No evidence that frailty modifies the positive impact of antihypertensive treatment in very elderly people: an investigation of the impact of frailty upon treatment effect in the HYpertension in the Very Elderly Trial (HYVET) study, a double-blind, placebo-controlled study of antihypertensives in people with hypertension aged 80 and over

BACKGROUND

Treatment for hypertension with antihypertensive medication has been shown to reduce stroke, cardiovascular events, and mortality in older adults, but there is concern that such treatment may not be appropriate in frailer older adults. To investigate whether there is an interaction between effect of treatment for hypertension and frailty in older adults, we calculated the frailty index (FI) for all available participants from the HYpertension in the Very Elderly Trial (HYVET) study, a double-blind, placebo-controlled study of antihypertensives in people with hypertension aged 80 and over, and obtained frailty adjusted estimates of the effect of treatment with antihypertensive medication on risk of stroke, cardiovascular events, and mortality.

METHODS

Participants in HYVET were randomised 1:1 to active treatment with indapamide sustained release 1.5 mg ± perindopril 2 to 4 mg or to matching placebo. Data relating to blood pressure, comorbidities, cognitive function, depression, and quality of life were collected at entry into the study and at subsequent follow-up visits. The FI was calculated at entry, based on 60 potential deficits. The distribution of FI was similar to that seen in population studies of adults aged 80 years and above (median FI, 0.17; IQR, 0.11-0.24). Cox regression was used to assess the impact of FI at entry to the study on subsequent risk of stroke, total mortality, and cardiovascular events. Models were stratified by region of recruitment and adjusted for sex and age at entry. Extending these models to include a term for a possible interaction between treatment for hypertension and FI provided a formula for the treatment effect as a function of FI. For all three models, the point estimates of the hazard ratios for the treatment effect decreased as FI increased, although to varying degrees and with varying certainty.

RESULTS

We found no evidence of an interaction between effect of treatment for hypertension and frailty as measured by the FI. Both the frailer and the fitter older adults with hypertension appeared to gain from treatment.

CONCLUSIONS

Further work to examine whether antihypertensive treatment modifies frailty as measured by the FI should be explored.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00122811 (July 2005).

Addition of transversus abdominis plane block to patient controlled analgesia for laparoscopic high anterior resection improves analgesia, reduces opioid requirement and expedites recovery of bowel function

INTRODUCTION

Opioid sparing in postoperative pain management appears key in colorectal enhanced recovery. Transversus abdominis plane (TAP) blocks offer such an effect. This study aimed to quantify this effect on pain, opioid use and recovery of bowel function after laparoscopic high anterior resection.

METHODS

This was a retrospective analysis of prospective data on 68 patients. Patients received an epidural (n=24), intravenous morphine patient controlled analgesia (PCA, n=22) or TAP blocks plus PCA (n=22) determined by anaesthetist preference. Outcome measures were numerical pain scores (0-3), cumulative intravenous morphine dose and time to recovery of bowel function (passage of flatus or stool).

RESULTS

There were no differences in patient characteristics, complications or extraction site. The TAP block group had lower pain scores (0.7 vs 1.36, p<0.001) and morphine requirements (8 mg vs 15 mg, p=0.01) than the group receiving PCA alone at 12 hours and 24 hours. Earlier passage of flatus (2.0 vs 2.7 vs 3.4 days, p=0.002), stool (3.1 vs 4.1 vs 5.5 days, p=0.04) and earlier discharge (4 vs 5 vs 6 days, p=0.02) were also seen.

CONCLUSIONS

Use of TAP blocks was found to reduce pain and morphine use compared with PCA, expedite recovery of bowel function compared with PCA and epidural, and expedite hospital discharge compared with epidural.

A case-control study to assess the impact of mammographic density on breast cancer risk in women aged 40-49 at intermediate familial risk

Mammographic density is a strong risk factor for breast cancer, but its potential application in risk management is not clear, partly due to uncertainties about its interaction with other breast cancer risk factors. We aimed to quantify the impact of mammographic density on breast cancer risk in women aged 40-49 at intermediate familial risk of breast cancer (average lifetime risk of 23%), in particular in premenopausal women, and to investigate its relationship with other breast cancer risk factors in this population. We present the results from a case-control study nested with the FH01 cohort study of 6,710 women mostly aged 40-49 at intermediate familial risk of breast cancer. One hundred and three cases of breast cancer were age-matched to one or two controls. Density was measured by semiautomated interactive thresholding. Absolute density, but not percent density, was a significant risk factor for breast cancer in this population after adjusting for area of nondense tissue (OR per 10 cm(2) = 1.07, 95% CI 1.00-1.15, p = 0.04). The effect was stronger in premenopausal women, who made up the majority of the study population. Absolute density remained a significant predictor of breast cancer risk after adjusting for age at menarche, age at first live birth, parity, past or present hormone replacement therapy, and the Tyrer-Cuzick 10-year relative risk estimate of breast cancer. Absolute density can improve breast cancer risk stratification and delineation of high-risk groups alongside the Tyrer-Cuzick 10-year relative risk estimate.

Variation in colorectal cancer treatment and survival: a cohort study covering the East Anglia region

AIM

National guidelines for colorectal cancer management aim to optimize cancer outcomes irrespective of postcode. However, in order to ensure equal performance of cancer services, variation in outcome must be monitored and intelligently assessed. In this study, detailed regional cancer registry data were used to quantify and explore the reasons for variation in colorectal cancer outcomes at nine hospitals in East Anglia.

METHOD

We analysed data on colorectal cancers registered by the Eastern Cancer Registry and Information Centre (ECRIC) between 1999 and 2005. Tumours were grouped by site, in keeping with surgical resection. Multivariable Cox regression models were used to identify the effects of patient, disease and treatment variables on an individual's risk of death.

RESULTS

After adjusting for demographic, disease and treatment variables there were significant differences in survival among hospitals in emergency admissions with cancer of the right colon, in elective admissions with cancer of the left, sigmoid or recto-sigmoid colon and in emergency admissions with cancer of the rectum. There were also differences among hospitals in terms of perioperative death, nonsurgical management and numbers of nodes examined. For rectal cancers, rates of anterior resection compared with abdominoperineal excision differed, as well as the use of neoadjuvant radiotherapy.

CONCLUSION

Detailed analysis of demographic, disease and treatment factors are required when comparing the survival of individuals with colorectal cancer across hospitals. The results imply that cancer management was not consistent across East Anglia in 1999-2005 but the reasons for this are uncertain. Nevertheless, 5-year age-standardized survival with colon cancer in the Anglia Cancer Network region is currently among the best in the UK.

Mammographic breast density refines Tyrer-Cuzick estimates of breast cancer risk in high-risk women: findings from the placebo arm of the International Breast Cancer Intervention Study I

INTRODUCTION

Mammographic density is well-established as a risk factor for breast cancer, however, adjustment for age and body mass index (BMI) is vital to its clinical interpretation when assessing individual risk. In this paper we develop a model to adjust mammographic density for age and BMI and show how this adjusted mammographic density measure might be used with existing risk prediction models to identify high-risk women more precisely.

METHODS

We explored the association between age, BMI, visually assessed percent dense area and breast cancer risk in a nested case-control study of women from the placebo arm of the International Breast Cancer Intervention Study I (72 cases, 486 controls). Linear regression was used to adjust mammographic density for age and BMI. This adjusted measure was evaluated in a multivariable logistic regression model that included the Tyrer-Cuzick (TC) risk score, which is based on classical breast cancer risk factors.

RESULTS

Percent dense area adjusted for age and BMI (the density residual) was a stronger measure of breast cancer risk than unadjusted percent dense area (odds ratio per standard deviation 1.55 versus 1.38; area under the curve (AUC) 0.62 versus 0.59). Furthermore, in this population at increased risk of breast cancer, the density residual added information beyond that obtained from the TC model alone, with the AUC for the model containing both TC risk and density residual being 0.62 compared to 0.51 for the model containing TC risk alone (P =0.002).

CONCLUSIONS

In women at high risk of breast cancer, adjusting percent mammographic density for age and BMI provides additional predictive information to the TC risk score, which already incorporates BMI, age, family history and other classic breast cancer risk factors. Furthermore, simple selection criteria can be developed using mammographic density, age and BMI to identify women at increased risk in a clinical setting.

CLINICAL TRIAL REGISTRATION NUMBER

http://www.controlled-trials.com/ISRCTN91879928 (Registered: 1 June 2006).

Therapeutic targeting of integrin αvβ6 in breast cancer

BACKGROUND

Integrin αvβ6 promotes migration, invasion, and survival of cancer cells; however, the relevance and role of αvβ6 has yet to be elucidated in breast cancer.

