Flow cytometry of ovarian neoplasms

Cell Cycle Control of Ovarian Granulosa Cells in Tumors and Cysts

Ovarian granulosa cell tumors (GCTs) behave unpredictably. Stage I patients suffer recurrences many years after treatment, and histopathologic evaluation of the primary GCT offers few clues. p21IPl/wafl (Waft), the principle downstream effector of the p53-dependent pathway of growth control, inhibits cyclin-dependent kinases responsible for conversion of GI to S in the cell cycle. This study hypothesizes that immunohistochemistry for these proliferation-related markers will help discern granulosa cell growth control and may predict the GCTs' clinical behavior. Paraffin sections from a surgical series of 43 GCTs (34 primary and 9 recurrent: 19 diffuse and 18 typical adult; 6 juvenile type) and 12 benign cysts (8 follicular and 4 corpora luteal) were immunostained for Waft and p53. Ki67 (MIB-1 clone) proliferation index is the percent of nuclei immunoreactive on a count of at least 400. The 43 GCTs stained as follows: 40% Waft + (11 St = < 10%, 4 S2 = 10-50%, and 2 S3 = > 50% of nuclei) and 28% p53 + (2 W = weak, 8 S 1, 2 S2). All p53 + GCTs stained with Waf 1; the number of immunoreactive nuclei correlated (P < .00001). Juvenile more often than adult type GCTs exhibited Waf 1 (6/6) and p53 staining (5/6) (P < .001). No difference in pS3 or Waft staining was present in primary compared with recurrent GCTs. Ki67 proliferation index for GCTs ranged from 1 to 50% (mean, 13.8%; median, 10.9%) and associated with both p53 and Waft (P < .000 1). The 12 benign cysts stained as follows: 100% Waft + (6 S1, 5 S2, 1 S3) and 75% p53+ (4 W, 4 S1, 1 S2). Of the 43 patients, 41 were available for follow-up study: 15 suffered recurrences after 16-133 (mean 59.3, median 55) months, and 26 were disease-free 21-369 (mean 78.2, median 57.5) months after diagnosis. Waft staining of the primary GCT does not help predict recurrence. All GCTs immunoreactive for p53 produce Waft, suggesting detection of an active wild type p53 rather than overproduction of mutant p53. Waft is produced by granulosa cells in all benign functional cysts, suggesting a physiologic role in the ovulation sequence. Waf t's association with proliferation in GCTs suggests possible physiologic feedback. Proliferation (correlated with histopathologic grading) in GCTs may signify appropriate feedback control; thus it is not a predictor of aggressive clinical behavior.

Histopathology and molecular biology of ovarian epithelial tumors

Carcinogenesis in the ovary presents special features related to that organ. First, the preinvasive or even invasive lesions are difficult to detect, which explains why most cases are diagnosed at an advanced stage. Second, the group of tumors of low malignant potential (borderline tumors) are still a controversial category of ovarian lesions. Finally, familial ovarian tumors represent an interesting hereditary model of carcinogenesis at the molecular level. Flow cytometry and immunohistochemistry for proliferative markers or oncogenes provide important prognostic information in patients with ovarian tumors. Molecular data, such as loss of heterozygosity at specific genetic loci, also have been correlated with prognosis. Clonality studies in patients with multiple ovarian/pelvian lesions analyzing chromosome X inactivation patterns and genetic deletions or mutations have contributed to the understanding of the origin of these lesions. New technologies to study gene expression patterns, such as cDNA library construction and DNA microarray technologies, are being applied to study histologic phases of tumor progression, such as normal, preinvasive, and tumor tissues. It is hoped that these studies will contribute important information not only for a better understanding of the process of carcinogenesis, but also for assessing the biology and behavior of individual tumors, determining patient prognosis, and eventually influencing therapy.

Long-term survival and DNA ploidy in advanced epithelial ovarian cancer

BACKGROUND AND OBJECTIVES

The relationship of the tumor DNA content to survival of patients with advanced epithelial cancer has not yet been clarified. A large amount of contradictory data exists in the literature. This study analyzes the putative relationship between ploidy and advanced ovarian carcinoma.

METHODS

A retrospective analysis of tumor ploidy, DNA index, and the S-phase fraction from 35 patients with nonborderline epithelial ovarian carcinomas was determined by flow cytometry of paraffin-embedded tissue. All patients had FIGO stage III or IV disease. Those patients who survived > 5 years were assigned to Group A (10 patients). Group B consisted of 25 age-matched subjects who succumbed to their disease within 5 years of diagnosis.

