Treatment outcome in advanced squamous cell carcinoma of the uterine cervix: relationships to pretreatment tumor oxygenation and vascularization.

Poor outcome of treatment was found to be associated with low oxygen tension in the primary tumor and not with high intratumor microvessel density in 40 patients with advanced squamous cell carcinoma of the uterine cervix. Multivariate Cox regression analysis identified the total volume of the hypoxic tumor regions, i. e. the tumor subvolume having pO(2) values below 5 mmHg, as a significant prognostic factor for locoregional control, disease-free survival, and overall survival. Other important prognostic factors, identified by univariate Cox regression analysis, were tumor volume, the fraction of pO(2) readings giving pO(2) values below 5 mmHg, and tumor stage.     

A pilot study comparing intratumoral oxygenation using the comet assay following 2.5% and 5% carbogen and 100% oxygen

PURPOSE: Tumor hypoxia has been purported to be an important biologic factor in the failure of radical radiotherapy to achieve local control in many tumor types. This study was designed to evaluate the effect of breathing high oxygen content gas mixtures (oxygen with 0%, 2.5%, or 5% carbon dioxide) on tumor oxygenation measured using the Eppendorf polarographic oxygen electrode and the comet assay in accessible, hypoxic human tumors. METHODS AND MATERIALS: Using Eppendorf pO2 histography to identify hypoxic tumors (median pO2 < or = 10 mmHg), eligible patients were systematically allocated either 100% oxygen (O2) or oxygen with 2.5% or 5% carbon dioxide (CO2). Tumors were treated with 6-10 Gy during which two fine needle aspirates (FNA) were obtained from different regions of the lesion, one at midway and the other at completion of the radiation exposure. Gas breathing was initiated 4 min before radiation was commenced. A 10-min interval was specified between the first and second halves of the radiation exposure to allow near maximal DNA repair prior to the second half of the radiation treatment. FNAs were performed within 2 min of cessation of radiation and the cells immediately suspended in buffered saline at 4 degrees C for analyses of hypoxic fraction using the comet assay. RESULTS: Fifteen evaluations were performed in 13 patients with hypoxic tumors (median O2 tension 2.75 mmHg) treated with a median dose of 8 Gy. The median hypoxic fraction determined using the comet assay fell from 0.36 to 0.13 (p = 0.001, Wilcoxon signed rank test) due to the addition of high oxygen content gases. CONCLUSIONS: In tumors defined as hypoxic using Eppendorf pO2 histography, a statistically significant reduction in the hypoxic fraction with the comet assay was found following administration of high oxygen content gases. These preliminary findings reveal a trend suggesting that 5% carbogen may reduce the hypoxic fraction by a greater margin than either 100% oxygen or 2.5% carbogen.     

Ultrasound guided pO2 measurement of breast cancer reoxygenation after neoadjuvant chemotherapy and hyperthermia treatment.

The objective of this study was to determine whether neoadjuvant chemotherapy in combination with hyperthermia (HT) would improve oxygenation in locally advanced breast tumours. The study describes a new optimized ultrasound guided technique of pO2 measurement using Eppendorf polarographic oxygen probes in 18 stage IIB-III breast cancer patients. Prior to treatment, tumour hypoxia (median pO2<10 mmHg) was present in 11/18 patients (average median pO2=3.2 mmHg). Seven patients had well oxygenated tumours (median pO2 of 48.3 mmHg). Eight patients with hypoxic tumours prior to treatment had a significant improvement (p=0.0008) in tumour pO2 after treatment (pO2 increased to 19.2 mmHg). In three patients, tumours remained hypoxic (average median pO2=4.5 mmHg). The advantages of the ultrasound guided pO2 probe are in the accuracy of the Eppendorf electrode placement in tumour tissue, the ability to monitor electrode movement through the tumour tissue during the measurement and the ability to avoid electrode placement near or in large blood vessels by using colour Doppler imaging. The results of this preliminary study suggest that the combination of neoadjuvant chemotherapy and hyperthermia improves oxygenation in locally advanced breast tumours that are initially hypoxic.     

