Systematic review and economic modelling of the relative clinical benefit and cost-effectiveness of laparoscopic surgery and robotic surgery for removal of the prostate in men with localised prostate cancer

BACKGROUND

Complete surgical removal of the prostate, radical prostatectomy, is the most frequently used treatment option for men with localised prostate cancer. The use of laparoscopic (keyhole) and robot-assisted surgery has improved operative safety but the comparative effectiveness and cost-effectiveness of these options remains uncertain.

OBJECTIVE

This study aimed to determine the relative clinical effectiveness and cost-effectiveness of robotic radical prostatectomy compared with laparoscopic radical prostatectomy in the treatment of localised prostate cancer within the UK NHS.

DATA SOURCES

MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, BIOSIS, Science Citation Index and Cochrane Central Register of Controlled Trials were searched from January 1995 until October 2010 for primary studies. Conference abstracts from meetings of the European, American and British Urological Associations were also searched. Costs were obtained from NHS sources and the manufacturer of the robotic system. Economic model parameters and distributions not obtained in the systematic review were derived from other literature sources and an advisory expert panel.

REVIEW METHODS

Evidence was considered from randomised controlled trials (RCTs) and non-randomised comparative studies of men with clinically localised prostate cancer (cT1 or cT2); outcome measures included adverse events, cancer related, functional, patient driven and descriptors of care. Two reviewers abstracted data and assessed the risk of bias of the included studies. For meta-analyses, a Bayesian indirect mixed-treatment comparison was used. Cost-effectiveness was assessed using a discrete-event simulation model.

RESULTS

The searches identified 2722 potentially relevant titles and abstracts, from which 914 reports were selected for full-text eligibility screening. Of these, data were included from 19,064 patients across one RCT and 57 non-randomised comparative studies, with very few studies considered at low risk of bias. The results of this study, although associated with some uncertainty, demonstrated that the outcomes were generally better for robotic than for laparoscopic surgery for major adverse events such as blood transfusion and organ injury rates and for rate of failure to remove the cancer (positive margin) (odds ratio 0.69; 95% credible interval 0.51 to 0.96; probability outcome favours robotic prostatectomy = 0.987). The predicted probability of a positive margin was 17.6% following robotic prostatectomy compared with 23.6% for laparoscopic prostatectomy. Restriction of the meta-analysis to studies at low risk of bias did not change the direction of effect but did decrease the precision of the effect size. There was no evidence of differences in cancer-related, patient-driven or dysfunction outcomes. The results of the economic evaluation suggested that when the difference in positive margins is equivalent to the estimates in the meta-analysis of all included studies, robotic radical prostatectomy was on average associated with an incremental cost per quality-adjusted life-year that is less than threshold values typically adopted by the NHS (£30,000) and becomes further reduced when the surgical capacity is high.

LIMITATIONS

The main limitations were the quantity and quality of the data available on cancer-related outcomes and dysfunction.

CONCLUSIONS

This study demonstrated that robotic prostatectomy had lower perioperative morbidity and a reduced risk of a positive surgical margin compared with laparoscopic prostatectomy although there was considerable uncertainty. Robotic prostatectomy will always be more costly to the NHS because of the fixed capital and maintenance charges for the robotic system. Our modelling showed that this excess cost can be reduced if capital costs of equipment are minimised and by maintaining a high case volume for each robotic system of at least 100-150 procedures per year. This finding was primarily driven by a difference in positive margin rate. There is a need for further research to establish how positive margin rates impact on long-term outcomes.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

FGF8 isoform b expression in human prostate cancer

Overexpression of fibroblast growth factor 8 (FGF8) mRNA has been previously described in prostate cancer. Of its four isoforms, FGF8b is thought to be the most important in carcinogenesis. We hypothesised that immunodetection of FGF8b in archival prostate cancer specimens is of potential prognostic value. Using a selected cohort of prostate tumours from transurethral (n=30) and radical prostatectomies (n=59), an optimised protocol for FGF8b immunoreactivity was used to corroborate expression with clinical parameters. No expression was observed in benign prostates (n=10). In prostate cancer, immunoreactivity was localised to the malignant epithelium with weak signals in the adjacent stroma. Expression of FGF8b in stage T1 and T2 cancers were 40 and 67%, respectively. In contrast, FGF8b expression was present in 94% of T3 and 100% of T4 cancers. By histological grade, FGF8b was found in 41% of low-grade cancers (Gleason score 4-6), 60% of intermediate-grade cancers (Gleason score 7 and 92% of high-grade cancers (Gleason score 8-10). The intensity of expression was significantly associated with stage (P=0.0004) and grade (P<0.0001) of disease. We further hypothesised that FGF8b overexpression resulted from enhanced transcription and translation rather than from abnormalities involving the FGF8 gene locus. This was tested by means of fluorescent in situ hybridisation in 20 cancer specimens to map the FGF8 gene locus. FGF8 gene copy number in benign and malignant nuclei was found to be similar (2.33+/-0.57 and 2.0+/-0.81, respectively P=0.51). Based on these findings, we propose a multicentre study on cohorts of patients to further evaluate FGF8b as a potential prognostic marker in prostate cancer.

Combined p21WAF1/CIP1 and p53 overexpression predict improved survival in muscle-invasive bladder cancer treated by radical radiotherapy

PURPOSE

The prognostic value of p21 and p53 expression was evaluated for patients with muscle-invasive bladder cancer treated by radical radiotherapy.

METHODS AND MATERIALS

Sixty-eight paraffin-embedded sections from surgically resected tumors taken prior to irradiation were immunostained for p21 and p53.

RESULTS

Nuclear staining for p21 and p53 was demonstrated in 32/68 (47%) and 46/68 (68%) tumors, respectively. There was no correlation between p21 and p53 immunopositivity in this group (r = 0.067, p = 0.56). Patients were stratified into four distinct groups depending on staining for p21 and p53: p21+p53+, p21+p53-, p21-p53+, and p21-p53-. Patients with p21+p53+ tumors had the best prognosis with a 3-year survival of 82% compared to 12% for p21-p53+ tumors (p = 0.0031), 29% for p21+p53- tumors (p = 0.0108); and 45% for p21-p53- tumors (p = 0.0375). The p21+p53+ group also demonstrated significantly improved survival when a combined analysis was performed of p21-p53+, p21-p53-, and p21+p53- tumors (3-year survival = 30%, p = 0.0062). In a multivariate model, p21+p53+ tumors (p = 0.0108, relative risk [RR] = 5.18) and complete/partial response (p = 0.0019, RR = 3.76) were the only independent predictors of improved survival.