METHODS

Protein expression of integrin subunit beta6 (β6) was measured in breast cancers by immunohistochemistry (n > 2000) and ITGB6 mRNA expression measured in the Molecular Taxonomy of Breast Cancer International Consortium dataset. Overall survival was assessed using Kaplan Meier curves, and bioinformatics statistical analyses were performed (Cox proportional hazards model, Wald test, and Chi-square test of association). Using antibody (264RAD) blockade and siRNA knockdown of β6 in breast cell lines, the role of αvβ6 in Human Epidermal Growth Factor Receptor 2 (HER2) biology (expression, proliferation, invasion, growth in vivo) was assessed by flow cytometry, MTT, Transwell invasion, proximity ligation assay, and xenografts (n ≥ 3), respectively. A student's t-test was used for two variables; three-plus variables used one-way analysis of variance with Bonferroni's Multiple Comparison Test. Xenograft growth was analyzed using linear mixed model analysis, followed by Wald testing and survival, analyzed using the Log-Rank test. All statistical tests were two sided.

RESULTS

High expression of either the mRNA or protein for the integrin subunit β6 was associated with very poor survival (HR = 1.60, 95% CI = 1.19 to 2.15, P = .002) and increased metastases to distant sites. Co-expression of β6 and HER2 was associated with worse prognosis (HR = 1.97, 95% CI = 1.16 to 3.35, P = .01). Monotherapy with 264RAD or trastuzumab slowed growth of MCF-7/HER2-18 and BT-474 xenografts similarly (P < .001), but combining 264RAD with trastuzumab effectively stopped tumor growth, even in trastuzumab-resistant MCF-7/HER2-18 xenografts.

CONCLUSIONS

Targeting αvβ6 with 264RAD alone or in combination with trastuzumab may provide a novel therapy for treating high-risk and trastuzumab-resistant breast cancer patients.

Kisspeptin-54 triggers egg maturation in women undergoing in vitro fertilization

BACKGROUND

Patients with mutations that inactivate kisspeptin signaling are infertile. Kisspeptin-54, the major circulating isoform of kisspeptin in humans, potently stimulates reproductive hormone secretion in humans. Animal studies suggest that kisspeptin is involved in generation of the luteinizing hormone surge, which is required for ovulation; therefore, we hypothesized that kisspeptin-54 could be used to trigger egg maturation in women undergoing in vitro fertilization therapy.

METHODS

Following superovulation with recombinant follicle-stimulating hormone and administration of gonadotropin-releasing hormone antagonist to prevent premature ovulation, 53 women were administered a single subcutaneous injection of kisspeptin-54 (1.6 nmol/kg, n = 2; 3.2 nmol/kg, n = 3; 6.4 nmol/kg, n = 24; 12.8 nmol/kg, n = 24) to induce a luteinizing hormone surge and egg maturation. Eggs were retrieved transvaginally 36 hours after kisspeptin injection, assessed for maturation (primary outcome), and fertilized by intracytoplasmic sperm injection with subsequent transfer of one or two embryos.

RESULTS

Egg maturation was observed in response to each tested dose of kisspeptin-54, and the mean number of mature eggs per patient generally increased in a dose-dependent manner. Fertilization of eggs and transfer of embryos to the uterus occurred in 92% (49/53) of kisspeptin-54-treated patients. Biochemical and clinical pregnancy rates were 40% (21/53) and 23% (12/53), respectively.

CONCLUSION

This study demonstrates that a single injection of kisspeptin-54 can induce egg maturation in women with subfertility undergoing in vitro fertilization therapy. Subsequent fertilization of eggs matured following kisspeptin-54 administration and transfer of resulting embryos can lead to successful human pregnancy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01667406.

Abstract P4-15-01: Integrin avb6 is a therapeutic target for high-risk breast cancer and enhances trastuzumab efficacy

The integrin avβ6 promotes migration, invasion and survival of cancer cells, but the biological relevance has yet to be ascertained in breast cancer. Our immunhistochemical analysis of over 2000 breast cancers has revealed that high expression of the protein for the integrin subunit beta6 (β6) is associated with very poor survival (HR = 1.99, P = 2.9×10-6) and increased metastases to distant sites (P = 0·02). This correlation was confirmed at the mRNA level via bioinformatic analysis of the 2000 women in the METABRIC cohort. Furthermore, co-expression of HER2 gave a significantly worse prognosis (HR = 3.43, P = 4×10-12), which we investigated further.

We report from in vitro studies that HER2-driven invasion is mediated by αvβ6 in an Akt2-dependent manner. Using the well-tolerated αvβ6-blocking antibody 264RAD in vivo we show that antibody-blockade of this integrin suppressed growth of BT-474 and MCF-7/HER2-18 human breast cancer xenografts similarly to trastuzumab alone (P&lt;0.001), the antibody used for treating HER2-positive cancers (both 10mg/kg, bi-weekly). Moreover, when 264RAD was co-administered it significantly enhanced the ability of trastuzumab to suppress BT-474 tumor growth with a reduction in mean tumor volume of 94.8%+/-1.18% compared to 70.8%+/-5.98% observed with trastuzumab alone (P&lt;0.0001) after 2 weeks treatment. This trend was reproduced even in the MCF-7/HER2-18 trastuzumab-resistant breast cancer tumors where a 76.24%+/-10.15% reduction was observed with combination therapy (P&lt;0.0001) compared with only 44.62%+/-10.43% (P = 0.0006) and 46.6%+/-14.71% (P = 0.0004) reductions in final volume with 264RAD and trastuzumab respectively. The combination therapy was so effective it almost eradicated 100mm3 BT-474 tumors and completely eliminated small (10-20mm3) MCF-7/HER2-18 tumors.

264RAD or trastuzumab prolonged survival to a similar degree (14.3% and 33.33% treated mice alive after 100d, respectively, no significant difference) but again, when both drugs were combined 85.7% of mice were alive after 100d, a highly significant response compared with PBS (P&lt;0.0001) or monotherapies (264RAD: P&lt;0.0001, trastuzumab: P&lt;0.0001). Post-therapy biochemistry revealed residual tumors expressed significantly reduced αvβ6, HER2, HER3 and downstream signaling molecules including Akt2 and Smad2, essentially a much lower ‘grade’ tumour.

Since 70% of women treated with trastuzumab either have, or develop resistance, we suggest combined targeting of αvβ6 and HER2 could provide an important novel therapy for thousands of women with breast cancer. In fact, over 39,000 American women annually (NIH statistics) will develop HER2+ breast cancers for which no specific therapies exist. Our data shows that in excess of 40% of these women with trastuzumab-resistant disease are also likely to express high levels of αvβ6.

Our data also suggest that routine determination of the level of expression of αvβ6 on breast cancers would be a valuable clinical tool as it identifies novel high-risk groups of women that require enhanced therapeutic intervention.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-15-01.

Integrated imaging - the complementary roles of radiology and nuclear medicine

This article was first published in the August 2013 issue of Continuing Medical Education (Vol. 31, Issue 8), and is reproduced here because of its topicality and desirability of reaching a broader audience.

Abstract B046: Therapeutic targeting of integrin αvβ6 in high-risk breast cancer

Background: Integrin αvβ6 promotes migration, invasion and survival of cancer cells, however, the relevance and role of αvβ6 has yet to be elucidated in breast cancer.

Methods: Protein expression of integrin subunit beta6 (β6) was measured in over 2000 breast cancers by immunohistochemistry and ITGB6 mRNA expression measured in the METABRIC dataset. Overall survival was assessed using Kaplan-Meier curves and bioinformatics statistical analyses were performed in R statistical environment v2.14.1. Using antibody (264RAD; supplied by AZ-Medimmune) blockade and siRNA knockdown of β6 in breast cell lines, the role of αvβ6 in HER2 biology (expression, proliferation, invasion, growth in vivo) was assessed by flow cytometry, MTT assays and Transwell invasion assays and xenografts, respectively. All statistical tests were two-sided.

Results: High expression of either the mRNA or protein for the integrin subunit β6 correlated with very poor survival (HR=1.99, P=2.9x10-6) and increased metastases to distant sites (P=0.02). Co-expression of β6 and HER2 gave a worse prognosis (HR=3.43, P=4x10-12). HER2-driven invasion was mediated by αvβ6 in an Akt2-dependent manner. Monotherapy with 264RAD or trastuzumab, slowed growth of MCF-7/HER2-18 and BT-474 xenografts to a similar degree (P&lt;0.001) but combining 264RAD with trastuzumab effectively stopped tumor growth, even in trastuzumab-resistant MCF-7/HER2-18 xenografts.

