Three novel mouse monoclonal antibodies, OM-A, OM-B, and OM-C, reactive with mucinous type ovarian tumors

Three mouse IgG1 monoclonal antibodies (MoAbs) reactive predominantly with cytoplasmic antigens of mucinous type ovarian tumors were produced. OM-A MoAb was reactive with 11 of 14 mucinous type and two of three endometrioid type ovarian tumors, although only a minor population of the tumor cells was positive in the latter type. This MoAb was not reactive with serous type, clear cell type, or other types of ovarian tumors, nor with various types of uterine carcinoma. Normal adult and fetal tissues of female genital organs were not positive with this MoAb. Among nongynecological carcinomas, three of six metastatic tumors to the ovary from the gastrointestinal tract, one of five gastric carcinomas, and one of eight lung adenocarcinomas were positive. As for normal adult and fetal tissues of nongynecological origin, epithelium of the normal stomach, small bowel, and bronchus as well as epithelium of fetal small and large bowel and secretory products were weakly positive. Thus, this MoAb showed a selected specificity against mucinous and endometrioid types of ovarian tumors. OM-B MoAb showed a broader specificity than OM-A, reacting with all mucinous type, two of three endometrioid type, and three of 16 serous type ovarian tumors, but not with clear cell type tumors. Adenoma type, but not squamous type, cervical carcinomas and one-half of endometrial carcinomas were positive. This antigen is present in cervical mucosa, but not in ovary or endometrium. OM-C MoAb showed a specificity similar to, but broader than that of, OM-B; i.e., 11 of 14 mucinous type, two of three endometrioid type, nine of 16 serous type, and one of nine clear cell type ovarian tumors were positive. It is reactive with adenoma type uterine carcinoma and normal mucosa of the uterine cervix and with normal surface epithelium of the oviduct. Among nongynecological tumors, OM-B antigen was present in metastatic tumors to the ovary as well as in gastric and pancreatic carcinomas, while OM-C was in metastatic tumors to the ovary and gastric and colonic carcinomas. Thus, the serological analysis showed that these three MoAbs showed selective specificities to mucinous and endometrioid types of ovarian tumors. Preliminary characterization of these three OM antigens suggested that these are distinct from carcinoembryonic antigen or ABH blood group-related antigens.     

Whole-genome allelotyping identified distinct loss-of-heterozygosity patterns in mucinous ovarian and appendiceal carcinomas.

PURPOSE: Mucinous adenocarcinoma of the ovary is one of the common histologic types of ovarian cancer. Its pathogenesis is largely unknown. In addition, the differential diagnosis of metastatic mucinous carcinomas to the ovaries, particularly those originating from the appendix, remains challenging. The purpose of this study is to identify molecular biomarkers for mucinous ovarian adenocarcinoma and compare them with those of appendiceal origin. EXPERIMENTAL DESIGN: Genome-wide loss-of-heterozygosity (LOH) analysis was done on DNA isolated from 28 microdissected primary mucinous ovarian carcinomas and five appendiceal adenocarcinomas. Markers from high-loss regions were selected for further analysis on a total of 32 ovarian and 14 appendiceal cancers. RESULTS: High levels of LOH rates (>40%) were detected on chromosome arms 9p, 17p, and 21q in mucinous ovarian carcinoma cases. The frequency of allelic loss was similar between high-grade and low-grade mucinous ovarian carcinoma cases but was significantly higher in ovarian versus appendiceal cases. In addition, LOH rates on five chromosomal loci were statistically different between ovarian and appendiceal carcinomas. CONCLUSION: A high frequency of LOH can be found in mucinous ovarian adenocarcinomas independent of grade. Despite histologic similarities between mucinous ovarian carcinomas and metastatic appendiceal carcinomas, they have distinct LOH profiles, which may be used for distinguishing the two diseases.     