Ultrasound guided pO 2 measurement of breast cancer reoxygenation after neoadjuvant chemotherapy and hyperthermia treatment

The objective of this study was to determine whether neoadjuvant chemotherapy in combination with hyperthermia (HT) would improve oxygenation in locally advanced breast tumours. The study describes a new optimized ultrasound guided technique of pO 2 measurement using Eppendorf polarographic oxygen probes in 18 stage IIB-III breast cancer patients. Prior to treatment, tumour hypoxia (median pO 2 < 10 mmHg) was present in 11/18 patients (average median pO 2 = 3.2 mmHg). Seven patients had well oxygenated tumours (median pO 2 of 48.3 mmHg). Eight patients with hypoxic tumours prior to treatment had a significant improvement ( p = 0.0008) in tumour pO 2 after treatment (pO 2 increased to 19.2 mmHg). In three patients, tumours remained hypoxic (average median pO 2 = 4.5 mmHg). The advantages of the ultrasound guided pO 2 probe are in the accuracy of the Eppendorf electrode placement in tumour tissue, the ability to monitor electrode movement through the tumour tissue during the measurement and the ability to avoid electrode placement near or in large blood vessels by using colour Doppler imaging. The results of this preliminary study suggest that the combination of neoadjuvant chemotherapy and hyperthermia improves oxygenation in locally advanced breast tumours that are initially hypoxic.     

Comparison between the comet assay and the oxygen microelectrode for measurement of tumor hypoxia.

BACKGROUND AND PURPOSE: Hypoxic cells are present in some solid tumours and are known to limit radiocurability. To compare two measures of tumour hypoxia, 25 patients with locally advanced disease and accessible tumours or metastatic nodes were examined using an oxygen microelectrode and the alkaline comet assay. MEASUREMENTS AND METHODS: For the comet assay, fine needle aspirate biopsies were taken immediately following a dose of 5-10 Gy. Single cells were examined for radiation-induced DNA strand breaks, and the percentage of radio-resistant hypoxic cells within the population was calculated from DNA damage histograms. For oxygen tension (pO2) measurements, multiple tracks were made using an Eppendorf oxygen microelectrode. The possibility that application of the first method might influence hypoxic fraction measurement by the second method was examined in a more controlled system by creating four tracks in murine SCC-VII tumours using an oxygen electrode, and measuring hypoxic fraction at subsequent times. RESULTS: For 28 tumours from 25 patients, hypoxic fraction measured by comet assay correlated with the percentage of PO2 values < 5 mmHg (r2 = 0.46, P < 0.001). The mean comet hypoxic fraction was 0.36 for five tumours with a median PO2 < 10 mmHg. For the remaining 23 tumours with a median PO2 > 10 mmHg, the mean hypoxic fraction was 0.09. Advancement of an oxygen electrode through SCCVII tumours had no significant effect on hypoxic fraction measured 5 min to 24 h later using the alkaline comet assay. CONCLUSIONS: Tumours defined as hypoxic based on a median pO2 < 10 mmHg appear to contain more than 20% radio-biologically hypoxic cells as estimated by the comet assay. In an animal tumour model, puncture of the tumour with an oxygen electrode did not influence hypoxic fraction measured using the comet assay, in agreement with the clinical data that the order in which the two methods were performed was not important.     

Disease control of uterine cervical cancer: relationships to tumor oxygen tension, vascular density, cell density, and frequency of mitosis and apoptosis measured before treatment and during radiotherapy.

Identification of biological parameters of major importance for the control of malignant diseases can be useful for the design of optimal treatment regimes for individual patients. Tumor oxygen tension (pO2), vascular density, cell density, and frequency of mitosis and apoptosis were measured before treatment (40 patients) and after 2 weeks of radiotherapy (22 patients) in patients with uterine cervical cancer. The aim was to investigate whether one of the parameters was more important for disease control than the others. Three sets of data were considered; the pretreatment parameters, the parameters measured after 2 weeks of radiation, and the changes in the parameters during this time. The pO2 was measured polarographically; the other parameters were determined by histological analyses of tumor biopsies. Hypoxic subvolume (HSV5), ie., the fraction of pO2 readings <5 mm Hg multiplied with tumor volume, showed the strongest correlation to control. Patients with a small HSVs before treatment had a higher control probability after a median follow-up time of 50 months than patients with a large HSV5 (P < 0.001). All other parameters or changes in parameters showed impaired correlation to control compared with pretreatment HSV5. The present results suggest that pretreatment oxygenation is more important for disease control of cervical cancer than the oxygenation after 2 weeks of radiotherapy or the changes in oxygenation during this time. Moreover, vascular density, cell density, and frequency of mitosis and apoptosis before treatment or after 2 weeks of therapy are probably not as important as pretreatment oxygenation as well. Although significant correlations between disease control and some of the parameters other than pretreatment oxygenation can occur in studies based on a large number of patients, the specificity of these parameters in the prediction of control is probably not as high as for oxygenation.     

