Ovarian carcinomas: five distinct diseases with different origins, genetic alterations, and clinicopathological features.

Abstract

Malignant epithelial tumors (carcinomas) are the most common ovarian cancers and also the most lethal gynecological malignancies.
Based on histopathology and molecular genetic alterations, ovarian carcinomas are divided into five main types (high-grade serous (70%), endometrioid (10%), clear cell (10%), mucinous (3%), and low-grade serous carcinomas (5%)) that account for over 95% of cases.

These types are essentially distinct diseases, as indicated by differences in epidemiological and genetic risk factors, precursor lesions, patterns of spread, and molecular events during oncogenesis, response to chemotherapy, and prognosis. For a successful specific treatment, reproducible histopathological diagnosis of the tumor cell type is critical.

The five tumor types are morphologically diverse and resemble carcinomas of the uterus. Actually, recent investigations have demonstrated that a significant number of cancers, traditionally thought to be primary ovarian tumors (particularly serous, endometrioid, and clear cell carcinomas), originate in the fallopian tube and the endometrium and involve the ovary secondarily. This review summarizes recent advances in the molecular pathology which have greatly improved our understanding of the biology of ovarian carcinoma and are also relevant to patient management.

Correspondence: Authors' response: 'Focusing on HER2 as a potential therapeutic target in primary ovarian mucinous carcinomas' (includes stats on serous/endometrioid/clear cell/mucinous)

Blogger's Note: without a subscription ($$$), the following is available for viewing:

Authors' response: 'Focusing on HER2 as a potential therapeutic target in primary ovarian mucinous carcinomas':
In a study involving a large series of epithelial ovarian carcinomas (EOCs), McCaughan et al1 reported human epidermal growth factor receptor 2 (HER2) protein overexpression and amplification in all major histological subtypes, an observation consistent with the literature.2 3 Specifically, they document HER2 gene amplification in 3.0% (7/259) of serous papillary carcinomas, 2.1% (2/92) of endometrioid carcinomas, 25.0% (3/12) of mucinous carcinomas, 4.0% (1/25) of clear cell carcinomas and 11.9% (7/60) of mixed type carcinomas. Although their number of mucinous carcinomas was low (n=12), the higher prevalence of HER2 gene amplification relative to the other histological subtypes is also consistent with the literature.4 5
We had previously reported similar findings of primary ovarian mucinous carcinomas having the highest prevalence of HER2 genomic amplification and protein overexpression among the various EOC histological subtypes and had proposed that ovarian mucinous carcinomas represent a...