Alteration of BRCA-1 tumor suppressor gene expression in serous and mucinous ovarian neoplasms in the benign-borderline-malignant pathway

Alteration of expression of the tumor suppressor gene BRCA-1 has been widely studied in breast and ovarian carcinoma. However, pattern of this alteration in the benign-borderline-carcinoma sequence in serous and mucinous ovarian neoplasms have not yet fully described. Tissue sections from 214 formalin-fixed paraffin-embedded ovarian specimens were stained immunohistochemically with BRCA-1 antibody. Specimens were 10 normal ovarian surface epithelium, 10 fallopian tube epithelium, 70 benign adenoma (50 serous and 20 mucinous), 28 borderline (13 serous and 15 mucinous), 78 carcinoma (58 serous and 20 mucinous), and 18 metastatic deposit (13 serous and 5 mucinous). Expression was evaluated into 0, +1, +2, and +3. Score +3 staining similar to normal tissues was considered normal and other scores were considered altered expression. Strong expression was seen in all normal epithelium specimens. Altered expression was seen in 34 serous neoplasms; 17 of 50 (34%) of benign cystadenomas, 6 of 13 (46%) of borderline tumors, 43 of 58 (74%) of primary carcinoma, and in 8 of 13 (62%) of metastatic carcinoma. This alteration was significantly associated with higher histopathologic grade (P = 0.049), presence of necrosis (P = 0.0001), and higher proliferation rate (P = 0.001). In mucinous neoplasms; altered BRCA-1 was detected in 25 specimens; 7 of 20 (41%) of benign cystadenomas, 5 of 15 (33%) of borderline neoplasms, 9 of 20 (45%) of primary carcinoma, and 4 of 5 (80%) of the metastatic deposits. This alteration was not associated with any of the clinicopathologic tumor characteristics. In conclusion, alteration of BRCA-1 expression is more frequent in serous than in mucinous carcinomas and is associated with tumors of higher grades and high proliferation rate.     

Utility of anti‐L523S antibody in the diagnosis of benign and malignant serous effusions

BACKGROUND.

Immunohistochemistry is helpful in distinguishing metastatic carcinoma from atypical mesothelial cells; however, it is not useful in differentiating atypical mesothelial cells from malignant mesothelial cells. K homolog domain containing protein overexpressed in cancer (KOC), a member of the insulin‐like growth factor mRNA‐binding protein (IMP) family, also known as L523S and IMP3, is expressed during embryogenesis and in various malignancies. Using a mouse monoclonal antibody (L523S) against KOC, KOC expression was investigated in malignant tumors and reactive mesothelial cells in serous effusions.

METHODS.

Seventy‐six cases with paraffin‐embedded pleural, pericardial, and peritoneal serous effusion cell blocks including 60 malignant serous effusions (11 malignant pleural mesotheliomas and 49 metastatic carcinomas) and benign pleural effusions (14 cases with reactive mesothelial cells and 2 cases with atypical cells with uncertain significance) were selected for immunohistochemical analysis with L523S, calretinin, and CK5/6.

RESULTS.

Immunohistochemical studies showed that positive staining for KOC of variable degrees of intensity was observed in 47 of 60 cases in malignant serous effusions including 10 of 11 mesotheliomas and 36 of 49 metastatic carcinomas. The associated reactive mesothelial cells were negative for KOC but positive for calretinin and CK5/6. All 11 malignant mesotheliomas exhibited positivity for calretinin, and 9 of 11 cases had CK5/6 staining. In addition, 16 cases that were originally diagnosed either as pleural effusions with reactive mesothelial cells (14) or atypical cells with uncertain significance (2) were also tested for KOC expression. Interestingly, 3 of 16 cases exhibited various degrees of positivity for KOC, 2 of which were diagnosed as lung adenocarcinoma with a recurrence after tumor resection and 1 as malignant pleural mesothelioma.

CONCLUSIONS.

Anti‐L523S antibody is a useful marker for the detection of malignant cells in serous effusions and it can have significant utility in differentiating reactive mesothelial cells from malignant mesothelioma and metastatic carcinoma in combination with calretinin and CK5/6 staining. Cancer (Cancer Cytopathol) 2008. © 2007 American Cancer Society.     

