Breastfeeding in a patient with chronic myeloid leukemia during tyrosine kinase inhibitor therapy

Abstract

Introduction Although imatinib is the first-line of therapy for Philadelphia chromosome (Ph)-positive chronic myeloid leukemia (CML), in Japan, it is recommended by the manufacturer that lactating women treated with imatinib mesylate for CML should discontinue breastfeeding their infants. Case A 32-year-old pregnant patient was diagnosed with Ph-positive CML at 13 weeks of gestation. She received imatinib (400 mg/day) after 28 weeks of gestation. A female infant was delivered at a gestational age of 35 weeks and 3/7 days after preterm premature rupture of membranes. It was decided to feed only colostrum to the infant and formula feeding was done subsequently because of the risk of the transfer of imatinib to breast milk. The milk/plasma (M/P) ratio and the relative infant dose (RID) for imatinib were calculated to be 0.35 and 1.4%, respectively at 5 days of life. Moreover, the serum level of imatinib in the child of age 5 days was 27 ng/mL, which was much lower than the target trough value for CML (1000 ng/mL). Conclusion The M/P ratio and RID values for maternally administered imatinib were within the safe range for breastfeeding, as reported in previous studies. In addition, it was found that the serum concentration of imatinib in the child was relatively low during short-term breastfeeding.

Therapeutic Monitoring of Orally Administered, Small-Molecule Anticancer Medications with Tumor-Specific Cellular Protein Targets in Peripheral Fluid Spaces—A Review

“…In the most recently published case report the milk/plasma ratio of imatinib attained 0.35 at 5 days postpartum. Blood was also collected from the infant on the same day to reveal a 27-ng/mL concentration of imatinib, which was considered to be safe by the authors [ 25 ].…”

Analysis on the current situation of twin breastfeeding and its influencing factors

“…Breastfeeding can reduce the risks of sudden infant death syndrome and infectious diseases, so many countries and related organizations worldwide advocate and encourage breastfeeding. [ 12 ] As the most ideal food for infants, breast milk is of great significance for the growth of infants, which can both strengthen the immune function of infants and be helpful for the recovery of mothers’ uterus and the reduction of breast cancer incidence. [ 13 ] In recent years, the exclusive breastfeeding rate has increased worldwide, but it is still low due to the many factors that affect it.…”

Cancer and Pregnancy: A Comprehensive Review

“…Imatinib and its metabolites were shown to be excreted in human milk [ 86 ]. Even though the estimated exposure of the neonate to imatinib was approximately at around 10% of the therapeutic dose and breastfeeding showed no developmental abnormalities after short-term breastfeeding, long-term breastfeeding should be discouraged in these patients [ 87 , 88 ].…”