Performance of Biopsies in Clinical Research

Ethical Framework for Including Research Biopsies in Oncology Clinical Trials: American Society of Clinical Oncology Research Statement

In contrast to clinical biopsies, where tissue is collected to inform patient care, research biopsies are performed for scientific purposes to potentially enhance understanding of the biologic bases of cancer and drug action, thereby improving diagnosis and treatment, but they may offer no direct benefit to participants and have known risks. The widespread use of research biopsies that do not have the potential to directly benefit participants has come under scrutiny, with critics raising ethical concerns related to the adequacy of participant protections, informed consent, and participant understanding of the risks and benefits, as well as the scientific impact of research biopsies on drug development and treatment. This manuscript presents the American Society of Clinical Oncology’s (ASCO’s) ethical framework for incorporation of research biopsies in trials. The framework provides guidance on the circumstances to include optional and mandatory biopsies, as well as provides recommendations to stakeholders on necessary steps for improving the conduct of research biopsies overall.

Safety and diagnostic accuracy of tumor biopsies in children with cancer

BACKGROUND

Tumor biopsies are central to the diagnosis and management of cancer and are critical to efforts in personalized medicine and targeted therapeutics. In the current study, the authors sought to evaluate the safety and accuracy of biopsies in children with cancer.

METHODS

All biopsies performed in children at the study institution with a suspected or established diagnosis of cancer from 2003 through 2012 were reviewed retrospectively. Patient characteristics and disease-related and procedure-related factors were correlated with procedure-related complications and diagnostic accuracy using logistic regression analysis.

RESULTS

A total of 1073 biopsies were performed in 808 patients. Of 1025 biopsies with adequate follow-up, 79 (7.7%) were associated with an adverse event, 35 (3.4%) of which were minor (grade 1-2) and 32 (3.1%) of which were major (grade 3-4) (grading was performed according to the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]). The most common major adverse events were blood transfusion (>10 mL/kg; 24 cases) and infection requiring intravenous antibiotics (6 cases). Eleven deaths (1.4%) occurred within 30 days after the procedure, but the procedure may have contributed to the outcome in only 2 cases. A total of 926 biopsies (90.3%) provided definitive histologic diagnoses. Using multivariable analysis, biopsy site, preprocedure hematocrit level, and body mass index were found to be associated with the risk of postprocedural complications (P<.0001, P<.0001, and P =.0029, respectively). Excisional biopsy and biopsy site were found to be independently associated with obtaining a diagnostic result (P =.0002 and P =.0008, respectively).

CONCLUSIONS

Tumor biopsies in children with cancer are associated with a low incidence of complications and a high rate of diagnostic accuracy. The predictive factors identified for adverse outcomes may aid in risk assessment and preprocedural counseling.

Research biopsies in the context of early phase oncology studies: clinical and ethical considerations

The Personalized Medicine approach in oncology is a direct result of an improved understanding of complex tumor biology and advances in diagnostic technologies. In recent years, there has been an increased demand for archival and fresh tumor analysis in early clinical trials to foster proof-of-concept biomarker development, to understand resistance mechanisms, and ultimately to assess biological response. Although phase I studies are aimed at defining drug safety, pharmacokinetics, and to recommend a phase II dose for further testing, there is now increasing evidence of mandatory tumor biopsies even at the earliest dose-finding stages of drug development. The increasing demand for fresh tumor biopsies adds to the complexity of novel phase I studies and results in different challenges, ranging from logistical support to ethical concerns. This paper investigates key issues, including patients’ perceptions of research biopsies, the need for accurate informed consent, and alternative strategies that may guide the drug development process.

Reporting practices of pharmacodynamic studies involving invasive research procedures in cancer trials

Background:

Tumour biopsy for pharmacodynamic (PD) study is increasingly common in early-phase cancer trials. As they are non-diagnostic, the ethical justification for such procedures rests on their knowledge value. On the premise that knowledge value is related to reporting practices and outcome diversity, we assessed in a sample of recent invasive PD studies within cancer trials.

Methods:

We assessed reporting practices and outcomes for PD studies in a convenience sample of cancer trials published from 2000 to 2010 that employed invasive, non-diagnostic tissue procurement. Extracted data were used to measure outcome reporting in individual trials. Using a reporting scale we developed for exploratory purposes, we tested whether reporting varied with study characteristics, such as funding source or drug novelty.

Results:

Reporting varied widely within and across studies. Some practices were sporadically reported, including results of all planned tests (78% trials reporting), use of blinded histopathological assessment (43% trials reporting), biopsy dimensions (38% trials reporting), and description of patient flow through PD analysis (62%). Pharmacodynamic analysis as a primary end point and mandatory biopsy had statistically significant positive relationships with overall quality of reporting. A preponderance of positive results (61% of the studies described positive PD results) suggests possible publication bias.

