Prognostic and Predictive Factors

Slide 1 · Prognostic and Predictive Factors

Invasive breast carcinoma

Disease extent • tumor biology • therapeutic vulnerability

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning objectives

Distinguish prognostic from treatment-predictive information.

Interpret anatomic extent, grade, subtype, and biomarker findings.

Relate treatment response and actionable alterations to clinical decisions.

Integrate these variables without treating any single factor as destiny.

Slide 3 · Outcome depends on two complementary dimensions

Disease extent

Distant metastasis, regional nodal involvement, primary tumor size, and local invasion.

Tumor biology

Grade, histologic subtype, ER/PR/HER2, proliferation, gene expression, and treatment sensitivity.

Slide 4 · What makes a factor prognostic?

Observed tumor characteristic

Association with recurrence or survival

Risk estimate in a defined setting

Prognosis estimates the likely course of disease

Prognostic information may matter even when no specific treatment is being selected.

Slide 5 · What makes a factor predictive?

Identify biomarker

Match biomarker to therapy

Anticipate relative treatment response

Prediction concerns benefit from a particular intervention

A predictive association is specific to a therapy and does not guarantee response.

Slide 6 · Diagnostic, prognostic, and predictive are not synonyms

Biomarker role

Clinical question

Diagnostic

What tumor or molecular phenotype is present?

Prognostic

How is this cancer likely to behave?

Predictive

Does this finding imply benefit or resistance for a defined therapy?

Slide 7 · Anatomic findings and biology answer different questions

Primarily prognostic

Often prognostic and predictive

Tumor size and local extension

ER expression and endocrine responsiveness

Regional lymph node metastasis

HER2 status and HER2-directed treatment

Distant metastatic spread

Proliferation and chemotherapy sensitivity

Slide 8 · Major factor groups in the breast cancer report

Extent

M category

Nodal disease

Tumor size/local spread

Morphology

Nottingham grade

Special histologic type

Lymphovascular invasion

Biology

ER / PR / HER2

Gene profiles

Treatment response

Categories interact; They are not independent substitutes for complete staging.

Slide 9 · Why prognostic markers matter

Patient counseling

Clarify anticipated disease course and the uncertainty around individual estimates.

Treatment selection

Balance recurrence risk against potential benefit and treatment toxicity.

Research

Stratify risk groups and interpret therapeutic trial results.

Slide 10 · Extent of disease: Descending prognostic hierarchy

Distant metastasis (M)

Regional nodal disease (N)

Primary tumor extent (T)

Among extent-related factors, metastatic spread is paramount.

Slide 11 · Distant metastasis is the dominant adverse factor

Metastasis beyond regional lymph nodes carries the greatest prognostic weight.

When distant metastases are present, cure is generally unlikely.

Meaningful long-term remission or palliation remains possible, especially in selected ER-positive or HER2-positive cancers.

Slide 12 · Metastatic disease: Prognosis is not a therapeutic absolute

Anatomic implication

Distant disease defines systemic spread and supersedes primary-tumor size as the major prognostic signal.

Biologic qualification

ER and HER2 expression may identify effective systemic treatment options despite metastatic presentation.

Slide 13 · Axillary nodes: Most informative when M0

In the absence of distant metastasis, axillary nodal status is the leading anatomic prognostic factor.

Extent of nodal involvement matters: The number of positive nodes refines risk.

A clinical examination cannot reliably replace histologic assessment.

Slide 14 · Clinical nodal assessment has both error directions

False positive

Palpable lymph nodes may be reactive rather than metastatic.

False negative

Small metastatic deposits may exist in clinically unremarkable nodes.

Slide 15 · Histology determines the pathologic nodal finding

Sample regional lymph node

Assess tissue for metastasis

Document nodal involvement and burden

Histopathology improves nodal assessment compared with palpation alone.

Slide 16 · Sentinel nodes are the first drainage station

Tracer or dye identifies draining node

Targeted sentinel-node biopsy

Histologic evaluation of sentinel node

Negative sentinel nodes make more distant axillary involvement less likely.

Slide 17 · Node burden and long-term disease-free survival

10-year disease-free survival; Approximate ranges (%)

No involved axillary nodes

70–80%

1–3 involved nodes

35–40%

>10 involved nodes

10–15%

Historical textbook group-level estimates; Not contemporary individualized forecasts.

