A11. Ovarian cancer; classification, symptoms and diagnosis

Ovarian cancer is the second most common gynaecological cancer (after endometrial), but the most common cause of gynaecological cancer death due to its poor prognosis. It has no early symptoms, it has potential to grow very large, and it has aggressive behaviour. There is no effective screening for it in the general population. The most common type is the epithelial type (90% of cases), which has the worst prognosis. It is mostly a disease of postmenopausal women in the 55 – 65 age group. The 5-year survival is 30 – 35%. 70% of cases are stage III or IV at the time of diagnosis. The only real opportunity for survival is early diagnosis with complete surgical excision.

Ovarian germ cell tumours (like teratoma) account for < 3% of ovarian cancers. They mostly affect younger women, rarely affecting those over 30. They’re most commonly benign. Most are diagnosed at an early stage and are highly curable (5-year survival > 95%).

Etiology

Risk factors include any which increase oestrogen exposure:

• Old age
• BRCA1/BRCA2 mutation
• Family history
• Early menarche
• Late menopause
• Lynch syndrome

Protective factors include:

• Oral contraceptive pills
• Multiparity
• Breastfeeding

High oestrogen exposure is involved in the pathogenesis, which explains many of the risk and protective factors.

Pathology

We can distinguish multiple histological types of ovarian cancer:

• Epithelial ovarian carcinoma – arise from ovarian surface epithelium
  • Serous type
  • Endometrioid type
  • Clear cell type
  • Mucinous type
  • Brenner tumour
• Germ cell tumours
  • Dysgerminoma
  • Teratoma
• Sex cord-stromal tumours
• Krukenberg tumour
  • Bilateral ovarian metastatic spread from gastric cancer

The epithelial type is the most common, accounting for 90%.

The FIGO classification is used for staging.

Clinical features

Ovarian cancer is characteristically asymptomatic until the late stages, which is part of the reason for the poor prognosis.

When symptoms do appear, these are the most common:

• Abdominal enlargement (due to ascites)
• Symptoms of pressure on surrounding organs
  • Dysuria
  • Constipation
  • UTI
• Symptoms relating to complications of the tumour (usually acute)
  • Torsion – acute pain and vomiting
  • Rupture – generalised abdominal pain
  • Haemorrhage – abdominal pain and haemorrhagic shock

Some present with an asymptomatic adnexal mass which is discovered on bimanual examination or on ultrasound. Germ cell tumours grow quickly and therefore often cause pelvic pain or symptoms of bladder or bowel compression.

Diagnosis and evaluation

Physical examination should be performed for an adnexal mass as well as inguinal and cervical lymphadenopathy. Ultrasound (usually transvaginal) of the adnexal mass can reveal features suspicious for malignancy (solid mass, irregularity, papillary structures, etc.) and ascites. Chest, abdominal, and pelvic CT or MRI are used to look for ascites and disease spread. FNAB is never performed as it may cause spreading.

The definite diagnosis of ovarian cancer, as well as determination of its histological type, requires histology. Biopsy causes tumour seeding and is not performed. All cases of suspected ovarian cancer undergo complete surgical staging, involving total hysterectomy with bilateral salpingo-oophorectomy with pelvic and paraaortic lymph node dissection and omentectomy. Peritoneal cytology is also acquired by peritoneal washing. Only after histological evaluation of these samples can the diagnosis be made.

It’s important to distinguish germ cell tumours from other ovarian tumours during the diagnostic evaluation, as the treatment is different. Germ cell tumours are more often solid on ultrasound than epithelial tumours. Because germ cell tumours frequently are bilateral, both sides must be examined (bilateral examination is performed routinely in all cases anyway). If germ cell tumour is suspected in a young girl, we may perform karyotyping (as the probability of intersex disorder is high). Ovarian germ cell tumours often produce tumour markers, especially hCG, AFP, and lactate dehydrogenase (LDH).