Invasive Recurrence Risk Examined for HER2+ Breast CA
Low risk for T1a tumors; higher risk of distant invasive recurrence for T1b tumors reported at 1.0 cm
WEDNESDAY, June 4, 2014 (HealthDay News) -- For patients with human epidermal growth factor receptor 2-positive (HER2+) breast cancer, distant invasive recurrence is low for T1a tumors and is higher for T1b tumors, especially those with T1b tumors reported at 1.0 cm, according to a study published online June 2 in the Journal of Clinical Oncology.
Lou Fehrenbacher, M.D., from Kaiser Permanente in Northern California, and colleagues investigated the risk of invasive recurrence among 234 patients with small, node-negative HER2+ breast cancer. Participants with T1a+bN0M0 tumors, identified from a large, integrated health care system, had a median follow-up of 5.8 years.
The researchers identified 15 invasive recurrences, of which 47 percent were local/regional only. The five-year distant invasive relapse-free interval (RFI) was 98.2 percent among 171 T1ab patients not treated with adjuvant trastuzumab or chemotherapy; 99.0 percent for T1a patients; and 97.0 percent for T1b patients. For T1a, T1b, and T1b tumors reported at 1.0 cm, the local/regional plus distant five-year invasive RFI was 97.0, 91.9, and 89.4 percent, respectively. About one-quarter (24 percent) of the T1ab cohort comprised T1b tumors reported at 1.0 cm, which accounted for 61 percent of the cohort total tumor volume and three-quarters of distant recurrences (75 percent). The invasive RFI was lower for T1b 1.0 cm tumors (84.5 percent) than for T1a tumors (97.4 percent; P = 0.009).
"Potential risk differences for T1a and T1b, including the 1.0 cm tumors, should be considered when making treatment decisions," the authors write.