Optimizing the use of combined radioimmunotherapy and hypoxic cytotoxin therapy as a function of tumor hypoxia.

Combined radioimmunotherapy (RAIT) and hypoxic cytotoxin therapy (SR4233 or NLCQ-1) have been evaluated with both modalities administered on the same day with only moderate improvement compared with the effects of RAIT alone. In a series of studies using oxygen electrodes, immunohistochemistry and radiotracers, we have demonstrated that RAIT induces a prolonged state of hypoxia in most tumors, without affecting the pO(2) levels in normal tissues. Using serial microelectrode measurements through subcutaneous (s.c.) GW-39 human colonic xenografts, we established that the median pO(2) was unrelated to the initial size of the tumor, over a range of sizes from 1.0 to 4.0 cm. Fourteen days after mice were given a 240-microCi dose of (131)I-MN-14 anti-carcinoembryonic antigen immunoglobulin G, their median pO(2) declined from 26.1 +/- 9.6 mmHg to 9.8 +/- 3.9 mmHg (p < 0.001). Using the radiotracer (3)H-MISO that accumulates in hypoxic regions, uptake in GW-39, LoVo and LS174T s.c. human colonic tumors increased 3.0- to 4.2-fold from day 14 through day 28 post-RAIT, but uptake of (3)H-MISO in CALU-3 tumors remained unchanged after RAIT. Normal tissue (liver, kidney, lung) uptake of (3)H-MISO did not exhibit significant changes. The increase in tumor hypoxia was also demonstrated visually using anti-PIMO staining of tumor sections. We postulated that sequential delivery of the 2 therapeutic agents, with the hypoxic cytotoxin given 2 weeks after RAIT when tumor pO(2) levels were at their nadir, would improve the therapeutic response above either modality alone or above the 2 agents delivered on the same day. Tumor growth was compared in mice given either RAIT or cytotoxin alone, the combined treatment on the same day or with the cytotoxin delivered 14 days after RAIT. Tumor size on day 35 for RAIT-treated and SR4233-treated GW-39 were 3.56 +/- 0.40 and 7.98 +/- 2.50 cm(3). When RAIT + SR4233 were delivered on the same day, tumor size dropped to 2.78 +/- 0.80 cm(3). If RAIT was given on day 0 and SR4233 on day 14, size further declined further to 1.74 +/- 0.32 cm(3) (p < 0.05 compared with same day delivery). For LS174T, tumor size on day 28 for RAIT-treated and SR4233-treated tumors were 1.14 +/- 0.36 cm(3) and 3.65 +/- 0.78 cm(3), respectively. When RAIT + SR4233 were delivered on the same day, size was 0.51 +/- 0.174 cm(3). If RAIT was dosed on day 0 and SR4233 was given on day 14, tumor size was 0.13 +/- 0.07 cm(3) (p < 0.05). Similar results were obtained for LoVo, but not for CALU-3 tumors. Another hypoxic cytotoxin, NLCQ-1, was also more efficacious 2 weeks after RAIT, compared with same-day dosing. Thus, information on tumor hypoxia after radioantibody therapy could be important for ascertaining a window of opportunity when the surviving tumor regions are most responsive to hypoxic cytotoxins.     

