Plasminogen activator inhibitor-1 (PAI-1) expression in relation to hypoxia and oncoproteins in clinical cervical tumors

PURPOSE

Explore the role of plasminogen activator inhibitor-1 (PAI-1) in cervical cancer and its relationship to hypoxia and the expression of p53, Ku70/80, and cyclin D1.

MATERIAL AND METHODS

The expression of PAI-1, cyclin D1, and p53, together with tumor oxygenation, were determined in 43 consecutive patients suffering from localized cervical carcinoma. Oncoprotein expression was determined by immunohistochemistry. Tumor oxygenation was measured using a polarographic probe system, "pO2 histography."

RESULTS

PAI expression was considered negative in 32.6% and overexpressed in 18.6% of cases. Cyclin D1 showed a median expression of 5.0 (range 0-70). We observed a positive association between PAI expression and altered p53 (p = 0.049) and cyclin D1 (p = 0.020). An inverse association was detected between PAI and Ku70/80 expression (p = 0.042). Cyclin D1 staining increased according to tumor volume (r = 0.314, p = 0.009). We did not observe a significant association between PAI and hypoxia or other clinicopathological parameters.

CONCLUSION

The present results show that PAI-1 overexpression is associated with nonhomologous end-joining DNA repair down-regulation (low Ku70/80 expression) and with increased p53 and cyclin D1 expression, and they suggest that PAI-1 plays a role in the tumor behavior in cervical carcinoma.

Predictive factors in advanced head and neck cancer treated by radio-chemotherapy and hypoxia modification

6085

Background: Anemia and tumor hypoxia are known factors for resistance to radio-chemotherapy (RT-CT). In a previous report we have suggested that spinal cord stimulation (SCS) can modify tumor oxygenation and regional blood flow in head and neck cancer (HNC). The aim of the present prospective study was to test the predictive value of pO2 measurement in HNC treated by RT-CT and hypoxia modification using SCS. Methods: Twelve male patients with advanced HNC were analyzed. Stage IVb-IVa: 8–4; mean age 58 + 7.6 years (46–70). Scheduled therapy was hyperfractionated RT (120 cGy/fraction, two fractions/day, total dose 81.6 Gy) from a Co- 60 source, and tegafur 800 mg/day. SCS devices were placed before RT-CT under local anesthesia. During treatment, SCS was connected from 20–30 min before to 20–30 min after each radiotherapy session. Before treatment, they were assessed: Hemoglobin levels and tumor oxygenation pre-SCS and pos-SCS (measured by a polarographic probe system ‘pO2 Histograph‘), expressed as median-pO2, and the fraction of pO2 values less than 5 mmHg (HF5) and less than 2.5 mmHg (HF2.5). Correlations were assessed using Pearson and Spearman tests, and actuarial survival using Kaplan-Meier estimates and Log-rank test. Results: Hemoglobin levels were correlated with oxygenation pre-SCS and pos-SCS: median-pO2 (p=0.005 and p=0.011), HF5 (p=0.048 and p=0.005) respectively. Anemia was associated with more advanced stage (IVb vs IVa, p=0.022), higher HF5 pos-SCS (p=0.028) and lower disease-free survival (p=0.019). The HF2.5 pos-SCS was adversely correlated with the 2 years actuarial: disease-free survival (p=0.027), cause-specific survival (p=0.008) and overall survival (p=0.008). HF2.5 was also correlated with hematocrit (p=0.044). Conclusions: Low hemoglobin levels and anemia are associated with more hypoxic and more advanced tumors. Pre-treatment tumor hypoxia (assessed by the fraction of pO2 values less than 2.5 mmHg during-SCS) is a strong predictive factor for survival in advanced HNC. Patients with highly hypoxic tumors should be selected for more aggressive treatments. Partially supported by: Grant ‘FUNCIS: PI 31–98‘. Scientific supervision was carried out by GICOR.

No significant financial relationships to disclose.

