A trial of consent procedures for future research with clinically derived biological samples

Background:

The aims of this study were to determine which consent procedure patients prefer for use of stored tissue for research purposes and what the effects of consent procedures on actual consenting behaviour are.

Methods:

We offered 264 cancer patients three different consent procedures: ‘one-time general consent'' (asked written informed consent), ‘opt-out plus'' (had the opportunity to opt out by a form), or the standard hospital procedure (control group). The two intervention groups received a specific leaflet about research with residual tissue and verbal information. The control group only received a general hospital leaflet including opt-out information, which is the procedure currently in use. Subsequently, all patients received a questionnaire to examine their preferences for consent procedures.

Results:

In all, 99% of patients consented to research with their residual tissue. In the ‘one-time consent'' group 85% sent back their consent form. Patients preferred ‘opt-out plus'' (43%) above ‘one-time consent'' (34%) or ‘opt-out'' (16%), whereas 8% indicated that they did not need to receive information about research with residual tissues or be given the opportunity to make a choice.

Conclusions:

The ‘opt-out plus'' procedure, which places fewer demands on administrative resources than ‘one-time consent'', can also address the information needs of patients.     

Clustering of health behaviours in adult survivors of childhood cancer and the general population

Background:

Little is known about engagement in multiple health behaviours in childhood cancer survivors.

Methods:

Using latent class analysis, we identified health behaviour patterns in 835 adult survivors of childhood cancer (age 20–35 years) and 1670 age- and sex-matched controls from the general population. Behaviour groups were determined from replies to questions on smoking, drinking, cannabis use, sporting activities, diet, sun protection and skin examination.

Results:

The model identified four health behaviour patterns: ‘risk-avoidance'', with a generally healthy behaviour; ‘moderate drinking'', with higher levels of sporting activities, but moderate alcohol-consumption; ‘risk-taking'', engaging in several risk behaviours; and ‘smoking'', smoking but not drinking. Similar proportions of survivors and controls fell into the ‘risk-avoiding'' (42% vs 44%) and the ‘risk-taking'' cluster (14% vs 12%), but more survivors were in the ‘moderate drinking'' (39% vs 28%) and fewer in the ‘smoking'' cluster (5% vs 16%). Determinants of health behaviour clusters were gender, migration background, income and therapy.

Conclusion:

A comparable proportion of childhood cancer survivors as in the general population engage in multiple health-compromising behaviours. Because of increased vulnerability of survivors, multiple risk behaviours should be addressed in targeted health interventions.     

Genomic Grade Index predicts postoperative clinical outcome of GIST

Background:

Prognosis of localised gastrointestinal stromal tumour (GIST) is heterogeneous, notably for patients with AFIP intermediate or high risk of relapse, who are candidates to adjuvant imatinib. We hypothesised that gene expression profiles might improve the prognostication and help to refine the indications for imatinib.

Methods:

We collected gene expression and histoclinical data of 146 pre-treatment localised GIST samples treated with surgery alone. We searched for a gene expression signature (GES) predictive for relapse-free survival (RFS) and compared its performances to that of three published prognostic proliferation-based GES (Genomic Grade Index (GGI), 16-Kinase, and CINSARC) and AFIP classification. We also analysed a data set from 28 patients with advanced GIST treated with neo-adjuvant imatinib.

Results:

We identified a 275-gene GES (gene expression signature) predictive of RFS in a learning set and validated its robustness in an independent set. However, the GGI outperformed its prognostic performances, and those of the two other signatures and the AFIP intermediate-risk classification in two independent tests sets in uni- and multivariate analyses. Importantly, GGI could split the AFIP intermediate/high-risk samples into two groups with different RFS. Genomic Grade Index ‘high-risk'' tumours were more proliferative and genetically unstable than ‘low-risk'' tumours, and more sensitive to imatinib.

Conclusion:

GGI refines the prediction of RFS in localised GIST and might help tailor adjuvant imatinib.     

