Secreted protein acidic and rich in cysteine as a regulator of murine ovarian cancer growth and chemosensitivity.

OBJECTIVE: Secreted protein acidic and rich in cysteine (SPARC) influences the growth of several solid tumors. Our objectives were to determine the effect of SPARC on the growth and response to cisplatin therapy of platinum-resistant ovarian cancer. STUDY DESIGN: SPARC expression was determined in 4 platinum-resistant ovarian cancer cell lines. The effect of increasing SPARC on cell proliferation was determined in vitro. The effect of host-derived SPARC on tumor growth and response to therapy was determined in vivo using the murine ovarian cancer cell line, OSEID8, which was injected into the peritoneum of wild-type (WT) and SPARC-null (SP-/-) mice. RESULTS: Forced expression of SPARC decreased growth of platinum-resistant ovarian cancer cell lines in vitro. In vivo, tumor growth was more aggressive in the absence of host-derived SPARC resulting in decreased survival compared with WT mice (P = .005). Cisplatin did not improve survival of WT mice. In contrast, cisplatin therapy resulted in a significant survival advantage (P = .0048) and decreased tumor volume (P = .02) in SP-/- animals. CONCLUSION: We conclude that SPARC is an important extracellular matrix protein that regulates the growth and chemosensitivity of ovarian cancer. In general, SPARC appears to control tumor cell growth but also impede the efficacy of cisplatin therapy. Therefore, selective inhibition of SPARC may provide an attractive strategy for increasing the efficacy of therapy in platinum-resistant ovarian tumors.

Implications of EGFR inhibition in ovarian cancer cell proliferation.

OBJECTIVES: Epidermal Growth Factor Receptor (EGFR) is one of the four members of the Human Epidermal Receptor (HER) family and is over-expressed in multiple malignancies. EGFR over-expression in ovarian cancer has been associated with poor prognosis. Targeted inhibition of EGFR via its tyrosine kinase domain is a successful treatment in lung cancer. Our objective was to correlate EGFR over-expression and growth inhibition, by EGF receptor inhibitors, in ovarian cancer. MATERIALS AND METHODS: HER expression in nine epithelial ovarian cancer cell lines and one lung cancer cell line was determined by Western blot analysis. EGFR phosphorylation sites were analyzed and DNA sequencing was performed. Cell proliferation assays were performed in the presence of the tyrosine kinase inhibitor, gefitinib, and the EGFR monoclonal antibody, cetuximab. Inhibitory concentrations of 50% of these therapies were determined and compared across all cell lines. The lung cancer cell line, HCC827, was used as a control. RESULTS: Four of nine (44%) ovarian cancer cell lines and the control lung cancer cell line expressed EGFR. These same cell lines showed a common phosphorylated residue at position 992, while other residues were variably phosphorylated. All but one cell line expressed at least one HER family member. Mutational analysis of the ovarian cancer cell lines showed no mutations in EGFR exons 18-21. Cell proliferation assays using gefitinib and cetuximab showed minimal response in the ovarian cancer cell lines when compared to the control HCC827, but relative sensitivity compared to the one cell line that had no HER family expression. CONCLUSIONS: Ovarian cancer cell lines show variable expression of activated EGFR. EGFR inhibition alone, in ovarian tumors that lack a tyrosine kinase mutation or over-express EGFR is unlikely to result in clinical response.

Fertility-sparing surgery in 101 women with adenocarcinoma in situ of the cervix.

OBJECTIVES: Cervical adenocarcinoma in situ (AIS) is a precursor of invasive disease that is increasing in incidence primarily among reproductive-age women of low parity. Conization is an alternative to hysterectomy that allows future pregnancy, but has an inherent risk of residual AIS. The purpose of this study was to determine the outcomes of patients treated by this fertility-sparing strategy over an extended period of surveillance. METHODS: Women diagnosed with cervical AIS who underwent primary fertility-sparing surgery with either loop excision or cold knife conization between 1993 and 2001 were identified at three institutions. A retrospective medical record review was performed. Patients 40 years of age and older and those undergoing hysterectomy within 12 months of diagnosis were excluded. RESULTS: A total of 101 women underwent cone biopsy and expectant management. The median age was 29 years. Fifty-seven percent were nulliparous and 23% primiparous. Cold knife conization was most commonly performed (69 vs. 32 procedures) and had a higher efficacy of achieving negative margins (72% vs. 47%; P=0.036). Thirty-five women had a total of 49 pregnancies during a mean follow-up of 51 months. Thirty-five gestations were delivered at term. There were two preterm births, eight spontaneous miscarriages, three elective terminations, and one ectopic pregnancy. Thirty-six patients had a repeat cone biopsy. Five ultimately underwent hysterectomy. No invasive cervical adenocarcinomas were observed during the study interval. CONCLUSION: Fertility-sparing surgery enables women with cervical AIS to achieve pregnancy with minimal risk of developing invasive disease during surveillance.