Slide 18 · Node-negative status does not eliminate systemic risk

What it supports

Absence of histologically detected axillary metastasis predicts a more favorable outcome.

What it does not exclude

About 10–20% of axillary node-negative patients develop distant recurrence estimates.

Slide 19 · Breast cancer may disseminate through several routes

Primary invasive breast carcinoma

Axillary lymphatic drainage

Internal mammary lymphatic routes

Hematogenous dissemination

Slide 20 · Primary-tumor diameter also stratifies outcome

10-year survival in node-negative breast carcinoma (textbook estimates)

Primary tumor <1 cm

>90%

Primary tumor >2 cm

77%

The >90% group is represented by a 90% lower-bound bar; Values are not risk-adjusted contemporary predictions.

Slide 21 · Size matters, but is not the entire T category

Dimension

Maximum invasive tumor size contributes to the T category.

Skin

Ulceration or dermal involvement may alter local-stage assessment.

Chest wall

Deep local invasion confers a more advanced pattern of disease.

Slide 22 · Locally advanced extension complicates control

Invasion of skin or chest-wall structures represents aggressive local spread.

Large infiltrative tumors can be harder to control through local therapy.

Local extension is clinically important even before distant metastasis is established.

Slide 23 · Inflammatory carcinoma is a clinical presentation

Pathologic driver

Extensive tumor emboli plug dermal lymphovascular channels.

Clinical phenotype

Diffuse erythema, edema, skin thickening, and often peau d’orange; Usually no discrete palpable mass.

Slide 24 · Why skin becomes red and edematous

Dermal lymphatic channels infiltrated by carcinoma

Obstruction of lymph drainage

Breast edema and skin changes

“Inflammatory” does not necessarily imply inflammatory-cell infiltration.

Slide 25 · Do not confuse inflammatory carcinoma with infection

Observation

Interpretation

Erythema and edema

Can reflect lymphovascular tumor emboli rather than infection.

Peau d’orange

Edematous skin tethered by Cooper ligaments.

Diagnostic consequence

Clinical mimicry may delay recognition of carcinoma.

Slide 26 · Histologic grade adds information within stage

Nottingham grading assesses degree of differentiation in invasive carcinoma.

High-grade tumors have worse outcomes than low-grade tumors within comparable stage groups.

Grade contributes to the AJCC 8th-edition prognostic staging framework.

Slide 27 · Three components of Nottingham grade

Tubule formation

How strongly do malignant cells retain gland-forming differentiation?

Nuclear pleomorphism

How variable and atypical are tumor-cell nuclei?

Mitotic activity

How frequent is cell division on microscopy?

Slide 28 · Grade 1: Well-differentiated morphology

Simplified morphology schematic — not a histologic specimen

Tubular or cribriform architecture

Small relatively uniform nuclei

Low proliferative activity

Slide 29 · Grade 2: Intermediate differentiation

Simplified morphology schematic — not a histologic specimen

Mixture of glandular and solid growth

Greater nuclear variation

Intermediate mitotic activity

Slide 30 · Grade 3: Poorly differentiated morphology

Simplified morphology schematic — not a histologic specimen

Ragged nests or solid sheets

Enlarged pleomorphic nuclei

Frequent mitoses; Necrosis may occur

Slide 31 · Grade is prognostic beyond tumor dimensions

Comparable T / N / M

Different tumor grades

Different expected clinical course

Patients with similar anatomic extent can differ biologically

The relative direction is supported; No grade-specific survival percentage is inferred.

Slide 32 · Special histologic types are clinically informative

Invasive carcinoma of no special type is morphologically heterogeneous.

Some special types are closely linked to favorable clinical behavior.

Other types show substantial prognostic variation within the category.

Slide 33 · Favorable special types: Why morphology matters

Histologic type

Source-supported implication

Tubular carcinoma

Well-formed infiltrating tubules; Consistently favorable prognosis.

Cribriform carcinoma

Invasive cribriform nests; Consistently favorable prognosis.

Adenoid cystic carcinoma

Rare salivary gland-like TNBC subtype with relatively favorable outcome.

Secretory carcinoma

Rare salivary gland-like subtype; May harbor actionable NTRK fusion.

