Recent Advances in the Pathology of Ovarian Cancer

Phenotypic modifications in ovarian cancer stem cells following Paclitaxel treatment

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy. Despite initial responsiveness, 80% of EOC patients recur and present with chemoresistant and a more aggressive disease. This suggests an underlying biology that results in a modified recurrent disease, which is distinct from the primary tumor. Unfortunately, the management of recurrent EOC is similar to primary disease and does not parallel the molecular changes that may have occurred during the process of rebuilding the tumor. We describe the characterization of unique in vitro and in vivo ovarian cancer models to study the process of recurrence. The in vitro model consists of GFP+/CD44+/MyD88+ EOC stem cells and mCherry+/CD44-/MyD88- EOC cells. The in vivo model consists of mCherry+/CD44+/MyD88+ EOC cells injected intraperitoneally. Animals received four doses of Paclitaxel and response to treatment was monitored by in vivo imaging. Phenotype of primary and recurrent disease was characterized by quantitative polymerase chain reaction (qPCR) and Western blot analysis. Using the in vivo and in vitro models, we confirmed that chemotherapy enriched for CD44+/MyD88+ EOC stem cells. However, we observed that the surviving CD44+/MyD88+ EOC stem cells acquire a more aggressive phenotype characterized by chemoresistance and migratory potential. Our results highlight the mechanisms that may explain the phenotypic heterogeneity of recurrent EOC and emphasize the significant plasticity of ovarian cancer stem cells. The significance of our findings is the possibility of developing new venues to target the surviving CD44+/MyD88+ EOC stem cells as part of maintenance therapy and therefore preventing recurrence and metastasis, which are the main causes of mortality in patients with ovarian cancer.

Pediatric malignant ovarian tumors: a 43-year review

Thirty-eight girls with malignant ovarian tumors were reviewed and studied during a 43-year period, 1945 to 1988 inclusive. The age range was 3 to 16 years. Eighteen girls were prepubertal and 16 were pubertal at diagnosis. Precocious puberty was noted in 4 children. The most common presenting symptoms and signs were pain, abdominal swelling, and pelvic mass. Emergency surgery for acute pain (? appendicitis) was needed in only 7 patients. Tumor size and cysts did not relate to histology or outcome. Tumors were classified histologically (germ cell, sex cord/stromal, epithelial tumors). Twenty-one (54%) of the patients survived 1 to 27 years (median, 8 years). Sixteen were left with ovarian tissue, 11 functioning. Diagnosis and treatment have been aided by better noninvasive radiological methods, tumor markers, newer and better chemotherapy, and pathological review and reclassification of these tumors as pediatric experience slowly increases. We can make at least four statements that differ from our past experience: (1) pure endodermal sinus tumor was previously confused histologically with embryonal carcinoma; (2) gonadoblastoma is associated with 45,X/46,Y, 45,X, or 46,Y karyotype and is known to be premalignant; (3) sex cord/stromal tumors are not necessarily malignant and metastatic behavior cannot be predicted from the histology; and (4) currently, epithelial tumors are classified as cystadenomas and are considered to be borderline malignancy. Current management should aim at both cure and preservation of fertility with conservative surgery whenever possible. The future must lie in chemotherapy.

Hormonal activity of epithelial ovarian tumours in post-menopausal women

Concentrations of progesterone and oestradiol in peripheral serum and tumour cyst fluid were measured in 42 post-menopausal women with epithelial ovarian tumours (17 cancer, 6 borderline malignant, 19 benign tumours) and in 19 post-menopausal women without ovarian neoplasms. The hormonal response of the endometrium was assessed, progestogen and oestrogen receptor content in the tumour tissue case recorded, and tumour deoxyribonucleic acid (DNA) ploidy was measured by flow cytometry. No significant differences were found between the mean serum steroid levels in patients with malignant, borderline or benign tumours, but the mean serum levels of oestradiol in patients with malignant or benign ovarian tumours were higher than those in the controls. Endometrial hormonal activity was seen in 19% of the samples studied. Malignant and benign mucinous epithelial tumours were the types most frequently associated with hormonal activity. Increased levels of sex steroids were seen in the cyst fluid of serous malignant and borderline malignant tumours, while benign tumours were inactive. The steroid receptor content of the various tumour types did not vary significantly. Ten (59%) out of 17 ovarian carcinomas were found to be aneuploid and 41% diploid as measured by flow cytometry. No significant differences in serum levels of progesterone and oestradiol were found between aneuploid and diploid ovarian carcinomas. These results contribute to our knowledge of the hormonal activity of epithelial ovarian tumours in post-menopausal women.

The value of cancer antigen-125 as a tumor marker in malignant germ cell tumors of the ovary

The value of cancer antigen-125 (CA-125) as a tumor marker for malignant germ cell tumors (MGCT) of the ovary was investigated and compared with the other recognized tumor markers (human chorionic gonadotrophin (hCG), alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and lactate dehydrogenase (LDH) isoenzymes. In the 10 months following June 1984, 4 new cases with MGCT and 1 patient with active disease on treatment were evaluated. In all cases prior to planned surgery the levels of CA-125 were significantly elevated. The serum values ranged from 154 to 617 U/ml (normal less than 20 U/ml). In 1 case (pure dysgerminoma) CA-125 was the only tumor marker. In 3 patients (2 mixed germ cell tumors and 1 immature teratoma) serum LDH (LD 1, 2, and 3) was elevated, and AFP was elevated in 1 of these. In the fifth case (mixed germ cell tumor), on treatment, serum AFP was used to monitor the disease. Four patients underwent cytoreductive surgery followed by combination chemotherapy. The changes in the serum levels of CA-125 paralleled those of the other tumor markers while on therapy. In our experience CA-125 is an invaluable indicator of the clinical status of the patient and could be a new tumor marker in patients with MGCT.