Conclusion:

Our results highlight the need for PD-reporting guidelines, and suggest several avenues for improving the risk/benefit for studies involving invasive, non-diagnostic tissue procurement.

Use of research biopsies in clinical trials: are risks and benefits adequately discussed?

PURPOSE

Although the incorporation of research biopsies into clinical trials is increasing, limited information is available about how study protocols and informed consents integrate and describe their use.

METHODS

All therapeutic clinical trials in which image-guided research biopsies were performed from January 1, 2005, to October 1, 2010, were identified from an interventional radiology database. Data from study protocols and informed consents were extracted and analyzed. Procedural complications were recorded.

RESULTS

A total of 57 clinical trials were identified, of which 38 (67%) contained at least one mandatory biopsy. The analysis of the research biopsy tumor tissue was a study end point in 95% of trials. The primary indication for a research biopsy was for integral biomarker analysis in 32% and for correlative science in 68% of trials. A statistical analytic plan for the correlative science research biopsy tumor tissue was mentioned in 26%, described as exploratory in 51%, and not mentioned in 23% of trials. For studies with mandatory biopsies, biopsy was an eligibility criterion in 71% of trials, and a statistical justification for the research biopsy sample size was present in 50% of trials. A total of 745 research biopsies were performed on 576 patients. Overall and major complication rates were 5.2% (39 of 745 biopsies) and 0.8% (six of 745 biopsies), respectively. Complication rates for intrathoracic and abdominal/pelvic solid organ biopsies were 17.1% (36 of 211 biopsies) and 1.6% (three of 189 biopsies), respectively. Site-stratified research biopsy-related risks were discussed in five consents.

CONCLUSION

A better representation of the risks and benefits of research biopsies in study protocols and informed consents is needed.

The frequency and significance of radiologically detected indeterminate pulmonary nodules in patients with colorectal cancer

OBJECTIVE

To investigate the frequency and significance of pulmonary nodules in patients with colorectal cancer (CRC).

SUBJECTS AND METHODS

Medical records of 1,344 patients with CRC who underwent thoracic computerized tomography scans between January 2003 and December 2009 were reviewed. Those with any distant metastatic disease or who were already known to have pulmonary malignancies were excluded. Number, size, shape and location of the nodules were evaluated. A multivariate analysis was performed to determine the predictive factors for evidence of metastases.

RESULTS

Of the 1,344 patients, 55 (4.09%) had nodules that met the criteria of an indeterminate pulmonary nodule. The mean follow-up time was 25 ± 17.9 months and the mean time to develop pulmonary metastasis was 15.5 ± 6.4 months. The nodules of 17 (30.9%) patients showed progression at follow-up; 8 had metastasized. Multivariate analysis showed multiple indeterminate pulmonary nodules (p = 0.006) of parenchymal localization (p = 0.016) with an irregular border (p = 0.002), which is predictive of metastatic disease.

CONCLUSION

Our study has shown that multiple indeterminate pulmonary nodules with an irregular border in a parenchymal location were more likely to represent metastatic disease. However, the frequency of the occurrence of indeterminate pulmonary metastases of CRC was low.

The ethical use of mandatory research biopsies

Increasingly, clinical trials incorporate translational research questions aimed at identifying biomarkers of response or resistance to agents under investigation. Biomarker assays can require tissue samples to be collected through a research biopsy before therapy, during treatment, or at the time of tumor progression. Such biopsy samples will generally not provide a direct benefit to the patient and, given the risks associated with any surgical procedure, ethical concerns have been raised when the participant's enrollment on a clinical trial depends on their consent to undergo a research biopsy. In this Perspectives article, we present the rationale for mandatory research biopsies and offer suggestions for standardization to ensure that high-quality, patient-centered, clinical trials continue to be designed with scientific and ethical rigor.

Patient willingness to undergo pharmacodynamic and pharmacokinetic tests in early phase oncology trials

BACKGROUND

Increasingly, early phase clinical trials involve pharmacodynamic (PD) and pharmacokinetic (PK) assays as well as frequent imaging studies. The authors conducted a prospective study examining patients' willingness to undergo such tests and the number of tests the patients would tolerate.

METHODS

A prospective, correlative study was conducted using a self-reported questionnaire to measure patients' willingness on a scale from 1 (not willing) to 10 (very willing) to undergo various procedures (eg, tumor and skin biopsies, blood tests) and imaging studies (eg, magnetic resonance imaging, echocardiogram). In addition, correlations were assessed between the number and type of tests and demographics, previous test experience, inconvenience, and insurance coverage. Sixty-one patients (22 women and 39 men) with advanced malignancies were enrolled. Descriptive, nonparametric, and parametric inferential statistics were used.

