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ABSTRACT: In this study, we tested the ability of a panel of hypermethylation markers to improve the sensitivity of histologic prostate cancer detection in sextant needle biopsies.
We obtained fresh-frozen sextant biopsies from 72 excised prostates and directly compared blinded histologic review and quantitative real-time methylation-specific PCR for hypermethylation of four genes, Tazarotene-induced gene 1 (TIG1), adenomatous polyposis coli (APC), retinoic acid receptor beta2 (RARbeta2), and glutathione S-transferase pi (GSTP1) to detect the presence of prostate cancer. Results were compared with the final surgical pathological review of the resected prostates as the gold standard.
Histologic review alone detected carcinoma with a sensitivity of 64% (39 of 61 cases) and 100% specificity. Quantitative real-time methylation-specific PCR for TIG1, APC, RARbeta2, and GSTP1 detected carcinoma with a sensitivity of 70%, 79%, 89%, and 75%, respectively, with 100% specificity for all of the genes. Using this panel of methylation markers in combination with histology resulted in the detection of 59 of 61 (97%) cases of prostate with 100% specificity, a 33% improvement over histology alone.
The use of a panel of methylation markers as an adjunct to histologic review may substantially augment prostate cancer diagnosis from needle biopsies.
Clinical Cancer Research 09/2004; 10(16):5518-22. · 7.74 Impact Factor
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ABSTRACT: We have developed a real-time semiquantitative gap ligase chain reaction for detecting p53 point mutations at low level in a background of excess of wild-type DNA.
This method was validated by direct comparison to a previously validated but cumbersome phage plaque hybridization assay. Forty-one surgical margins and lymph nodes from 10 cases of head and neck squamous cell carcinoma and lung carcinoma were tested for p53 mutant clones.
Both methods detected p53 mutants in margins from 8 of the 10 cases, whereas standard pathology detected cancer cells in only 3 cases. Positive margins included tissue samples with a tumor/normal DNA ratio of up to 1:1000.
This novel molecular approach can be performed in <5 h facilitating intraoperative use for real-time surgical resection.
Clinical Cancer Research 04/2004; 10(7):2379-85. · 7.74 Impact Factor
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ABSTRACT: To assess inter-clinician variability amongst specialist paediatric radiation oncologists in delineating clinical target volumes for treating medulloblastoma as a quality assurance exercise prior to the introduction of the SIOP PNET 4 trial protocol of conformal radiotherapy to the posterior fossa and tumour bed.
Participants from 17 UK centres attended an educational meeting and then completed a clinical planning exercise to outline: (1) the whole posterior fossa and (2) the tumour bed. Quantitative analysis of the volumes, lengths, spatial positioning and axial planes for each individual was carried out and variation between individuals analysed.
Outlining of the posterior fossa was reasonably consistent, although most variation was seen in defining the superior border of the tentorium. A major difference was the decision whether or not to include the post-surgical meningocoele in the clinical target volume (CTV). The CTV for the tumour bed was under treated by all participants due to lack of inclusion of pre-operative tumour extent.
This exercise demonstrated several ambiguities in the draft protocol and highlighted particular areas of inter-clinician variation. Consequently the protocol was revised and improved to take account of these findings. We recommend that planning exercises, in conjunction with education and training, should be implemented before the start of any new radiotherapy trial. In the future, the use of image transfer will allow prospective peer review of target volumes before treatment commences. These measures are essential to ensure that alterations in clinical practice are achieved in a uniform way.
Radiotherapy and Oncology 12/2003; 69(2):189-94. · 5.58 Impact Factor
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ABSTRACT: Hypermethylation of the 5' promoter region of the glutathione S-transferase pi gene (GSTP1) occurs at a very high frequency in prostate adenocarcinoma. We compared the results of blinded histologic review of sextant biopsy samples from 72 excised prostates with those obtained using a quantitative methylation-specific polymerase chain reaction assay (QMSP) for GSTP1. Formal surgical pathologic review of the resected prostates was used to determine the number of patients with (n = 61) and without (n = 11) prostate cancer. Histology alone detected prostate carcinoma with 64% sensitivity (95% confidence interval [CI] = 51% to 76%) and 100% specificity (95% CI = 72% to 100%), whereas the combination of histology and GSTP1 QMSP at an assay threshold greater than 10 detected prostate carcinoma with 75% sensitivity (95% CI = 63% to 86%) and 100% specificity (95% CI = 72% to 100%), an 11% improvement (95% CI = 5% to 22%) in sensitivity over histology alone. The combination of histology and GSTP1 QMSP at an assay threshold greater than 5 detected prostate adenocarcinoma with 79% sensitivity (95% CI = 68% to 89%), a 15% improvement (95% CI = 7% to 26%) over histology alone. Thus, GSTP1 QMSP improved the sensitivity of histologic review of random needle biopsies for prostate cancer diagnosis. Further studies should determine whether detection of GSTP1 hypermethylation in a biopsy sample with normal histology indicates the need for an early repeat biopsy at the same site.
CancerSpectrum Knowledge Environment 12/2003; 95(21):1634-7. · 14.07 Impact Factor
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ABSTRACT: Cranio-spinal irradiation for medulloblastoma can impair fertility in girls. The literature indicates that an ovarian dose of 4 Gy causes permanent infertility in 30% of young females and that doses of <1.5 Gy over the whole treatment are desirable. We report a modified radiotherapy technique using a non-divergent beam edge inferiorly to reduce the ovarian dose.
