Table 3. Analysis of pre- and post- treatment HER2 expression on overall survival.

HER2 expression	HR	95% CI for HR	P
Pre CRT
Negative	1.000
Intermediate	0.584	0.234-1.460	0.2503
Positive	0.747	0.222-2.518	0.6385
Post CRT
Negative	1.000
pCR/NET	0.706	0.286-1.744	0.451
Intermediate	1.175	0.416-3.316	0.7607
Positive	0.367	0.112-1.203	0.0979
Association between pre- and post-tx HER2 expression	G=0.403	−0.147-0.953	0.1857

HER2, human epidermal growth factor receptor 2; CRT, chemoradiotherapy; pCR, pathologic complete response; NET, not enough tumor to examine.