Conclusions: Targeting αvβ6 with 264RAD alone or in combination with trastuzumab may provide a novel therapy for treating high-risk and trastuzumab-resistant breast cancer patients, giving hope to the 70% of women treated who have, or develop, resistance. Moreover, routine determination of the level of expression of αvβ6 on breast cancers would stratify women into higher-risk categories, requiring enhanced therapeutic intervention.

Citation Format: Kate M. Moore, Gareth J. Thomas, Stephen W. Duffy, Jane Warwick, Rhian Gabe, Patrick Chou, Ian O. Ellis, Andrew R. Green, Syed Haider, Kellie Brouilette, Antonio Saha, Sabari Vallath, Rebecca Bowen, Claudia Chelala, Diana Eccles, William J. Tapper, Alastair M. Thompson, Phillip Quinlan, Lee Jordan, Cheryl Gillett, Adam Brentnall, Sheila Violette, Paul Weinreb, Jane Kendrew, Simon T. Barry, Ian R. Hart, Louise Jones, John F. Marshall. Therapeutic targeting of integrin αvβ6 in high-risk breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B046.

Is multiple SNP testing in BRCA2 and BRCA1 female carriers ready for use in clinical practice? Results from a large Genetic Centre in the UK

BRCA1 and BRCA2 are major breast cancer susceptibility genes. Nineteen single nucleotide polymorphisms (SNPs) at 18 loci have been associated with breast cancer. We aimed to determine whether these predict breast cancer incidence in women with BRCA1/BRCA2 mutations. BRCA1/2 mutation carriers identified through the Manchester genetics centre between 1996 and 2011 were included. Using published odds ratios (OR) and risk allele frequencies, we calculated an overall breast cancer risk SNP score (OBRS) for each woman. The relationship between OBRS and age at breast cancer onset was investigated using the Cox proportional hazards model, and predictive ability assessed using Harrell's C concordance statistic. In BRCA1 mutation carriers we found no association between OBRS and age at breast cancer onset: OR for the lowest risk quintile compared to the highest was 1.20 (95% CI 0.82-1.75, Harrell's C = 0.54), but in BRCA2 mutation carriers the association was significant (OR for the lowest risk quintile relative to the highest was 0.47 (95% CI 0.33-0.69, Harrell's C = 0.59). The 18 validated breast cancer SNPs differentiate breast cancer risks between women with BRCA2 mutations, but not BRCA1. It may now be appropriate to use these SNPs to help women with BRCA2 mutations make maximally informed decisions about management options.

Ovarian cancer among 8,005 women from a breast cancer family history clinic: no increased risk of invasive ovarian cancer in families testing negative for BRCA1 and BRCA2

BACKGROUND

Mutations in BRCA1/2 genes confer ovarian, alongside breast, cancer risk. We examined the risk of developing ovarian cancer in BRCA1/2-positive families and if this risk is extended to BRCA negative families.

PATIENTS AND METHODS

A prospective study involving women seen at a single family history clinic in Manchester, UK. Patients were excluded if they had ovarian cancer or oophorectomy prior to clinic. Follow-up was censored at the latest date of: 31/12/2010; ovarian cancer diagnosis; oophorectomy; or death. We used person-years at risk to assess ovarian cancer rates in the study population, subdivided by genetic status (BRCA1, BRCA2, BRCA negative, BRCA untested) compared with the general population.

RESULTS

We studied 8005 women from 895 families. Women from BRCA2 mutation families showed a 17-fold increased risk of invasive ovarian cancer (relative risk (RR) 16.67; 95% CI 5.41 to 38.89). This risk increased to 50-fold in women from families with BRCA1 mutations (RR 50.00; 95% CI 26.62 to 85.50). No association was found for women in families tested negative for BRCA1/2, where there was 1 observed invasive ovarian cancer in 1613 women when 2.74 were expected (RR 0.37; 95% CI 0.01 to 2.03). There was no association with ovarian cancer in families untested for BRCA1/2 (RR 0.99; 95% CI 0.45 to 1.88).

DISCUSSION

This study showed no increased risk of ovarian cancer in families that tested negative for BRCA1/2 or were untested. These data help counselling women from BRCA1/2 negative families with breast cancer that their risk of invasive ovarian cancer is not higher than the general population.

Abstract P3-08-01: The prospective risk of ovarian cancer in 1433 women in a breast cancer family history clinic: no increased risk in families testing negative for BRCA1 and BRCA2

Since the identification of the BRCA1 and BRCA2 genes speculation has continued regarding the breast and ovarian cancer risk associated with mutations in these genes. Also, as to whether mutations in these genes account for the majority of the association between breast and ovarian cancer. Identification of RAD51C and RAD51D mutations in breast/ovarian cancer families has reawakened the debate as to whether it is safe to reassure women from BRCA negative families that they are not at increased risk of ovarian cancer. 1433 women from breast cancer families that had tested negative for BRCA1/2 were followed for a total of between 0.04 and 25 years and checked against a cancer registry for ovarian cancer incidence. Data was censored at ovarian cancer diagnosis, oophorectomy or death. During 16358 women years of follow up no invasive epithelial ovarian cancer occurred, although 2 borderline tumors were diagnosed. Expected rates for this cohort from cancer registry data were 2.75 epithelial ovarian tumors with 2.52 for invasive cancer and 0.23 for borderline tumors. The upper confidence limit for invasive RR was 1.3 and for borderline tumors 0.97–31. In conclusion this the largest prospective follow up of a BRCA negative cohort has demonstrated that there is no increase in risk of invasive ovarian cancer in families that have tested negative for BRCA1/2.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-08-01.

Assessing individual breast cancer risk within the U.K. National Health Service Breast Screening Program: a new paradigm for cancer prevention

The aim of this study is to determine breast cancer risk at mammographic screening episodes and integrate standard risk factors with mammographic density and genetic data to assess changing the screening interval based on risk and offer women at high risk preventive strategies. We report our experience of assessing breast cancer risk within the U.K. National Health Service Breast Screening Program using results from the first 10,000 women entered into the "Predicting Risk Of breast Cancer At Screening" study. Of the first 28,849 women attending for screening at fifteen sites in Manchester 10,000 (35%) consented to study entry and completed the questionnaire. The median 10-year Tyrer-Cuzick breast cancer risk was 2.65% (interquartile range, 2.10-3.45). A total of 107 women (1.07%) had 10-year risks 8% or higher (high breast cancer risk), with a further 8.20% having moderately increased risk (5%-8%). Mammographic density (percent dense area) was 60% or more in 8.3% of women. We collected saliva samples from 478 women for genetic analysis and will extend this to 18% of participants. At time of consent to the study, 95.0% of women indicated they wished to know their risk. Women with a 10-year risk of 8% or more or 5% to 8% and mammographic density of 60% or higher were invited to attend or be telephoned to receive risk counseling; 81.9% of those wishing to know their risk have received risk counseling and 85.7% of these were found to be eligible for a risk-reducing intervention. These results confirm the feasibility of determining breast cancer risk and acting on the information in the context of population-based mammographic screening.

Prevention of breast cancer in the context of a national breast screening programme

Breast cancer is not only increasing in the west but also particularly rapidly in eastern countries where traditionally the incidence has been low. The rise in incidence is mainly related to changes in reproductive patterns and lifestyle. These trends could potentially be reversed by defining women at greatest risk and offering appropriate preventive measures. A model for this approach was the establishment of Family History Clinics (FHCs), which have resulted in improved survival in younger women at high risk. New predictive models of risk that include reproductive and lifestyle factors, mammographic density and measurement of risk-associated single nucleotide polymorphisms (SNPs) may give more precise information concerning risk and enable better targeting for mammographic screening programmes and of preventive measures. Endocrine prevention using anti-oestrogens and aromatase inhibitors is effective, and observational studies suggest lifestyle modification may also be effective. However, referral to FHCs is opportunistic and predominantly includes younger women. A better approach for identifying older women at risk may be to use national breast screening programmes. Here were described pilot studies to assess whether the routine assessment of breast cancer risk is feasible within a population-based screening programme, whether the feedback and advice on risk-reducing interventions would be welcomed and taken up, and to consider whether the screening interval should be modified according to breast cancer risk.