Interrelationship of proliferation and hypoxia in carcinoma of the cervix

PURPOSE: In human cervix cancer treated with radiotherapy, we have previously shown from separate groups of patients that tumor hypoxia and proliferation rate as measured by bromodeoxyuridine (BrdU) labeling index (LI) are important determinants of clinical outcome. We now examine the relationship of these two pre-treatment predictive assays in 43 patients studied prospectively from 1994-98 where both tests were performed for each patient. MATERIAL AND METHODS: Newly diagnosed patients with carcinoma of the cervix were examined under anesthesia for staging purposes. Patients were given BrdU (200 mg) by intravenous route prior to the procedure. Tumor oxygenation was measured with the Eppendorf pO2 histograph. Biopsy of tumor was then performed and the BrdU LI was obtained by flow cytometry. The degree of tumor hypoxia for each tumor was expressed as median pO2 values, and as the percentage of pO2 readings <5 mm Hg (HP5). RESULTS: The median age was 53 years (range 23-79 years). There were 32 squamous, and 11 non-squamous carcinomas. FIGO stages were: IB and IIA, 8; IIB, 17; IIIB, 18; with a median tumor size of 6 cm (range 2-10 cm). The patients received uniform treatment with radical radiation therapy. There were 22 diploid and 21 aneuploid tumors. The median LI, pO2, and HP5 were 8.0%, 5.4 mm Hg, and 46.8%, respectively. Tests for linear associations showed no significant correlation between median pO2 vs. LI (r = 0.078, p = 0.62), and HP5 vs. LI (r = -0.14, p = 0.38). CONCLUSIONS: The clinical outcome in this group of patients is immature, but these results suggest that tumor hypoxia and proliferation measurements are independent and potentially complementary predictive assays in cervix carcinoma. Further investigations are required to examine the distribution of proliferating tumor cells and its relationship with hypoxic tumor cells in tissue sections with the use of immunohistological techniques and image analysis systems.     

Radiobiological hypoxia, oxygen tension, interstitial fluid pressure and relative viable tumour area in two human squamous cell carcinomas in nude mice during fractionated radiotherapy

Very little is known about the correlation between the radiobiological hypoxic fraction (rHF) and other measures of tumour oxygenation during fractionated irradiation. In the present study the rHF is determined in untreated human FaDu and GL squamous cell carcinoma in nude mice and in tumours irradiated with 10 fractions in 2 weeks and 20 fractions in 4 weeks, using tumour control as the experimental endpoint. The results were compared with measurements of the pO2, the interstitial fluid pressure (IFP) and the relative viable tumour area. In FaDu tumours the radiobiological hypoxic fractions (rHFs) before and during irradiation were not statistically different from 100%. Depending on the assumptions made for D0, the rHFs of GL tumours were between 0.2 and 4% or 30 and 53%. The median pO2 values were 2.8 mmHg for untreated FaDu tumours and 0.2 mmHg for GL tumours (p < 0.001). The median IFP values were 2.6 mmHg in FaDu and 5.3 mmHg in GL tumours (p = 0.01). No important changes in the pO2 and IFP values were observed during fractionated irradiation. The relative viable tumour area during irradiation decreased by 83% in FaDu tumours (p = 0.002) and by 54% in GL tumours (p = 0.003). It is concluded that differences in rHF exist between FaDu and GL tumours before and during fractionated irradiation and that these differences are not reflected by pO2 and IFP values and the relative viable tumour area.     

Hypoxia-induced treatment failure in advanced squamous cell carcinoma of the uterine cervix is primarily due to hypoxia-induced radiation resistance rather than hypoxia-induced metastasis

Poor outcome of treatment in advanced cervix carcinoma has been shown to be associated with poor oxygenation of the primary tumour. Hypoxia may cause radiation resistance and promote lymph-node metastasis. The purpose of the study reported here was to investigate whether hypoxia-induced treatment failure in advanced cervix carcinoma is primarily a result of hypoxia-induced radiation resistance or the presence of hypoxia-induced lymph-node metastases at the start of treatment. Thirty-two patients with squamous cell carcinoma of the uterine cervix were included in the study. Radiation therapy was given with curative intent as combined external irradiation and endocavitary brachytherapy. The oxygenation status of the primary tumour was measured prior to treatment using the Eppendorf PO2 Histograph. Pelvic and para-aortal lymph-node metastases were detected by magnetic resonance imaging at the time of initial diagnosis. The primary tumours of the patients with metastases (n = 18) were significantly more poorly oxygenated than those of the patients without metastases (n = 14). Multivariate Cox regression analyses involving biological and clinical parameters identified the tumour subvolume having PO2 values below 5 mmHg (HSV (pO2 < 5 mmHg) as the only significant, independent prognostic factor for locoregional control, disease-free survival and overall survival. The probabilities of locoregional control, disease-free survival and overall survival were significantly lower for the patients with HSV (PO2 < 5 mmHg) above the median value than for those with HSV (PO2 < 5 mmHg) below the median value. On the other hand, the outcome of treatment was not significantly different for the patients with metastases and the patients without metastases at the start of treatment, irrespective of clinical end-point. Consequently, treatment failure was primarily a result of hypoxia-induced radiation resistance rather than hypoxia-induced lymph-node metastasis, suggesting that novel treatment strategies aiming at improving tumour oxygenation or enhancing the radiation sensitivity of hypoxic tumour cells may prove beneficial in attempts to improve the radiation therapy of advanced cervix carcinoma.     

