ERBB2 and cancer: However, no significant increase in hazard ratio was seen in Trast –ve HER2+(ER−) cancers compared to the Trast +ve group in 5-year DFS (HR 2000.18, 95% CI 0.63–7.52; p = 0.598) or OS (HR 1.36, 95% CI 0.39–4.72 p = 0.962).