Association of a common genetic variant of the IGF1 gene with clinical outcome in patients with HER2-positive breast cancer

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Background: Insulin-like growth factor 1 (IGF1) stimulates mitosis and inhibits apoptosis. Circulating IGF1 levels may be linked with an increased risk of colorectal and breast cancer. Further, IGF1 single nucleotide polymorphisms (SNPs), especially variant rs2946834, recently have been associated with a poor clinical outcome in patients with colorectal cancer. However, the influence of IGF1 SNPs on the prognosis of patients with breast cancer is unknown. Therefore, we aimed at investigating the influence of IGF1 tagging polymorphisms associated with IGF1 levels on event-free survival in patients with HER2-positive breast cancer.

Methods: The present study included 161 consecutive white patients with HER2-positive breast cancer treated between 2000 and 2010 at the Department of Gynecology and Obstetrics, Medical University of Innsbruck, Austria. Event-free survival was calculated as the time from cancer diagnosis to either relapse or death from any cause. Genomic DNA was extracted from archived formalin-fixed paraffin embedded tumor tissue samples; five IGF1 tagging polymorphisms (rs2946834, rs6220, rs1520220, rs5742694, and rs5742678) were genotyped by SNaPshot assays.

Results: Mean follow up period was 4.3 (± 2.5) years. Kaplan-Meier analysis showed a poorer clinical outcome for carriers of the rare allele of SNP rs2946834 (log-rank test, p = 0.029). Concordantly, in univariate Cox regression analyses the rare allele of SNP rs2946834 was significantly associated with a decreased event-free survival (HR = 2.87 [1.07 –7.70]; p = 0.036). Multivariate analysis adjusted for age and tumor stage confirmed this result (HR = 2.86 [1.06 –7.71]; p = 0.038). Thus, our results are in concordance with a recent report that the same SNP is associated with poorer clinical outcome in colorectal cancer patients. Other investigated genetic variants of the IGF1 gene were not significantly associated with event-free survival (all p-values > 0.05).

Conclusions: For the first time, our study investigates the influence of IGF1 tagging polymorphisms on the clinical outcome of HER2-positive breast cancer patients suggesting SNP rs2946834 as a predictor for reduced event-free survival.

Regulation of the EGFR-E2F3a axis by the interferon regulatory factor (IRFs) and by promoter methylation of miR-34a in ovarian cancer

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Background: Although, EGFR targeting has reached “bedside” in various tumor entities, including ovarian cancer, the essential role of E2F3a in EGFR mediated proliferation remained uncovered. Recently, we outlined the clinical relevance of E2F3a in ovarian cancer. Now we were able to elucidate the pathway between EGFR activation and E2F3a induction. Methods: Promoter mapping of E2F family members was assessed using the JASPER software. E2F3a protein was assessed by immunoblot analyses in siRNA based IRF-1, IRF-2 knockdown HOC-7 cells. Cell growth was determined by MTT assays after siRNA based knockdown of E2F3a. Expression of E2F3a regulating miR-34a, miR-210 and miR-20a were assessed by RT-PCR in 130 ovarian cancer patients and methylation status of the E2F3a promoter and of miRNA promoters were estimated using Methyllight. 6p22 amplification status of patients was determined by FISH analyses. Results: Promoter mapping of E2F family members revealed that IRF-1 and IRF-2 are potential intermediate components of the herein described EGFR-E2F3a axis. As evidenced by knock-down of IRF-1, IRF-2 or both, the ratio between the two mutually antagonistic IRF-1 and IRF-2 was found to be substantial for EGF induced E2F3a up-regulation. E2F3a knock-down yielded a complete abolishment of EGF induced cancer cell proliferation. Although, activated EGFR status showed a highly significant correlation with E2F3a expression, a subgroup of patients presented high E2F3a mRNA levels without EGFR activation. Within this subgroup promoter methylation of miRNA-34a, that regulates E2F3a, was revealed to represent an alternative mechanism of E2F3a regulation in ovarian cancer, whereas promoter methylation of E2F3a itself was not relevant in E2F3a control. Unlike in prostate or bladder cancer 6p22 amplification was not found to be relevant for E2F3a up-regulation in ovarian cancer. Conclusions: Our present data point to the substantial role of the ratio between IRF-1 and IRF-2 in EGFR mediated E2F3a induction. Furthermore, in vivo regulation of E2F3a involves methylation and thereby silencing of miR-34a. Targeting of the herein described molecular pathway, downstream EGFR, could represent an appealing therapeutic approach in ovarian cancer.

No significant financial relationships to disclose.

Interferon-gamma in combination with carboplatin and paclitaxel as a safe and effective first-line treatment option for advanced ovarian cancer: results of a phase I/II study

We have previously shown that interferon-gamma 1b (IFN-gamma) in combination with cyclophosphamide and cisplatin significantly prolongs progression-free survival in ovarian cancer. In this phase I/II study, we examined if administration of IFN-gamma is also safe in combination with the current standard treatment, paclitaxel and carboplatin. Thirty-four patients with newly diagnosed advanced epithelial ovarian cancer, FIGO stage III/IV, were treated for six to nine cycles with paclitaxel (175 mg/m(2)) and carboplatin (area under the curve [AUC] 5) every 3 weeks. IFN-gamma was administered in an escalating dose from 6 days/cycle with 0.025 mg sc up to 9 days/cycle with 0.1 mg sc. As expected, administration of IFN-gamma was associated with flu-like symptoms. Grade 3/4 neutropenia was observed in 74% (25 out of 34) of patients. Other side effects, in particular peripheral neuropathies, were within the previously observed ranges for the paclitaxel plus carboplatin combination. Overall response rate (complete or partial response) in patients who received either six or nine doses (0.1 mg) of IFN-gamma/cycle (n = 28) was 71%. IFN-gamma is safe in combination with carboplatin and paclitaxel for first-line treatment of patients with advanced ovarian cancer. This combination should be further evaluated as an immunotherapeutic treatment option for ovarian cancer.