P4-11-07: Feasibility and Acceptability of Offering Breast Cancer Risk Estimation in the Context of the UK National Health Service Breast Cancer Screening Programme: A New Paradigm for Cancer Prevention

Background: Currently there are no real attempts internationally to tailor breast screening programmes to individual risk Methods: We have assessed the feasibility of collecting breast cancer risk information during routine mammographic screening in the National Health Service Breast Screening Programme (NHSBSP) in England, in order to consider, ultimately, adapting the screening interval to risk of breast cancer and introducing preventive strategies in women at high risk. The study Predicting Risk Of Cancer At Screening (PROCAS) aims to recruit 60,000 women over 3 years. Results: 26,000 women (June 8th 2011) have so far given consent to join the study. Thirty six percent of the first 20,000 women in nineteen screening sites in Manchester consented to enter the study and completed a risk factor questionnaire. The median 10 year breast cancer risk was 2.65%, with 926 (9.26%) of the first 10,000 women having a 10 year risk of ≥5% and 92 (0.92%) having a 10 year risk of ≥8% (Tyrer-Cuzick), IQR:1.35. 832 (8.32%) women had a mammographic density of 60% or greater (Visual Analogue Scale). We collected saliva samples from 1019 women for genetic analysis and will extend this to 18% of participants. Of those who agreed to participate in the study, 94% indicated that they wished to know their breast cancer risk. Women with a 10-year risk of ≥8%, and women with a 10-year risk of ≥5% and mammographic density ≥60% were invited to attend or be telephoned to be counselled. To date 138 have accepted with 135, so far, having received risk counselling. Nineteen percent of the high-risk women identified subsequently decided to enter a randomised breast cancer prevention study with either a dietary or drug intervention (IBIS2, anastrazole vs placebo). Results from the first 1,000 women who provided DNA samples suggest that the risk information from the 18 validated SNPS may enhance existing risk models. Conclusion: This study demonstrates that it is feasible to determine individual breast cancer risk and offer women appropriate risk-reducing interventions within the context of a population-based mammographic screening programme.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-07.

Tamoxifen-induced reduction in mammographic density and breast cancer risk reduction: a nested case-control study

BACKGROUND

Mammographic breast density is a strong risk factor for breast cancer. Tamoxifen, which reduces the risk of breast cancer in women at high risk, also reduces mammographic breast density. However, it is not known if tamoxifen-induced reductions in breast density can be used to identify women who will benefit the most from prophylactic treatment with this drug.

METHODS

We conducted a nested case-control study within the first International Breast Cancer Intervention Study, a randomized prevention trial of tamoxifen vs placebo. Mammographic breast density was assessed visually and expressed as a percentage of the total breast area in 5% increments. Case subjects were 123 women diagnosed with breast cancer at or after their first follow-up mammogram, which took place 12-18 months after trial entry, and control subjects were 942 women without breast cancer. Multivariable logistic regression was used to adjust for other risk factors. All statistical tests were two-sided.

RESULTS

In the tamoxifen arm, 46% of women had a 10% or greater reduction in breast density at their 12- to 18-month mammogram. Compared with all women in the placebo group, women in the tamoxifen group who experienced a 10% or greater reduction in breast density had 63% reduction in breast cancer risk (odds ratio = 0.37, 95% confidence interval = 0.20 to 0.69, P = .002), whereas those who took tamoxifen but experienced less than a 10% reduction in breast density had no risk reduction (odds ratio = 1.13, 95% confidence interval = 0.72 to 1.77, P = .60). In the placebo arm, there was no statistically significant difference in breast cancer risk between subjects who experienced less than a 10% reduction in mammographic density and subjects who experienced a greater reduction.

CONCLUSION

The 12- to 18-month change in mammographic breast density is an excellent predictor of response to tamoxifen in the preventive setting.

Measuring the accuracy of diagnostic imaging in symptomatic breast patients: team and individual performance

OBJECTIVE

The combination of mammography and/or ultrasound remains the mainstay in current breast cancer diagnosis. The aims of this study were to evaluate the reliability of standard breast imaging and individual radiologist performance and to explore ways that this can be improved.

METHODS

A total of 16,603 separate assessment episodes were undertaken on 13,958 patients referred to a specialist symptomatic breast clinic over a 6 year period. Each mammogram and ultrasound was reported prospectively using a five-point reporting scale and compared with final outcome.

RESULTS

Mammographic sensitivity, specificity and receiver operating curve (ROC) area were 66.6%, 99.7% and 0.83, respectively. The sensitivity of mammography improved dramatically from 47.6 to 86.7% with increasing age. Overall ultrasound sensitivity, specificity and ROC area was 82.0%, 99.3% and 0.91, respectively. The sensitivity of ultrasound also improved dramatically with increasing age from 66.7 to 97.1%. Breast density also had a profound effect on imaging performance, with mammographic sensitivity falling from 90.1 to 45.9% and ultrasound sensitivity reducing from 95.2 to 72.0% with increasing breast density.

CONCLUSION

The sensitivity ranges widely between radiologists (53.1-74.1% for mammography and 67.1-87.0% for ultrasound). Reporting sensitivity was strongly correlated with radiologist experience. Those radiologists with less experience (and lower sensitivity) were relatively more likely to report a cancer as indeterminate/uncertain. To improve radiology reporting performance, the sensitivity of cancer reporting should be closely monitored; there should be regular feedback from needle biopsy results and discussion of reporting classification with colleagues.

Molecular subtyping of DCIS: heterogeneity of breast cancer reflected in pre-invasive disease

Background:

Molecular profiling has identified at least four subtypes of invasive breast carcinoma, which exhibit distinct clinical behaviour. There is good evidence now that DCIS represents the non-obligate precursor to invasive breast cancer and therefore it should be possible to identify similar molecular subtypes at this stage. In addition to a limited five-marker system to identify molecular subtypes in invasive breast cancer, it is evident that other biological molecules may identify distinct tumour subsets, though this has not been formally evaluated in DCIS.

Methods:

Tissue microarrays were constructed for 188 cases of DCIS. Immunohistochemistry was performed to examine the expression patterns of oestrogen receptor (ER), progesterone receptor (PR), Her2, EGFR, cytokeratin (CK) 5/6, CK14, CK17, CK18, β4-integrin, β6-integrin, p53, SMA, maspin, Bcl-2, topoisomerase IIα and P-cadherin. Hierarchical clustering analysis was undertaken to identify any natural groupings, and the findings were validated in an independent sample series.

Results:

Each of the intrinsic molecular subtypes described for invasive breast cancer can be identified in DCIS, though there are differences in the relative frequency of subgroups, in particular, the triple negative and basal-like phenotype is very uncommon in DCIS. Hierarchical cluster analysis identified three main subtypes of DCIS determined largely by ER, PR, Her2 and Bcl-2, and this classification is related to conventional prognostic indicators. These subtypes were confirmed in an analysis on independent series of DCIS cases.

Conclusion:

This study indicates that DCIS may be classified in a similar manner to invasive breast cancer, and determining the relative frequency of different subtypes in DCIS and invasive disease may shed light on factors determining disease progression. It also demonstrates a role for Bcl-2 in classifying DCIS, which has recently been identified in invasive breast cancer.

Measuring performance in clinical breast examination

BACKGROUND

Clinical breast examination (CBE) remains an essential part of triple assessment of breast lumps, but to date there are no performance measures for clinicians using this technique. The aim of this retrospective audit was to compare the performance and accuracy of CBE to identify key indicators that could be used to monitor performance prospectively.

METHODS

Clinical examination findings (E1, normal, to E5, malignant) for 16,585 patients who had CBE as part of triple assessment were obtained from electronic medical records. The performance of CBE, by age group, mammographic density and clinician, was assessed by calculating the sensitivity, specificity and area under the receiver operating characteristic (ROC) curve.

RESULTS

There was marked variation in sensitivity between clinicians (range 44.6-65.9 per cent). There was a strong downward trend in the percentage classified as E5 as sensitivity for breast cancer detection decreased, and a corresponding strong downward trend in the proportion of E4 and E5 cancers classified as E5. Both of these measures could be used as indicators to monitor CBE performance.

CONCLUSION

The performance measures outlined here could help to identify clinicians who have a lower sensitivity for CBE and who may therefore require feedback and further training.

Expression of DNA mismatch repair proteins and MSH2 polymorphisms in nonmelanoma skin cancers of organ transplant recipients

BACKGROUND

Organ transplant recipients (OTRs) have an increased risk of skin cancer. Treatment with azathioprine, commonly used in post-transplant immunosuppressive regimens, results in incorporation of 6-thioguanine (6-TG) into DNA. Mismatch repair (MMR)-defective cells are resistant to killing by 6-TG. Azathioprine exposure confers a survival advantage on MMR-defective cells, which are hypermutable and may therefore contribute to azathioprine-related nonmelanoma skin cancer, a phenomenon we have previously demonstrated in transplant-associated sebaceous carcinomas. The MSH2 protein is an important component of DNA MMR. The -6 exon 13 T>C MSH2 polymorphism is associated with impaired MMR, drug resistance and certain cancers.