CONCLUSIONS

With muscle-invasive bladder tumors treated by radical radiotherapy, stratification for p21 and p53 identifies distinct prognostic groups, with p21+p53+ tumors being associated with the best survival and p21-p53+ the worst.

Caveolin-1 expression is associated with high-grade bladder cancer

OBJECTIVES

To assess the levels of caveolin-1 in a series of bladder tumor specimens of varying stage and grade and to identify possible links between caveolin-1 status and clinical behavior. Caveolae have emerged as sites of important regulatory events at the cell membrane in many different cell types. Caveolins are the main structural components of caveolae and belong to a family of highly conserved integral membrane proteins. The function of caveolin-1 appears to be intrinsically linked to cell signaling modulation by multiple pathways. Modification of CAV-1 gene expression appears to be a common feature of the oncogenically transformed phenotype.

METHODS

Using a rabbit polyclonal antibody against caveolin-1 and immunohistochemistry, we assessed caveolin-1 protein expression in 89 formalin-fixed, paraffin-embedded bladder tumor sections. The patient group studied included 71 men and 18 women (mean age +/- SD 69.7 +/- 10.9 years). The stage was Ta-T1 in 68 and T2-T4 in 21 tumors in this series. The clinical follow-up was 1 to 38 months (mean 21.2 +/- 9.9).

RESULTS

A statistically significant association was observed between caveolin-1 immunoreactivity and tumor grade (P = 0.0118, chi-square test), with 8 (21%) of 38 G3, 1 (3%) of 30 G2, and 0 of 21 G1 tumors positive for caveolin-1. When the clinical data were examined in conjunction with caveolin-1 status, no statistically significant relationship was seen between caveolin-1 expression and tumor multiplicity, tumor recurrence, tumor progression, or patient survival.

CONCLUSIONS

The results of our study demonstrate that altered expression of caveolin-1 protein is a component of tumor dedifferentiation in a subset of high-grade bladder cancers. This pilot study provides a basis for further investigation of the role of caveolin-1 and the function of caveolae in the most aggressive forms of this tumor.

Localization and quantification of mRNA for matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in human benign and malignant prostatic tissue

BACKGROUND

The family of matrix metalloproteinases (MMPs) has been shown to be involved in proteolytic degradation of the extracellular matrix, which is an essential step in tumor invasion and metastasis. MMPs are tightly regulated by the levels of active enzymes and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs). MMP-2 and its ratio to TIMP-2 have been associated with tumor recurrence and progression in a number of human malignancies.

METHODS

We examined the relationship between MMP-2 and TIMP-2 mRNA expression in 42 men with malignant (n = 32) and benign (n = 10) prostates using nonisotopic in situ hybridization and Northern blot analysis.

RESULTS

mRNA for MMP-2 and TIMP-2 was localized to the malignant epithelial cells of both high- and low-grade tumors in the periphery of the glands and in areas of extracapsular involvement, and to the glandular epithelium in the benign prostates. Using Northern blot analysis, the mean MMP-2 to TIMP-2 ratio was approximately one in the benign prostates and low-grade and -stage cancers. The MMP-2 to TIMP-2 ratio increased to 3.3 in the high-grade and 2.8 in the high-stage tumors.

CONCLUSIONS

The results suggest a close association between MMP-2/TIMP-2 expression and local tumor invasion, with a disruption in expression of the two genes leading to disease progression. Future studies should focus on the activity of these enzymes and on the ratio of enzyme/inhibitor expression, which may become a useful prognostic marker in prostate cancer.

aFGF immunoreactivity in prostate cancer and its co-localization with bFGF and FGF8

Fibroblast growth factors (FGFs) have been implicated in the development of numerous malignancies including prostate cancer. In a pilot study it has been shown that FGF8 mRNA is up-regulated in prostate cancer. The aim of the present study was to determine whether aFGF and bFGF were co-expressed with FGF8 in human prostate cancer. Twenty-nine cases of prostate cancer of different histological grades were examined. Immunohistochemical analysis was employed to study aFGF and bFGF expression. In the light of the results, aFGF immunoreactivity was studied in a further 43 cases. aFGF and bFGF immunoreactivity was identified in the cytoplasm of the malignant prostatic epithelium. aFGF was overexpressed in 62/72 (86.1 per cent) cases and bFGF in 19/29 (65.5 per cent). High levels of aFGF immunoreactivity were noted in areas of high-grade prostatic intraepithelial neoplasia (PIN). In this series, aFGF immunoreactivity was most commonly observed and correlated closely with Gleason score and tumour stage ( p=0.007 and 0.007, respectively). Co-localization of aFGF, bFGF, and FGF8 was detected in 9/29 (31.0 per cent) cases. There was a significant correlation between aFGF and FGF8 expression. In conclusion, aFGF, bFGF, and FGF8 are co-localized in human prostate cancer; they may have a synergistic effect in prostate cancer growth and progression.

TP53 accumulation predicts improved survival in patients resistant to systemic cisplatin-based chemotherapy for muscle-invasive bladder cancer

To examine retrospectively the prognostic significance of TP53 immunoreactivity for both tumor response and patient survival in 83 patients with nonmetastatic muscle-invasive bladder cancer treated with a single transurethral resection (TUR) of tumor and combined cisplatin-based systemic chemotherapy followed by repeat TUR, paraffin-embedded sections of a bladder tumor obtained at TUR before chemotherapy (1 T2, 52 T3, and 30 T4) were immunostained for TP53 using monoclonal PAb1801 and DO-7 antibodies. For the entire cohort, TP53 immunopositivity (PAb1801 or DO-7) did not predict complete response (CR), complete or partial response (PR), progressive disease, or time to death from bladder cancer. There was a highly significant correlation between PAb1801 and DO-7 nuclear immunoreactivity (r = 0.8242; P<0.0001). In 76 patients in which complete clinical data were available, tumor stage (T2/T3; P = 0.0499), CR and PR (P = 0.0016) and CR (P<0.0001) were associated with patient survival. In a multivariate model, CR (P<0.0001) was the only independent predictor of improved survival. In complete responders, neither TP53 immunostaining nor clinicopathological factors stratified patients into prognostic groups. However, in the subset of patients (n = 38) who were chemoresistant (PR or progressive disease), improved survival was associated with > or =20% TP53 immunoreactivity (PAb1801; P = 0.0191) and tumor stage (T2/T3; P = 0.0358). TP53 immunopositivity (PAb1801 or DO-7) did not predict overall survival or response to systemic chemotherapy in patients with nonmetastatic but predominantly clinical stage > or =T3 bladder cancer, but it had prognostic significance within the chemoresistant subgroup.