Spinal cord stimulation in the treatment of post-stroke patients: current state and future directions

A decrease in cerebral blood flow (CBF) and brain metabolic activity are well-known complications of stroke. Spinal cord stimulation (SCS) is successfully being used for the treatment of several low-perfusion syndromes. The aim of this chapter is to describe the data that support the effect of SCS on CBF and the use of SCS in the treatment of stroke and cerebral low perfusion syndromes. In addition, we present our relevant studies. Since April 1995, we have assessed 49 non-stroke patients. The following parameters were measured pre- and post-stroke: (1) CBF in healthy contralateral tissue by single photon emission computed tomography (SPECT), (2) systolic and diastolic velocity in the middle cerebral artery (MCA) by transcranial Doppler, (3) blood flow quantification in the common carotid artery (CCA) by color Doppler, and (4) glucose metabolism in healthy contralateral tissue by positron emission tomography (PET). Our results showed that during cervical SCS there was a significant (p < 0.001) increase in systolic (> or =21%) and diastolic (>26%) velocity in the MCA, and CCA blood flow (> or =51%) as well as glucose metabolism (44%). We concluded that cervical SCS (cSCS) can modify CBF and brain metabolism. Its potential role in the management of stroke and low-perfusion syndromes is further investigated by experimental studies and reports describing clinical experience. Appropriate clinical trials are warranted.

Cerebral blood flow increase in cancer patients by applying cervical spinal cord stimulation

INTRODUCTION

Generally, high-grade gliomas and head and neck tumors have decreased loco-regional blood flow resulting in reduced delivery of chemotherapy and oxygen, as well as an increases in radiation resistance to radiotherapy. The aim of this study was to analyze the effect of cervical spinal cord electrical stimulation (cSCS) on cerebral blood flow in patients with those tumors.

PATIENTS AND METHODS

We have evaluated 27 cancer patients with 12 with high grade gliomas and 15 with advanced head and neck tumors, who had cSCS devices placed after tumor diagnoses and before the commencement initiating of radio-chemotherapy. They were 12 high grade gliomas and 15 advanced head and neck tumors. Before and after cSCS, cerebral blood flow was assessed bilaterally by transcranial Doppler.

RESULTS

During cSCS there was a significant (p<0.001) increase in systolic (mean > 22%) and diastolic (> 29%) blood-flow velocities in both, healthy and tumor middle cerebral arteries. The analyses by subgroup of tumors showed similarly significant outcomes findings.

CONCLUSIONS

The results suggest that neuro-stimulation spinal cord electrical stimulation can increase cerebral blood flow in cancer patients. The implication is that this technique could be useful in modifying locoregional ischemia in brain tumors thus improving the outcomes of after radio-chemotherapy. Further research is in progress to confirm the advantages of the technique.

The role of spinal cord stimulation in the management of patients with brain tumors

High grade gliomas (HGG) have decreased blood flow resulting in hypoxia, limited access by chemotherapeutic agents, and reduced radiation-sensitivity. Spinal cord stimulation (SCS) has been used successfully in the treatment of pain and ischemic syndromes. The present article summarizes our investigations into the effects of SCS in patients with HGG. Before their scheduled radio-chemotherapy, 23 patients with HGG were assessed pre- and post-SCS using several evaluation techniques: (1) transcranial Doppler (TCD) for middle cerebral artery blood flow; (2) color Doppler for common carotid artery blood flow; (3) single photon emission computed tomography (SPECT) for tumor blood flow; (4) polarographic probe technique for tumor pO2 measurement; (5) positron emission tomography (PET) for tumor glucose metabolism. Pre-SCS, the tumors were more ischemic and more hypoxic than healthy tissues. Post-SCS, there was significant: (1) increase in blood flow measured by TCD (> or =18%), color Doppler (> or =61%) and SPECT (15%), (2) increase in oxygenation and decrease (> or =45%) in percentage of hypoxic values <10 mmHg and <5 mmHg, and (3) increase (43%) in glucose metabolism. Our studies show that SCS can modify loco-regional blood flow and oxygen supply, as well as glucose-metabolism in HGG. This suggests that SCS could prove useful as an adjuvant treatment to radio-chemotherapy. These data merit further confirmatory studies.