OBJECTIVES

To investigate (i) whether loss of MMR protein expression and microsatellite instability are over-represented in squamous cell carcinomas (SCCs) from OTRs on azathioprine compared with SCCs from immunocompetent patients, and (ii) whether the MSH2 -6 exon 13 polymorphism is over-represented in OTRs with skin cancer on azathioprine.

METHODS

(i) Immunohistochemical staining was used to assess expression of the MMR proteins MSH2 and MLH1 in cutaneous SCCs from OTRs on azathioprine and from immunocompetent patients. (ii) Blood samples from OTRs on azathioprine with and without skin cancer were genotyped for the -6 exon 13 MSH2 polymorphism.

RESULTS

(i) MSH2 and MLH1 protein expression was not altered in SCCs from OTRs on azathioprine and there was no difference in expression between SCCs from OTRs and immunocompetent patients. (ii) There was no association between MSH2 polymorphism genotype frequency and OTR skin cancer status.

CONCLUSIONS

Despite previous findings in transplant-associated sebaceous carcinomas, defective MMR and the -6 exon 13 MSH2 polymorphism are unlikely to play a significant role in the development of SCC in OTRs on azathioprine.

Determinants of percentage and area measures of mammographic density

Mammographic density is one of the strongest predictors of breast cancer risk. Typically expressed as a percentage of the breast area occupied by radiologically dense tissue on a mammogram, its full value may not be realized because of its negative association with body mass index. A simpler measure of mammographic density, independent of other breast cancer risk factors and equally predictive of risk, would be preferable for risk prediction models. Percentage and area measures of mammographic density were determined for 815 women at high risk for breast cancer from the baseline assessments in the International Breast Cancer Intervention Study I, a trial of tamoxifen for breast cancer prevention conducted between 1992 and 2001. Multivariate linear regression was used to assess associations between risk factors and the mammographic measures. Percent dense area was negatively associated with age, body mass index, menopausal status, predicted risk, and smoking status (R(2) = 24%). Dense area was negatively associated with only age and body mass index (R(2) = 7%), and the latter association was much weaker than for percent dense area. Nondense area was positively associated with age, body mass index, and predicted risk (R(2) = 36%). Dense area was not associated with the multitude of risk factors that percent dense area was, making it a simpler biomarker for risk prediction modeling. Both dense area and percent dense area should be presented whenever possible for comparisons in research.

Visually assessed breast density, breast cancer risk and the importance of the craniocaudal view

INTRODUCTION

Mammographic density is known to be a strong risk factor for breast cancer. A particularly strong association with risk has been observed when density is measured using interactive threshold software. This, however, is a labour-intensive process for large-scale studies.

METHODS

Our aim was to determine the performance of visually assessed percent breast density as an indicator of breast cancer risk. We compared the effect on risk of density as measured with the mediolateral oblique view only versus that estimated as the average density from the mediolateral oblique view and the craniocaudal view. Density was assessed using a visual analogue scale in 10,048 screening mammograms, including 311 breast cancer cases diagnosed at that screening episode or within the following 6 years.

RESULTS

Where only the mediolateral oblique view was available, there was a modest effect of breast density on risk with an odds ratio for the 76% to 100% density relative to 0% to 25% of 1.51 (95% confidence interval 0.71 to 3.18). When two views were available, there was a considerably stronger association, with the corresponding odds ratio being 6.77 (95% confidence interval 2.75 to 16.67).

CONCLUSION

This indicates that a substantial amount of information on risk from percentage breast density is contained in the second view. It also suggests that visually assessed breast density has predictive potential for breast cancer risk comparable to that of density measured using the interactive threshold software when two views are available. This observation needs to be confirmed by studies applying the different measurement methods to the same individuals.

Correcting for lead time and length bias in estimating the effect of screen detection on cancer survival

Determination of survival time among persons with screen-detected cancer is subject to lead time and length biases. The authors propose a simple correction for lead time, assuming an exponential distribution of the preclinical screen-detectable period. Assuming two latent categories of tumors, one of which is more prone to screen detection and correspondingly less prone to death from the cancer in question, the authors have developed a strategy of sensitivity analysis for various magnitudes of length bias. Here they demonstrate these methods using a series of 25,962 breast cancer cases (1988-2004) from the West Midlands, United Kingdom.

A case-control study of the impact of the East Anglian breast screening programme on breast cancer mortality

Although breast cancer screening has been shown to work in randomised trials, there is a need to evaluate service screening programmes to ensure that they are delivering the benefit indicated by the trials. We carried out a case–control study to investigate the effect of mammography service screening, in the NHS breast screening programme, on breast cancer mortality in the East Anglian region of the UK. Cases were deaths from breast cancer in women diagnosed between the ages of 50 and 70 years, following the instigation of the East Anglia Breast Screening Programme in 1989. The controls were women (two per case) who had not died of breast cancer, from the same area, matched by date of birth to the cases. Each control was known to be alive at the time of death of her matched case. All women were known to the breast screening programme and were invited, at least once, to be screened. There were 284 cases and 568 controls. The odds ratio (OR) for risk of death from breast cancer in women who attended at least one routine screen compared to those who did not attend was 0.35 (CI: 0.24, 0.50). Adjusting for self-selection bias gave an estimate of the breast cancer mortality reduction associated with invitation to screening of 35% (OR=0.65, 95% CI: 0.48, 0.88). The effect of actually being screened was a 48% breast cancer mortality reduction (OR=0.52, 95% CI: 0.32, 0.84). The results suggest that the National Breast Screening Programme in East Anglia is achieving a reduction in breast cancer deaths, which is at least consistent with the results from the randomised controlled trials of mammographic screening.

Treatment of post-transplant premalignant skin disease: a randomized intrapatient comparative study of 5-fluorouracil cream and topical photodynamic therapy

BACKGROUND

Organ transplant recipients (OTR) are at high risk of developing nonmelanoma skin cancer and premalignant epidermal dysplasia (carcinoma in situ/ Bowen's disease and actinic keratoses). Epidermal dysplasia is often widespread and there are few comparative studies of available treatments.

OBJECTIVES

To compare topical methylaminolaevulinate (MAL) photodynamic therapy (PDT) with topical 5% fluorouracil (5-FU) cream in the treatment of post-transplant epidermal dysplasia.

METHODS

Eight OTRs with epidermal dysplasia were recruited to an open-label, single-centre, randomized, intrapatient comparative study. Treatment with two cycles of topical MAL PDT 1 week apart was randomly assigned to one area of epidermal dysplasia, and 5-FU cream was applied twice daily for 3 weeks to a clinically and histologically comparable area. Patients were reviewed at 1, 3 and 6 months after treatment. The main outcome measures were complete resolution rate (CRR), overall reduction in lesional area, treatment-associated pain and erythema, cosmetic outcome and global patient preference.

RESULTS

At all time points evaluated after completion of treatment, PDT was more effective than 5-FU in achieving complete resolution: eight of nine lesional areas cleared with PDT (CRR 89%, 95% CI: 0.52-0.99), compared with one of nine lesional areas treated with 5-FU (CRR 11%, 95% CI: 0.003-0.48) (P = 0.02). The mean lesional area reduction was also proportionately greater with PDT than with 5-FU (100% vs. 79% respectively). Cosmetic outcome and patient preference were also superior in the PDT-treated group.

CONCLUSIONS

Compared with topical 5-FU, MAL PDT was a more effective and cosmetically acceptable treatment for epidermal dysplasia in OTRs and was preferred by patients. Further studies are now required to confirm these results and to examine the effect of treating epidermal dysplasia with PDT on subsequent development of squamous cell carcinoma in this high risk population.