Staging of prostate cancer using 3-dimensional transrectal ultrasound images: a pilot study

PURPOSE

We used conventional transrectal ultrasound images for 3-dimensional (D) reconstruction of the prostate, and determined its value in staging clinically localized prostate cancer.

MATERIALS AND METHODS

A total of 36 patients with newly diagnosed clinically localized prostate cancer were studied. All patients underwent conventional transrectal ultrasonography with 3-D reconstruction. Images were examined and analyzed blindly, and findings were compared to histopathological staging following radical prostatectomy.

RESULTS

Pathological staging of specimens revealed 15 sites of extracapsular extension in 10 patients, of whom 8 had positive margins and 2 had seminal vesicle invasion. The 3-D imaging identified 12 sites of extracapsular extension in 9 patients with 80% sensitivity, 96% specificity and 90% positive predictive value. Of the 2 patients with seminal vesicle invasion 1 was identified correctly on 3-D images. Overall staging accuracy of 3-D imaging was 94%.

CONCLUSIONS

The 3-D reconstruction of conventional transrectal ultrasonography imaging is superior to 2-D imaging for staging localized prostate cancer. However, this advantage relies entirely on the visibility of prostate cancer lesions on conventional ultrasonography. Further studies are warranted to evaluate this technology for the management of prostate cancer.

FGF8 over-expression in prostate cancer is associated with decreased patient survival and persists in androgen independent disease

Identification of prostate cancers at high risk of progression is difficult and a better understanding of how peptide growth factors influence cellular function might be useful. Fibroblast growth factors (FGFs) have been implicated in prostate cancer development. FGF8 was identified in the Shionogi mouse mammary carcinoma SC-3 cell line as an androgen-induced mitogen. We tested if FGF8 was over-expressed in human prostate cancer and if its expression correlated with clinical data and outcome. One hundred and six cases of prostate cancer and ten cases of BPH were examined. In situ hybridization was employed to detect FGF8 mRNA expression, which was identified within the malignant prostatic epithelium in 85/106 (80.2%) cases. Increased expression of FGF8 correlated significantly with higher Gleason scores (P=0.0004) and advanced tumour stage (P=0.0016). Using immunohistochemistry, we confirmed over-expression of the FGF8b isoform. Men with tumours which expressed high levels of FGF8 had worse survival (P=0.034), although FGF8 mRNA was not able to provide additional prognostic information in a multivariate analysis. Additionally, FGF8 expression was shown to persist in androgen independent prostate cancer. Using a range of normal adult tissues, FGF8 expression was restricted to neurones and the germinal epithelium in addition to the prostate. In vitro studies demonstrated that in the presence of neutralizing antibody to FGF8b there was significant inhibition of prostate cancer cell growth, confirming the biological significance of FGF8 in prostate carcinogenesis.

Expression of Bcl-2, Bax, and p53 in high-grade prostatic intraepithelial neoplasia and localized prostate cancer: relationship with apoptosis and proliferation

BACKGROUND

Apoptosis-regulating genes have been shown to be important in the biology of prostate cancer. The aim of this study was to examine and correlate the expression of the apoptosis-regulating genes bcl-2, bax, and p53 with the frequency of apoptosis and rate of proliferation in benign prostatic epithelium (BP), prostate cancer, and high-grade prostatic intraepithelial neoplasia (HGPIN), which is currently considered the most likely precursor of prostate cancer.

METHODS

Forty-four patients with histologically proven prostate cancer were investigated. All the men underwent radical prostatectomy. Immunohistochemistry was performed to assess expression of bcl-2, bax, and p53, and proliferation rate, as measured by the Ki-67 index. The frequency of apoptotic bodies was assessed by morphological criteria.

RESULTS

The apoptotic index (AI) was highest in prostate cancer, and was significantly greater in HGPIN compared to benign prostate. The Ki-67 index was greatest in cancer, intermediate in HGPIN, and lowest in BP. The AI was increased in areas of BP in patients treated with neoadjuvant androgen ablation. No change in AI was seen in treated cases of HGPIN or cancer. Accumulation of p53 protein was infrequent in prostate cancer (2/43: 4.6%), and was absent in HGPIN. Bcl-2 overexpression was present in 2.3% of cancers (1/43) and in 34.9% of cases of HGPIN (15/43). Bax expression was seen in all cases of cancer and HGPIN. There was no correlation between bcl-2 expression and the apoptotic and Ki-67 indices in HGPIN.

CONCLUSIONS

p53 and bcl-2 expression is infrequent in clinically organ confined prostate cancer. Bcl-2 expression is significantly higher in HGPIN than in both the associated prostate cancer and BP. The AI and Ki-67 index appeared intermediate in the putative precursor lesion HGPIN compared to prostate cancer and BP.

Neural network analysis of combined conventional and experimental prognostic markers in prostate cancer: a pilot study

Prostate cancer is the second most common malignancy in men in the UK. The disease is unpredictable in its behaviour and, at present, no single investigative method allows clinicians to differentiate between tumours that will progress and those that will remain quiescent. There is an increasing need for novel means to predict prognosis and outcome of the disease. The aim of this study was to assess the value of artificial neural networks in predicting outcome in prostate cancer in comparison with statistical methods, using a combination of conventional and experimental biological markers. Forty-one patients with different stages and grades of prostate cancer undergoing a variety of treatments were analysed. Artificial neural networks were used as follows: eight input neurons consisting of six conventional factors (age, stage, bone scan findings, grade, serum PSA, treatment) and two experimental markers (immunostaining for bcl-2 and p53, which are both apoptosis-regulating genes). Twenty-one patients were used for training and 20 for testing. A total of 80% of the patients were correctly classified regarding outcome using the combination of factors. When both bcl-2 and p53 immunoreactivity were excluded from the analysis, correct prediction of the outcome was achieved in only 60% of the patients (P = 0.0032). This study was able to demonstrate the value of artificial neural networks in the analysis of prognostic markers in prostate cancer. In addition, the potential for using this technology to evaluate novel markers is highlighted. Further large-scale analyses are required to incorporate this methodology into routine clinical practice.