Prognostic evaluation of tumour type and other histopathological characteristics in advanced epithelial ovarian cancer, treated with surgery and paclitaxel/carboplatin chemotherapy: cell type is the most useful prognostic factor

AimOvarian carcinomas have been classified into types I and II according to the hypothesised mode of carcinogenesis and molecular characteristics. The prognostic significance of this classification has not been studied.Patients and methodsFive hundred and sixty-eight patients with histologically confirmed, ovarian, fallopian tube or peritoneal carcinomas, international federation of gynecology and obstetrics (FIGO) stages IIC–IV, treated with paclitaxel/platinum following cytoreductive surgery, were included in this analysis. Type I included low-grade serous, mucinous, endometrioid and clear-cell and type II high-grade serous, unspecified adenocarcinomas and undifferentiated carcinomas.ResultsMedian overall survival (OS) was 49 months for type I versus 45 for type II (p = 0.576). In contrast to type II, there was considerable prognostic heterogeneity among the subtypes included in type I. Cox regression analysis showed that cell-type classification: low-grade serous, mucinous, endometrioid, clear-cell, type II (high-grade serous, unspecified adenocarcinomas, undifferentiated carcinoma) was an independent predictor of survival (respective median OS 121 versus 15 versus 64 versus 29 versus 45 months, p = 0.003). On the contrary, histopathological subtype or tumour type (I versus II) did not offer additional prognostic information.ConclusionThe proposed model of ovarian tumourigenesis does not reflect tumour behaviour in advanced disease. Tumour-cell type is the most relevant histopathological prognostic factor in advanced ovarian cancer treated with platinum/paclitaxel.     

Utility of paired box gene 8 (PAX8) expression in fluid and fine‐needle aspiration cytology

BACKGROUND:

Metastases from ovarian neoplasms are commonly encountered in peritoneal fluids. In addition, reactive mesothelial cells in effusion specimens can mimic ovarian serous carcinoma, making the diagnosis difficult. Calretinin has been recognized as a reliable immunohistochemical marker for mesothelial cells, whereas WT1 has proven useful in the diagnosis of ovarian serous carcinoma. This can present a diagnostic pitfall in effusion cytology, because mesothelial cells can demonstrate immunoreactivity for WT1. Recently, paired box gene 8 (PAX8) has been used in distinguishing ovarian from mammary carcinoma. To the authors' knowledge, no studies using PAX8 have been performed on peritoneal cytology specimens to date, and its expression in metastatic ovarian serous carcinoma has not been studied.

METHODS:

These markers, along with BerEP4 and MOC‐31, were evaluated in cytology cell block preparations from 30 fluid cytology specimens and 11 fine‐needle aspiration specimens.

RESULTS:

PAX8 was found to be positive in 37 of 41 (90%) ovarian carcinoma cases studied, and was a sensitive (90%) and specific (100%) marker for the detection of metastatic ovarian carcinoma. In addition, calretinin was found to be useful for identifying mesothelial cells in fluid cytology. Furthermore, although PAX8 and WT1 have demonstrated comparable sensitivity (90% and 93%, respectively) in diagnosing metastatic ovarian carcinoma, PAX8 appears to have superior specificity because staining is not observed in mesothelial cells. BerEP4 and MOC‐31 were found to have a lower sensitivity and specificity compared with PAX8.

CONCLUSIONS:

PAX8‐positive, calretinin‐negative staining appears to be highly specific and sensitive for detecting metastatic ovarian serous carcinoma in cytologic preparations and can be useful in distinguishing it from mesothelial cells in fluid cytology. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.     

9p21 Deletion in the diagnosis of malignant mesothelioma in serous effusions additional to immunocytochemistry,DNA‐ICM,and AgNOR analysis

BACKGROUND

The diagnosis of malignant mesothelioma (MM) in serous effusions is difficult but may be achieved by the application of adjuvant methods.

METHODS

The authors cytologically diagnosed 33 effusions as suspicious or positive for MM cells by using DNA‐image cytometry (DNA‐ICM), immunocytochemistry and AgNOR analysis. The authors further detected 9p21 deletions by chromosomal fluorescence in situ hybridization (FISH). In addition, 31 cases of metastatic carcinomas and 39 of tumor cell‐negative effusions were investigated. All diagnoses were confirmed by histologic and/or clinical follow‐up.