Slide 34 · Metaplastic carcinoma is not prognostically uniform

Typical pattern

Many metaplastic carcinomas are triple-negative and associated with unfavorable clinical outcomes.

Important exceptions

Low-grade adenosquamous and fibromatosis-like metaplastic variants may be indolent.

Slide 35 · Histologic type can influence chemotherapy response

Pattern

Neoadjuvant response

Invasive carcinoma of no special type

Reference pattern for response comparison.

Invasive lobular carcinoma

Less responsive to neoadjuvant chemotherapy.

Metaplastic carcinoma

Less responsive to neoadjuvant chemotherapy.

Slide 36 · Lymphovascular invasion is a vascular-space finding

Invasive tumor at periphery

Malignant cells within small vascular spaces

Risk of dissemination or local relapse

Simplified causal schematic; Identification requires histologic assessment.

Slide 37 · Lymphovascular invasion adds risk when nodes are negative

Overall survival

Associated with adverse prognosis, particularly in patients without nodal metastasis.

Local control

Associated with a higher probability of local recurrence.

Slide 38 · Different anatomic contexts of tumor emboli

Lymphovascular finding

Clinical significance

Peritumoral lymphovascular invasion

Additional adverse prognostic information.

Extensive dermal lymphatic tumor emboli

Can underlie inflammatory breast carcinoma presentation.

Slide 39 · Tumor biology is captured through multiple assays

Immunohistochemistry

ER and PR nuclear staining; HER2 membrane staining; Proliferation markers.

Molecular analysis

HER2 amplification and tumor DNA alterations.

Expression signatures

Quantitative tumor mRNA panels enriched for proliferation-related genes.

Slide 40 · Major clinical biomarker phenotypes

Luminal

Typically ER-positive and HER2-negative; Variable grade and proliferation.

HER2-positive

HER2-driven cancers may be ER-positive or ER-negative.

Triple-negative

ER-negative, PR-negative, HER2-negative; Biologically heterogeneous.

Slide 41 · Estrogen receptor: Prognostic and predictive

Prognostic dimension

Higher ER expression usually corresponds to a more favorable tumor phenotype.

Predictive dimension

ER expression identifies cancers likely to benefit from endocrine therapy.

Slide 42 · ER status is based on nuclear immunoreactivity

Immunostain invasive carcinoma

Assess tumor-cell nuclei

Classify ER staining, including low-positive range

Robbins 11th ed. Uses ≥1% nuclear staining to define ER positivity.

Slide 43 · ER-low positive tumors need a distinct interpretation

ER expression

Source-supported implication

<1% tumor-cell nuclei

Below the textbook positivity threshold.

1–10% positive nuclei

Low-positive group; Worse prognosis than ER-high cancers.

High ER expression

Often more endocrine responsive, but extent and grade remain relevant.

Slide 44 · ER expression connects marker to therapy

ER-positive cancer

Endocrine-directed intervention

Lower recurrence probability; Survival benefit

Predictive implication applies to endocrine treatment, not every therapy.

Slide 45 · Progesterone receptor adds biologic resolution

ER-positive carcinomas commonly coexpress PR.

PR positivity is defined by ≥1% nuclear staining.

Low PR in an ER-positive tumor is associated with worse outcomes than high ER/high PR expression.

Slide 46 · Joint ER and PR patterns modify prognostic thinking

ER-high / PR-high

Relatively favorable receptor-expression combination.

ER-positive / PR-low

Clinical outcomes are less favorable than high expression of both receptors.

ER-/PR-/HER2-

Triple-negative phenotype lacks endocrine and HER2 treatment targets.

Slide 47 · HER2 biology: Amplified growth signaling

ERBB2 (HER2) locus amplification

HER2 receptor overexpression

RAS and PI3K–AKT signaling

Proliferation and survival

Schematic shows source-described growth/survival signaling, not a complete molecular pathway.

Slide 48 · HER2 is evaluated at protein and gene levels

Immunohistochemistry

Assesses HER2 protein expression at the tumor-cell membrane.

In situ hybridization

Assesses HER2 gene amplification; Source figure describes comparison with a chromosome 17 probe.

Slide 49 · HER2 has adverse biology and therapeutic value

Untreated tumor biology

HER2 positivity is associated with aggressive clinical behavior.

Therapy prediction

HER2 positivity can identify cancers responsive to HER2-targeted treatment.