Alterations of TP53 in microdissected transitional cell carcinoma of the human urinary bladder: high frequency of TP53 accumulation in the absence of detected mutations is associated with poor prognosis

We have used microdissection of paraffin-embedded histological sections and polymerase chain reaction (PCR)-based direct DNA sequencing for 54 transitional cell carcinoma (TCC) of the bladder, to examine critically the association between TP53 nuclear accumulation determined by immunohistochemistry and the presence of TP53 mutations, and to examine their relationship to tumour stage and grade, as well as patient survival. There was a significant association between the presence of TP53-positive nuclei (> 10%) and a higher histological stage and grade (P = 0.0115, P = 0.0151 respectively; Fisher's exact). A significant association between TP53 gene mutations and TP53 nuclear reactivity in more than 10% of tumour cell nuclei was also observed (P = 0.0003; Fisher's exact). Mutations were detected in 18/54 (33%) cases together with the wild-type sequence when analysed from bulk frozen samples, with significant clustering of mutations in exons 7 and 8. The microdissection method distinguished more clearly between heterozygous and/or homozygous alterations of the TP53 tumour-suppressor gene, and clearly showed frequent accumulation of TP53 in the absence of mutations. When microdissecting immunonegative regions from the same paraffin sections, three out of ten samples showed the identical mutations detected in the immunopositive regions. There was a significant association between TP53 immunoreactivity in more than 50% of tumour cell nuclei and decreased survival among all patients (P = 0.0325; log-rank test). The patients with TP53 mutations showed a trend for a shorter survival period; however, the association was not statistically significant at the 95% confidence level (P = 0.132; log-rank test). In conclusion, our observations show that accumulation of TP53 occurs frequently in the absence of mutations, and that such accumulation is nevertheless associated with poor survival when it occurs in a high proportion (> 50%) of tumour cell nuclei.

The immunohistochemical detection of cripto-1 in benign and malignant human bladder

The recently identified epidermal growth factor-related peptide cripto-1 has been previously implicated in the development of the malignant phenotype. The identification of gene products that can act as prognostic markers in bladder cancer would be value in determining the management of this heterogeneous group of patients. This study examines cripto-1 expression in benign and malignant bladder using immunohistochemical techniques. The expression of cripto-1 protein in benign and malignant bladder was examined in 45 bladder tumours (Ta/T1 n = 26, T2 n = 5, T3/T4 n = 14) and six benign controls. All 45 tumours showed positive cytoplasmic staining for cripto-1, including areas of carcinoma in situ. None of the six benign controls showed any evidence of positive cripto-1 staining. Twenty-three (60 per cent) bladder tumours had areas of papillary tumour that showed strong positive staining for cripto-1 as opposed to six (29 per cent) sections of histologically normal urothelium adjacent to tumour (P < 0.05). There was no association between cripto-1 staining and tumour grade, stage, or clinical outcome. Cripto-1 protein appears to be specifically expressed in malignant and benign adjacent urothelium of patients with bladder cancer. Its clinical significance, however, remains to be determined.

Immunolocalization and messenger RNA expression of bone morphogenetic protein-6 in human benign and malignant prostatic tissue

Skeletal metastases are common in advanced prostate cancer, causing considerable morbidity, and they are usually osteoblastic in nature with no clear explanation for this phenomenon. Bone morphogenetic proteins (BMPs) induce bone formation in vivo, and preliminary work showed a possible association between BMPs and prostatic skeletal metastases; differential expression favors BMP-6 as a potential new marker and mediator of osteosclerotic deposit formation. We investigated BMP-6 mRNA and protein expression by in situ hybridization and immunohistochemistry in malignant and benign prostates from 40 men. BMP-6 mRNA expression was detected exclusively in malignant epithelial cells in 20 of 21 patients (95%) with metastases and in 2 of 11 patients (18%) with localized cancer, and it was absent in 8 benign samples. Immunostaining for BMP-6 was predominantly cytoplasmic and was present in all primary tumors with established metastases and in 4 of 11 (36%) organ-confined cancers. In benign prostatic hyperplasia, basal cells and areas of basal cell hyperplasia were positive for BMP-6 by immunohistochemistry. The results suggest a close association between BMP-6 expression in primary malignant prostatic tissue and skeletal metastases. BMP-6 may be responsible, in part, for the osteoblastic changes in metastatic lesions secondary to prostate cancer.

Development of a minimally invasive technique for coronary revascularization in a porcine model

BACKGROUND

This porcine model was designed to develop a minimally invasive method for internal mammary artery (IMA) grafting using an anterior mediastinal approach and without routine use of cardiopulmonary bypass.

METHODS

Assessment was made of IMA mobilization through a small parasternal incision, the feasibility of coronary artery grafting with cardiopulmonary bypass using this approach, and conditions for off-pump bypass grafting.

RESULTS

In group 1, 6 pigs underwent IMA mobilization through a 5-cm horizontal midparasternal incision. Of the 2 group 2 pigs, 1 underwent IMA grafting to the left anterior descending coronary artery and the other, bilateral IMA grafting to the left anterior descending and right coronary arteries using femoral-vessel cardiopulmonary bypass. In group 3, 4 of 10 pigs had successful off-pump grafting during retrograde regional coronary venous perfusion of arterial blood. Retrograde coronary venous perfusion could not be established in the other 6 pigs, and attempts at off-pump grafting failed.

CONCLUSIONS

The study demonstrates that coronary artery grafting with the IMA by this minimally invasive off-pump method is feasible, although it draws attention to areas of concern and potential methods of correction. The model provides a realistic and important learning platform for the surgical issues involved with this minimally invasive technique.

Transient ventricular asystole using adenosine during minimally invasive and open sternotomy coronary artery bypass grafting

BACKGROUND

The emergence of minimally invasive coronary artery bypass grafting and recent off-pump open sternotomy clinical reports have refocused attention on the technical aspects and outcome of grafting on the beating heart.

METHODS

To optimize the surgical field we report a method using adenosine for induction of controlled intervals of ventricular asystole to produce a transiently still cardiac field that facilitates anastomotic accuracy.