Transdominant DeltaTAp73 isoforms are frequently up-regulated in ovarian cancer. Evidence for their role as epigenetic p53 inhibitors in vivo

Despite strong homology, the roles of TP53 and TP73 in tumorigenesis seem to be fundamentally different. In contrast to TP53, tumor-associated overexpression of TP73 in many different cancers, combined with virtual absence of inactivating mutations and lack of a cancer phenotype in the TP73 null mouse are inconsistent with a suppressor function but instead support an oncogenic function. The discovery of NH(2)-terminally truncated p73 isoforms, collectively called DeltaTAp73, is now the focus of intense interest because they act as potent transdominant inihibitors of wild-type p53 and transactivation-competent TAp73. Therefore, establishing deregulated DeltaTAp73 expression in tumors could be the crucial link to decipher which of the two opposing roles of this bipolar gene is the biologically relevant one. This study is the largest to date and encompasses 100 ovarian carcinomas with complete expression profile of all NH(2)-terminal isoforms, discriminating between TAp73 and DeltaTAp73 (DeltaNp73, DeltaN'p73, Ex2p73, and Ex2/3p73) by isoform-specific real-time reverse transcription-PCR. We find that the set of NH(2)-terminal p73 isoforms distinguishes ovarian cancer patients from healthy controls and thus is a molecular marker for this diagnosis. Ovarian cancers strongly and almost universally overexpress DeltaN'p73 compared with normal tissues (95% of cancers). About one-third of tumors also exhibit concomitant up-regulation of the antagonistic TAp73, whereas only a small subgroup of tumors overexpress DeltaNp73. Thus, deregulation of the E2F1-responsive P1 promoter, rather than the alternate P2 promoter, is mainly responsible for the production of transdominant p53/TAp73 antagonists in ovarian cancer. Tumor stage, grade, presence of metastases, p53 status, and residual disease after resection are significant prognostic markers for overall and recurrence-free survival. A trend is found for better overall survival in patients with low expression of DeltaN'p73/DeltaNp73, compared with patients with high expression. A strong correlation between deregulated DeltaTAp73 and p53 status exists. p53 wild-type cancers exhibit significantly higher deregulation of DeltaN'p73, DeltaNp73, and Ex2/3p73 than p53 mutant cancers. This data strongly supports the hypothesis that overexpression of transdominant p73 isoforms can function as epigenetic inhibitors of p53 in vivo, thereby alleviating selection pressure for p53 mutations in tumors.

[The evaluation of the second-look operation of patients with ovarian carcinoma and tubal carcinoma by means of a retrospective comparison study]

INTRODUCTION

This investigation is a retrospective analysis to evaluate the influence of second-look surgery on the relapse-free and overall survival of patients with ovarian and tubal carcinomas.

METHOD

For 208 patients with and without second-look operation out of 469 of the total collective, a matched analysis and a Cox regression model were established in the framework of a multivariate analysis.

RESULTS

Second-look surgery in patients with ovarian cancer had no significant influence on the relapse-free and overall survival. The 10-year survival was equal in both groups:

CONCLUSION

Second-look surgery cannot be justified on the basis of clinically noninvasive methods such as radiological findings with additional use of tumor markers. It should only be done in control clinical trials to evaluate new means of treatment.

Immunohistochemical determination of HER2 expression in breast cancer from core biopsy specimens: a reliable predictor of HER2 status of the whole tumor

HER2 overexpression in breast cancer is associated with a poor prognosis, resistance to endocrine therapy and chemosensitivity to anthracyclines and paclitaxel. Moreover, trastuzumab (Herceptin) shows therapeutic benefit in patients with HER2 overexpressing tumors. Therefore, knowledge of the pretherapeutical HER2 status allows an optimal selection of patients for treatment. In addition to a definitive histological diagnosis, core biopsies of tumors offer the opportunity to evaluate the HER2 status preoperatively. In 64 patients with invasive breast cancer, sections of core biopsies and of the subsequently removed whole tumor were investigated immuno-histochemically with the DAKO HercepTest. Fifteen tumors (23%) revealed HER2 overexpression, and 44 tumors (69%) were negative in both, the core biopsy and the whole tumor sections. Two core biopsies were negative whereas the corresponding final specimen was 2+ positive. In 3 cases weak overexpression was observed in the core biopsy, but the whole tumor was negative. The overall concordance of the results achieved at core biopsy and whole tumor sections was 92% (kappa = 0.8). A negative HER2 result on core biopsy was never associated with a score 3+ tumor specimen nor was there a case of negative whole tumor specimen with a preceding 3+ score in the biopsy. If one demands the highest degree of overexpression (3+), 100% of our study patients would have been selected correctly using the results on core biopsy alone. We thus conclude, that the immunohistochemical investigation of core biopsies offers the opportunity for a valid preoperative estimation of HER2 overexpression.