Operable non-small cell lung cancer: correlation of volumetric helical dynamic contrast-enhanced CT parameters with immunohistochemical markers of tumor hypoxia.

PURPOSE: To assess the relationship between helical dynamic contrast material-enhanced (DCE) computed tomographic (CT) parameters and immunohistochemical markers of hypoxia in patients with operable non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: After institutional review board approval was obtained, 20 prospective patients who were suspected of having NSCLC underwent whole-tumor DCE CT with kinetic modeling (Patlak analysis) 24 hours before scheduled surgery. Flow-extraction product (in milliliters per 100 milliliters per minute) and blood volume (in milliliters per 100 milliliters) were derived. After surgery, matched whole-tumor sections were stained for exogenous and endogenous markers of hypoxia (pimonidazole infused intravenously 24 hours before surgery, immediately after DCE CT; glucose transporter protein). Correlation between DCE CT parameters and immunohistochemical markers was assessed by using the Spearman rank correlation. DCE CT parameters and immunohistochemical markers were also compared according to pathologic subtype, grade, stage, and nodal status by using the Mann-Whitney test. P values less than .05 indicated a statistically significant difference. RESULT: Fourteen patients with confirmed primary NSCLC underwent resection. There were negative correlations between blood volume and pimonidazole staining (r = -0.48, P = .004), and between flow-extraction product and glucose transporter protein expression (r = -0.50, P = .002). Flow-extraction product was significantly higher in adenocarcinomas than in squamous cell tumors (17.73 vs 11.46; P = .043). Glucose transporter protein expression was significantly lower for adenocarcinomas than for squamous tumors (14.07 vs 33.03; P < .001) and in node negative than in node positive tumors (15.63 vs 23.85; P = .005). CONCLUSION: Blood volume and flow-extraction product derived at DCE CT correlated negatively with pimonidazole and glucose transporter protein expression, indicating the potential of these CT parameters as imaging biomarkers of hypoxia.

Hypoxia in prostate cancer: correlation of BOLD-MRI with pimonidazole immunohistochemistry-initial observations.

PURPOSE: To investigate the ability of blood oxygen level-dependent (BOLD) MRI to depict clinically significant prostate tumor hypoxia. METHODS AND MATERIALS: Thirty-three patients with prostate carcinoma undergoing radical prostatectomy were studied preoperatively, using gradient echo sequences without and with contrast medium enhancement, to map relative tissue oxygenation according to relaxivity rates and relative blood volume (rBV). Pimonidazole was administered preoperatively, and whole-mount sections of selected tumor-bearing slices were stained for pimonidazole fixation and tumor and nontumor localization. Histologic and imaging parameters were independently mapped onto patient prostate outlines. Using 5-mm grids, 861 nontumor grid locations were compared with 237 tumor grids (with >50% tumor per location) using contingency table analysis with respect to the ability of imaging to predict pimonidazole staining. RESULTS: Twenty patients completed the imaging and histologic protocols. Pimonidazole staining was found in 33% of nontumor and in 70% of tumor grids. The sensitivity of the MR relaxivity parameter R(2)* in depicting tumor hypoxia was high (88%), improving with the addition of low rBV information (95%) without changing specificity (36% and 29%, respectively). High R(2)* increased the positive predictive value for hypoxia by 6% (70% to 76%); conversely, low R(2)* decreased the likelihood of hypoxia being present by 26% (70% to 44%) and by 41% (71% to 30%) when combined with rBV information. CONCLUSION: R(2)* maps from BOLD-MRI have high sensitivity but low specificity for defining intraprostatic tumor hypoxia. This together with the negative predictive value of 70% when combined with blood volume information makes BOLD-MRI a potential noninvasive technique for mapping prostatic tumor hypoxia.

Epidermal growth factor receptor expression in pretreatment biopsies from head and neck squamous cell carcinoma as a predictive factor for a benefit from accelerated radiation therapy in a randomized controlled trial.