RESULTS

Adenosine was used in 57 patients, 31 included off-pump coronary artery bypass grafting (27 by minimally invasive technique, 4 by open sternotomy). In a further 26 patients adenosine pauses were used for suture placement to control anastomotic bleeding after cardiopulmonary bypass. Average adenosine boluses per anastomosis were 9 (6-14), mean dose of adenosine per bolus (mg/kg) was 0.24 (0.15-0.35), mean duration of pause (seconds) was 6 (3-19), and mean time for arterial blood pressure (mean) to return to baseline (seconds) was 35 (13-48). Presence of repolarization arrhythmias was noted in 1 patient. There were no deaths. Two patients had recurrent myocardial ischemia shown on angiography to be the result of technical problems.

CONCLUSIONS

This report describes our experience with the emerging procedure of minimally invasive coronary operations and off-pump grafting with the adenosine technique. The method also includes mechanical devices and other pharmacological therapy to optimize the surgical field, and the technique has now become a standard component of our off-pump revascularization methods.

The expression of waf-1, p53 and bcl-2 in prostatic adenocarcinoma

OBJECTIVE

To determine the associations between the expression of waf-1 (a cyclin-dependent kinase inhibitor regulated by p53), p53, bcl-2 and tumour progression in prostate cancer.

PATIENTS AND METHODS

Samples of prostatic tissue were obtained by biopsy or at prostatectomy from 40 men (mean age 73 years, range 55-88) with histologically confirmed prostate cancer, examined using immunohistochemical staining for the three gene products, and the expression related to the stage, grade, disease progression and survival of the patients.

RESULTS

Fifteen of 18 patients whose tumours were positive for waf-1, 10 of 12 positive for bcl-2 and 17 of 19 positive for p53 had disease progression. Fifteen of 19 patients positive for p53 had poorly differentiated tumours compared with 11 of 21 negative for p53 (P < 0.05). A significant number of patients positive for p53 progressed and had a shorter time to progression compared to those negative for p53 (P < 0.05). There was no correlation between either waf-1 and/or bcl-2 staining and clinical grade, stage or tumour progression.

CONCLUSIONS

This study confirmed the association of p53 protein accumulation with aggressive behaviour in prostate cancer and identified waf-1 protein in prostatic tumours. There was no evidence that the upregulation of waf-1 was associated with a better outcome in patients with prostate cancer.

bcl-2 overexpression combined with p53 protein accumulation correlates with hormone-refractory prostate cancer

Seventy-seven men with histologically proven and newly diagnosed prostate cancer we investigated for the presence of bcl-2 protein overexpression and p53 protein accumulation 1 immunohistochemistry. Forty-five men had evidence of locally advanced and metastatic disease and we treated by means of hormone manipulation. Twenty-eight patients either failed to respond to initial hormone manipulation or relapsed within 37 months from diagnosis (median 20 months). Of the 77 cancers, 37 (48% showed bcl-2 overexpression at diagnosis. Twenty-seven of those were treated with androgen ablation and 2 (74%) had hormone-refractory disease (P = 0.0128). Twenty-three of 77 men (29.8%) had nuclear staining for p53 protein. Twenty-one of those were treated with hormone manipulation and 14 (66.6%) showed hormone resistance (P = 0.0012). Seventeen patients had both bcl-2 overexpression and p53 protein accumulation, 16 of whom were hormonally treated, with 13 (81.2%) having hormone-refractory disease (P < 0.0001). These findings suggest that the combined detection of p53 protein accumulation and bcl-2 overexpression may be useful in predicting hormone resistance in prostate cancer. By deregulating programmed cell death, alteration in these genes may prevent patients from responding to androgen ablation, or allow them to escape hormonal control of the disease.

A systematic study of hypothermic lung preservation solutions: Euro-Collins solution

BACKGROUND

Testing lung function after preservation is difficult because a suitable model is still lacking; thus, the effectiveness of different solutions for lung preservation has not been confirmed. This study tested the effectiveness of Euro-Collins solution alone for hypothermic preservation of rat lungs.

METHODS

A living rat perfusion model was used, which allowed more than 5 hours of continuous perfusion for isolated lung function studies. Group 1 lungs (control, n = 8) were tested without preservation. In groups 2 through 6 (n = 8 lungs each), the lungs were flushed with 4 degrees C Euro-Collins solution and preserved for 4, 6, 8, 12, and 24 hours, respectively. Lung function studies were carried out after preservation.

RESULTS

In groups 1 and 2, pulmonary arterial blood flow and pulmonary venous oxygen tension were higher and pulmonary resistance was lower than in the other groups. Airway pressure and resistance were lowest in group 1. Lungs in groups 5 and 6 demonstrated the worst function, but the lung tissue wet to dry ratio was higher only in group 6.

CONCLUSIONS

At 4 degrees C, Euro-Collins solution can effectively preserve rat lungs for 4 hours. Six to 8 hours of preservation resulted in depressed lung function. More than 12 hours of preservation resulted in uniformly deficient lung function, rendering the lungs unsuitable for transplantation.

Primary choriocarcinoma of the urinary bladder: a case report

We present a 37-year-old patient with primary choriocarcinoma arising in the urinary bladder, who received 5 months of intensive chemotherapy with a very good response. He died of a pulmonary embolus before his treatment could be completed. A post-mortem examination revealed extensive necrotic nodules in the lungs and brain. There was only one small focus of viable tumour in the brain. There was no residual tumour in the bladder, and no testicular tumours or scars fulfilling the criteria for a true extragonadal teratoma. It is likely that the origin of the bladder choriocarcinomas is from metaplasia/de-differentiation of a transitional cell carcinoma to the level of trophoblast. Lesser degrees of differentiation producing functional changes in the carcinoma cells with secretion of beta hCG without structural changes are much more common.