Severe anemia is associated with poor tumor oxygenation in head and neck squamous cell carcinomas

PURPOSE: To investigate the relationship between tumor oxygenation and the blood hemoglobin (Hb) concentration in patients with squamous cell carcinoma of the head and neck (SCCHN). METHODS AND MATERIALS: A total of 133 patients with SCCHN underwent pretreatment polarographic pO2 measurements of their tumors. In 66 patients measurements were also made in sternocleidomastoid muscles. The patients were divided into three groups according to their Hb concentration-severe anemia (Hb < 11.0 g/dl), mild anemia (female: Hb 11.0-11.9 g/dl; male: Hb 11.0-12.9 g/dl), and normal Hb concentration (female: Hb > or =12.0 g/dl; male: > or =13.0 g/dl). RESULTS: No significant difference in tumor oxygenation could be detected between mildly anemic patients and patients with a normal Hb level. However, the tumor oxygenation in the severely anemic group was significantly below that of each of the other two groups (p < 0.0001). There was no significant difference between the Hb groups in oxygenation of sternocleidomastoid muscles. In a multivariate analysis including Hb group, tumor volume, smoking habits, gender, T-stage, N-stage, and histologic grade a Hb level < 11 g/dl was found to be the strongest predictor for a poor tumor oxygenation. Smoking also had a marginal influence on median pO2. CONCLUSION: Our data suggest that a low Hb concentration and cigarette smoking contribute to inadequate oxygenation of SCCHN and thus for increased radioresistance. Consequently, Hb correction and abstinence from smoking may significantly improve tumor oxygenation.     

Long-term performance of interstial fluid pressure and hypoxia as prognostic factors in cervix cancer.

OBJECTIVES: Hypoxia and high interstitial fluid pressure (IFP) have been shown to independently predict for nodal and distant metastases, as well as survival, in patients with cervix cancer. Using data from our prospective trial, we updated a cohort of patients treated with definitive radiation alone without chemotherapy, to assess the long-term prognostic impact of these microenvironmental features. METHODS: Between April 1994 and January 1999, 107 eligible patients with cervix cancer were entered into a prospective study of tumor oxygenation and IFP prior to primary radiation therapy. Oxygenation data are presented as the hypoxic proportion, defined as the percentage of pO(2) readings <5 mm Hg (abbreviated as HP(5)). Patients with HP(5) values >50% were considered to have hypoxic tumors. IFP is presented in mmHg, divided into high and low IFP groups by the median value. Patients ranged in age from 23 to 78 years with a mean of 53 years. The maximum tumor size ranged from 2 to 10 cm, with a median diameter of 5 cm. FIGO stage was IB in 28 patients, IIA in 4, IIB in 42 and IIIB in 33 patients. Twenty-two patients (21%) had evidence of pelvic lymph node involvement on staging CT abdomen/pelvis or MR pelvis. HP(5) ranged from 0% to 99% with a median of 48%. IFP ranged from -3 to 48 mm Hg (median 19 mm Hg). Median follow-up was 6.7 years (range 0.9-10.6). RESULTS: Disease-free survival (DFS) at 5 years was 50%. Five year DFS was 42% for patients with hypoxic tumors (HP(5)>50%), and 58% in patients with oxygenated tumors (HR 1.01 per %, p=0.05). DFS at 5 years was 42% for patients with interstitial hypertension (IFP >19 mm Hg), and 63% in patients with IFP 相似文献   