How many strata in an RCT? A flexible approach

Background:

The need to allow for prognostic factors when designing and analysing cancer trials is well recognised, but the possibility of overstratification should be avoided by restricting the number of strata. The proposed method improves on existing guidance by being based on explicit principles and being more adaptable to circumstances, and should be of particular use to clinicians when designing a trial.

Methods:

Given a proposed sample size, a minimum allowable number in a stratum and an acceptable risk of observing fewer than this minimum, the number of strata can then be obtained by assuming a Poisson distribution for the number of observations per stratum. This can easily be programmed into Excel.

Results:

An example is given for a hypothetical typical trial of 250 patients, which for 80% power and 5% two-sided significance would correspond to a Cohen''s effect size of 0.355 (about halfway between the ‘small'' and ‘moderate'' thresholds). To have a <1% risk of fewer than 10 patients in a stratum, no >13 strata should be considered. For a survival analysis with the same overall sample size but 170 deaths, no >9 strata would be prudent. In the context of a cancer trial this could easily be met by only two prognostic variables.

Conclusion:

The method proposed is flexible and based on explicit principles and may be applied in the design or analysis of both clinical trials and epidemiological studies.     

What is the lifetime risk of developing cancer?: the effect of adjusting for multiple primaries

Background:

The ‘lifetime risk'' of cancer is generally estimated by combining current incidence rates with current all-cause mortality (‘current probability'' method) rather than by describing the experience of a birth cohort. As individuals may get more than one type of cancer, what is generally estimated is the average (mean) number of cancers over a lifetime. This is not the same as the probability of getting cancer.

Methods:

We describe a method for estimating lifetime risk that corrects for the inclusion of multiple primary cancers in the incidence rates routinely published by cancer registries. The new method applies cancer incidence rates to the estimated probability of being alive without a previous cancer. The new method is illustrated using data from the Scottish Cancer Registry and is compared with ‘gold-standard'' estimates that use (unpublished) data on first primaries.

Results:

The effect of this correction is to make the estimated ‘lifetime risk'' smaller. The new estimates are extremely similar to those obtained using incidence based on first primaries. The usual ‘current probability'' method considerably overestimates the lifetime risk of all cancers combined, although the correction for any single cancer site is minimal.

Conclusion:

Estimation of the lifetime risk of cancer should either be based on first primaries or should use the new method.     

Prediction of tumour response induced by chemotherapy using modelling of CA-125 kinetics in recurrent ovarian cancer patients

Background:

The main objective of the present study was to establish the relationships between CA-125 kinetics and tumour size changes during treatment.

Methods:

The data from the CALYPSO-randomised phase III trial, comparing two platinum-based regimens in recurrent ovarian cancer (ROC) patients, was randomly split into a ‘learning data set'' to estimate model parameters and a ‘validation data set'' to validate model performances. A kinetic–pharmacodynamic semi-mechanistic model was built to describe tumour size and CA-125 kinetics during chemotherapy. The ability of the model to predict tumour response induced by chemotherapy, based on CA-125 values, was assessed.

Results:

Data from 535 ROC patients were used to model CA-125 kinetics and tumour size changes during the first 513 days after treatment initiation. Using the validated model, we could predict with accuracy the tumour size changes induced by chemotherapy based on the baseline imaging assessment and longitudinal CA-125 values (mean prediction error: 0.3%, mean absolute prediction error: 10.6%).

Conclusions:

Using a semi-mechanistic model, the dynamic relationships between tumour size changes and CA-125 kinetics induced by chemotherapy were established in ROC patients. A modelling approach allowed CA-125 to be assessed as a biomarker for tumour size dynamics, to predict treatment efficacy for research and clinical purposes.     

BubR1 as a prognostic marker for recurrence-free survival rates in epithelial ovarian cancers

Background:

Epithelial ovarian cancer is one of the most lethal malignancies, and has a high recurrence rate. Thus, prognostic markers for recurrence are crucial for the care of ovarian cancer. As ovarian cancers frequently exhibit chromosome instability, we aimed at assessing the prognostic significance of two key mitotic kinases, BubR1 and Aurora A.