RESULTS

DNA aneuploidy was found in 71% of MMs, 100% of metastatic carcinomas, and in none of the negative effusions. Calretinin was positive in 100% of MMs, in none of the metastatic carcinomas, and in 94.9% of negative effusions. BerEP4 showed positivity in 15.6% of MMs, 87.1% of metastatic carcinomas, and in none of the negative effusions. With AgNOR analysis, 89.3% of MMs and 96.7% of metastatic carcinomas showed ≥2.5 AgNOR dots as satellites and ≥4.5 as total AgNOR counts. 9p21 deletions were demonstrated in 90.9% of MM cases, 45.2% of metastatic carcinomas, and in none of the negative effusions. By cytology alone, 81.8% of MMs were identified unequivocally. Addition of DNA‐ICM improved the prevalence of tumor cell detection to 87.9% and of AgNOR analysis to 97%. The introduction of 9p21 deletions by FISH improved this prevalence to 100%.

CONCLUSIONS

Because of these results, the authors propose the sequential application of immunocytochemistry, DNA‐ICM, and AgNOR analysis to establish a cytological diagnosis of malignant mesothelioma in serous effusions. In persistent doubtful diagnoses, the authors recommend fluorescence in situ hybridization to analyze the 9p21 deletion. Cancer (Cancer Cytopathol) 2008. © 2008 American Cancer Society.     

Identification of two different surface epitopes of human ovarian epithelial carcinomas by monoclonal antibodies

Monoclonal antibodies (Mabs) against human ovarian mucinous and serous carcinoma were obtained by the Mab technique. Their reactivities against human tumors were tested by indirect immunofluorescence. One of the Mabs, named 4C7, derived from the spleen cells of mice immunized with mucinous carcinoma line OVA-1, reacted to ovarian mucinous carcinoma, endometrioid carcinoma, and mesonephroid carcinoma but did not react to ovarian serous carcinoma. Another Mab, 3C2, obtained from the spleen cells of mice immunized with serous carcinoma line HOC-21, reacted to serous carcinoma and endometrioid carcinoma of ovary, but never reacted to mucinous carcinoma or mesonephroid carcinoma. Neither of the Mabs reacted to other types of ovarian carcinomas such as undifferentiated carcinoma, dysgerminoma, endodermal sinus tumor, and malignant teratoma of ovary, and also did not react to any benign ovarian tumors or other normal human tissues. Both Mabs 3C2 and 4C7 had no reactivity to carcinoma of other organs such as stomach, colon, lung, lymphoid system, and kidney and also did not react to human lymphocytic or carcinoembryonic antigen as confirmed by using many human cell lines and surgically resected samples. Since the cross-reactivities of these Mabs were limited within the ovarian epithelial carcinomas, it is suggested that two distinct epitopes are expressed on the ovarian epithelial carcinomas. One epitope, identified by Mab 4C7, is expressed only on mucinous carcinoma, endometrioid carcinoma, and mesonephroid carcinoma, while the epitope, identified by Mab 3C2, appears only on serous and endometrioid carcinoma.     

Thymidine phosphorylase-mediated angiogenesis regulated by thymidine phosphorylase inhibitor in human ovarian cancer cells in vivo

Metastasis or progression of ovarian cancer cells is known to be due to the action of various angiogenic factors. We determined the expression of thymidine phosphorylase/platelet-derived endothelial cell growth factor (TP/PD-ECGF) and vascular endothelial growth factor (VEGF) in cell lines established from 3 serous adenocarcinomas, 3 clear cell carcinomas and 2 mucinous carcinomas of the human ovary. TP activity and the TP mRNA level were much higher in the serous adenocarcinoma cells than in the clear cells and mucinous carcinoma cells, and TP expression was extremely low in the clear cell carcinoma cells. Expression of VEGF mRNA was variable, but not significantly different between the 3 histological types of ovarian cancer. In vivo angiogenesis in the ovarian cancer cells was evaluated by the dorsal air sac assay and revealed that SHIN-3 and HRA serous adenocarcinoma cells, which have high levels of TP expression, induced angiogenesis, while KK clear cell carcinoma cells with low TP expression, did not. The degree of ovarian-cancer-induced angiogenesis seemed to be independent of expression of VEGF in the cells. To confirm that the serous adenocarcinoma-induced angiogenesis is dependent on TP levels, a potent and specific inhibitor of TP was administered orally to mice implanted with a chamber containing SHIN-3 or HRA cells. The TP inhibitor significantly inhibited the angiogenesis induced by the serous adenocarcinoma cells. These results suggest that the angiogenic potency of ovarian cancer cells differs with the histological type and is controlled by expression of TP/PD-ECGF, not by VEGF, and that TP-mediated angiogenesis may be the main factor responsible for progression or metastasis of ovarian serous adenocarcinomas.     