Electrical spinal cord stimulation during radiotherapy and temozolomide in high grade gliomas. A phase II report

11510

Background: Ischemia-hypoxia in high grade gliomas (HGG) turns tumor cells more aggressive and more resistant to radiotherapy (RT) and temozolomide (TMZ). Higher glucose metabolism pre-treatment has been correlated with better response to TMZ using 18-FDG-PET. In preliminary works, we have reported that electrical spinal cord stimulation (SCS) can modify loco-regional oxygenation, blood flow and metabolism in HGG. The aim of this study was to evaluate tumor response and toxicity in HGG using SCS during RT plus TMZ. Methods: 10 patients (males/females: 8/2; median age: 51 years (30–68)) were enrolled in this trial. Tumors were 6 glioblastomas and 4 relapsed anaplastic gliomas. Diagnosis was after complete resection (1), subtotal resection (6), biopsy (1) or MRI + PET (2 relapsed HGG). Tetrapolar electrode for SCS was percutaneously inserted on the posterior surface of the cervical spinal cord at C2-C4 level. RT was at 2 Gy/fraction, 5 fractions/week, total dose 60 Gy (40 Gy in previously irradiated tumors). TMZ was administered at 75 mg/m2 daily during RT, followed by at least 6 cycles of adjuvant TMZ at 200 mg/m2. Tumor response was evaluated by CT and PET. Results: After concurrent RT+TMZ, CT showed: 5 partial response (PR), 3 complete response (CR), 2 stable disease (SD). After 6 adjuvant cycles of TMZ, CT (median 10 months after surgery) showed: 4 PR, 3 CR, 3 progression disease (PD). PET showed post-surgical residual tumor in the 9 evaluated patients. After 6 cycles of TMZ, PET showed: 4 CR, 2 PR (they obtained delayed CR after 12 and 18 cycles of TMZ), PD n = 2, and two patients without PET assessment (1 with PR in CT, and 1 without tumor in CT). For the study group median overall survival (OS) was 22 months (95% CI = 14–30) and for glioblastomas 16 months (95% CI = 6–26). For relapsed anaplastic gliomas mean OS was 37 months (95% CI = 22–52). One patient did not finish scheduled adjuvant TMZ and only one patient experienced hematological toxicity with neutropenia G-I and thrombopenia G-III. Conclusions: Electrical SCS during RT+TMZ did not increase toxicity. Preliminary data about tumor response and OS seem to be encouraging and they support further research. Supported by Grants: FUNCIS 03/09 and ISCiii, RTICCC C03/10.

No significant financial relationships to disclose.

Effect of cervical spinal cord stimulation on regional blood flow and oxygenation in advanced head and neck tumours

BACKGROUND

Tumour ischaemia leads to decreased delivery of oxygen, chemotherapy and radiosensitisers. Hypoxia in head and neck (H&N) tumours is an important adverse prognostic factor. Spinal cord stimulation (SCS) is a well-established neurosurgical technique in the treatment of several ischaemic syndromes. This prospective study evaluated the effect of cervical-SCS on common carotid artery (CCA) blood flow and tumour oxygenation in patients with advanced H&N cancer.

PATIENTS AND METHODS

Sixteen patients with advanced H&N tumours were enrolled. Cervical-SCS devices were inserted subcutaneously prior to commencement of scheduled chemoradiotherapy. Pre- and post-SCS measurements were as follows: (i) tumour oxygenation (mmHg) using polarographic probes; (ii) blood flow quantification (ml/min) and diastolic and systolic velocimetry (cm/s) in the CCA using colour Doppler.

RESULTS

After SCS, median tumour oxygenation increased in two-thirds of patients (34%; P = 0.023), all patients had improved CCA blood flow (50%; P <0.001) and almost all patients showed an increased CCA diastolic velocity (26%; P = 0.003) and systolic velocity (20%; P = 0.011).

CONCLUSIONS

Cervical-SCS increased tumour oxygenation and CCA blood flow, and could enhance the loco-regional delivery of oxygen, radiosensitising and chemotherapeutic drugs. Cervical-SCS as adjuvant in chemoradiotherapy of these tumours warrants further investigation.