of spread: excision of lesion, omentum, and regional lymph nodes for staging
- Cancer with evidence of abdominal spread: excision of all lesions greater than 1cm
  - Typically involves a total hysterectomy, salpingectomy, oophorectomy
  - If bowel obstructed or infiltrated, small and/or large bowel resection is indicated
Laparoscopy and biopsy if laparotomy not done.
Percutaneous aspiration and paracentesis with cytology performed.

Epithelial ovarian tumours (90% of ovarian cancer)
- Serous papillary tumors (80* of ovarian cancer)
- Mucinous
- Endometrioma (high malignant potential)/clear cell
- Mixed tumours
Germ cell tumours
- Immature teratoma
- Dysgeminoma (produces LDH)
- Yolk sac tumors (produces AFP)
- Embryonal carcinoma (AFP and hCG)
- Choriocarcinoma (produces hCG)
Stromal tumours
- Sertoli-Leydig (produces testosterone)
- Granulosa cell (produces estrogen)

Simply put

Stage 1: confined to the ovary (survival 90% at 5yr)
Stage 2: confined to the pelvis (survival 60-75% at 5yr)
Stage 3: confined to the abdomen, without invasion of liver parenchyma (survival 30-40% at 5yr)
Stage 4: invasion of liver parenchyma and/or beyond (survival 10% at 5yr)

If BRCA 1 positive, prophylactic surgery at age 35.
If BRCA 2 positive, prophylactic surgery at menopause.
- There is approximately a 5-10% chance of finding tubal cancer at surgery.
Stage I, Grade I-II cancer, follow postoperatively (see operative indications in Approach. All other grades and stages may only be treated with chemotherapy (Carbo/Taxol).