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author:("krep, J. R.")
1.  Thyroid function alters during neoadjuvant chemotherapy in breast cancer patients: results from the NEOZOTAC trial (BOOG 2010-01) 
This side study investigated the effect of chemotherapy on thyroid function and the extent to which it can predict pathological complete response (pCR) in patients with early breast cancer taking part in NEOZOTAC phase III trial, randomizing between neoadjuvant chemotherapy with or without additional zoledronic acid. Moreover, we examined the impact of thyroid function on toxicity. Serum samples of 38 patients were available for analyses. Free thyroxin (fT4) and thyroid stimulating hormone (TSH) levels were compared between baseline and before the 6th cycle and between subjects with and without pCR. The relation between toxicity and the variation in fT4 and TSH levels during chemotherapy was tested. Samples at baseline and before the 6th cycle were available for 31 and 21 patients, respectively. The mean baseline fT4 level was 16.0 pmol/L and TSH level 1.11 mU/L, and these did not differ between both arms at each time point. During six cycles of chemotherapy, fT4 levels decreased (p = 0.0001), and TSH levels increased significantly (p = 0.019). Interestingly, the decrease of fT4 was significantly greater in patients without nausea, vomiting, or neuropathy, than in patients with those side effects (p = 0.037, p = 0.043, and p = 0.050, respectively). Baseline TSH levels tended to be higher in patients with pCR (p = 0.035 univariate analysis and p = 0.074 multivariate analysis). Chemotherapy blunts thyroid function, which was associated with less side effects. These data urge further evaluation of the effects of thyroid function on toxicity and outcome of breast cancer therapy.
PMCID: PMC4308642  PMID: 25556355
Breast cancer; Thyroid hormones; Chemotherapy; Toxicity; pCR
2.  Quality assessment of estrogen receptor and progesterone receptor testing in breast cancer using a tissue microarray-based approach 
Assessing hormone receptor status is an essential part of the breast cancer diagnosis, as this biomarker greatly predicts response to hormonal treatment strategies. As such, hormone receptor testing laboratories are strongly encouraged to participate in external quality control schemes to achieve optimization of their immunohistochemical assays. Nine Dutch pathology departments provided tissue blocks containing invasive breast cancers which were all previously tested for estrogen receptor and/or progesterone receptor expression during routine practice. From these tissue blocks, tissue microarrays were constructed and tested for hormone receptor expression. When a discordant result was found between the local and TMA result, the original testing slide was revised and staining was repeated on a whole-tissue block. Sensitivity and specificity of individual laboratories for testing estrogen receptor expression were high, with an overall sensitivity of 99.7 and 95.4 %, respectively. Overall sensitivity and specificity of progesterone receptor testing were 94.8 and 92.6 %, respectively. Out of 96 discordant cases, 36 cases would have been concordant if the recommended cut-off value of 1 % instead of 10 % was followed. Overall sensitivity and specificity of estrogen and progesterone receptor testing were high among participating laboratories. Continued enrollment of laboratories into quality control schemes is essential for achieving and maintaining the highest standard of care for breast cancer patients.
Electronic supplementary material
The online version of this article (doi:10.1007/s10549-015-3444-x) contains supplementary material, which is available to authorized users.
PMCID: PMC4491103  PMID: 26041687
Estrogen receptor; Progesterone receptor; Quality control; Tissue microarray; Breast cancer
3.  First-line chemotherapy for malignant peripheral nerve sheath tumor (MPNST) versus other histological soft tissue sarcoma subtypes and as a prognostic factor for MPNST: an EORTC Soft Tissue and Bone Sarcoma Group study 
Annals of Oncology  2010;22(1):207-214.
Background: The role of chemotherapy in advanced malignant peripheral nerve sheath tumor (MPNST) is unclear.
Patients and methods: Chemotherapy-naive soft tissue sarcomas (STS) patients treated on 12 pooled nonrandomized and randomized European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group trials were retrospectively analyzed. Clinical outcomes, overall survival, progression-free survival (PFS) and response were determined for MPNST and other STS histotypes and compared. Additionally, prognostic factors within the MPNST population were defined. Studied cofactors were demographics, sarcoma history, disease extent and chemotherapy regimen.
Results: After a median follow-up of 4.1 years, 175 MPNST out of 2675 eligible STS patients were analyzed. Outcome was similar for MPNST versus other STS histotypes, with a response rate, median PFS and overall survival of 21% versus 22%, 17 versus 16 weeks and 48 versus 51 weeks, respectively. Performance status was an independent prognostic factor for overall survival. Chemotherapy regimen was an independent prognostic factor for response (P < 0.0001) and PFS (P = 0.009). Compared with standard first-line doxorubicin, the doxorubicin–ifosfamide regimen had the best response, whereas ifosfamide had the worst prognosis.
Conclusion: This series indicates the role of chemotherapy in treatment of advanced MPNST. This first comparison showed similar outcomes for MPNST and other STS histotypes. The apparent superiority of the doxorubicin–ifosfamide regimen justifies further investigations of this combination in randomized trials.
PMCID: PMC3003614  PMID: 20656792
adriamycin; chemotherapy; ifosfamide; malignant peripheral nerve sheath tumor; soft tissue sarcoma
4.  Sequence dependent effect of paclitaxel on gemcitabine metabolism in relation to cell cycle and cytotoxicity in non-small-cell lung cancer cell lines 
British Journal of Cancer  2000;83(8):1069-1076.
Gemcitabine and paclitaxel are active agents in the treatment of non-small-cell lung cancer (NSCLC). To optimize treatment drug combinations, simultaneously and 4 and 24 h intervals, were studied using DNA flow cytometry and multiple drug effect analysis in the NSCLC cell lines H460, H322 and Lewis Lung. All combinations resulted in comparable cytotoxicity, varying from additivity to antagonism (combination index: 1.0–2.6). Gemcitabine caused a S (48%) and G1 (64%) arrest at IC-50 and 10 × IC-50 concentrations, respectively. Paclitaxel induced G2/M arrest (70%) which was maximal within 24 h at 10 × IC-50. Simultaneous treatment increased S-phase arrest, while at the 24 h interval after 72 h the first drug seemed to dominate the effect. Apoptosis was more pronounced when paclitaxel preceded gemcitabine (20% for both intervals) as compared to the reverse sequence (8%, P = 0.173 for the 4 h and 12%, P = 0.051 for the 24 h time interval). In H460 cells, paclitaxel increased 2-fold the accumulation of dFdCTP, the active metabolite of gemcitabine, in contrast to H322 cells. Paclitaxel did not affect deoxycytidine kinase levels, but ribonucleotide levels increased possibly explaining the increase in dFdCTP. Paclitaxel did not affect gemcitabine incorporation into DNA, but seemed to increase incorporation into RNA. Gemcitabine almost completely inhibited DNA synthesis in both cell lines (70–89%), while paclitaxel had a minor effect and did not increase that of gemcitabine. In conclusion, various gemcitabine–paclitaxel combinations did not show sequence dependent cytotoxic effects; all combinations were not more than additive. However, since paclitaxel increased dFdCTP accumulation, gemcitabine incorporation into RNA and the apoptotic index, the administration of paclitaxel prior to gemcitabine might be favourable as compared to reversed sequences. © 2000 Cancer Research Campaign
PMCID: PMC2363564  PMID: 10993656
gemcitabine; paclitaxel; NSCLC cell lines; cell cycle; cytotoxicity; dFdCTP

Results 1-4 (4)