Adjunct to the diagnostic distinction between adenocarcinomas of the ovary and the colon utilizing a monoclonal antibody (COL-4) with restricted carcinoembryonic antigen reactivity

Malignant ovarian tumors may represent either primary ovarian cancers or metastatic lesions (from patients with demonstrated primary cancers at other body sites) whose distinction may be difficult using clinical, surgical, and pathological criteria. Monoclonal antibody (MAb) COL-4, reactive with carcinoembryonic antigen, has previously been shown to react preferentially with adenocarcinomas of the colon versus a variety of normal tissues. We report here that MAb COL-4 is strongly reactive with primary colonic carcinomas (N = 50), as well as regional (N = 42), and distant (N = 20) metastases of colonic adenocarcinoma. In contrast, MAb COL-4 demonstrated little to no reactivity with primary (N = 53) and metastatic carcinomas of the ovary (N = 23) including serous, mucinous, and poorly differentiated adenocarcinomas using immunohistochemical techniques. This differential reactivity was statistically significant (P less than 0.001), suggesting the potential clinical utility of MAb COL-4 in the differentiation of ovarian from colonic adenocarcinoma. Solid-phase quantitative radioimmunoassays and Western blotting techniques confirmed these results. Data are also presented that the carcinoembryonic antigen molecules or epitopes recognized by a more classical broadly reactive anti-carcinoembryonic antigen MAb are distinct from those recognized by MAb COL-4. Other carcinomas which also metastasize to the ovary and may be confused clinically with a primary ovarian tumor such as adenocarcinomas of the stomach and breast were also evaluated for reactivity with MAb COL-4. COL-4 was also reactive with all gastric carcinomas evaluated, but failed to react with breast carcinomas. Hence, COL-4 can now be utilized as an immunohistochemical adjunct for the differentiation of ovarian from gastrointestinal adenocarcinoma which can be difficult to distinguish by clinical, surgical, and histological parameters.     

SALL4 is a novel sensitive and specific marker for metastatic germ cell tumors,with particular utility in detection of metastatic yolk sac tumors

BACKGROUND:

The correct diagnosis of metastatic germ cell tumors is critical, because these tumors can be effectively treated and are even cured with modern therapy. Their histopathologic diagnosis can be challenging without immunohistochemical markers, which currently have limitations. SALL4 is a novel stem cell marker essential to maintain pluripotency and self‐renewal of embryonic stem cells. In the current study, the authors investigated the utility of SALL4 as a potential diagnostic marker for metastatic germ cell tumors.

METHODS:

Ninety metastatic germ cell tumors from testis, ovary, and extragonadal sites were stained with a monoclonal SALL4 antibody. In addition, 170 metastatic nongerm cell malignancies, including 158 carcinomas (6 head and neck, 8 thyroid, 12 lung, 8 breast, 7 hepatocellular, 3 cholangiocarcinomas, 2 ampullary, 10 pancreatic, 18 gastric, 15 esophageal, 10 renal cell, 10 urothelial, 12 prostatic, 18 ovarian, 6 uterine, and 13 colonic) and 12 melanomas, were also stained to test SALL4 specificity.

RESULTS:

All 22 seminomas, 7 dysgerminomas, 22 embryonal carcinomas, and 14 of 15 yolk sac tumors displayed strong and diffuse SALL positivity in >90% of tumor cells (80% of tumor cells were strongly positive in the remaining yolk sac tumor). Five of 7 choriocarcinomas and 9 of 18 teratomas were also variably positive for SALL4. In contrast, only 10 (esophageal, gastric, and colonic adenocarcinomas) of 170 metastatic somatic tumors demonstrated focally weak SALL4 reactivity (<25% tumor cells).

