Stathmin 1, a marker of PI3K pathway activation and regulator of microtubule dynamics, is expressed in early pelvic serous carcinomas

BACKGROUND

Most high-grade pelvic serous carcinomas (HGPSCs) arise from fallopian tube epithelium (FTE). To date, few markers have been shown to characterize FTE transformation. Stathmin 1 (STMN1) is a candidate oncogene whose activity is influenced by p53, p27Kip1 (p27), and PI3K/Akt pathway activation. As a microtubule destabilizing protein, STMN1 regulates cytoskeletal dynamics, cell cycle progression, mitosis, and cell migration. This study examines the expression of STMN1 and its negative regulator p27 along the morphologic continuum from normal FTE to invasive carcinoma.

METHODS

STMN1 and p27 expression were examined by immunohistochemistry (IHC) in benign (n=12) and malignant (n=13) fallopian tubes containing normal epithelium, morphologically benign putative precursor lesions ("p53 signatures"), potential transitional precursor lesions ("proliferative p53 signatures"), tubal intraepithelial carcinoma (TIC), and/or invasive serous carcinoma. STMN1 expression was further assessed in 131 late-stage HGPSCs diagnosed as primary ovarian and in 6 ovarian cancer cell lines by IHC and Western blot, respectively.

RESULTS

STMN1 expression was absent in benign FTE and infrequently detected in p53 signatures. However, it was weakly expressed in proliferative p53 signatures and robustly induced upon progression to TIC and invasive carcinoma, typically accompanied by decreased p27 levels. STMN1 was expressed in >80% of high-grade serous ovarian carcinomas and cell lines.

CONCLUSIONS

STMN1 is a novel marker of early serous carcinoma that may play a role in FTE tumor initiation. Our data are consistent with a model by which STMN1 overexpression, resulting from loss of p27-mediated regulation, may potentiate aberrant cell proliferation, migration, and/or loss of polarity during early tumorigenesis.

Reclassification of a tubal leiomyosarcoma as an eGIST by molecular evaluation of c-KIT

BACKGROUND

Extragastrointestinal stromal tumors (eGISTs) are rare mesenchymal-derived tumors arising outside of the GI tract. eGISTs are often histologically confused with leiomyosarcoma. Distinction between eGIST and leiomyosarcoma is critical because of the unique responsiveness of eGISTs to the molecularly targeted agent imatinib.

CASE

A woman presented with a history of tubal spindle cell tumor that was initially diagnosed and treated as a leiomyosarcoma. Because of minimal response to sarcoma directed chemotherapy, the possibility that the tumor was in fact an eGIST was investigated and supported by immunohistochemical and mutational analyses of the c-Kit receptor tyrosine kinase. The patient currently has stable disease control on imatinib for the last 18 months.

CONCLUSIONS

The possibility of eGIST should be considered in the differential diagnosis of tumors with a spindle cell morphology in the gynecologic tract especially when involving the ovary, fallopian tube, or uterine serosa.

Telomerase activity as a biological marker in some gynecological tumors: comparison with tissue and serum CA 125

BACKGROUND

Since telomerase activity is detectable in cancer cells but not in some normal somatic cells, it has been considered as a potential diagnostic marker as well as a target for possible anticancer strategies. The purpose of this study was to assess the value of telomerase activity determination in some gynecological tumors and to compare it with the CA 125 tissue and serum profile.

PATIENTS AND METHODS

The telomerase activity was determined in 11 gynecological tumors: 7 ovarian carcinomas, 2 carcinomas of the fallopian tube and 2 cervical carcinomas, and compared to the activity in the normal peritoneal tissue of the same patients. Additionally, the levels of CA 125 were measured in the tumor and normal peritoneum tissue samples as well as in the patients' sera.

RESULTS

In ovarian tumors, the telomerase activity was detected in 71.4% (5 out of 7), while in the carcinomas of the fallopian tube and cervical carcinomas such activity was not observed. Negative for telomerase activity were also all samples of peritoneum. The range of CA 125 in the tumor tissue was 99 U/g-803667 U/g of tissue and in the normal peritoneum 71 U/g-4925 U/g of tissue.

CONCLUSION

In conclusion, telomerase activity could be detected in some of the gynecological tumors, but for clinical use as a diagnostic marker it is inferior to CA 125.

Serum placental-type alkaline phosphatase activity in women with squamous and glandular malignancies of the reproductive tract

AIM

To investigate serum placental-type alkaline phosphatase (PLAP-type) activities in women with squamous and glandular malignancies of the reproductive tract using an immunoradiometric assay.

METHODS

PLAP-type immunoreactivity was measured in 180 women with non-ovarian malignancies of the reproductive tract and the values were compared with those from 334 controls. The cases comprised 18 vulval, nine vaginal, 103 cervical, 46 endometrial, and five fallopian tube cancers.

RESULTS

Serum PLAP-type activities were no different from controls in patients with squamous cell tumours. Women with adenocarcinoma of the cervix, endometrium, and fallopian tube had increased values: women with endometrial cancer had a median value nearly four times greater than that of controls. There was no direct correlation between PLAP-type activities and stage of disease in patients with endometrial cancer, but values reverted to normal after treatment.

CONCLUSIONS

Serum PLAP-type measurements are of no value in the management of patients with squamous cell tumours of the female reproductive tract. Raised activities can, however, be found in glandular tumours, in particular endometrial cancer where serum PLAP-type measurements may be of value in predicting remission.