Minimally invasive coronary artery bypass grafting: a new method using an anterior mediastinotomy

The benefit of internal mammary artery (IMA) grafting as a long-lasting intervention for coronary artery disease is well recognized. However, largely because they are less invasive, catheter based alternatives are frequently chosen, particularly to treat single or double vessel disease. To retain the advantages of the IMA graft, and to offset the invasiveness of conventional coronary artery bypass grafting, we developed a new minimally invasive method using an anterior mediastinotomy for treating left anterior descending (LAD) or right coronary artery disease, or both. Feasibility studies using 16 pigs and a human cadaver led to approval by the Institutional Review Board for use of this procedure to treat six patients (four men, two women; mean age, 63.8 +/- 13.6 [SD] yrs) who granted informed consent. Pedicle dissection of the IMA, using video assisted thoracoscopy if necessary, was made through a 2- to 3-inch horizontal anterior mediastinotomy. The underlying LAD artery was grafted during femoral vessel cardiopulmonary bypass, with cooling to 30 degrees C, induced ventricular fibrillation, and left ventricular venting if required. Transesophageal echocardiography performed after bypass showed that two patients maintained normal wall motion and four had improvement from the original impairment. One patient suffered a recurrence of angina 4 weeks after the procedure; recatheterization showed an acutely angled IMA, subsequently corrected by balloon angioplasty. The results of follow-up dobutamine echocardiographic stress tests were negative in all patients. With this minimally invasive approach, the procedure should provide the benefits of IMA grafting with shorter hospital stay, more rapid recovery, and less overall cost.

Tc-99m MAA lung perfusion scintigraphy performed before and after pulmonary embolectomy for saddle-type pulmonary embolism

A 58-year-old man had shortness of breath, hypotension, and decreased partial pressure of oxygen (PO2) on the eighteenth day after undergoing craniotomy for a meningioma. Tc-99m MAA pulmonary perfusion scintigraphy showed little perfusion to the right lung and left lower lung and multiple perfusion defects in the left upper lung. Although the results of concurrent chest radiography were negative for pulmonary infiltrates, pulmonary angiography demonstrated a saddle-type embolism. The patient underwent emergency pulmonary artery embolectomy to remove blood clots and organized thromboemboli from the main pulmonary artery and the right and left pulmonary arteries. The patient's postoperative course was uneventful, and a second Tc-99m MAA lung perfusion scan demonstrated marked improvement in lung perfusion.

c-jun oncogene expression in transitional cell carcinoma of the urinary bladder

OBJECTIVE

To investigate c-jun oncoprotein expression in transitional cell carcinomas (TCCs) of the urinary bladder and to determine its relationship to tumour grade and stage, and to the expression of epidermal growth factor receptor (EGFR), c-erbB-2 and p53 oncoproteins.

MATERIALS AND METHODS

The expression of c-jun was studied using immunohistochemistry in a series of 48 TCCs of known EGFR, c-erbB-2 and p53 status.

RESULTS

Forty-four of 48 (92%) tumours showed c-jun specific nuclear immunoreactivity of variable intensity. The intensity of c-jun immunostaining was significantly related to tumour stage (P = 0.009) and EGFR status (P = 0.01). There was no correlation between c-jun oncoprotein expression and c-erbB-2 or p53 immunoreactivity. c-jun expression was not related to clinical outcome in terms of patient survival or rate of tumour recurrence.

CONCLUSION

The c-jun oncoprotein is expressed in the majority of TCCs of the urinary bladder. There is a positive association between intense c-jun immunoreactivity and muscle invasive growth, and EGFR positivity in TCCs.

P53 expression, ploidy and progression in pT1 transitional cell carcinoma of the bladder

OBJECTIVE

To investigate a potential role for overexpression of the p53 protein in the identification of pT1 bladder tumours destined to progress.

PATIENTS AND METHODS

The protein expression of the tumour suppressor gene p53, nuclear ploidy and tumour grade were studied in 25 patients with pT1 bladder tumours. Follow-up data was available for 21 tumours over a 10 year period. p53 expression was determined by immuno-histochemistry on paraffin embedded sections and flow cytometry was performed on cell suspensions derived from the same blocks.

RESULTS

Ten of 21 (48%) tumours progressed to muscle invasive disease. Nuclear staining for the protein was seen in 16 (64%) tumours and of these nine (56%) progressed. All tumours with abnormal DNA content and all high grade tumours demonstrated overexpression of p53. Significantly more patients with high levels of p53 expression (> 10% nuclear staining) progressed compared with tumours with less than 10% of nuclei staining (P = 0.007). However, grade was the most specific predictor of progression (100%), with all grade 3 tumours progressing and grade was also the most significant prognostic indicator in terms of survival (P = 0.025).

CONCLUSION

Tumour grade is likely to remain as the most useful aid to management decisions in pT1 bladder tumours.

Abnormalities in p53 and DNA content in transitional cell carcinoma of the bladder

OBJECTIVE

To determine if transitional cell tumours of the bladder which contain mutations in the p53 gene have alterations in their DNA content.

MATERIALS AND METHODS

In 33 transitional cell tumours of the bladder, DNA content was determined by flow cytometry and compared with expression of mutant p53 as assessed by immuno-histochemistry.

RESULTS

Abnormal DNA content was associated with increased staining for p53 (P < 0.05), high tumour stage (P < 0.001) and increased histological grade (P < 0.01). Although positive staining for p53 was frequently associated with abnormal DNA content, a significant number of non-diploid tumours stained negatively for mutant p53.

CONCLUSION

These data demonstrate that increased staining for p53 is associated with abnormalities in DNA content suggesting that mutation of the p53 gene is associated with an increased rate of chromosomal abnormalities and an increased rate of cell proliferation.

Cholesterol-lowering effect of barley bran flour and oil

OBJECTIVE

To compare the effects of adding barley bran flour and a barley oil extract to a fat-modified diet on serum lipids in persons with hypercholesterolemia.

DESIGN

The basic design of the study was a randomized, 30-day intervention trial. It included a neutral-fiber control group and a 1-week preintervention period for the collection of baseline data.

SUBJECTS

The subjects were 79 men and women with hypercholesterolemia. Subjects had a mean age of 48.2 years, and all completed the study.

INTERVENTION

All participants were instructed to follow the National Cholesterol Education Program (NCEP) step 1 diet and were randomly assigned to one of three treatment groups: 20 g added cellulose, 3 g added barley oil extract, or 30 g added barley bran flour.

MAIN OUTCOME MEASURES

Total serum cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and very-low-density lipoprotein cholesterol were measured, along with serum triglycerides, before the intervention, at week 1, at week 3, and at the end of the intervention.

STATISTICAL ANALYSES PERFORMED

Student's paired t test was used to detect significant changes within each treatment group from baseline to the end of the 30-day intervention. In addition, Pearson's correlation coefficients were used to detect significant correlations between the variables measured.