CONCLUSIONS:

SALL4 is a novel sensitive and highly specific marker for metastatic germ cell tumors, and is particularly useful for detecting metastatic yolk sac tumors. Cancer 2009. © 2009 American Cancer Society.     

Reclassification of serous ovarian carcinoma by a 2-tier system: a Gynecologic Oncology Group Study

BACKGROUND:

A study was undertaken to use the 2‐tier system to reclassify the grade of serous ovarian tumors previously classified using the International Federation of Gynecology and Obstetrics (FIGO) 3‐tier system and determine the progression‐free survival (PFS) and overall survival (OS) of patients treated on Gynecologic Oncology Group (GOG) Protocol 158.

METHODS:

The authors retrospectively reviewed demographic, pathologic, and survival data of 290 patients with stage III serous ovarian carcinoma treated with surgery and chemotherapy on GOG Protocol 158, a cooperative multicenter group trial. A blinded pathology review was performed by a panel of 6 gynecologic pathologists to verify histology and regrade tumors using the 2‐tier system. The association of tumor grade with PFS and OS was assessed.

RESULTS:

Of 241 cases, both systems demonstrated substantial agreement when combining FIGO grades 2 and 3 (overall agreement, 95%; kappa statistic, 0.68). By using the 2‐tier system, patients with low‐grade versus high‐grade tumors had significantly longer PFS (45.0 vs 19.8 months, respectively; P = .01). By using FIGO criteria, median PFS for patients with grade 1, 2, and 3 tumors was 37.5, 19.8, and 20.1 months, respectively (P = .07). There was no difference in clinical outcome in patients with grade 2 or 3 tumors in multivariate analysis. Woman with high‐grade versus low‐grade tumors demonstrated significantly higher risk of death (hazard ratio, 2.43; 95% confidence interval, 1.17‐5.04; P = .02).

CONCLUSIONS:

Women with high‐grade versus low‐grade serous carcinoma of the ovary are 2 distinct patient populations. Adoption of the 2‐tier grading system provides a simple yet precise framework for predicting clinical outcomes. Cancer 2012;118: 3087–94. © 2011 American Cancer Society.     

Nuclear reactivity for estrogen. A possible diagnostic tool in differentiating colon cancer metastases in the ovary from primary mucinous ovarian tumors

Tissue distribution of carcinoembryonic antigen (CEA) and estrogen was analyzed in eight primary ovarian mucinous carcinomas, three primary mucinous colonic cancers, and four ovarian metastatic lesions from colonic and pancreatic adenocarcinomas. Primary ovarian mucinous carcinomas and metastatic colonic carcinomas had similar localization of CEA within the epithelial cytoplasm. Estrogen localization, in contrast, was shown within the epithelial nuclei of seven of eight primary ovarian mucinous tumors; whereas the nuclei of metastatic and primary mucinous colonic carcinomas did not have intranuclear estrogen. The cytoplasm and the stroma of both primary ovarian and metastatic colonic carcinomas stained for estrogen.     

First‐line chemotherapy with capecitabine and temozolomide in patients with metastatic pancreatic endocrine carcinomas

BACKGROUND.

Temozolomide is an active agent in metastatic pancreatic endocrine carcinomas. In vitro data indicate that the combination of capecitabine and temozolomide is synergistic for induction of apoptosis in neuroendocrine tumor cell lines. The authors retrospectively evaluated the efficacy of capecitabine and temozolomide in 30 patients with metastatic pancreatic endocrine carcinomas to assess response rate, progression free survival (PFS), and overall survival (OS).

METHODS.

Patients with metastatic, well, or moderately differentiated pancreatic endocrine carcinomas who had not received prior systemic chemotherapy were treated with capecitabine (750 mg/m² twice daily, days 1‐14) and temozolomide (200 mg/m² once daily, days 10‐14) every 28 days.

RESULTS.

Among 30 patients treated, 21 (70%) patients achieved an objective radiographic response. Median progression‐free survival was 18 months. The rate of survival at two years was 92%. Only 4 patients (12%) experienced grade 3 or 4 adverse events.

CONCLUSIONS.