RESULTS

Overall willingness to undergo study-required tests was very high. Patients were most willing to undergo urine, blood, ultrasound, x-rays, echocardiogram, and computed tomography studies and were least willing to undergo tumor and skin biopsies and magnetic resonance imaging (all P ≤ .01). Significant inverse relations were observed between the frequency of a particular test and patient's willingness to undergo such tests. Inconvenience and prior negative experiences for more invasive tests (eg, skin biopsies) modestly affected willingness to undergo these tests again. College education, insurance coverage, and the requirement of tests for enrollment were correlated positively with willingness to undergo tests.

CONCLUSIONS

The current findings provide the first prospectively collected data on patients' willingness to undergo PK/PD tests and imaging studies associated with early stage oncology drug trials and can serve as basis for further exploration toward the design of patient-friendly, biomarker-driven clinical studies in oncology.

Ethics of mandatory research biopsy for correlative end points within clinical trials in oncology

Clinical investigators in oncology are increasingly interested in using molecular analysis of cancer tissue to understand the biologic bases of response or resistance to novel interventions and to develop prognostic and predictive biomarkers that will guide clinical decision making. Some scientific questions of this nature can only be addressed, or may best be addressed, through the conduct of a clinical trial in which research biopsies are obtained from all participants. However, trial designs with mandatory research biopsies have raised ethical concerns related to the risk of harm to participants, the adequacy of voluntary informed consent, and the potential for misunderstanding among research participants when access to an experimental intervention is linked to the requirement to undergo a research biopsy. In consideration of the ethical and scientific issues at stake in this debate, the Cancer and Leukemia Group B Ethics Committee proposes guidelines for clinical trials involving mandatory research biopsies. Any cancer clinical trial that requires research biopsies of participants must be well designed to address the scientific question, obtain the biopsy in a way that minimizes risk, and ensure that research participants are fully informed of the risks, rationale, and requirements of the study, as well as of treatment alternatives. Further guidelines and discussions of this issue are specified in this position paper. We feel that if these principles are respected, an informed adult with cancer can both understand and voluntarily consent to participation in a clinical trial involving mandatory research biopsy for scientific end points.

Performing nondiagnostic research biopsies in irradiated tissue: a review of scientific, clinical, and ethical considerations

PURPOSE

Recent development of drugs that target specific pathways in tumors has increased scientific interest in studying drug effects on tumor tissue. As a result, biopsies have become an important part of many early-phase clinical trials. Performing nondiagnostic tumor biopsies raises technical and ethical concerns mostly related to the use of a potentially harmful procedure with no potential benefit to the patient. This issue is complicated by uncertainty about whether performing biopsies in irradiated fields adds significant risk. This article reviews the clinical, scientific, and ethical considerations involved in performing nondiagnostic tumor biopsies in competent adults for research purposes, with a focus on biopsies performed in the setting of therapeutic irradiation.

METHODS

Clinical trials that performed biopsies during or within 4 months of the completion of radiotherapy were identified with a literature review.

RESULTS

Twenty-nine studies with 2,160 patients were identified. Sixteen of 29 studies reported adverse events (AEs) but did not report active evaluation for biopsy complications. Ten studies did not mention AEs within the study report. At least three studies actively evaluated patients for biopsy complications. Taking this into consideration, 17 (>1%) of 2,160 patients were reported to have biopsy complications, although reporting of AEs was suboptimal in most studies.

CONCLUSION

Limited data suggest that biopsies can be performed in irradiated tissues without clinically significant excess risk. Ongoing and future trials including nondiagnostic research biopsies should record and report AEs related to this procedure to provide additional data on safety and toxicity.

The clinical significance of radiologically detected silent pulmonary nodules in early breast cancer

BACKGROUND

Increasing numbers of patients with early cancer undergo routine staging using computerized tomography (CT). Those in whom indeterminate pulmonary nodules are visualized without the presence of other metastatic lesions represent a clinical dilemma regarding their management as early breast cancer or metastatic disease.

PATIENTS AND METHODS

Medical records of breast cancer patients who underwent thoracic CT scans between the years 2002 and 2008 were analyzed. Those with obvious metastatic disease were excluded. Patients were identified via the radiology database by searching for the terms: 'suspicious lung metastases' and 'indeterminate nodules'.

RESULTS

Out of 1578 new patients assessed from 2002 to 2008, we carried out 802 staging CT scans. Thirty-four cases (4.2%) with indeterminate pulmonary nodules were identified. We categorized cases by size and number of nodules. At a median follow-up of 18 months, there were no changes in lesion size in 86% of patients with a solitary nodule <1 cm and 89% with multiple subcentimeter nodules. In contrast, in 100% of cases with pulmonary nodules >1 cm, the nodules had progressed at follow-up (chi(2), P = 0.004).

CONCLUSIONS

Breast cancer cases with subcentimeter indeterminate pulmonary lesions and no evidence of metastases elsewhere are unlikely to represent metastatic disease. Treatment with curative intent or entry into clinical trials should not be excluded.