Population-based family case-control proband study on familial aggregation of metabolic syndrome: finding from Taiwanese people involved in Keelung community-based integrated screening (KCIS no. 5)

A population-based case-control proband study was undertaken to elucidate familial aggregation, independent environmental factors, and the interaction between them. A total of 7308 metabolic syndrome (MET-S) cases were identified from the Keelung community-based integrated screening programme between 1999 and 2002. The study has a case-control/family sampling design. A total of 1417 case probands were randomly selected from 3225 metabolic syndrome cases and the corresponding 2458 controls selected from 16,519 subjects without metabolic syndrome by matching on sex, age (+/-3 years) and place of residence. The generalized estimation equation model was used to estimate odds ratios and corresponding 95% confidence intervals. The risk for having metabolic syndrome among family members for cases versus control probands was 1.56-fold (1.29-1.89) after controlling for significant environmental factors. Higher risk of metabolic syndrome was found in parents than spouse. Low education against high education had 2.06-fold (1.36-3.13) risk for metabolic syndrome. Betel quid chewing was positively associated with the risk of MET-S, with 1.99-fold (1.13-3.53) risk for 1-9 pieces and 1.76-fold (0.96-3.23) risk for >or=10 pieces compared with non-chewer. Moderate and high intensity of non-occupational exercise led to 21.0% (OR=0.79 (0.63-0.98)) and 26.0% (OR=0.74 (0.59-0.94)) reduction in the risk for metabolic syndrome, respectively. The frequent consumption of vegetable reduced 24.0% (OR=0.76 (0.62-0.92)) risk for MET-S. The frequent consumption of coffee was associated the increased risk for metabolic syndrome (OR=1.32 (1.07-1.64)). The present study confirmed the risk of metabolic syndrome not only has the tendency towards familial aggregation but is affected by independent effect of environmental or individual correlates.

Cost-effectiveness analysis of colorectal cancer screening with stool DNA testing in intermediate-incidence countries

Background

The aim of this study is to compare the cost-effectiveness of screening with stool DNA testing with that of screening with other tools (annual fecal occult blood testing, flexible sigmoidoscopy every 5 years, and colonoscopy every 10 years) or not screening at all.

Methods

We developed a Markov model to evaluate the above screening strategies in the general population 50 to 75 years of age in Taiwan. Sensitivity analyses were performed to assess the influence of various parameters on the cost-effectiveness of screening. A third-party payer perspective was adopted and the cost of $13,000 per life-year saved (which is roughly the per capita GNP of Taiwan in 2003) was chosen as the ceiling ratio for assessing whether the program is cost-effective.

Results

Stool DNA testing every three, five, and ten years can reduce colorectal cancer mortality by 22%, 15%, and 9%, respectively. The associated incremental costs were $9,794, $9,335, and $7,717, per life-year saved when compared with no screening. Stool DNA testing strategies were the least cost-effective with the cost per stool DNA test, referral rate with diagnostic colonoscopy, prevalence of large adenoma, and discount rate being the most influential parameters.

Conclusion

In countries with a low or intermediate incidence of colorectal cancer, stool DNA testing is less cost-effective than the other currently recommended strategies for population-based screening, particularly targeting at asymptomatic subjects.

Surgical dexterity after a 'night out on the town'

BACKGROUND

This study examines the effect of alcohol intake on surgical dexterity immediately after and the morning after alcohol intake and minimal sleep deprivation by simulating a typical night out on the town.

METHODS

Five surgeons (all men, aged 31-40 years) were trained on a laparoscopic surgical simulator (minimally invasive surgical trainer-virtual reality) to reach a desired standard of performance. Three experimental settings were used: (i) a control night with no alcohol and full night's sleep; (ii) a sham night out (sleep deprived) without alcohol; and (iii) a night out with alcohol ad libitum. The parameters recorded were the average time taken to carry out a task, error rate, average diathermy time and diathermy (damage) time to main object. Comparisons between baseline readings, those in the middle of the night and those of the following morning were made by applying ANOVA methods after logarithmic transformation of the data.

RESULTS

The candidates consumed, on average, 10.33 units (range, 6-15 units) of alcohol and had 0.86% (range, 0.71-1.1%) of breath alcohol levels and an average of 3.75 h (range, 3-5 h) of sleep after a typical night out. The morning-after breath alcohol levels were 0%. There was significant deterioration in performance, as measured by all indicators, immediately after alcohol consumption. The adverse effects on time taken to complete the task and total diathermy time were still apparent the morning after. The sham night out appeared to affect only 'time parameters'. No significant changes in performance were seen in the control setting.

CONCLUSION

Both alcohol consumption and sleep deprivation adversely affect the ability to carry out surgical procedures. Our simulation study suggests that the adverse effects of alcohol intake persist the following morning.

Tumor size and breast cancer detection: what might be the effect of a less sensitive screening tool than mammography?

In some limited-resource areas, a state-of-the-art mammography program is not affordable. In such circumstances, one might consider a less resource-intensive, but also less sensitive screening tool such as clinical breast examination (CBE). We used data from the Swedish Two-County Trial to estimate the shift in tumor size resulting from invitation to mammographic screening. By postulating a lesser benefit of a less sensitive screening tool (CBE), particularly in terms of detecting very small tumors, we predicted its likely effect on tumor size distribution. In addition, using the observed association between tumor size and nodal status, and between tumor size and fatality, we predicted the likely benefit in terms of reductions in node-positive disease and in breast cancer mortality. An invitation to mammographic screening was associated with a 27% reduction in the number of node-positive tumors and a 31% reduction in the number of breast cancer deaths. We estimate that in the trial population, screening with CBE alone would have led to an 11% reduction in node-positive tumors and an 11% reduction in breast cancer deaths (approximately 42 deaths prevented per 1,000 cases). Assuming instead a tumor size distribution typical of a limited-resource setting (70% of tumors are 30 mm at presentation), we estimate that screening with CBE alone would lead to a 13% reduction in node-positive tumors and a 12% reduction in breast cancer deaths (approximately 72 deaths prevented per 1,000 cases). Thus, although the relative benefit of CBE is only slightly greater in the limited-resource setting, the absolute reduction in deaths per case is about 70% higher. Our findings suggest that a less sensitive tool might be expected to confer a breast cancer mortality reduction about half of that observed with mammography.

Some issues in screening for breast and other cancers

BACKGROUND

There are some issues in screening for cancer, especially breast cancer, which are worthy of further study.

METHODS

We reviewed some approaches to the following issues in breast cancer screening: absolute benefit, overdiagnosis, separation of effects of screening from effects of others on deaths from breast cancer over time and determination of which tumours benefit most from early detection. For separation of screening effects from other effects, we developed a simple analysis of survival by tumour size. For the other issues, we identified methods and results from the literature on the randomized trials of screening and on service screening programmes. We also reviewed screening issues pertaining to other selected cancers, including some cancers common or becoming common in Asia.

RESULTS

Published results from the Swedish Two-County Trial showed that for 350 women screened for 10 years, one life would be saved. Results from service screening programmes in Florence and elsewhere suggested that overdiagnosis is a minor phenomenon and mainly confined to ductal carcinoma in situ. Data from before and after the inception of screening in East Anglia suggested that 40-60% of the recent improvement in survival of breast cancer cases was due to early detection. Published data from the Swedish Two-county Trial indicated that the majority of the benefit of breast screening derives from early detection of grades 2 and 3 ductal carcinoma.

CONCLUSIONS

Mammographic screening is effective in saving lives from breast cancer. Other cancers, which have strong evidence for a benefit of screening in terms of saving lives from cancer, are cervical and colorectal cancers. There is also evidence of a reduction in mortality associated with ultrasound screening for liver cancer in subjects at very high risk of the disease. There are a number of other cancers that are potential candidates for early detection. There is clearly an opportunity for saving lives from further development and implementation of cancer screening.

Overdiagnosis and overtreatment of breast cancer: estimates of overdiagnosis from two trials of mammographic screening for breast cancer

Randomised controlled trials have shown that the policy of mammographic screening confers a substantial and significant reduction in breast cancer mortality. This has often been accompanied, however, by an increase in breast cancer incidence, particularly during the early years of a screening programme, which has led to concerns about overdiagnosis, that is to say, the diagnosis of disease that, if left undetected and therefore untreated, would not become symptomatic. We used incidence data from two randomised controlled trials of mammographic screening, the Swedish Two-county Trial and the Gothenburg Trial, to establish the timing and magnitude of any excess incidence of invasive disease and ductal carcinoma in situ (DCIS) in the study groups, to ascertain whether the excess incidence of DCIS reported early in a screening trial is balanced by a later deficit in invasive disease and provide explicit estimates of the rate of 'real' and non-progressive 'overdiagnosed' tumours from the study groups of the trials. We used a multistate model for overdiagnosis and used Markov Chain Monte Carlo methods to estimate the parameters. After taking into account the effect of lead time, we estimated that less than 5% of cases diagnosed at prevalence screen and less than 1% of cases diagnosed at incidence screens are being overdiagnosed. Overall, we estimate overdiagnosis to be around 1% of all cases diagnosed in screened populations. These estimates are, however, subject to considerable uncertainty. Our results suggest that overdiagnosis in mammography screening is a minor phenomenon, but further studies with very large numbers are required for more precise estimation.