Invasive oxygen measurements and pimonidazole labeling in human cervix carcinoma

PURPOSE: This study was designed to compare tumor hypoxia assessed by invasive O2 sensitive electrodes and pimonidazole labeling in primary human cervix carcinomas. METHODS AND MATERIALS: Twenty-eight patients with primary cervix carcinomas (FIGO Stage Ib-IVa) were investigated. Both invasive pO2 measurements and pimonidazole labeling were obtained in all patients. Before treatment, patients were given pimonidazole as a single injection (0.5 g/m2 i.v.). Ten to 24 h later, oxygenation measurements were done by Eppendorf histography, and after this procedure biopsies were taken for pimonidazole-binding analysis. Tumor oxygen partial pressure (pO2) was evaluated as the median tumor pO2 and the fraction of pO2 values < or = 10 mmHg (HF10). Biopsies were formalin fixed and paraffin embedded, and hypoxia was detected by immunohistochemistry using monoclonal antibodies directed against reductively activated pimonidazole. Pimonidazole binding was evaluated by a semiquantitative scoring system. RESULTS: Both Eppendorf measurements and pimonidazole binding showed large intra-and intertumor variability. A comparison between pimonidazole binding expressed as the fraction of fields at the highest score and HF10 showed a trend for the most well-oxygenated tumors having a low fraction of fields; however, the correlation did not reach statistical significance (p = 0.43, r = 0.165; Spearman's rank correlation test). CONCLUSION: Hypoxia measured in human uterine cervix carcinomas is heterogeneously expressed both within and between tumors when assessed by either invasive pO2 measurements or pimonidazole binding. Despite a trend that tumors with high pO2 values expressed less pimonidazole binding, no correlation was seen between the two assays in this preliminary report.     

Changes in oxygenation during radiotherapy in carcinoma of the cervix.

PURPOSE: The aim of this study was to investigate changes in tumor oxygenation, assessed by polarographic needle electrode measurements, following fractionated external beam radiotherapy in carcinoma of the cervix. METHODS AND MATERIALS: Normal and tumor tissue oxygenation was measured in 19 patients prior to radiotherapy and after 40-45 Gy of external beam radiotherapy delivered in 20 fractions over 4 weeks. All measurements were performed during anesthesia. RESULTS: There was no significant difference in the level of normal tissue oxygenation pre- and post radiotherapy. The individual patient median tumor pO2 values ranged from 0 to 31 mmHg pre-radiotherapy and 1 to 61 mmHg post-radiotherapy. The mean of the 19 median pO2 values increased from 8 (SD +/- 10) mmHg to 20 (+/- 20) mmHg following external beam radiotherapy. The increase was significant by paired Wilcoxon test (p = 0.011). There was also a significant fall in the proportion of values < 5 mmHg (p = 0.040). Although this value remained constant, or fell, in the majority of patients (15/19), it increased in 4 tumors. Tumor size pre- and postradiotherapy did not correlate with the level of pretreatment oxygenation; neither did the change in tumor size and change in level of oxygenation. CONCLUSION: The level of tumor oxygenation increased in the majority of patients (15/19) following 40-45 Gy of radiotherapy in carcinoma of the cervix.     

Oxygenation of head and neck cancer: changes during radiotherapy and impact on treatment outcome.

BACKGROUND AND PURPOSE: To evaluate the long term clinical significance of tumor oxygenation in a population of head and neck cancer patients receiving radiotherapy and to assess changes in tumor oxygenation during the course of treatment. METHODS AND MATERIALS: Patients with head and neck cancer receiving primary RT underwent pretreatment polarographic tumor oxygen measurement of the primary site or a metastatic neck lymph node. Treatment consisted of once daily (2 Gy/fraction to a total dose of 66-70 Gy) or twice daily irradiation (1.25 Gy/fraction to 70-75 Gy) to the primary site. Twenty-seven patients underwent a second series of measurements early in the course of irradiation. RESULTS: Sixty-three patients underwent pretreatment tumor oxygen assessment (primary site, n = 24; nodes, n = 39). The median pO2 for primary lesions was 4.8 mmHg, and it was 4.3 mmHg for cervical nodes. There was a weak association between anemia and more poorly oxygened tumors, but many non-anemic patients still had poorly oxygenated tumors. Repeat assessments of tumor oxygenation after 10-15 Gy were unchanged compared to pretreatment baselines. Poorly oxygenated nodes pretreatment were more likely to contain viable residual disease at post-radiation neck dissection. Median follow-up time for surviving patients was 20 months (range 3-50 months). Hypoxia (tumor median pO2 <10 mmHg) adversely affected 2 year local-regional control (30 vs. 73%, P = 0.01), disease-free survival (26 vs. 73%, P = 0.005), and survival (35 vs. 83%, P = 0.02). CONCLUSION: Tumor oxygenation affects the prognosis of head and neck cancer independently of other known prognostic variables. This parameter may be a useful tool for the selection of patients for investigational treatment strategies.     