The combination of capecitabine and temozolomide is associated with an exceptionally high and durable response rate in metastatic endocrine carcinomas of the pancreas. Clinical endpoints, including response rate, survival, and toxicity, are superior to those observed with streptozocin‐based regimens Cancer 2011. © 2010 American Cancer Society.     

Impact of mutational status on survival in low-grade serous carcinoma of the ovary or peritoneum

Background:

Low-grade serous carcinoma of the ovary or peritoneum is a distinct, well- recognized histologic subtype characterized by young age at diagnosis, relative chemoresistance, and prolonged overall survival. Common mutations reported to be found within this subtype include KRAS and BRAF.

Methods:

Using clinical information of patients from our IRB-approved registry and tissue from a subset of these patients, we performed mutational analysis for KRAS and BRAF using the direct Sanger sequencing technique and correlated findings with the clinical outcome, overall survival (OS).

Results:

In 79 cases, patients with KRAS or BRAF mutations (n=21) had a significantly better OS than those with wild-type KRAS or BRAF (n=58) (106.7 months (95% CI, 50.6, 162.9) vs 66.8 months (95% CI, 43.6, 90.0)), respectively (P=0.018).

Conclusions:

Mutational status appears to be a potential prognostic factor in low-grade serous carcinoma of the ovary or peritoneum.     

TFF3 Expression as Stratification Marker in Borderline Epithelial Tumors of the Ovary

Borderline tumors (BOT) of the ovary account for 10% to 20% of ovarian neoplasms. Like ovarian cancer, BOT encompass several different histological subtypes (serous, mucinous, endometrioid, clear cell, transitional cell and mixed) with serous (SBOT) and mucinous (MBOT) the most common. Current hypotheses suggest low-grade serous carcinoma may develop in a stepwise fashion from SBOT whereas the majority of high grade serous carcinomas develop rapidly presumably from inclusion cysts or ovarian surface epithelium. The pathogenesis of mucinous ovarian tumors is still puzzling. Molecular markers could help to better define relationships between such entities. Trefoil factor-3 (TFF3) is an estrogen-regulated gene associated with prognosis in different types of cancer. It has also been included in a recent marker panel predicting subtypes of ovarian carcinoma. We analyzed the expression of TFF3 by immunohistochemistry in a cohort of 137 BOT and its association with histopathological features. Overall expression rate of TFF3 was 21.9%. None of the BOT with serous and endometrioid histology displayed strong TFF3 expression. On the other hand, TFF3 was highly expressed in 61.4% of MBOT cases and 33.3% of BOT with mixed histology (P < 0.001) suggesting a potential function of the protein in that subtypes. Associations of TFF3 expression with FIGO stage and micropapillary pattern were significant in the overall cohort but confounded by their correlation with histological subtypes. The highly specific expression of TFF3 in MBOT may help to further clarify potential relationships of tumors with mucinous histology and warrants further studies.     

Is Immunohistochemical Sex Hormone Binding Globulin Expression Important in the Differential Diagnosis of Adenocarcinomas?

Adenocarcinomas (AC) are the most frequently encountered carcinomas. It may be quite challenging to detect the primary origin when those carcinomas metastasize and the first finding is a metastatic tumor. This study evaluated the role of sex hormone binding globulin (SHBG) positivity in tumor cells in the subclassification and detection of the original organ of adenocarcinomas. Between 1994 and 2008, 64 sections of normal tissue belonging to ten organs, and 116 cases diagnosed as adenoid cystic carcinoma and mucoepidermoid carcinoma of the salivary gland, lung adenocarcinoma, invasive ductal carcinoma of the breast, adenocarcinoma of stomach, colon, gallbladder, pancreas and prostate, endometrial adenocarcinoma and serous adenocarcinoma and mucinous adenocarcinoma of the ovary, were sent to the laboratory at the Department of Pathology at the Yuzuncu Yil University School of Medicine, where they were stained immunohistochemically, using antibodies against SHBG. The SHBG immunoreactivity in both the tumor cells and normal cells, together with the type, diffuseness and intensity of the staining were then evaluated. In the differential diagnosis of the adenocarcinomas of the organs, including the glandular structures, impressively valuable results are encountered in the tumor cells, whether the SHBG immunopositivity is evaluated alone or together with other IHC markers. Further extensive research with a larger number of cases, including instances of cholangiocarcinoma and cervix uteri AC [which we could not include in the study for technical reasons] should be performed, in order to appropriately evaluate the role of SHBG in the differential diagnosis of AC.     

