Table 1.
Clinical and molecular classification of BC.
| Cancer Type | Benign | Pre-Malignant/ In-Situ (20–25%) [13] |
Malignant/Invasive [IDC (80%), ILC (20%)] [13] | |||||
|---|---|---|---|---|---|---|---|---|
| Categories | Fibroadenoma Intraductal papilloma Lipoma |
Early Breast Cancer Detection |
Molecular Subtypes (St Gallen) | Recurrence/ Metastatic |
||||
| Lubular Carcinoma In-situ (LCIS) | Ductal Carcinoma In-situ (DCIS) | Luminal A | Luminal B (HER2-) |
Luminal B (HER2+) | HER2+ Enriched | TNBC | ||
| Cancer/Bio markers [11,12] |
ER, PR, HER2 & Ki67 (low < 10%); Germline test BRCA1 & 2 (High risk group) |
ER+; PR+; HER2−; Ki67 low (<10–14%); Germline test BRCA1 & 2 (High Risk Group) |
ER+; PR−; HER2−; Ki67 high (>14–30%); Germline test BRCA1 & 2 (High Risk Group) |
ER+; PR+/−; HER2+; Ki67 high/low; Germline test BRCA1 & 2 (High Risk Group) |
ER−; PR−; HER2+; Ki67 high; Germline test BRCA1 & 2 (High Risk Group) |
ER−; PR−; HER2−; Ki67 high; (CK 5/6+; EGFR+); Germline test BRCA1 & BRCA2 (High Risk Group) |
Metastatic Site: Bone, liver, lungs, brain ESCAT score: I = Good prognosis II = Poor Prognosis |
|
| Frequency of cases [14] | 20–25% | 40–50% | 20–30% | 20–30% | 15–20% | 10–20% | 4% | |
| Histological grade (Majority) | Well differentiated (G1) |
Moderately differentiated (G2) |
Moderately differentiated (G2) |
Poorly differentiated (G3) |
Poorly differentiated (G3) |
Poorly differentiated (G4) |
||
| TNM Stage | NR | I-III | I-III | I-III | I-III | I-III | IV | |
| Prognosis | NR | Good | Intermediate | Intermediate | Poor | Poor | Poor | |
| Response to therapies [11,12,14] | Surgery Breast-conserving surgery (BCS) Radiotherapy Lumpectomy Mastectomy |
Endocrine | Endocrine Chemotherapy |
Endocrine Chemotherapy Targeted Therapy |
Chemotherapy Targeted Therapy |
Chemotherapy PARP inhibitors |
Chemotherapy CKD4/6 Inhibitor Fulvestrant |
|
Abbreviations: BRCA 1 & 2: Breast Cancer gene 1 and 2; TNM: tumor, node, and metastasis; DCIS: Ductal Carcinoma In-situ; ESCAT: ESMO Scale for Clinical Actionability of molecular Targets; ER: Estrogen receptor; HER2: Human epidermal growth factor receptor; IDC: Invasive Ductal Carcinoma; ILC: Invasive Lobular Carcinoma; LCIS: Lubular Carcinoma In-situ; PALB2: Partner and localizer of BRCA2; PDL1: Program death-ligand 1; PR: Progesterone receptor, 2; MSI: Microsatellite instability.