Tumor oxygenation correlates with molecular growth determinants in breast cancer

Hypoxic tumor cells may represent a fraction of cells that are not susceptible to radiation or chemotherapy. Intratumoral oxygen partial pressure (pO₂) is the result of oxygen delivery and consumption. Cell proliferation is one factor to effect oxygen consumption and we therefore studied the correlation between tumor pO₂ and histological parameters. Patients and methods: In 36 women and one man (age range 29–80 years) with suspected breast cancer. Before tumor resection, intralesional pO₂ was determined with a polarographic needle electrode. Under ultrasound control, 200 tumor measurements were obtained; Hb levels, Hk, arterial blood gas parameters, and tissue temperature were determined. The median of pO₂ values and the percentage of hypoxic areas (pO₂ < 10 mmHg) were calculated and correlated with the histological type, grading, ER, PR, and the expression of Ki-67, p53, EGFR, pS2, and c-erb-B2. Results: The overall median pO₂ was 44 mmHg, and 1024 measurements (13.8%) represented hypoxic areas. Ductal and lobular invasive cancers showed median pO₂ of 41 mmHg. The mean pO₂ of G1 tumors was 59 mmHg and the hypoxic fraction 8%, in contrast to G2 tumors with 43 mmHg and 17%, and G3 tumors with 36 mmHg and 20.4% (p < 0.01). We observed a correlation with tumor size and an increased rate of hypoxic areas in T3–4 lesions (p < 0.02). Also tumors with negative nodes or positive ER had significantly higher pO₂ values, as did tumors with an overexpression of c-erb-B2, p53, and cathepsin D. Conclusion: Oxygenation of human breast cancers can safely be measured in patients prior to surgical therapy. pO₂ values correlate both with prognostic markers examined histologically and with molecular growth factors. As the efficacy of preoperative or adjuvant treatment in individuals may depend on oxygen partial pressure, efforts to manipulate tumor pO₂ for therapeutic purpose could be promising.     

Oxygenation of cervical cancers during radiotherapy and radiotherapy + cis-retinoic acid/interferon

PURPOSE: We have evaluated the tumor tissue pO2 in cervical cancers during radiotherapy with special emphasis on the course of the pO2 in primarily hypoxic tumors and in patients treated with radiotherapy plus 13-cis-retinoic acid/interferon-alpha-2a. METHODS AND MATERIALS: From June 1995 through April 1997, 49 patients with squamous cell carcinoma FIGO IIB-IVA of the cervix who were treated with definitive radiotherapy with curative intent underwent polarographic measurement of tumor tissue pO2 with an Eppendorf pO2-histograph prior to and during radiation treatment. Radiotherapy consisted of external irradiation with 50.4 Gy in 28 fractions of 1.8 Gy plus high dose rate (HDR) brachytherapy. Twenty-two patients had additional treatment with 13-cis-retinoic acid (cRA, isotretinoin) and interferon-alpha-2a (IFN-alpha-2a). Therapy with cRA/IFN in these patients started 2 weeks before radiotherapy; during this induction period, cRA was administered in a dosage of 1 mg per kilogram body weight orally daily and IFN-alpha-2a in a dosage of 6x10(6) I.U. subcutaneously daily. After start of external radiotherapy (XRT), cRA/IFN was continued concomitantly with radiotherapy in reduced doses (0.5 mg cRA per kg body weight orally daily plus 3x10(6) I.U. IFN-alpha-2a subcutaneously three times weekly until the end of the radiation treatment). PO2 measurements were performed prior to radiotherapy, at 20 Gy, and at the end of radiotherapy. RESULTS: A poor oxygenation defined as a median pO2 of 10 mm Hg or less was present in 15/38 tumors (39%) in which measurements prior to any treatment were done. Low pO2 readings below 5 mm Hg were present in 70% of all tumors prior to treatment. In 13 of 15 hypoxic tumors, pO2 measurements at 19.8 Gy were performed. In these tumors, a significant increase of the median pO2 from 6.0+/-3.1 mm Hg to 20.7+/-21.2 mm Hg was found, p<0.01. The increase in the median pO2 was more pronounced in patients with radiotherapy plus additional cRA/IFN treatment as compared to patients treated with irradiation alone (median pO2 raised from 7.0+/-3.5 mm Hg to 40.9+/-21.3 mm Hg versus 5.7+/-3.1 mm Hg to 14.7+/-17.9 mm Hg). In a multivariate analysis, both the effect of radiation dose (pretreatment versus 19.8 Gy) and the type of treatment (XRT alone versus XRT plus cRA/IFN) had significant impact on the pO2 (P = 0.003 and p = 0.04). In patients with well-oxygenated tumors (pretreatment median pO2>10 mm Hg), 20/23 (87%) achieved a clinically complete response. In patients with primarily hypoxic tumors, 6/6 patients whose primarily hypoxic tumors showed an increase of the median pO2 above 10 mm Hg at 19.8 Gy achieved a complete remission (CR). In contrast, only 4/7 patients with a low pretreatment and persisting low median pO2 achieved a CR. CONCLUSIONS: There are evident changes in the oxygenation of cervical cancers during a course of fractionated radiotherapy. In primarily hypoxic tumors, a significant increase of the median pO2 was found. An additional treatment with cis-retinoic acid/interferon further improved the oxygenation. An impact of the different patterns of oxygenation on local control is to be evaluated.     

