C

The study found that although HER2 immunoreactivity correlated with progression-free and disease-specific survival on univariate analysis, it did not retain independent significance on multivariate analysis; the authors concluded it “might have a limited prognostic value” for patients receiving adjuvant M-VEC, indicating the evidence is inconclusive rather than definitively positive or negative [Tsai, 2007, PMID 17940352].