PURPOSE: Accelerated repopulation is a main reason for locoregional failure after fractionated radiotherapy for head and neck squamous cell carcinoma (HNSCC). Epidermal growth factor receptor (EGFR) is a key controller of cellular proliferation in HNSCC, which stimulated the current study to look for a direct link between EGFR status and a possible clinical advantage of accelerated radiotherapy. PATIENTS AND METHODS: Immunohistochemical staining for EGFR was performed in 304 patients with available pretreatment tumor biopsy material among 918 patients randomized to receive continuous hyperfractionated accelerated radiotherapy versus conventionally fractionated radiotherapy. The EGFR index was estimated as the proportion of tumor cells with EGFR membrane staining. RESULTS: Significant benefit in locoregional tumor control from continuous hyperfractionated accelerated radiotherapy was seen in patients with HNSCC with high EGFR expression (2P = .010) but not in those with low EGFR expression (2P = .85). EGFR status had no significant effect on survival or rate of distant metastases. The EGFR index was significantly associated with histologic grade and microvessel density. There was moderate support for an association between EGFR status and subsite within the head and neck region but no significant association with Ki-67 index, Ki-67 pattern, p53 index, p53 intensity, bcl-2 expression, or cyclin D1 index. CONCLUSION: This study indicates a key role for the EGFR receptor in determining the proliferative cellular response to fractionated radiotherapy in HNSCC. It also shows that we can select the dose-fractionation regime that has the greatest chance of benefiting the patient. These results also encourage further development of EGFR targeting combined with fractionated radiotherapy in HNSCC.

Pre-treatment proliferation and the outcome of conventional and accelerated radiotherapy.

This study investigated the influence of pre-treatment proliferation characteristics, assessed by Ki-67 staining, in patients treated in the CHART trial of accelerated radiotherapy in head and neck cancer. Histological material from 402 patients was collected and stained for the presence and pattern of Ki-67 staining. Locoregional control and overall survival were the main clinical endpoints. Increasing Ki-67 positivity was associated with decreasing differentiation (P < 0.001) and increasing N-stage (P < 0.004). Increasing N-stage was also associated with the progression of proliferation pattern from marginal to random (P < 0.001). Using a multivariate model, a trend was seen towards a greater benefit from CHART in the lower Ki-67 tumours (P = 0.08); this became significant by pooling the low and intermediate Ki-67 groups in comparison with the high Ki-67 group (P = 0.032). Tumours with marginal proliferation pattern showed a lower hazard ratio with CHART versus conventional for locoregional control (P = 0.005). The data presented in this study do not support that a high pre-treatment Ki-67 is associated with a therapeutic benefit from accelerated radiotherapy.

An immunohistochemical assessment of hypoxia in prostate carcinoma using pimonidazole: implications for radioresistance.

PURPOSE: To investigate the presence of hypoxia in human prostate carcinoma by using pimonidazole immunohistochemical labeling in radical prostatectomy specimens. METHODS AND MATERIALS: Forty-three patients (median age, 69 years; range, 49-83 years) with localized prostate adenocarcinoma received 0.5 gm/m2 i.v. pimonidazole 16-24 h before radical prostatectomy. Hypoxia was detected with a monoclonal antibody directed against pimonidazole and scored in formalin-fixed, paraffin-embedded sections. Median and maximal vessel counts were measured with CD34. RESULTS: Thirty-seven patients completed the study. Pimonidazole binding was present in prostate carcinomas in 34 of 37 patients (92%) and in benign prostatic hyperplasia in 35 of 37 patients (95%). A positive correlation of 3+ pimonidazole binding with Gleason score was demonstrated (Spearman's rank, p = 0.044). Vascularity scores did not correlate with hypoxic status or clinical prognostic parameters. CONCLUSION: Prostate carcinoma and benign prostatic hyperplasia have significant areas of hypoxia; greater hypoxia scores are seen with more aggressive prostate cancer. It is postulated that a hypoxic microenvironment within the prostate might be responsible for the promotion of secondary genetic alterations and angiogenic stimulation, leading to malignant progression, a more aggressive cell phenotype, and greater radioresistance. Modification of radiation regimens to specifically target hypoxia might improve local tumor control.

Correlation of spectral imaging and visual grading for the quantification of thymidylate synthase protein expression in rectal cancer.

Quantification of protein expression in tissue sections stained by immunohistochemistry has traditionally involved visual grading techniques. However, if these results are to be used to predict tumor behavior and permit targeted therapy, there is a need for more accurate, objective, and reproducible methods. This study investigated the utility of spectral imaging as a method of quantifying thymidylate synthase protein expression in immunohistochemically stained sections of primary rectal cancer and normal rectal mucosa by comparing it with the current gold standard of manual visual grading. There was good correlation between estimates of thymidylate synthase stain intensity and area derived by spectral imaging and visual grading in both tumor and normal mucosal sections, suggesting that spectral imaging is a valid way of quantifying biologic sections stained by immunohistochemistry.

nm23 as a prognostic marker in primary cutaneous melanoma: evaluation using tissue microarray in a patient group with long-term follow-up.