Thyroid fine‐needle aspiration with atypia of undetermined significance

BACKGROUND:

Atypia of undetermined significance is a controversial category in thyroid fine‐needle aspiration (FNA), not only for its questioned clinical utility, but also for its very existence as an expression of uncertainty. The current study was performed to investigate the potential impact of eliminating this category on the sensitivity and specificity for detecting thyroid neoplasms by FNA.

METHODS:

Forty cases originally diagnosed as atypia of undetermined significance with histologic follow‐up were selected for the present study. These cases were reinterpreted blindly by 2 experienced reviewers, who eliminated atypia of undetermined significance as a diagnostic possibility and reclassified these cases as either benign, follicular neoplasm, suspicious for malignancy, or malignant. Twenty‐six cases of atypia of undetermined significance were randomly selected and reevaluated 6 months later to study intraobserver variation.

RESULTS:

After eliminating the atypia of undetermined significance category, the sensitivity for detecting papillary thyroid carcinoma (PTC) was reduced from 100% to 27% (P = .04). In those atypia of undetermined significance cases that were reclassified as benign, 37% had PTC. In those reclassified as follicular neoplasm or suspicious for malignancy, 38% were histologically proven to be benign lesions. Unanimous interobserver and intraobserver agreement was observed in only 60% of cases.

CONCLUSIONS:

Eliminating the diagnosis of atypia of undetermined significance substantially decreases the sensitivity of thyroid FNAs and increases both false‐positive and false‐negative rates. In addition, it increases interobserver and intraobserver variability. Therefore, the atypia of undetermined significance category should not be eliminated; but we advocate minimizing its use. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society.     

Alteration of the p53 Tumor Suppressor Gene Occurs Independently of K-ras Activation and More Frequently in Serous Adenocarcinomas than in Other Common Epithelial Tumors of the Human Ovary

To clarify the role of the p53 tumor suppressor gene in the development of human ovarian epithelial tumors and to study the association of p53 alterations with K-ras activation, a series of 70 common epithelial ovarian tumors from Japanese patients was studied. These included 31 serous adenocarcinomas, 12 mucinous adenocarcinomas, 5 mutinous tumors of borderline malignancy, 13 endometrioid adenocarcinomas, and 9 clear cell carcinomas. Allelic loss, recognized at the polymorphic site in codon 72 of the p53 gene, was detected in 14 of 36 (39%) informative cases by restriction fragment length polymorphism analysis and by single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction(PCR)-amplified DNA fragments. Mutations in the highly conserved regions of the p53 gene were detected by SSCP analysis of PCR-amplifled fragments. Mutations were found in 22 of 70 (31%) ovarian tumors, including 1 of 5 mucinous tumors of borderline malignancy. Mutations were subsequently characterized by direct sequencing. Single missense base substitutions were detected in 13 ovarian carcinomas and in one case of mucinous tumor of borderline malignancy. Short (1-8 bp) deletions and insertions were found in 8 cases. Mutations in the p53 gene occurred more frequently in serous adenocarcinomas (14/31, 45%) than in all nonserous types of malignant epithelial tumors combined (7/34, 21%;P=0.032). Point mutations in K-ras were identified by dot blot hybridization analysis of PCR-amplified fragments with mutation-specific oligonucleotides and by direct sequencing. The overall frequency of K-ras mutations was 19/70 (27%).K-ras mutations were found in 12 of 17 (71%) mucinous tumors (8/12 mucinous carcinomas [67%] and 4/5 mucinous tumors of borderline malignancy [80%]), and occurred more frequently than in serous carcinomas (4/31, 13%;P=0.00009) or in all nonmucinous types of ovarian epithelial tumors combined (7/53, 13%; p=0.00002). These data suggest that different combinations of oncogenes and/or tumor suppressor genes may be involved in the genesis and development of histologically distinct categories of common epithelial tumors of the human ovary.