Measurement of 5-fluorouracil in scalp hair: a possible index of patient compliance with oral adjuvant chemotherapy

Abstract.

 Objective: Little is known about patient compliance with oral adjuvant chemotherapy. It is estimated to be poor especially in Japan, where it is still unusual for patients to be directly informed of their diagnosis of malignancy. 5-Fluorouracil (5-FU) was measured in hair samples to assess patient exposure to 5-FU, and its potential usefulness is discussed as an index of compliance with postoperative adjuvant chemotherapy.

Methods:

Hair samples obtained from 55 patients, who had received oral 5-FU (total dose 27-41 g) as postoperative adjuvant chemotherapy over a 6-month period, were used for the analysis of 5-FU. The drug was extracted from the hair using ethyl acetate, and its fluorescence derivatization was employed for measurement with HPLC. The detection limit of 5-FU in hair was 0.01 ppm.

Results:

In 22 out of 55 samples 5-FU content was under the detection limit, whereas in the remaining 33 samples the drug was detected in a range of 0.006-2.125 ng per hair strand; in addition, drug content showed a log-normal distribution. 5-FU was detected in the hair collected from those patients who were possibly compliant with the postoperative oral adjuvant chemotherapy.

Conclusion:

As many as 40% of the patients analysed were supposed to be much less compliant. Even in the possibly compliant patients, the degree of compliance with the therapy varied according to a log-normal distribution.