Use of pegfilgrastim primary prophylaxis and risk of infection, by chemotherapy cycle and regimen, among patients with breast cancer or non-Hodgkin's lymphoma.

PURPOSE: This study aims to examine granulocyte colony-stimulating factor (G-CSF) prophylaxis by cancer type, chemotherapy regimen, and cycle in a real-world setting to assess if practice conforms to clinical guidelines, which recommend G-CSF prophylaxis every cycle when a patient's risk of febrile neutropenia (FN) is 20% or greater, and to describe the incidence of FN among patients who discontinue pegfilgrastim (peg) prophylaxis. METHODS: The cohort was selected from administrative claims data and includes adults diagnosed with non-Hodgkin's lymphoma (NHL) or breast cancer (BC) who began chemotherapy 2005-2010. RESULTS: About 83.2% of the 4,470 patients with BC treated with dose-dense doxorubicin, cyclophosphamide (ddAC), 83.6% of 2,197 patients with BC treated with docetaxel, doxorubicin, cyclophosphamide (TAC), and about 55.6% of the 2,722 patients with NHL treated with cyclophosphamide, doxorubicin, vincristine, with or without prednisone for 3-week cycles (CHOP-R Q3W) received peg prophylaxis in cycle 1. Among patients on these regimens who received peg prophylaxis in cycle 1 and were still on the regimen in cycle 4, about 90% received peg prophylaxis in that cycle. Among patients with BC or NHL who discontinued G-CSF, the incidence proportion of infection or FN varied by regimen and cycle, with a range from 0 to 14%. CONCLUSIONS: Despite clinical guidelines recommending G-CSF prophylaxis with chemotherapy regimens with a high risk of FN, many NHL and BC patients do not receive FN prophylaxis in cycle 1. However, among patients who receive G-CSF in cycle 1 and remain on the regimen, the majority appear to continue prophylaxis as indicated.

Mammographic density and breast cancer in three ethnic groups.

The extent of radiodense tissue on a mammogram (mammographic densities) is strongly associated with breast cancer risk among (non-Latina) white women, but few data exist for African-American and Asian-American women. We collected prediagnostic mammograms from 622 breast cancer patients and 443 control subjects ages 35-64 years from three different ethnic groups (whites, African Americans, and Asian Americans) who participated as cases and controls in one of two ongoing breast cancer studies. Percent and absolute mammographic density were assessed using a previously validated computer-assisted method. In all three ethnic groups combined, breast cancer risk increased with increasing percent mammographic density. After adjustment for ethnicity, age, body mass index, age at menarche, breast cancer family history, age at and number of full-term pregnancies, menopausal status, and hormone replacement therapy use, women with the highest percent density had 5-fold greater breast cancer risk than women with no density (P(trend) = 0.0001). The impact of percent density on risk was stronger for older than for younger women (>/=50 versus <50 years; P = 0.05). Risk estimates did not differ significantly by ethnicity, with breast cancer risk (95% confidence interval) increasing 15% (4-27%) in whites, 30% (5-61%) in Asian Americans, and 11% (-2-26%) in African Americans for each 10% increase in density. The trends were similar for absolute density. Our results confirm that increases in computer-assisted mammographic density measurements are associated with a strong gradient in breast cancer risk. Furthermore, our findings suggest that mammographic density is as strong a predictor of risk for African-American and Asian-American women as for white women.