Slide 50 · Triple-negative does not mean one uniform disease

The triple-negative definition is absence of ER, PR, and HER2 expression.

Most TNBCs are high-grade and show marked proliferation and genomic instability.

Rare special histologic types of TNBC have much more favorable behavior.

Slide 51 · Molecular grouping should not override histology

Typical TNBC

High-grade tumor, often TP53 altered, with greater genomic instability.

Important subtype exception

Adenoid cystic, secretory, and some low-grade metaplastic tumors behave differently.

Slide 52 · Proliferation links biology to outcome

High mitotic or proliferative activity

Faster tumor growth and higher grade

Greater recurrence risk; Often greater chemotherapy sensitivity

The last association is subtype-dependent; Molecular assays often enrich for proliferation genes.

Slide 53 · What multigene expression tests measure

Tumor mRNA sampled

Panel of proliferation-weighted genes quantified

Expression profile supports risk stratification

No proprietary score thresholds are asserted because the source excerpt does not provide them.

Slide 54 · Principal clinical role of gene expression profiling

Population most relevant

Selected slowly proliferating, ER-positive breast cancers.

Decision supported

Identify patients unlikely to derive sufficient chemotherapy benefit to justify its toxicity.

Slide 55 · Neoadjuvant treatment provides a response readout

Obtain pretreatment phenotype

Give systemic therapy before surgery

Evaluate residual carcinoma in resection

The observed response is new biologic information beyond the initial biopsy.

Slide 56 · Pathologic complete response is an observed endpoint

Complete regression

No residual invasive carcinoma in the post-treatment specimen (conceptual description; Definitions may differ by protocol).

Residual disease

Persistent carcinoma after treatment indicates an incomplete pathologic response.

Slide 57 · Response predicts prognosis differently by subtype

Tumor group

Prognostic importance of response

Triple-negative breast carcinoma

A strong response is associated with better prognosis.

HER2-positive carcinoma

A strong response is associated with better prognosis.

Most luminal carcinomas

Pathologic response is less powerful as a prognostic indicator.

Slide 58 · Tumor-infiltrating lymphocytes: What is measured?

Cellular constituents

Lymphocytes and plasma cells within tumor tissue and stroma.

Clinical association

Prominent TILs correlate with improved prognosis and greater neoadjuvant responsiveness in HER2 cancers and TNBC.

Slide 59 · Why immune context is biologically relevant

Genomic damage and tumor neoantigens

Tumor-associated immune-cell infiltration

Potential sensitivity to immune-modulating therapy

Conceptual context from adjacent TNBC section; No direct deterministic causal claim.

Slide 60 · ESR1 mutation is an endocrine-resistance mechanism

ESR1 alteration in metastatic ER-positive cancer

Constitutive estrogen-receptor signaling

Resistance to endocrine treatment

Source describes acquired resistance and adverse clinical behavior.

Slide 61 · When ESR1 testing becomes informative

ER-positive / HER2-negative metastatic cancer

Recurrence or progression on endocrine therapy

ESR1 analysis informs subsequent treatment selection

Timing/setting follows the Robbins 11th-edition discussion; Not a complete clinical guideline.

Slide 62 · Germline BRCA1/BRCA2 predicts PARP targeting

Germline BRCA1 or BRCA2 mutation

Homologous recombination repair defect

Predicted response to PARP inhibition

Specific patient selection and treatment eligibility require current clinical protocols.

Slide 63 · PIK3CA identifies a PI3K-pathway vulnerability

ER-positive / HER2-negative disease

Tumor PIK3CA alteration

Predicted benefit from PI3K-pathway inhibition

Actionability depends on indication, treatment line, and regimen; No drug-specific eligibility rules shown.

Slide 64 · NTRK fusion is important in secretory carcinoma

Secretory breast carcinoma

NTRK gene fusion

Potential response to an NTRK-targeting kinase inhibitor

Rare histologic subtype supplies a strong prompt to assess an actionable alteration.

Slide 65 · Immune checkpoint biomarkers are context-specific

PD-L1

Expression assessed in tumor cells and/or immune cells.

Tumor mutational burden

Sequencing-based estimate of somatic mutational load.

Mismatch repair deficiency

Potential immunotherapy-associated feature; Rare in breast cancer.