RESULTS

Addition of barley bran flour significantly (P = .0001) decreased total serum cholesterol (-0.60 mmol/L) as did addition of barley oil (-0.50 mmol/L; P = .002) after 30 days of intervention. Similarly, LDL-C decreased 6.5% with addition of barley bran flour (P = .036) and 9.2% with addition of barley oil (P = .003). Total serum cholesterol or LDL-C of the cellulose control group did not decrease significantly over the same period. HDL-C decreased significantly in the cellulose control group and the barley bran flour group (-0.15 mmol/L, P = .012, and -0.15 mmol/L, P = .006, respectively), but not in the barley oil group.

CONCLUSION

We conclude that addition of barley bran flour or barley oil enhances the cholesterol-lowering effect of the NCEP step 1 diet in individuals with hypercholesterolemia.

Ischemic heart disease in the elderly: the role of coronary angioplasty and coronary artery bypass grafting

Management of ischemic heart disease in the elderly is complex. Invasive therapies such as percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) are associated with significant morbidity and mortality. The short-term advantage of PTCA is that its associated noncardiac morbidity and mortality are less than that of CABG, particularly in the incidence of stroke. Unfortunately, PTCA revascularization is less complete and less durable than CABG revascularization. The advantages of CABG are that cardiac revascularization is more complete, the result is more durable, and long-term results are improved over those of PTCA. Conversely, the initial morbidity and mortality are higher for CABG and are adversely affected by factors such as recent myocardial infarction, lung disease, and renal failure. We provide an overview of the results and outcomes of PTCA and CABG in the elderly, as well as suggestions for management.

Barley bran flour accelerates gastrointestinal transit time

The effect of barley bran flour on colon physiology was studied in 44 volunteers. Twenty-two subjects followed the National Cholesterol Education Program (NCEP) step 1 diet supplemented with 20 g cellulose and the other 22 followed the NCEP diet supplemented with 30 g barley bran flour. To measure gastrointestinal transit time, subjects ingested 20 polyethylene pellets impregnated with barium sulfate in two gelatin capsules. Subjects collected fecal samples for 5 days during the baseline period and again during the period of fiber supplementation. Each stool sample was radiographed, and the number of recovered markers was used to calculate mean transit time. Daily fecal weights were recorded and dry weights were determined. The group that consumed barley bran flour significantly decreased transit time by 8.02 hours from baseline, whereas the group that consumed cellulose increased transit time by 2.95 hours from baseline. Similarly, cellulose supplementation did not result in increased fecal weight, whereas daily fecal weight increased significantly by 48.6 g with supplementation with barley bran flour. This study shows that barley bran flour accelerates gastrointestinal transit and increases fecal weight.

Surgical correction of the Wolff-Parkinson-White syndrome

The results of corrective surgery in 75 consecutive patients with Wolff-Parkinson-White (WPW) syndrome are reported. There were 47 male and 28 female patients with a median age of 27 years. Intraoperative mapping disclosed 88 accessory pathways, of which 83 were successfully divided at the primary operation without mortality. Two patients underwent successful reoperation at three days and two years respectively. Patient success rates were 93% and 96% for first and total operations. Complications, usually minor, occurred in 20 patients, including permanent pacemaker implantation in two. Surgical correction of WPW syndrome is recommended as a safe alternative to lifelong medical treatment.

Results of Medical Research Council phase II study of low dose cisplatin and methotrexate in the primary treatment of locally advanced (T3 and T4) transitional cell carcinoma of the bladder

A series of 49 previously untreated patients with category T3 or T4 bladder cancer underwent treatment with low dose methotrexate and cisplatin; 44 patients were eligible for assessment of response. Complete response (CR) was seen in 5 patients (11%) and partial response in 15 (34%) (overall response rate 45%). Treatment was reasonably well tolerated with no major morbidity and no treatment-related deaths. After a median follow-up of 3.5 years, the 1-year and 2-year survival rates were 70 and 30% respectively. Ten patients remain recurrence-free without having received "definitive local therapy" (cystectomy and/or radiotherapy) at follow-up extending from 20 to 50 months.

Operations for Wolff-Parkinson-White syndrome

Forty-six patients with symptomatic tachycardia underwent operations to divide 55 atrioventricular accessory pathways. Mean age was 29 years (range 11 to 63). Ten patients (22%) had associated cardiac disease, including two with a congenital diverticulum of the coronary sinus and six (13%) who had concomitant surgical procedures. A bipolar hand-held electrode was used in 22 operations, and simultaneous multisite mapping in the last 24 operations. Ten patients (22%) had multiple accessory pathways. A modified endocardial approach was used. The overall patient success rate was 93% with 91% to 93% of accessory pathways successfully divided. The perioperative morbidity was 17%. There were two reoperations. There were no early or late deaths. Patients have been followed up for a mean of 16 months. There were five recurrences of preexcitation (two early, three late). Two of these patients (both with a congenital diverticulum of the coronary sinus) had reoperation. One patient had late recurrence of atrial fibrillation. Operation for the Wolff-Parkinson-White syndrome has a high probability of success with a low operative risk.

In vitro antimicrobial susceptibilities of 349 methicillin-resistant Staphylococcus aureus isolates from veterans

Three hundred and forty-nine methicillin resistant Staphylococcus aureus (MRSA) isolates from veterans were tested (by disc agar diffusion) for their in vitro activity against 18 antimicrobial agents. At least 90% of the isolates were susceptible to bacitracin, nitrofurantoin, hydrogen peroxide, novobiocin, netilmicin and vancomycin. We feel that the aminoglycoside, netilmicin, might provide an alternative agent (to intravenously administered vancomycin) for treating multiply-antimicrobial resistant MRSA. In addition, hydrogen peroxide exhibited very good activity against the test isolates and may have some use as a topical agent for reduction of MRSA on skin and some mucous membranes. This study suggests that further evaluation of netilmicin and hydrogen peroxide (topical only) might be useful.

Cell cycling in bladder carcinoma determined by monoclonal antibody Ki67

Current methods of predicting prognosis in transitional cell carcinoma of the bladder fail to provide consistently reliable information about future tumour behaviour. The monoclonal antibody Ki67 recognises an antigen present in actively dividing cells and Ki67 reactivity has been shown to correlate with conventional prognostic indicators in several tumours. In this study, Ki67 antibody was used to determine the proportions of cells undergoing active division in 26 transitional cell carcinomas of the bladder. The proportion of cells stained in muscle invasive tumours (12.3 +/- 5.4%) was significantly greater than in superficial tumours (4.3 +/- 1.9%) and poorly differentiated tumours showed significantly greater proportions of cells staining compared with well or moderately well differentiated tumours. These results show that Ki67 reactivity correlates with high tumour stage and poor differentiation. Ki67 staining provides an easy method of determining tumour cell turnover that might provide additional prognostic information.