Methods:

We analysed paraffin-embedded tissue sections from 160 ovarian cancer patients whose clinical outcomes had been tracked after first-line treatment.

Results:

The median recurrence-free survival in patients with a positive and negative expression of BubR1 was 27 and 83 months, respectively (P<0.001). A positive BubR1 expression was also associated with advanced stage, serous histology and high grade. In contrast, Aurora A immunostaining did not correlate with any of the clinical parameters analysed.

Conclusion:

BubR1, but not Aurora A, is a prognostic marker for recurrence-free survival rates in epithelial ovarian cancers.     

CD8+ lymphocytes/?tumour-budding index: an independent prognostic factor representing a ‘pro-/anti-tumour' approach to tumour host interaction in colorectal cancer

Background:

The tumour-host interaction at the invasive front of colorectal cancer, including the epithelial–mesenchymal transition and its hallmark ‘tumour budding'', is an important area of investigation in terms of prognosis. The aim of this study was to determine the prognostic impact of a ‘pro-/anti-tumour'' approach defined by an established ‘pro-tumour'' (tumour budding) and host-related ‘anti-tumour'' factor of the adaptive immunological microenvironment (CD8+ lymphocytes).

Methods:

Double immunostaining for CK22/CD8 on whole tissue sections (n=279; Cohort 1) and immunohistochemistry for CD8+ using tissue microarrays (n=191; Cohort 2) was carried out. Tumour buds, CD8+ and CD8+ T-lymphocytes : tumour buds indices were evaluated per high-power field.

Results:

In Cohort 1, a low-CD8+/ buds index was associated with lymph node metastasis (P<0.001), vascular invasion (P=0.009), worse survival in univariate (P<0.001) and multivariable (P<0.001) analysis, and furthermore in lymph node-negative patients (P=0.002). In Cohort 2, the CD8+/ buds index was associated with T stage (P<0.001), N stage (P=0.041), vascular invasion (P=0.005) and survival in patients with TNM stage II (P=0.019), stage III (P=0.004), and adjuvantly untreated (P=0.009) and treated patients (P<0.001).

Conclusion:

The CD8+ lymphocyte : tumour-budding index is an independent prognostic factor in colorectal cancer and a promising approach for a future prognostic score for patients with this disease.     

Predictors of survival in patients with recurrent ovarian cancer undergoing secondary cytoreductive surgery based on the pooled analysis of an international collaborative cohort

Background:

This study aims to identify prognostic factors and to develop a risk model predicting survival in patients undergoing secondary cytoreductive surgery (SCR) for recurrent epithelial ovarian cancer.

Methods:

Individual data of 1100 patients with recurrent ovarian cancer of a progression-free interval at least 6 months who underwent SCR were pooled analysed. A simplified scoring system for each independent prognostic factor was developed according to its coefficient. Internal validation was performed to assess the discrimination of the model.

Results:

Complete SCR was strongly associated with the improvement of survival, with a median survival of 57.7 months, when compared with 27.0 months in those with residual disease of 0.1–1 cm and 15.6 months in those with residual disease of >1 cm, respectively (P<0.0001). Progression-free interval (⩽23.1 months vs >23.1 months, hazard ratio (HR): 1.72; score: 2), ascites at recurrence (present vs absent, HR: 1.27; score: 1), extent of recurrence (multiple vs localised disease, HR: 1.38; score: 1) as well as residual disease after SCR (R1 vs R0, HR: 1.90, score: 2; R2 vs R0, HR: 3.0, score: 4) entered into the risk model.

Conclusion:

This prognostic model may provide evidence to predict survival benefit from secondary cytoreduction in patients with recurrent ovarian cancer.     

Leg length, sitting height and postmenopausal breast cancer risk

Background:

Tallness has consistently been associated with an increased risk of breast cancer. We investigated the association further by decomposing height into leg length and sitting height.

Methods:

From the prospective Danish cohort ‘Diet, Cancer and Health'', 23 864 postmenopausal women enrolled during 1993–1997 were followed for a diagnosis of breast cancer in the Danish Cancer Registry through 2009.