Tumor oxygenation after radiotherapy, chemotherapy, and/or hyperthermia predicts tumor free survival

PURPOSE: To investigate the influence of different treatment modalities (radiotherapy, chemotherapy, and hyperthermia) on the oxygenation of human tumor xenografts and to correlate it with the tumoricidal effect we conducted this study. METHODS AND MATERIALS: Human-derived head-and-neck squamous cell carcinoma xenografts (implanted in nude mice/nine groups of 10 mice) were treated with various treatment modalities and combinations of them (radiation with 5 x 2 or 10 x 2 Gy, hyperthermia at 41 degrees C or 41.8 degrees C, chemotherapy with ifosfamide [32 mg/kg] or cisplatin [2 mg/kg]). The tumor volume was evaluated 3 times per week until Day 60. Tumor pO(2) was measured at Day 1, 5, 8, and 12 with a polarographic pO(2) histograph. RESULTS: Within treatment time (maximum, 10 days) the median pO(2) increased in all groups (except the control group), concomitantly the fraction of measurements of pO(2) that were less than 10 mm Hg showed a constant decrease (p < or = 0.001). The highest difference between the median pO(2) values and the fraction of measurements of pO(2) that were less than 10 mm Hg at the start and 1 week after the end of therapy occurred in the groups with radiochemothermotherapy (triple-modality therapy; p< or = 0.001). At Day 60, the highest rate of complete remissions was observed in the triple-modality therapy groups. CONCLUSION: Tumor oxygenation under a single or combined cancer treatment is correlated with treatment efficacy in terms of complete remissions at Day 60. The posttherapeutic fraction of measurements of pO(2) that were less than 10 mm Hg correlates even better with the long term tumor free survival than the median pO(2) values or the pretherapeutic fraction of measurements of pO(2) that were less than 10 mm Hg.     

Hypoxia in human soft tissue sarcomas: adverse impact on survival and no association with p53 mutations

Clinical and experimental studies have suggested that tumour hypoxia is associated with poor treatment outcome and that loss of apoptotic potential may play a role in malignant progression of neoplastic cells. The tumour suppressor gene p53 induces apoptosis under certain conditions and microenvironmental tumour hypoxia may select for mutant tumour cells with diminished apoptotic potential due to lack of p53 function. The aim of this study was to evaluate the prognostic relevance of oxygenation status for treatment outcome and to compare pre-treatment tumour oxygenation measurements were done in 31 of those by PCR using DNA extracted from paraffin-embaedded sections (n = 2) or frozen biopsies (n = 29). The overall median of the tumour median pO(2)was 19 mmHg (range 1-58 mmHg). Only 6 tumours had functional p53 mutations and no association was found between mutant p53 and tumour hypoxia. Five out of 6 STS with lower histopathological grade were well-oxygenated whereas high-grade STS were both hypoxic and well-oxygenated. At a median follow-up of 74 months, 16 patients were still alive among 28 available for survival analysis. When stratifying into hypoxic and well-oxygenated tumours patients with the most hypoxic tumours has a statistically poorer disease-specific and overall survival at 5 years. In conclusion hypoxia was an indicator for both a poorer disease specific and overall survival in human STS but hypoxic tumours were not characterized by mutations in the p53 gene.