Acute dissection of the internal mammary artery: a fatal complication of coronary artery bypass grafting

A case of acute traumatic dissection of the right internal mammary artery is presented in a patient who had both IMAs grafted for recurrent angina 10 years after initial vein coronary revascularisation. The event was mistaken for spasm, but because of severe circulatory collapse no time was available to treat the patient appropriately. The purpose of this report is to facilitate the early recognition and avoidance of this potentially fatal complication.

Effects of verapamil and carbon monoxide on blood pressure and heart mass in the spontaneously hypertensive rat

Studies were carried out to examine the relationship between blood pressure lowering using the Ca2+ channel blocker verapamil, and regression of ventricular hypertrophy, in the spontaneously hypertensive rat (SHR). Untreated male SHR showed rapidly developing hypertension (systolic pressure 194 +/- 2 mm Hg, 109 days of age) and moderate ventricular hypertrophy. Verapamil (Calan-SR, G.D. Searle Co.) treatment for 30 days at maximum doses of 18.7 and 49.9 mg/kg per day supplied in the food, lowered blood pressure maximally 37 mm Hg. The drug had no effect on heart rate. Decrease in the mass of the left ventricle plus interventricular septum was positively correlated with the verapamil-induced decrease in blood pressure (r = 0.69, P less than 0.001). SHR exposed continuously to 500 ppm carbon monoxide (CO) for 30 days showed a similar decrease in blood pressure (33.0 mm Hg). Such SHR, however, displayed increases in mass of the left ventricle plus septum and right ventricle, and of hematocrit, nearly identical to same age Sprague-Dawley rats similarly exposed to CO. Neither verapamil nor CO treatment altered myocardial water content. The results suggest that a modest lowering of blood pressure with verapamil in the SHR produces a relatively rapid decrease in left ventricular mass. It also shows that even when afterload is reduced in the SHR, as with CO, substantial ventricular hypertrophy develops, probably because of augmented preload, and that it is comparable to that produced in non-hypertensive rats.

Bladder carcinosarcomas: three cases with diverse histogenesis

Carcinosarcomas of the bladder are rare. We describe three such tumours, including an apparently unique case in which the components comprised liposarcoma and poorly-differentiated transitional cell elements. A second example included chondrosarcomatous elements. These two tumours showed architectural and immunocytochemical features which suggested that they had originated as carcinomas but had subsequently differentiated along both epithelial and mesenchymal pathways. The third tumour contained both carcinoma and osteosarcoma and may represent a collision tumour.

Cardiac transplantation in New Zealand: an initial report

During the first 18 months of its establishment, the cardiac transplant unit at Green Lane Hospital has undertaken 10 transplant operations. Fifty potential recipients have been referred and 15 were accepted for transplantation. Of the ten who have had surgery, 2 are making good progress at school, 1 is active at home and 5 have returned to work. Two patients have died.

Catheter ablation of the atrioventricular junction in patients with refractory atrial arrhythmias

Twelve patients with refractory symptomatic atrial arrhythmias were evaluated for closed chest ablation and permanent pacemaker implantation. This was successful in nine of the 11 patients in whom ablation was attempted. Two of these nine patients required two separate ablative procedures. Three patients underwent open surgical ablation. Electrical ablation had failed in two of these patients and had not been undertaken in the remaining patient (inadequate His recording). The mean His amplitude and delivered energy levels were not significantly different between the two groups. Complications occurred in three patients and were minor. Because ventricular arrhythmias and late sudden death are recognised complications in a minority of patients undergoing closed chest ablation of the A-V junction it should be restricted to patients with symptomatic atrial arrhythmias who have failed maximal medical treatment.

Structural features of saphenous vein and internal thoracic artery endothelium: correlates with susceptibility and resistance to graft atherosclerosis

Examination of saphenous vein (SV) and internal thoracic artery (ITA) endothelium at the time of coronary bypass surgery has confirmed the known susceptibility of SV to endothelial cell loss during preparation for grafting. In contrast the ITA showed only minimal cell loss. An ultrastructural morphometric analysis of the abluminal surface of the endothelium of both vessels showed significant differences in the numbers and depth of penetration of cytoplasmic processes or folds. Whereas the SV, perfusion-fixed at 110 mmHg, possessed relatively few (15/100 micron) and shallow (less than 1 micron deep) processes the ITA had significantly more (27/100 micron) and deeper (18% greater than 1 micron) processes. The ITA endothelial cells were also smaller and thicker. We suggest that the differences in the numbers and depth of the processes, which are believed to play a role in endothelial attachment, may account for the differing susceptibility of the two vessels to endothelial damage during grafting. This in turn correlates with the known susceptibility of SV grafts and resistance of ITA grafts to atherosclerotic changes.

Monocusp aortic valve replacement in dogs: an experimental model

Aortic valve replacement using human allograft valves is a well established procedure, following which histological evidence of a host-graft interaction is seen. This varies in intensity, depending on the types of sterilizing and storage agents to which the allograft is exposed prior to insertion. A canine experimental model which enables study of these tissue ingrowth patterns in variously treated allografts has been devised. The technique is described in detail.

Capacitance determination of the area thermal expansion of dielectric crystals

Both the area thermal expansion and the dielectric constant of a solid insulator are determined by a capacitance technique in which the change in area of a capacitor is first caused by the variation with temperature of the dimensions of the dielectric, and then by the variation over the same temperature range of the dimensions of copper electrodes, the same sample being used in both cases. This method is particularly convenient for small, flat crystals under hydrostatic pressure and for anisotropic crystals. It is believed that a similar method could be used to measure the compressibility. The apparatus and calculations are described, and the results of a test run on the thermal expansion of NaCl are compared with previous data. Between 77 and 250 K, the measured linear thermal expansion L (T)/L (300) of NaCl agrees with the results of a Fabry-Perot etalon experiment to within 0.03%, giving differences in the coefficient of linear expansion of 10% in the worst case.