Academic Research Curriculum (ARC) #3 – Attending Guide

Hematology/Oncology

Clinical Scenario:

Four researchers at competing academic hospitals conducted studies to determine risk of contralateral breast cancer (CBC) and adjuvant tamoxifen therapy. Each naturally believes that their study will find the Truth (with a capital "T") of what is really going on. Review the descriptions of their study designs and answer the associated questions.

  1. Study 1 identified patients with primary unilateral breast cancer that completed treatment. These patients were then arbitrarily placed into equal groups using a computer algorithm; ½ received adjuvant tamoxifen therapy and the other half received placebo. They followed these patients for 5 years and measured the incidence of CBC.
  2. Study 2 identified a group of patients with primary unilateral breast cancer that completed treatment. They identified which of these patients received adjuvant tamoxifen therapy as determined by their oncologist and followed patients for 5 years and measured how many developed CBC.
  3. Study 3 identified patients with primary unilateral breast cancer who now have evidence of CBC. They also identified patients with primary unilateral breast cancer who do not have CBC. Chart review was conducted to determine how many of these patients received adjuvant tamoxifen therapy.
  4. Study 4 chart reviewed patients to identify a group of those who had primary unilateral breast cancer by ICD-10 code. Prescription records were reviewed to determine which patients had received adjuvant tamoxifen. ICD-10 codes were subsequently used to determine which patients developed CBC.

Study / Exposure / Outcome / Prospective or Retrospective? / Type of Study
1
2
3
4
  1. What is the difference between studies 1 and 2?
  1. What is the difference between studies 3 and 4?
  1. What is the difference between studies 2 and 4?
  1. Fill out the table below regarding strengths/weaknesses of each type of study design

Study Design / Strengths / Weaknesses
RCT
Case-Control
Prospective Cohort
Retrospective Cohort

Gierach GL, Curtis RE, Pfeiffer RM, et al. Association of Adjuvant Tamoxifen and Aromatase Inhibitor Therapy With Contralateral Breast Cancer Risk Among US Women With Breast Cancer in a General Community Setting. JAMA Onco. 2016;20892(2):1–8.

  1. What was the purpose of this trial?
  1. What was the study design?
  1. How was this study funded? What was the role of the sponsor in the study?
  1. What were the inclusion criteria? Exclusion criteria? What are your reactions to these criteria?

Inclusion: / Exclusion:
  1. What were the exposure and outcome variables? How was this information obtained?
  1. What kind of follow-up was done?
  1. How did this study address potential confounding variables?
  1. What were the characteristics of the population studied (supplement eTable 1)? Anything stand out in particular?
  1. How do you interpret relative risk and confidence intervals?
  1. Evaluate eTable 2. Which patients were more or less likely to receive tamoxifen?
  1. What is demonstrated by Figure 2 and the Table below it?
  1. What were the effects of tamoxifen on ER positive vs negative CBC?
  1. What was the result of stratification by age (eTable 4 in the Supplement)?
  1. Evaluate Figure 3.
  1. What are some limitations of this study?
  1. How will this affect your practice at Hines or Loyola?