Table 2.
Mutations and pathologic complete response by pre- and postchemoradiation
| Pre-CRT (n = 26) | Post-CRT (n = 21) | p value (overall) | |||||
|---|---|---|---|---|---|---|---|
| Mutation | Total | pCR | No pCR | Total | pCR | No pCR | |
| APC | 7 (27 %) | 0 | 7 | 1 (5 %) | 0 | 1 | 0.06 |
| BRAF | 0 (0 %) | 0 | 0 | 2 (10 %) | 0 | 2 | 0.19 |
| KRAS | 12 (46 %) | 1 | 11 | 8 (38 %) | 0 | 8 | 0.77 |
| NRAS | 1 (4 %) | 0 | 1 | 1 (5 %) | 0 | 1 | 1.00 |
| PIK3CA | 2 (8 %) | 1 | 1 | 0 (0 %) | 0 | 0 | 0.50 |
| TP53 | 2 (8 %) | 0 | 2 | 3 (14 %) | 0 | 3 | 0.64 |
| Any mutation | 16 (62 %) | 1 (6 %) | 15 (94 %) | 14 (67 %) | 0 | 14 (100 %) | 0.77 |
| Wild type | 10 (38 %) | 3 (30 %) | 7 (70 %) | 7 (33 %) | 1 (14 %) | 6 (86 %) | 0.77 |
Five patients of the 47 analyzed had a pCR. One patient with a pCR had both KRAS and PIK3CA mutations. Overall, five patients had both APC/KRAS (pre-), one patient had KRAS/PIK3CA (pre-), one had APC/TP53 (pre-), one had PIK3CA/TP53 (pre-), and one patient had APC/BRAF (post-)
CRT chemoradiation, pCR pathologic complete response