The accurate estimation of prognosis in patients with melanoma is of increasing importance with novel adjuvant therapies on the horizon. The current prediction of prognosis employs techniques involving sentinel lymph node biopsy, which carries an associated morbidity and is of little use in patients who develop direct distant metastases or direct in-transit metastases. New strategies or factors are therefore needed to improve the accuracy of determination of prognosis. nm23 is a putative metastasis suppressor; however, conflicting data exist as to its role in melanoma progression and its use as a potential prognostic marker. The purpose of this study was to use the technique of tissue microarray to study a cohort of melanoma patients with long-term follow-up data in order to ascertain its potential use as a prognostic marker. One hundred and twenty patients with primary cutaneous melanoma were included in the tissue microarray and a commercially available immunohistochemical marker for nm23 was used for protein detection. nm23 expression was strongly correlated with Clark's level (P<0.001), Breslow depth (P=0.002) and patient age (P=0.014). nm23 expression was significantly associated with a poor patient outcome (chi2=7.2219, P=0.0072). Further analysis revealed that the intensity of nm23 expression also correlated with patient outcome (chi2=11.3281, P=0.0035). However, on multivariate analysis, nm23 was shown not to be an independent marker of prognosis. The results of this study, when taken with the existing literature, suggest a role for nm23 in melanoma disease progression. However, its use as a prognostic marker in routine practice does not appear to be justified.

Molecular marker profiles predict locoregional control of head and neck squamous cell carcinoma in a randomized trial of continuous hyperfractionated accelerated radiotherapy.

PURPOSE: Identification of factors that assist prediction of tumor response to radiotherapy may aid in refining treatment strategies and improving outcome. Possible association of molecular marker expression profiles with locoregional control of head and neck squamous cell carcinoma was investigated in a randomized trial of conventional versus continuous hyperfractionated accelerated radiotherapy (CHART). EXPERIMENTAL DESIGN: Tumor material was obtained from 402 patients. Immunohistochemistry was used to assess Ki-67, CD31, p53, Bcl-2, and cyclin D1 expression. A hierarchical clustering algorithm with a Bayesian information criterion was used to group tumors with similar marker expression; resulting expression profiles were then compared in terms of their difference in outcome after CHART and conventionally fractionated radiotherapy. RESULTS: Molecular marker profile was an independent prognostic factor for locoregional control. This was confirmed in multivariate analysis, including clinical variables such as tumor and nodal status, primary site, histological grade, age, and gender (P < 0.001 and P = 0.006 for local and nodal relapse, respectively). In particular, Bcl-2-positive tumors responded significantly better than average in both arms of the trial. Tumors negative for p53- and Bcl-2, with high and randomly patterned Ki-67 expression, responded worse than average with no benefit from CHART. Tumors with similarly negative p53 and Bcl-2, but low Ki-67 staining, with an organized pattern, benefit significantly from CHART schedule. CONCLUSIONS: This study demonstrates the potential of molecular profiles to predict radiotherapy response of head and neck squamous cell carcinoma and for treatment stratification. Distinct expression profiles correlate with three distinct clinical phenotypes, including good locoregional control, poor locoregional control, and an outcome strongly dependent upon fractionation schedule.

Molecular biomarkers and site of first recurrence after radiotherapy for head and neck cancer.

The prognostic significance of a panel of molecular biomarkers in head and neck squamous cell carcinoma (HNSCC) for first failure site (primary (T), nodal (N) or distant (M)) was analysed in 309 patients randomised to continuous hyperfractionated accelerated radiotherapy (CHART) vs. conventionally fractionated radiotherapy. Multivariate competing risks analysis was performed using an accelerated failure-time model. First-order interactions between each marker and trial arm were also tested. Bcl2-positivity increased the time to T- and N-failures, increasing cyclin D1 score decreased the time to N-failures. A random proliferative pattern and low Ki-67 decreased the time to M-failures. A high CD31 score was associated with a significantly longer time to T-failure after CHART, but not after conventional fractionation. Risks of T-, N- and M-failures could be estimated for individual patients. Competing risks analysis of failure sites allows the rational selection of patients for more aggressive loco-regional or systemic therapy.

Target validation of cytochrome P450 CYP1B1 in prostate carcinoma with protein expression in associated hyperplastic and premalignant tissue.