Slide 66 · Circulating tumor DNA samples evolving mutations

Nonviable tumor cells shed fragmented DNA

Blood sample contains tumor-derived DNA

Sequencing may detect emerging actionable changes

Textbook example: PIK3CA; Negative ctDNA does not logically exclude a tumor alteration.

Slide 67 · Biomarker-to-therapy map

Biologic feature

Therapeutic implication

ER expression

Endocrine-directed treatment

HER2 positivity

HER2-targeting agents

Germline BRCA1 / BRCA2

PARP inhibitor sensitivity

PIK3CA mutation

PI3K-pathway targeting

NTRK fusion

TRK-directed kinase therapy

Slide 68 · AJCC 8th-edition staging: Anatomic plus biology

Anatomic TNM category

Invasive tumor grade

ER, PR and HER2 phenotype

Prognostic stage assignment

Edition explicitly corresponds to the Robbins source, not a claim about all subsequent stage versions.

Slide 69 · Anatomic stage and prognostic stage are not identical

Anatomic framework

T: Primary tumor

N: Regional nodes

M: Distant metastasis

AJCC 8th prognostic framework

Uses anatomic extent plus grade and biomarker profile; Selected multigene results may contribute.

Slide 70 · Core elements of a prognosis-oriented pathology report

Size and locally advanced features of invasive carcinoma

Axillary or sentinel-node metastatic status and burden

Nottingham histologic grade and histologic subtype

Lymphovascular invasion, ER, PR, and HER2 findings

Relevant molecular test results and post-neoadjuvant response

Slide 71 · Application case: ER-low carcinoma

Clinical vignette

A patient has surgically excised invasive breast carcinoma with ER nuclear staining in 5% of tumor cells, low PR expression, and no known distant metastasis.

Why should “ER-positive” not be the entire prognostic summary?

Slide 72 · Case interpretation: Low ER is not equivalent to ER-high

Receptor positivity and expected biologic behavior must be separated.

ER staining of 5% falls in the low-positive range (1–10%).

Low ER expression is associated with less favorable behavior than high ER expression.

Stage, grade, PR, HER2, and nodal findings are still needed.

Slide 73 · Application case: Residual TNBC after chemotherapy

Clinical vignette

Pretreatment biopsy shows triple-negative invasive carcinoma. After neoadjuvant chemotherapy, viable residual invasive tumor remains in the operative specimen.

Which newly observed feature modifies the prognosis?

Slide 74 · Case interpretation: Treatment response is biologic information

Residual disease after neoadjuvant treatment is a prognostically relevant observation in TNBC.

Neoadjuvant therapy permits direct assessment of in vivo response.

For TNBC and HER2-positive cancers, response correlates strongly with prognosis.

Residual tumor implies a less favorable response than pathologic complete regression.

Slide 75 · Interpretation pitfalls

Pitfall

More defensible interpretation

One factor predicts an individual outcome

Use stage plus grade, subtype, biomarkers, and context.

Prognostic equals predictive

A poor prognosis does not itself specify a drug target.

ER-low is identical to ER-high

Low ER expression is a biologically distinct risk signal.

All TNBC has identical prognosis

Recognize rare favorable special histologic subtypes.

Slide 76 · Integrated clinical reasoning

Define disease extent

Grade and classify histology

Measure ER / PR / HER2

Assess indicated molecular or treatment-response factors

Integrate in prognosis and therapeutic planning

Management is multidisciplinary; No single pathology parameter replaces clinical assessment.

Slide 77 · Final synthesis

Extent

M status dominates; Nodal burden and local tumor extent sharpen baseline risk.

Biology

Grade, histologic type, ER/PR/HER2, proliferation, and immune infiltrates refine prognosis.

Prediction

Receptors, actionable alterations, and neoadjuvant response inform treatment-specific decisions.

Slide 78 · Principal reference

Robbins, Cotran & Kumar. Pathologic Basis of Disease. 11th ed. (2026).

Chapter 23, The Breast: “Prognostic and Predictive Factors,” pp. 964–965; adjacent sections on carcinoma subtypes and AJCC breast cancer staging (pp. 959–966).

Key source tables: 23.4 (molecular subtypes), 23.5 (prognostic factors), 23.6 (AJCC 8th-edition anatomic stage).