Eight female patients with medulloblastoma had magnetic resonance imaging (MRI) studies in the treatment position to identify the position of their ovaries relative to the radiation field. The information was transferred to the radiotherapy planning system and plans were generated using conventional spinal fields and modified fields with a half beam block at the inferior border.
Identifying the position of the ovaries by MRI enabled the dose to be estimated for the two techniques. Using a non-divergent beam inferiorly, the mean ovarian dose was reduced in all cases by a median value of 2.45 Gy (range 0.6-19.5 Gy) and the median percentage reduction was 66.8% (range 2.6-84.6%). The position of the ovary relative to the beam edge was critical in determining the dose reduction for each case. The modified technique doubled the number of patients receiving <4 Gy to a single ovary from three to six. With this alteration, three patients also had an ovary receiving <1.5 Gy whereas all exceeded this dose with conventional treatment.
We recommend using asymmetry at the inferior spinal border to achieve a non-divergent edge to the treatment field to reduce the dose to the ovary. Using MRI to localise the ovaries is important in estimating their dose and in assisting the counselling of patients and their families about future fertility.
Radiotherapy and Oncology 11/2003; 69(2):183-8. · 5.58 Impact Factor
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ABSTRACT: Promoter hypermethylation is an important pathway for repression of gene transcription in cancer cells and a promising marker for cancer detection. We tested five gene promoters [CDKN2A (p16), O(6)-methylguanine-DNA-methyltransferase, glutathione S-transferase P1 (GSTP1), adenomatous polyposis coli (APC), and death-associated protein kinase (DAPK)] by real-time methylation-specific PCR in primary tumors from 90 stage I lung cancer patients for aberrant DNA methylation. We then used the presence of tumor methylation as a marker to investigate the presence of occult metastasis in corresponding histologically negative lymph nodes. Of the primary tumors, 73 of 90 (81%) displayed promoter hypermethylation in at least one of the genes studied: 17% (15 of 90) at p16 (CDKN2A); 16% (14 of 90) at O(6)-methylguanine-DNA-methyltransferase; 8% (7 of 90) at GSTP1; 72% (65 of 90) at APC; and 17% (15 of 90) at DAPK. Squamous histology was predictive of worse overall survival (P = 0.074, log-rank test). APC methylation and GSTP1 methylation in the primary tumor were both correlated with nonsquamous histology (P = 0.02 and P = 0.01 likelihood ratio respectively). The presence of both APC methylation and DAPK methylation in the primary tumor predicted a worse outcome, with 7 of 13 (54%) deaths in this group compared with 21 of 77 (27%) deaths in cases without both genes methylated (P = 0.229, log-rank test). The same methylation pattern was detected in DNA from at least one of the corresponding lymph nodes in 11 of 73 (15%) cases. Five of 11 (45%) patients with occult metastasis detected by methylation analysis have died compared with 17 of 62 (27%) patients with negative lymph nodes, although survival analysis did not reach statistical significance (P = 0.632, log-rank test). Promoter hypermethylation is common in lung cancer and represents a promising marker for the molecular staging of lung cancer patients. Although this study showed important trends, a larger prospective study is required to better understand the value of methylation analysis in detecting occult metastasis.
Clinical Cancer Research 05/2003; 9(4):1370-5. · 7.74 Impact Factor
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ABSTRACT: Hypermethylation of the glutathione S-transferase gene (GSTP1) is the most common (greater than 90%) reported epigenetic alteration in prostate cancer. It occurs early in cancer progression and it is a promising marker for detecting organ confined disease. To evaluate its use as a diagnostic tool for cancer we used quantitative GSTP1 methylation to test for the presence of cancer in 45 prostate needle biopsy samples.
Paraffin tissue samples from 45 patients with minute foci of intermediate grade prostatic adenocarcinoma or benign disease on needle biopsy were tested for GSTP1 hypermethylation using quantitative fluorogenic real-time methylation specific polymerase chain reaction. This assay was performed in blinded fashion without previous knowledge of the histopathological diagnosis.
DNA from 29 of the 45 paraffin samples was amenable to polymerase chain reaction amplification. In these 29 samples GSTP1 methylation was detected in 11 of 15 cases of limited cancer and in 0 of 14 of benign disease (2-sided Fisher's exact test, p <0.0001). Thus, this assay had 73% sensitivity, 100% specificity, 100% positive and 78% negative predictive values.
Quantitation of GSTP1 hypermethylation accurately detects the presence of cancer even in small, limited tissue samples. It represents a promising diagnostic marker that could be used as an adjunct to tissue biopsy as part of prostate cancer screening.
The Journal of Urology 04/2003; 169(3):1138-42. · 3.75 Impact Factor
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ABSTRACT: Phyllodes tumours and angiosarcoma are both rare mesenchymal tumours. There are no reports of their coexistence in the literature except in families with germline p53 mutations. Here we report a case of an elderly woman who developed an extensive angiosarcoma of the scalp nearly 4 years after surgical removal of a borderline malignant phyllodes tumour of the breast. The scalp lesion was initially thought more likely to be a metastasis of her first rare tumour than a second equally rare primary tumour, but histologically this was not the case. The case and the literature are discussed.
Sarcoma 01/2003; 7(3-4):173-6.