PURPOSE: To investigate the localization and distribution of cytochrome P450 CYP1B1 protein expression in patients diagnosed with prostate carcinoma compared to those with bladder carcinoma. To validate CYP1B1 as a molecular target for the development of selective cancer therapeutics for use in combination with radiation. METHODS AND MATERIALS: Prostatectomy specimens (n = 33) of moderate Gleason grade (3 + 3 and 3 + 4) were analyzed immunohistochemically for CYP1B1 protein expression using a specific monoclonal antibody for the enzyme. The intensity of CYP1B1 staining was assessed both semiquantitatively using visual scoring and quantitatively by spectral imaging microscopy using reference spectra and compared with bladder carcinoma (n = 22). RESULTS: CYP1B1 protein expression was present in 75% of prostate carcinomas (n = 27) compared to 100% of bladder carcinomas (n = 22). In both cases, CYP1B1 protein expression was heterogeneous and localized in the cytoplasm of the tumor cells but absent from the surrounding stromal tissue. CYP1B1 was also detected in premalignant prostatic intraepithelial neoplasia (n = 2, 100%), as well as noncancerous tissues, including benign prostatic hyperplasia (n = 27, 82%), metaplastic prostatic urothelium (n = 8, 100%), and hyperplastic prostatic urothelium (n = 14, 100%). Higher CYP1B1 protein expression in bladder vs. prostate carcinoma was confirmed by their corresponding average normalized absorbances (+/- standard deviation), measured as 1.40 +/- 0.44 and 0.55 +/- 0.09, respectively. Overall CYP1B1 staining intensity in prostate carcinoma was similar to that in prostatic intraepithelial neoplasia, benign prostatic hyperplasia, and hyper-/metaplastic urothelial tissue. No CYP1B1 was detected in normal prostate tissue. CONCLUSIONS: CYP1B1 is overexpressed in prostate carcinoma at a high frequency and is also detectable in the associated premalignant and hyperplastic tissue, implicating a possible link with malignant progression and CYP1B1 as a suitable target for therapy. Spectral imaging microscopy has highlighted differences in CYP1B1 protein expression between different cancers.

The immunohistochemical assessment of hypoxia, vascularity and proliferation in bladder carcinoma.

BACKGROUND AND PURPOSE: Hypoxia and proliferation are important determinants of radiation responsiveness; prospective measures of these before radiotherapy may enable individualisation of treatment schedules. Immunohistochemical techniques offer a potential means of achieving this in routine biopsy material. MATERIAL AND METHODS: Cellular hypoxia as measured by pimonidazole fixation and immunohistochemistry has been evaluated in a series of human bladder cancers with dual staining of sections for pimonidazole and either the vascular markers, CD31/34, or proliferation markers, Ki-67 or cyclin A. Twenty one tumour specimens were examined suitable for the double staining technique. RESULTS: The median hypoxic fraction was 9% (range 0-38). Seven tumours did not stain for pimonidazole and 11 exhibited necrosis. The mean vascular density ranged from 16.7 to 160.6 vessels per mm2. The median hot spot count was 30 (range 16-43). There was a statistically significant increase in vessel density in hypoxic compared to oxic regions measured by both vessel density (P = 0.02) and hot spot count (P = 0.004). Proliferation indices decreased from oxic to hypoxic areas close to blood vessels. CONCLUSIONS: We have demonstrated that bladder cancer exhibits a range of hypoxia, proliferation and vascular density which may be used to form the basis for patient selection for hypoxia modification, accelerated radiotherapy and vascular targeting agents.

CD44v3 levels in primary cutaneous melanoma are predictive of prognosis: assessment by the use of tissue microarray.

Despite the use of sentinel node biopsy techniques, the search continues for other strategies to improve the accuracy of estimating prognosis in melanoma patients. Various biomarkers have previously been studied for use in this role, but none has yet achieved acceptance in routine practice. We have applied the novel technology of tissue microarray for the high throughput screening of a cohort of 120 primary cutaneous melanoma specimens for expression of the transmembrane glycoprotein CD44, splice variant 3 (v3), which has previously been implicated in tumor progression. A highly significant correlation between CD44v3 expression and Breslow thickness, Clark's level and patient age was demonstrated (Spearman correlation p < 0.001). Regarding clinical outcome, CD44v3 expression was shown to be significantly associated with better outcome (chi(2) = 7.2219, p = 0.0072). Furthermore, subgroup analysis revealed a sequentially improved survival probability associated with the intensity of CD44v3 staining (chi(2) = 12.5162, p = 0.0058). Analysis in a Cox multivariate model, however, did not show CD44v3 to be independently predictive of prognosis. The implications of these findings are considered, and the use of CD44v3 as a potential prognostic marker or a target for therapeutic manipulation are discussed.

Endogenous markers of two separate hypoxia response pathways (hypoxia inducible factor 2 alpha and carbonic anhydrase 9) are associated with radiotherapy failure in head and neck cancer patients recruited in the CHART randomized trial.