A case-control study to estimate the impact on breast cancer death of the breast screening programme in Wales

OBJECTIVES

The aim of this study was to estimate the effect of service screening, as provided by the NHS breast screening programme, on breast cancer mortality in Wales. Furthermore, we wished to ascertain whether a reduction in breast cancer mortality consistent with that observed in the randomised screening trials was being achieved.

SETTING

The NHS Breast Screening Programme in Wales, managed by Breast Test Wales, with headquarters in Cardiff.

METHODS

A case-control study design with 1:2 matching. The cases were deaths from breast cancer in women aged 50-75 years at diagnosis who were diagnosed after the instigation of screening in 1991 and who died after 1998. The controls were women who had not died of breast cancer or any other condition during the study period. One was from the same GP practice and the other from a different GP practice within the same district, matched by year of birth.

RESULTS

Based on 419 cases, the odds ratio for risk of death from breast cancer for women who have attended at least one routine screen compared to those never screened was 0.62 (95% confidence interval [CI] 0.47-0.82, p=0.001). After excluding cases diagnosed prior to 1995 and adjusting for self-selection bias, the estimated mortality reduction was 25% (odds ratio=0.75, 95% CI 0.49-1.14, p=0.09).

CONCLUSION

The Breast Test Wales screening programme is achieving a reduction in breast cancer mortality of 25% in women attending for screening, which is consistent with the results of the randomized controlled trials of mammographic screening.

[Myocardial perfusion scintigraphy with Tc-99m MIBI in patients with left bundle branch block: Visual quantification of the anteroseptal perfusion imaging for the diagnosis of left anterior descending artery stenosis]

INTRODUCTION

The non-invasive detection of myocardial ischaemia in patients with left bundle branch block (LBBB) remains a challenge. It is often associated with coronary artery disease or hypertension, but frequently there is no indication of cardiovascular pathology at presentation. Exercise-induced electrocardiographic ST segment changes are non-diagnostic. Confirming coronary artery disease has obvious implications for management. Several studies have shown greater cardiac mortality in the presence of LBBB. Generally, a good prognosis has been found in patients with LBBB and normal or near-normal myocardial perfusion scintigraphy (MPS). Various investigators report frequent anteroseptal defects with MPS in patients with LBBB in the absence of significant left anterior descending (LAD) coronary artery disease. Several mechanisms have been proposed to explain this false-positive phenomenon. Various interpretative methods and stress techniques have been evaluated in an attempt to improve the specificity of noninvasive studies for detecting LAD disease. A number of software packages for quantifying myocardial perfusion are commercially available. Quantification is recommended to improve diagnostic accuracy and intra- and inter-observer reproducibility.41 METHODS: Patients with LBBB on ECG, who were referred to our institution (February 2002 to September 2003) for myocardial perfusion scintigraphy, were included in the study. Patients with previous myocardial infarction were excluded, unless the location was confirmed to be not anteroseptal before the onset of LBBB. Patients who did not undergo coronary angiography within six months were also excluded, unless a LAD lesion of > or = 50% was diagnosed more than six months prior to MPS without subsequent intervention, or angiography more than six months later showed a LAD lesion of < or = 50%. Treadmill exercise, dipyridamole or dobutamine infusion were used according to standard protocols and imaging commenced 15-60 minutes later. QPS quantitative software, used to reconstruct the images and quantify perfusion, is described in detail elsewhere. Three experienced nuclear physicians interpreted the studies. Stress and rest perfusion, as well as reversibility, to the anteroseptal wall (excluding the apex), anteroseptal wall and apex, and apex only, were graded on a scale of 0 (normal) to 4 (absent perfusion), where 1 represents mild, 2 moderate, and 3 severe impairment of perfusion. A final decision was made by consensus. Using QPS, summed stress, rest and difference scores were obtained for the same regions. Angiographic correlation was obtained by reviewing the patients' records. Stenosis of the LAD or graft vessel to the LAD of > or =50% was regarded as significant. The Kruskal-Wallace non-parametric test was used to compare the groups with and without significant LAD stenosis. A Bonferroni correction was applied to make provision for multiple testing. Receiver operating characteristic (ROC) analysis was utilised to determine the optimal threshold of the significant measurements to distinguish between the two groups; for this threshold, the sensitivity and specificity were calculated.

RESULTS

Nine men and nine women (42-78 years) satisfied the inclusion criteria and were included in the study. Dipyridamole was used in nine patients, exercise in seven, dobutamine in one, and one patient was injected during a period of typical chest pain. Ten patients had a LAD stenosis of < 50% and eight > or = 50%. The only measurement that yielded a significant difference between the groups was visual improvement in perfusion to the anteroseptal wall and apex between the stress and rest study (p < 0.0096). Even after applying a Bonferroni correction, the value tended towards significance (p = 0.16). A ROC curve was calculated and an optimal threshold of 0.5 determined, which in turn had a sensitivity of 88% and specificity of 67%.

DISCUSSION

Our findings suggest that visual reversibility in the anteroseptal wall and apex gives an indication of significant LAD stenosis in patients with LBBB. This finding agrees with that of Mairesse et al. Wackers argues that cardiomyopathic changes cause anteroseptal perfusion defects in LBBB. It is possible that irreversible perfusion defects in the anteroseptal wall and apex are caused by a constant, stress-independent mechanism, whereas reversible defects indicate underlying ischaemia. Interestingly, quantitative analysis was not helpful in predicting LAD disease. The quantitative software we used is well validated. On the other hand, Svenssson et al. compared three myocardial perfusion quantification software packages and found considerable variation, especially in the presence of perfusion defects. The state of perfusion to the apex was not helpful to detect significant LAD disease. It is known that the LAD usually supplies the apex. Matzer et al. found that requiring the presence of an apical defect improved specificity. This could not be confirmed by Lebtahi et al. or Vaduganathan et al.

LIMITATIONS

A definite limitation of our study was that treadmill stress testing was performed in seven patients. It is currently recommended by most authors that pharmacological stress be performed in patients with LBBB Selection bias is also a limitation because only patients who also had angiography were included in the study (18 out of 91).

CONCLUSION

A visual improvement in anteroseptal and apical myocardial perfusion between stress and rest with Tc-99m MIBI in patients with LBBB probably indicates significant LAD stenosis. In our hands, quantitative software did not aid in the diagnosis. A well-designed, prospective study using a standardized stress protocol (probably dipyridamole or adenosine), which specifically evaluates visual reversibility in the anteroseptal wall and apex, will obviate the need for a Bonferroni correction, and could confirm these findings.

Overdiagnosis in screening: is the increase in breast cancer incidence rates a cause for concern?

OBJECTIVES

To estimate the degree of overdiagnosis of breast cancer in a mammographic screening programme.

SETTING

A mammography service screening programme in Florence, Italy.

METHODS

We studied the incidence of breast cancer in Florence between 1990 and 1999, following the introduction of screening in 1990. Incidence of breast cancer in this period was compared with incidence between 1985 and 1989, before the introduction of screening. It was necessary to estimate the number of cancers that would have arisen in the absence of screening, but after the end of followup (31 December 1999), so that these were not misclassified as overdiagnosed tumours. Around 60,000 women aged 50-69 were invited for screening during the period of study.

RESULTS

There were 2780 breast cancers diagnosed during the period of study (2626 were invasive). There was no significant evidence of overdiagnosis of invasive cancers. When invasive and in situ cancers were considered together, around 5% of cases were overdiagnosed.

CONCLUSIONS

There is a small amount of overdiagnosis of ductal carcinoma in situ in mammography screening; however, this should not deter women from being screened. Training and practice in mammographic screening should emphasise detection of small, invasive lesions. Research into the natural history and treatment of the disease should aim at minimising overtreatment of those in situ lesions that are less likely to progress to invasive disease.

A simple model for potential use with a misclassified binary outcome in epidemiology

STUDY OBJECTIVE

Error in determination of disease outcome occurs in epidemiology, but such error is not usually corrected for in statistical analysis. A method of correction of risk estimates for misclassification of a binary disease outcome is developed here.

METHODS

The method is a simple, closed form correction to the logistic regression estimate. A closed form variance estimate is also developed.

SETTING

The method is illustrated in two studies, a cross sectional survey of cervicitis in Iran in 1996-97, as determined by inflammation on cervical smear specimens, and a case-cohort study of benign proliferative epithelial disease of the breast, in Canada 1980-88.

MAIN RESULTS

The method provides corrected odds ratio estimates and corrects the spurious precision conferred by misclassification.