RESULTS

Group A had not reached a median overall survival with a median follow-up of 114 months (range 67-226), whereas Group B had a median overall survival of 17 months (range 1-48). Two of the patients in Group A and all of the patients in group B had died of the disease. The two groups were similar in age, histologic type, and treatment. In Group A, three patients had grade 1 tumors, in contrast to group B where all the patients had either grade 2 or 3 disease (P = 0.018). However, the distribution of aneuploidy was similar in both groups. Also, the DNA indices were similar: 1.40 +/- 0.42 in Group A, and 1.36 +/- 0.44 in Group B. The median S-phase fraction was 14% (range 3-23%) in Group A, and 15% (range 2-23%) in Group B. The grade and type of tumor were not related to the ploidy or the DNA index. There was no significant correlation between ploidy or the DNA index and survival.

CONCLUSION

This study suggests that the DNA content of tumor as measured by flow cytometry is not a predictor of long-term survival in ovarian cancer patients with advanced disease.

Transformation in recurrent ovarian granulosa cell tumors: Ki67 (MIB-1) and p53 immunohistochemistry demonstrates a possible molecular basis for the poor histopathologic prediction of clinical behavior

Ovarian granulosa cell tumors (GCTs) behave unpredictably. Stage I patients suffer recurrences many years after treatment, and histopathologic evaluation of the primary GCT offers only a few clues. Grading, in particular, is largely ineffective. Ki67 (MIB-1) and p53 monoclonal antibodies (active on paraffin embedded tissues) provide insight into nuclear proliferation and control, respectively. In this study, the authors hypothesized that these molecular markers will help predict the clinical behavior of GCTs. Paraffin sections from 68 GCTs (arising in 56 patients: 53 primary and 15 recurrent) including 34 typical and 27 diffuse adult, and seven juvenile types were immunostained for Ki67 (MIB-1 clone; Immunotech, Westbrook, ME) and p53 (DO7 clone; Novacastra Laboratories, UK). The Ki67 proliferation index (Ki67PI = percentage immunoreactive on a count of at least 400 nuclei) ranges from 1 to 50% (mean, = 12.2%; median, 9.3%). Nineteen percent of GCTs exhibited focal p53 immunoreactivity; the number of GCTs and proportion of nuclei decorated were as follows: four, <1%; seven, 1% to 10%; and one, 20%. Ki67PI was higher in recurrent tumors (P<.001) and correlated with mitotic rate (r = .75; P<.0001). p53 staining was associated with juvenile type GCTs (P<.001) and higher Ki67PI (P<.005). Other histopathologic features exhibited no association with p53 staining or Ki67PI. Follow-up was available for 54 of 56 patients: 18 suffered recurrences after 16 to 229 months (mean, 72.1 months; median 59 months), and 36 were disease free 16 to 369 months (mean, 78.2 months; median, 70 months) after diagnosis. Curiously, high Ki67PI and mitotic rates of primary GCT correlated weakly with a disease-free course (P=.03 and .07 respectively). Disease recurrence was associated with stage >I (P<.0005), vessel invasion in the capsule (P<.001), ruptured tumors (P<.005), and older patients (P<.02). p53 staining and size or subtype of GCT exhibited no prognostic value. For 12 patients, paired primary and first recurrence of GCT showed a striking increase in Ki67PI (P<.00005) and mitotic activity (P<.02) in the recurrence. p53 expression also appeared (de novo) in two recurrent GCTs. The interpretation of focal p53 staining (>10% nuclei decorated in only one GCT) is controversial. Some investigators suggest that this represents overexpression of wild type p53 rather than p53 gene mutation. Primary GCTs exhibit a wide spectrum of proliferative activity, and the seven juvenile GCTs (the most proliferative type) demonstrated no recurrences in this study. Recurrent GCTs displayed a transformation of molecular markers to increased proliferative activity and overexpression of p53, fundamentally, by these markers, a different GCT than the primary one. These findings suggest a molecular basis for the lack of histopathologic predictors for recurrence. Factors other than proliferation of the primary GCT (which relates most closely to grading) either extrinsic to the neoplasm (host dependent) or as yet undetectable must determine malignant behavior.