Results:

The incidence rate ratios for breast cancer were 1.11 (95% CI=1.06–1.16) for each 5 cm increase in total height and 1.09 (95% CI=1.01–1.17) and 1.14 (95% CI=1.04–1.25) for each 5 cm increase in leg length and sitting height, respectively. There was no statistical significant difference between the associations for leg length and sitting height (P=0.47).

Conclusion:

Leg length does not seem to be more strongly associated with breast cancer among postmenopausal women than sitting height.     

The Breakthrough Generations Study: design of a long-term UK cohort study to investigate breast cancer aetiology

Background:

The rationale, design, recruitment and follow-up methods are described for the Breakthrough Generations Study, a UK cohort study started in 2003, targeted at investigation of breast cancer aetiology.

Methods:

Cohort members have been recruited by a participant referral method intended to assemble economically a large general population cohort from whom detailed questionnaire information and blood samples can be obtained repeatedly over decades, with high completeness of follow-up and inclusion of large numbers of related individuals. ‘First-generation'' recruits were women contacted directly, or who volunteered directly, to join the study. They nominated female friends and family, whom we contacted, and those who joined (‘second generation'') nominated others, reiterated for up to 28 generations.

Results:

The method has successfully been used during 2003–2011 to recruit 112 049 motivated participants with a broad geographic and socioeconomic distribution, aged 16–102 years, who have completed detailed questionnaires; 92% of the participants gave blood samples at recruitment. When eligible, 2½ years after recruitment, >98% completed the first follow-up questionnaire. Thirty percent are first-degree relatives of other study members.

Conclusion:

The ‘generational'' recruitment method has enabled recruitment of a large cohort who appear to have the commitment to enable long-term continuing data and sample collection, to investigate the effects of changing endogenous and exogenous factors on cancer risk.     

Cytology of the vulva: feasibility and preliminary results of a new brush

Objective:

Taking a biopsy is a standard procedure to make the correct diagnosis in patients with suspicious premalignant vulvar lesions. The use of a less invasive diagnostic tool as triage instrument to determine whether biopsy is necessary may improve patient comfort especially in patients with chronic vulvar disorders that may warrant consecutive biopsies. This study was conducted to investigate whether vulvar brush cytology is feasible and may be used to detect (pre)malignant vulvar lesions.

Methods:

A pilot study was performed with patients having clinically normal vulvar skin, lichen sclerosus (LS), usual or differentiated vulvar intraepithelial neoplasia or squamous cell carcinoma. A total of 65 smears were taken with the use of a vulvar brush and biopsies were performed for histopathological analysis.

Results:

Out of 65 smears, 17 (26%) were discarded because of poor cellularity. A total of 28 of 29 (97%) smears with a histological proven (pre)malignancy had a smear classified as ‘suspicious'' or ‘uncertain''. Cytology classified 11 smears as ‘non-suspicious'', of which 10 (91%) were indeed normal skin or LS. The accuracy, based on the presence of a lesion, for (pre)malignant lesions with the use of the brush showed a sensitivity of 97% and a negative predictive value of 88%.

Conclusion:

Vulvar brush cytology is feasible and may be a first step in the development of a triage instrument to determine whether subsequent biopsy of a clinically (pre)malignant lesion is necessary.     

Follow-up care for cancer survivors: views of the younger adult

Background:

Since the launch of the National Cancer Survivorship Initiative, there has been a surge of interest surrounding the value and organisation of long-term follow-up care after cancer treatment. We report the views of 309 adult cancer survivors (aged 18–45 years) on provision of follow-up and preferences for care.

Methods:

A total of 207 survivors completed questionnaires before and after routine consultant-led follow-up appointments and 102 were recruited by post. Measures of health status (including late effects, perceived vulnerability to late effects and quality of life), reasons for attending follow-up (clinical and supportive), issues to be discussed at follow-up and preferences for different models of care were assessed.