PURPOSE: Randomized controlled trials have generally shown a benefit from accelerated radiotherapy in head and neck squamous cell carcinoma (HNSCC). However, the large randomized United Kingdom trial CHART (Continuous Hyperfractionated Accelerated Radiotherapy) failed to show a benefit of strongly accelerated over standard radiotherapy (RT) in 918 patients with HNSCC. In this study, we investigated the impact of tumor hypoxia on the outcome of HNSCC patients in the CHART trial. There are two distinct hypoxia inducible factors (HIFs) that control different gene response pathways and we assessed them both with endogenous markers of hypoxia, hypoxia inducible factor HIF-2 alpha (HIF-2) and carbonic anhydrase CA9, an indicator of HIF-1 alpha (HIF-1) function. METHODS: Tissue from pre-RT biopsies performed in 198 of 918 patients recruited was analyzed for the immunohistochemical expression of HIF-2 and CA9. RESULTS: A significant association of high HIF2 and of high CA9 reactivity with poor locoregional control (P < .0001 and P = .0002, respectively) and poor survival (P = .0004 and 0.002, respectively) was noted. In multivariate analysis, HIF-2 and CA9 maintained their independent prognostic significance. Coexpression of both pathways had an additive effect, supporting their independent role. The uni-directional hypothesis, that a benefit from randomization to CHART should be seen in the nonhypoxic tumors, was supported by the data (one-tailed P = .04). CONCLUSION: Expression of endogenous markers of hypoxia for the HIF-1 and HIF-2 pathway is strongly associated with radiotherapy failure. Using immunohistochemical methods it is possible to identify subgroups of HNSCC patients who are highly curable with radiotherapy, or who are excellent candidates for clinical trials on hypoxia-targeting drugs in two distinct pathways.

Development of a tissue array for primary melanoma with long-term follow-up: discovering melanoma cell adhesion molecule as an important prognostic marker.

Refining current prognostic capability is essential for improving the management of melanoma. This study was undertaken to develop a tumor array for the rapid assessment of novel prognostic markers in a series of specimens from melanoma patients with 7- to 10-year follow-up. A melanoma database of 120 patients with archival specimens was created after histopathological review of original specimens. A tissue array was developed allowing 480 biopsy samples from the 120 primary melanoma specimens to be embedded into a single paraffin block. This was sectioned and stained for the adhesion marker melanoma cell adhesion molecule (MCAM); after further review, 76 of the 120 specimens were suitable for further analysis. The slides were assessed by two independent observers without previous knowledge of the clinical outcome for staining positivity and stain intensity. Assessment of association between MCAM and clinicopathological features was carried out using chi-squared analysis, and univariate and Cox multivariate analyses were performed on the data. There was a high correlation between MCAM intensity and both Clark's level and Breslow thickness (Spearman correlation p < 0.001 for both). The data revealed that MACM was a highly specific prognostic marker for survival in univariate analysis (chi2 = 18, p < 0.0001). Subgroup analysis by stratification of the staining intensity revealed a sequentially worsening survival with increasing staining intensity (chi2 = 22.33, p < 0.0001). Multivariate analysis of survival showed MCAM to be an independent prognostic marker more accurate than all other clinicopathological parameters (p < 0.0001), including the Breslow depth. Further analysis within only intermediate-thickness tumors showed MCAM intensity added further refinement to outcome prediction (chi2 = 22.33, p < 0.0001). The tissue array provided a rapid method of analyzing up to 480 specimens within a single paraffin block. This will benefit many areas of plastic surgery research. The identification of adhesion markers revealed a valuable prognostic marker for predicting outcome and a potential target for therapeutic manipulation.

Identification of P-cadherin in primary melanoma using a tissue microarrayer: prognostic implications in a patient cohort with long-term follow up.

Sentinel lymph node biopsy is the most accurate technique for establishing melanoma patient prognosis but is associated with morbidity and is of little value in those tumors that first metastasize to sites other than the regional nodal basin. Noninvasive methods of establishing prognosis are therefore desirable. We have used the novel technology of tissue microarray to study a cohort of 120 patients with melanoma with long-term follow-up data for the expression of P-cadherin. The tissue microarray was successfully constructed and stained. Loss of P-cadherin expression was found to be significantly correlated with outcome (log rank chi2 = 10.1336, P = 0.0015). The results suggest a fundamental role for P-cadherin in melanoma progression and identify it as a potential prognostic marker and a possible target for therapeutic manipulation.