CONCLUSIONS

The method is easy to apply and potentially useful, although potential failures of the assumptions involved should be borne in mind. It is necessary to give careful consideration to the plausibility or otherwise of the assumptions in the context of the individual study. Correction for misclassification of disease outcome may become more common with the development of readily applicable methods.

Single photon emission computed tomography (SPECT) in obsessive-compulsive disorder before and after treatment with inositol

Inositol, a glucose isomer and second messenger precursor, regulates numerous cellular functions and has demonstrated efficacy in obsessive-compulsive disorder (OCD) through mechanisms that remain unclear. The effect of inositol treatment on brain function in OCD has not been studied to date. Fourteen OCD subjects underwent single photon emission computed tomography (SPECT) with Tc-99m HMPAO before and after 12 weeks of treatment with inositol. Whole brain voxel-wise SPM was used to assess differences in perfusion between responders and nonresponders before and after treatment as well as the effect of treatment for the group as a whole. There was 1) deactivation in OCD responders relative to nonresponders following treatment with inositol in the left superior temporal gyrus, middle frontal gyrus and precuneus, and the right paramedian post-central gyrus; 2) no significant regions of deactivation for the group as a whole posttreatment; and 3) a single cluster of higher perfusion in the left medial prefrontal region in responders compared to nonresponders at baseline. Significant reductions in the YBOCS and CGI-severity scores followed treatment. These data are only partly consistent with previous functional imaging work on OCD. They may support the idea that inositol effects a clinical response through alternate neuronal circuitry to the SSRIs and may complement animal work proposing an overlapping but distinct mechanism of action.

Time-dependent effects on survival in breast carcinoma: results of 20 years of follow-up from the Swedish Two-County Study

BACKGROUND

Tumor size, lymph node status, and histologic grade are reported to be important predictors of survival in the first 5 years after the diagnosis of invasive breast carcinoma. However, to the authors' knowledge, the effect of these factors in the longer term (>10 years after diagnosis) is not yet clear.

METHODS

It is now >20 years since the Swedish Two-County Trial of breast carcinoma screening with mammography was instigated and long-term follow-up is now available to December 1998. In the current study, the authors analyzed the effects of tumor size, lymph node status, and tumor grade on survival to death from breast carcinoma using Cox regression and frailty models that allow the baseline hazard and/or effect of a covariate to vary with time.

RESULTS

The effects of tumor size, lymph node status, and tumor grade were shown to progressively diminish with time from diagnosis. The Cox regression model with time-varying coefficients and a dampening parameter then was fitted to allow for the attenuation of prognostic effects; tumor size, lymph node status, and tumor grade were all found to be highly significant (P<0.001).

CONCLUSIONS

The results of the current study suggest that long-term survival in women with invasive breast carcinoma could be modelled satisfactorily using either frailty models or Cox regression models with time-varying coefficients. The results also suggest that the value of tumor grade, lymph node status, and tumor size at the time of diagnosis have a lasting influence on subsequent survival, albeit attenuated in later years. The long-term effects of these prognostic factors may explain the fact that the impact of mass screening programs on breast carcinoma mortality rates is still apparent many years later.

Tamoxifen and Breast Density in Women at Increased Risk of Breast Cancer

BACKGROUND

Although mammographic breast density is associated with the risk of breast cancer and is influenced by hormone levels, the effects of tamoxifen on breast density in healthy women and whether tamoxifen-induced density changes are associated with breast cancer risk are unclear. We investigated mammographic breast density in healthy women with an increased risk of breast cancer at baseline and during 54 months of tamoxifen treatment.

METHODS

Mammograms were reviewed from 818 breast cancer-free women (388 in the tamoxifen group and 430 in the placebo group) at high risk for breast cancer, from the International Breast Cancer Intervention Study I, a trial of tamoxifen for breast cancer prevention. Breast density measurements, at baseline and during treatment, were obtained at 12- to 18-month intervals. Multivariable analysis was used to assess associations with breast density. All statistical tests were two-sided.

RESULTS

Breast density at baseline was similar in placebo (42.6%, 95% confidence interval [CI] = 39.6% to 45.6%) and tamoxifen (41.9%, 95% CI = 38.8% to 45.0%) groups. The main determinants of breast density at baseline were age, menopausal status, body mass index, and previous atypical hyperplasia. A greater density reduction in the tamoxifen group (7.9%, 95% CI = 6.9% to 8.9%) than in the placebo group (3.5%, 95% CI = 2.7% to 4.3%) was apparent within 18 months of treatment (P<.001); the reduction in density continued until 54 months of treatment. After 54 months of tamoxifen treatment, breast density was 28.2% (decrease from baseline = 13.7%, 95% CI = 12.3% to 15.1%; P<.001) in the tamoxifen group and 35.3% (decrease from baseline = 7.3%, 95% CI = 6.1% to 8.4%; P<.001) in the placebo group. The tamoxifen-associated density reduction was apparent in all subgroups, but there was a statistically significant interaction with age. In women aged 45 years or younger at entry, the net reduction with tamoxifen was 13.4% (95% CI = 8.6% to 18.1%), whereas in women older than 55 years, it was 1.1% (95% CI = -3.0% to 5.1%).

CONCLUSION

Tamoxifen treatment was associated with reduction in breast density, most of which occurred during the first 18 months of treatment.

The Swedish Two-County Trial of mammographic screening: cluster randomisation and end point evaluation

BACKGROUND

The Swedish Two-County Trial has been criticised on the grounds of the cluster randomisation and alleged bias in classification of cause of death.

PATIENTS AND METHODS

In the Two-County Trial, 77 080 women were randomised to regular invitation to screening (active study population, ASP) and 55 985 to no invitation (passive study population, PSP), in 45 geographical clusters. After approximately 7 years, the PSP was invited to screening and the trial closed. We analysed data using hierarchical statistical models to take account of cluster randomisation, and performed a conservative analysis assuming a systematic difference between ASP and PSP in baseline breast cancer mortality in one of the counties. We also analysed deaths from causes other than breast cancer and from all causes among breast cancer cases diagnosed in the ASP and PSP.

RESULTS

Taking account of the cluster randomisation there was a significant 30% reduction in breast cancer mortality in the ASP. Conservatively, assuming a systematic difference between ASP and PSP clusters in baseline breast cancer mortality, there was a significant 27% reduction in mortality in the ASP. Ignoring classification of cause of death, there was a significant 13% reduction in all-cause mortality in breast cancer cases in the ASP.

CONCLUSIONS

Breast cancer mortality is a valid end point and mammographic screening does indeed reduce mortality from breast cancer. The criticisms of the Swedish Two-County Trial are unfounded.

All-cause mortality among breast cancer patients in a screening trial: support for breast cancer mortality as an end point

BACKGROUND

It has recently been suggested that all-cause mortality is a more appropriate end point than disease specific mortality in cancer screening trials, and that disease specific mortality is biased in favour of screening. This suggestion is based partly on supposed inconsistencies between all-cause mortality results and disease specific results in cancer screening trials, and alleged increases in deaths from causes other than breast cancer among breast cancer cases diagnosed among women invited to screening.

METHODS

We used data from the Swedish Two-County Trial of mammographic screening for breast cancer, in which 77 080 women were randomised to an invitation to screening and 55 985 to no invitation. We estimated relative risks (RRs) (invited v control) of death from breast cancer, death from other causes within the breast cancer cases, and death from all causes within the breast cancer cases. RRs were adjusted for age and took account of the longer follow up of breast cancer cases in the invited group due to lead time.

RESULTS

There was a significant 31% reduction in breast cancer mortality in the invited group (RR 0.69, 95% confidence interval (CI) 0.58-0.80; p<0.001). There was no significant increase in deaths from other causes among breast cancer cases in the invited group (RR 1.12, 95% CI 0.96-1.31; p=0.14). A significant 19% reduction in deaths from all causes was observed among breast cancer cases in the group invited to screening (RR 0.81, 95% CI 0.72-0.90; p<0.001). A more conservative estimation gave a significant 13% reduction (RR 0.87, 95% CI 0.78-0.97; p=0.01). These findings are consistent with the magnitude of the reduction in breast cancer mortality.

CONCLUSIONS

Invitation to screening was associated with a reduction in deaths from all causes among breast cancer cases, consistent with high participation rates in screening. There is no significant evidence of bias in cause of death classification in the Two-County Trial, and as breast cancer mortality is the targeted clinical outcome in breast cancer screening, it is the appropriate end point in a breast cancer screening trial. All-cause mortality is a poor and inefficient surrogate for breast cancer mortality.