Table 1. Study cases according to mutation status in pre- and post-chemotherapy samples and their clinicopathological and tumor response characteristics (n = 40 pairs).
| Category/Case | Mutation | Pre a /mutant allele frequency (if applicable) | Post b /mutant allele frequency (if applicable) | Arm c | Age d | Race | Baseline T stage | Met | ER | PgR | C1 | ORR |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| WT→WT cases | ||||||||||||
| HOB002 | none | WT | WT | A | 47 | Malay | T4 | - | + | + | + | PR |
| HOB005 | none | WT | WT | B | 55 | Chinese | T4 | - | - | - | + | NE |
| HOB007 | none | WT | WT | B | 63 | Chinese | T4 | - | - | - | + | PR |
| HOB014 | none | WT | WT | A | 47 | Chinese | T4 | - | + | + | + | PR |
| HOB015 | none | WT | WT | A | 51 | Chinese | T4 | - | - | - | + | PR |
| HOB019 | none | WT | WT | B | 64 | Malay | T4 | + | + | - | - | SD |
| HOB027 | none | WT | WT | B | 45 | Chinese | T3 | - | - | - | - | SD |
| HOB028 | none | WT | WT | B | 40 | Malay | T4 | - | - | - | + | PR |
| HOB031 | none | WT | WT | A | 48 | Chinese | T4 | - | + | - | + | PR |
| HOB036 | none | WT | WT | B | 46 | Chinese | T4 | - | + | - | - | SD |
| HOB042 | none | WT | WT | B | 59 | Indian | T4 | + | - | - | - | SD |
| HOB043 | none | WT | WT | A | 44 | Chinese | T4 | - | - | - | + | PR |
| HOB046 | none | WT | WT | B | 44 | Chinese | T4 | + | + | - | + | PR |
| HOB054 | none | WT | WT | A | 43 | Chinese | T3 | - | + | + | + | CR |
| HOB055 | none | WT | WT | B | 43 | Chinese | T4 | - | + | + | + | PR |
| HOB060 | none | WT | WT | A | 36 | Chinese | T3 | - | - | - | + | PR |
| HOB064 | none | WT | WT | A | 38 | Chinese | T3 | - | - | - | - | SD |
| HOB069 | none | WT | WT | A | 37 | Chinese | T3 | - | + | - | - | PR |
| HOB071 | none | WT | WT | A | 56 | Malay | T4 | + | - | + | - | CR |
| HOB073 | none | WT | WT | B | 45 | Malay | T4 | - | + | + | + | PR |
| HOB084 | none | WT | WT | A | 45 | Malay | T4 | - | - | + | - | PR |
| HOB089 | none | WT | WT | B | 49 | Chinese | T4 | + | + | + | - | PR |
| HOB091 | none | WT | WT | A | 63 | Chinese | T4 | - | + | + | - | PR |
| HOB099 | none | WT | WT | B | 32 | Chinese | T3 | - | + | + | + | PR |
| MT→MT cases | ||||||||||||
| HOB062 | PIK3CA H1047R | MT/18% | MT/24% | A | 64 | Chinese | T4 | - | + | + | + | PR |
| HOB085 | PIK3CA H1047R | MT/26% | MT/19% | A | 64 | Chinese | T4 | - | + | + | - | PR |
| HOB045 | PIK3CA E542K | MT/60% | MT/50% | B | 40 | Chinese | T3 | - | + | + | + | PR |
| HOB056 | PIK3CA E545K | MT/41% | MT/100% | A | 44 | Chinese | T4 | + | + | + | + | CR |
| HOB063 | PIK3CA N345K | MT/50% | MT/78% | A | 56 | Chinese | T4 | - | - | + | - | PR |
| MT→WT cases | ||||||||||||
| HOB076 | PIK3CA H1047R | MT/9% | WT | A | 34 | Chinese | T4 | - | + | + | + | CR |
| HOB026 | PIK3CA H1047L | MT/12% | WT | A | 54 | Chinese | T4 | - | + | + | + | PR |
| HOB044 | PIK3CA H1047L | MT/66% | WT | B | 48 | Malay | T3 | - | - | - | - | PR |
| HOB035 | EGFR S768I | MT/98% | WT | B | 56 | Malay | T4 | + | - | - | - | SD |
| HOB086 | KIT Y503-F504insAY | MT/20% | WT | B | 51 | Chinese | T3 | - | - | - | + | PR |
| WT→MT cases | ||||||||||||
| HOB096 | ABL Y253H | WT | MT/24% | B | 56 | Chinese | T3 | - | - | - | - | PR |
| HOB088 | EGFR H773-V774insH | WT | MT/51% | B | 45 | Chinese | T4 | + | - | - | + | PR |
| HOB077 | EGFR N771-P772>SVDNR | WT | MT/100% | B | 63 | Chinese | T4 | + | + | - | - | SD |
| HOB090 | MET Y1230C | WT | MT/20% | B | 61 | Chinese | T4 | - | + | - | + | PR |
| HOB052 | PDGFRA I843-S847>T | WT | MT/13% | B | 54 | Chinese | T4 | + | - | - | + | PR |
| HOB080 | PIK3CA H1047R | WT | MT/26% | B | 58 | Malay | T3 | - | + | - | + | PR |
Abbreviations: C1, + = tumor response ≥25% after cycle 1 chemotherapy, C1,— = tumour response <25% after cycle 1 chemotherapy; CR, complete response; ER, estrogen receptor status; Met, Presence of metastasis; MT, mutant; NE, non evaluable (patient had already started on another line of treatment); ORR, overall response rate; PgR, progesterone receptor; PR, partial response; SD, stable disease; T3, >50mm in greatest dimension; T4, tumor of any size with direct extension to the chest wall and/or to the skin (ulceration or skin nodules); WT, wildtype; -, negative/no; +, positive/yes
a Status of respective mutation in pre-chemotherapy sample
b Status of respective mutation in post-chemotherapy sample
c Arm A, randomized to receive doxorubicin in first cycle; Arm B, randomized to receive docetaxel in first cycle
d Age in years