abstract: Objectives: Published data are conflicting on the influence of cell type on prognosis in ovarian cancer. The recent separation of low-grade serous carcinoma as a distinctive cell type of ovarian cancer with an indolent behavior, in retrospect, suggests that survival in studies that have not separated this group may be inaccurate.

Blogger's Note:  the focus of this abstract is serous cell type

Conclusions:
Low-grade serous carcinoma has a significantly better prognosis than high-grade serous carcinoma and also differs with regard to substage distribution and proportion of patients optimally debulked. Because of its excellent prognosis, failure to separate low-grade serous carcinomas, notwithstanding its infrequent occurrence, can change the results of survival analyses that do not make this separation.

abstract: Mutation and Loss of Expression of ARID1A in Uterine Low-grade Endometrioid Carcinoma

Abstract:

ARID1A is a recently identified tumor suppressor gene that is mutated in approximately 50% of ovarian clear cell and 30% of ovarian endometrioid carcinomas. The mutation is associated with loss of protein expression as assessed by immunohistochemistry.

In this study, we evaluated ARID1A immunoreactivity in a wide variety of carcinomas to determine the prevalence of ARID1A inactivation in carcinomas. Mutational analysis of ARID1A was carried out in selected cases. Immunoreactivity was not detected (corresponding to inactivation or mutation of ARID1A) in 36 (3.6%) of 995 tumors.

Uterine low-grade endometrioid carcinomas showed a relatively high-frequency loss of ARID1A expression, as 15 (26%) of 58 cases were negative. The other tumor that had a relatively high-frequency loss of ARID1A expression was gastric carcinoma (11%). Mutational analysis showed 10 (40%) of 25 uterine endometrioid carcinomas; none of 12 uterine serous carcinomas and none of 56 ovarian serous and mucinous carcinomas harbored somatic ARID1A mutations. All mutations in endometrioid carcinomas were nonsense or insertion/deletion mutations, and tumors with ARID1A mutations showed complete loss or clonal loss of ARID1A expression.

In conclusion, this study is the first large-scale analysis of a wide variety of carcinomas showing that uterine low-grade endometrioid carcinoma is the predominant tumor type harboring ARID1A mutations and frequent loss of ARID1A expression. These findings suggest that the molecular pathogenesis of low-grade uterine endometrioid carcinoma is similar to that of ovarian low-grade endometrioid and clear cell carcinoma, tumors that have previously been shown to have a high-frequency loss of expression and mutation of ARID1A.

abstract/free full pdf access:P redictive and Prognostic Protein Biomarkers in Epithelial Ovarian Cancer: Recommendation for Future Studies Cancers

"Abstract: Epithelial ovarian cancer is the most lethal gynecological malignancy. Due to its lack of symptoms, this disease is diagnosed at an advanced stage when the cancer has already spread to secondary sites. While initial rates of response to first treatment is >80%, the overall survival rate of patients is extremely low, mainly due to development of drug resistance. To date, there are no reliable clinical factors that can properly stratify patients for suitable chemotherapy strategies. Clinical parameters such as disease stage, tumor grade and residual disease, although helpful in the management of patients after their initial surgery to establish the first line of treatment, are not efficient enough. Accordingly, reliable markers that are independent and complementary to clinical parameters are needed for a better management of these patients. For several years, efforts to identify prognostic factors have focused on molecular markers, with a large number having been investigated. This review aims to present a summary of the recent advances in the identification of molecular biomarkers in ovarian cancer patient tissues, as well as an overview of the need and importance of molecular markers for personalized medicine in ovarian cancer."
 ..........
"High grade serous tumors show particular differences in terms of their development, genetic alterations and prognosis. This has led to the classification of ovarian cancer into two types: type 1 tumors, which are low grade and slowly developing (endometrioid, mucinous and low grade serous tumors), and type 2 tumors, which rapidly progress (high grade serous). In addition, the association of biomarker expression with survival varies substantially between subtypes, and can easily be overlooked in whole cohort analyses. Although these data suggest substantial differences between subtypes, until recently ovarian carcinomas were typically approached as a monolithic entity by researchers and clinicians. This practice impeded progress in understanding the biology or improving the management of the less common ovarian carcinoma subtypes. To avoid this effect, each subtype within a cohort should be analyzed individually. Therefore, molecular classifiers of ovarian cancer are of high clinical relevance in the management of these cancer patients...." cont'd

abstract: Current Update on Borderline Ovarian Neoplasms

CONCLUSION. Borderline tumors are considered to be precursors of low-grade ovarian cancers. Accurate diagnosis and staging facilitate optimal patient management particularly in patients desiring to preserve fertility.