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1. From the “Gross Room” to the Proteome: Prognostic and Predictive Markers of Breast Carcinoma Omar Hameed
Associate Professor of Pathology and Oncologic Surgery
Director of Surgical Pathology
Vanderbilt University Medical Center
2. Overview Background
Prognostic versus predictive markers
Established markers
Newer markers
Gene expression profiles
Proteomics
3. Breast Carcinoma Worldwide
4. Breast Carcinoma in the US
5. Survival
6. Question What factors are associated with worse overall outcome and suggest the need for more aggressive therapy?
7. Management of breast carcinoma Biopsy
Surgery
Radiotherapy
Adjuvant drug therapy
Hormonal Rx
Chemotherapy
Herceptin®
8. Question Are there factors that might determine a particular response to a specific therapy and help guide management?
9. What are tumor (bio)markers? Tumor characteristics that may imply some future behavior/outcome; used for:
Screening
Diagnosis
Classification
Prognostication
Prediction of therapeutic response
10. Prognostic Markers Associated with outcome independent of treatment
Reflect the inherent ability of tumors to proliferate, invade and metastasize
11. Predictive Markers Predict response (or sometimes lack of response) to a particular therapy
12. Many are both
13. How do new markers become part of clinical practice?
14. How do new markers become part of clinical practice? Study issues (LOE)
Prospective versus retrospective
Untreated versus untreated versus mixed population
Analytic issues
Ease of measurement
Accuracy and precision
Reproducibility
Presence or absence of effective therapy
Clinical/statistical significance and strength
Cost/reimbursement issues
15. Established Pathologic Prognostic and Predictive Markers
16. Strong Prognostic Markers (RR>2) Pathological (TNM) stage
Tumor size
Lymph node (LN) status
Presence/absence of metastasis
17. Strong Prognostic Markers (RR>2) Pathological (TNM) stage
18. Moderate prognostic markers (RR 1.5-2) Histologic type
Histologic grade
Lymphovascular invasion
19. Survival associated with invasive breast cancer according to tumour gradeSurvival associated with invasive breast cancer according to tumour grade
20. Weak prognostic markers (RR<1.5) Estrogen receptor status
Progesterone receptor status
Human epidermal growth factor receptor-2 (HER2) status
MUCH STRONGER PREDITIVE MARKERS
21. Others-not established (“YAPIs”) Cathepsin D
Cyclin D
S-phase fraction and DNA ploidy
p53 bcl-2
TGF-a
EGFR
Tumor angiogenesis
Micrometastasis
22. How are these markers used? Indications for hormonal therapy:
Estrogen receptor expression
Progesterone receptor expression
Indications for HER2 antagonists [e.g. tratsuzumab (herceptin)]:
HER2 protein overexpression
HER2 gene amplification
23. How are these markers used? Indications for chemotherapy:
Positive axillary LNs
Negative LNs but with other features such as any of:
Larger tumor size (> 2 cm)
Higher histological grade
Negative hormone receptors
24. What might this mean? We could be treating 90% of patients with LN-negative disease
However, without treatment only 30% of those patients would relapse
A significant number of patients are being overtreated
25. The need for individualized management Identify pts more likely to have recurrences or relapses
Individualized counseling
Label those pts for more aggressive Rx
Identify pts more likely to respond to a particular therapeutic modality
26. Methods of identifying new (molecular) markers Genome-wide screening
Gene expression screening
Protein screening
Educated guessing
27. Breast Biomarkers >23,000 citations in Pubmed for “breast cancer” AND “biomarker”
Most of these are just “YAPIs”
Focus on
Gene expression profiling
Proteomic methods
28. Gene Expression Profiling (GEP) A technique in which the expression of hundreds or thousands of genes can be measured at once
In contrast to whole genome sequencing, GEP only measures the active genes, i.e. the ones being transcribed into mRNA
29. GEP of Breast Carcinoma Define biological subtypes of BC (type, ER, HER-2)
Perou, PNAS 1999
Perou, Nature 2000
Martin, Cancer Res 2000
Predict clinical status
West, PNAS 2001 (LN involvement)
Woelfe, Cancer Res 2003 (BM micrometastasis)
Predict outcome
v’ant Veer, Nature 2002
van de Vijer, NEJM 2002
Predict response to Rx
Chang, Lancet 2003
Pustzai, Proc Am Soc Clin Oncol 2003
30. GEP predicts Survival Patients, Methods
N = 98 (34 with mets, 44 met-free within 5 yrs, 20 controls)
RNA in vitro transcribed? cRNA hybridized? microarray
Results
70 genes (cell cycle, inv, angio and mets) correctly predicted outcome in 83% of pts
OR for mets within 5yrs = 18 (CI 3.3-94), P = 0.0001
32. GEP predicts survival Patients and Methods
N = 295 (<52 yr; 61 part of Nature 2002 study)
Median FU = 6.7 yrs
Results
HR = 4.6 (CI 2.3-9.2), P < 0.001
Was able to specifically classify pts with LN-ve disease
34. 21 genes can predict outcome
35. 21 genes can predict outcome Patients and Methods
Identified 250 candidate genes
Tested 447 pts and identified 16 robust marker genes
Validated on NSABP B-14 (LN-, ER+, Tamoxifen; N = 668; median FU, 14.1 yrs)
Developed a formula to calculate a recurrence score (0-100) based on weights of genes on prognosis
Low (<18)
Intermediate (18-30)
High (>30)
36. 21 gene assay
37. Oncotype assay
38. Commercially-available GEP-based genomic tests 70 gene expression (MAMMAPRINT)
21 gene expression (ONCOTYPE DX)
2 gene expression ratio (H:I)
5 gene expression (MOLECULAR GRADE INDEX)
39. GEP-based assays
40. Pros and Cons of GEP Pros
Impressive results
Combining multiple markers
Excellent screening tool
Cons
Study issues
Not widely available and expensive
Tumor vs. stroma vs. normal
Need for fresh tissue
41. The proteome: a new player? Large scale global analysis of expressed proteins
Various reports in BC
Identification of serum biomarkers/proteomic patterns
Identification of proteomic patterns in nipple aspiration fluid
Identification of characteristic proteomic patterns in benign/premalignant/malignant tissues
Shares many of the GEP cons
Has not reached the status of GEP
42. Can we combine established markers? Pathological stage (tumor size and LN status)
Nottingham Prognostic Index
Adjuvant Online
43. Nottingham Prognostic Index (NPI) Described in early 1980’s
NPI = 0.2 x tumor size + LN stage (NEG = 1; 1-3 POS = 2; >3 POS = 3) + HG (1-3)
Stratifies patients into 3 (or 6) prognostic groups
Has been validated as an excellent prognostic marker in >10,000 patients
44. Nottingham Prognostic Index (NPI)
45. Nottingham Prognostic Index (NPI)
46. Adjuvant Online! Described in 2000
SEER actuarial survival data were used to develop a computer program to predict outcomes
Validated in a population of >4,000 patients
47. Adjuvant Online!
48. Adjuvant Online
49. Can we do any better? Combine traditional and molecular markers?
50. Summary Breast carcinoma is heterogenous
Established prognostic and predictive markers include tumor size, LN status, stage, histological grade, hormone receptor status
Gene expression profiling is emerging as a powerful prognostic and predictive tool
The role of proteomics in prognostication, if any, is yet to be determined
Combining markers has a great potential in further increasing the prognostic/predictive power
51. Final note There is significant overlap between molecular and traditional markers, just different methods of measurement