Results:

In all, 59% of the survivors reported experiencing one or more cancer-related health problems. Survivors rated clinical reasons for attending follow-up more highly than supportive reasons (P<0.001), although nutritional advice and counselling were considered useful (60 and 47%, respectively). Those still receiving scheduled follow-up appointments did not discuss the range of issues intended with ‘late effects'' and ‘fertility'', which were particularly under-discussed. Hospital rather than GP follow-up was more highly rated.

Conclusion:

Survivors value the clinical reassurance currently provided by consultant-led care. However, supportive needs are not systematically addressed. Multi-disciplinary services are recommended to meet supportive needs in addition to clinical care.     

Gene expression profiles of gliomas in formalin-fixed paraffin-embedded material

Background:

We have recently demonstrated that expression profiling is a more accurate and objective method to classify gliomas than histology. Similar to most expression profiling studies, our experiments were performed using fresh frozen (FF) glioma samples whereas most archival samples are fixed in formalin and embedded in paraffin (FFPE). Identification of the same, expression-based intrinsic subtypes in FFPE-stored samples would enable validation of the prognostic value of these subtypes on these archival samples. In this study, we have therefore determined whether the intrinsic subtypes identified using FF material can be reproduced in FFPE-stored samples.

Methods:

We have performed expression profiling on 55 paired FF-FFPE glioma samples using HU133 plus 2.0 arrays (FF) and Exon 1.0 ST arrays (FFPE). The median time in paraffin of the FFPE samples was 14.1 years (range 6.6–26.4 years).

Results:

In general, the correlation between FF and FFPE expression in a single sample was poor. We then selected the most variable probe sets per gene (n=17 583), and of these, the 5000 most variable probe sets on FFPE expression profiles. This unsupervised selection resulted in a better concordance (R²=0.54) between expression of FF and FFPE samples. Importantly, this probe set selection resulted in a correct assignment of 87% of FFPE samples into one of seven intrinsic subtypes identified using FF samples. Assignment to the same molecular cluster as the paired FF tissue was not correlated to time in paraffin.

Conclusion:

We are the first to examine a large cohort of paired FF and FFPE samples. We show that expression data from FFPE material can be used to assign samples to intrinsic molecular subtypes identified using FF material. This assignment allows the use of archival material, including material derived from large-randomised clinical trials, to determine the predictive and/or prognostic value of ‘intrinsic glioma subtypes'' on Exon arrays. This would enable clinicians to provide patients with an objective and accurate diagnosis and prognosis, and a personalised treatment strategy.     

Cytology history preceding cervical cancer diagnosis: a regional analysis of 286 cases

Background:

Despite programmed screening in the Netherlands, the decrease in incidence of cervical carcinoma lags behind. We analysed screening results preceding carcinoma cases, timeliness in case of follow-up, and FIGO (International Federation of Gynaecology and Obstetrics) stages as efficiency parameters for screening were taken.

Methods:

We analysed 286 women with cervical cancer between 2005 and 2007 for cytology history preceding carcinoma, hierarchically arranging cytology history (if present) into three groups: ‘screened'', ‘work-up'', and ‘underscreened'' (>6 yrs before diagnosis). For screen- and work-up smears, we analysed timeliness. FIGO stage was measured in relation to cytology history.

Results:

A total of 105 out of 286 (36.7%) women with cervical carcinoma were screened preceding the diagnosis. Delayed time intervals in case of abnormal cytology were 43.5% for borderline/mild dyskaryosis (BMD) and 38.0% for BMD (moderate dyskaryosis or worse; P=0.51). A total of 108 out of 286 (36.4%) women were underscreened, and 73 out of 286 (25.5%) were unscreened. Advanced carcinoma or FIGO stage ⩾2B in screened women was 16.0 vs 48.7% in work-up, underscreened, or unscreened (P<0.001).

Conclusion:

Women with cervical cancer are underscreened and have poor timeliness in case of abnormal cytology. Being un- or underscreened correlates significantly with higher cervical cancer stages, especially in older women (aged ⩾49 years; P<0.001). Improvement of attendancy is needed to meet the standard of quality for screening programmes.