Treatment of primary breast cancer with L-PAM/5-FU and tamoxifen: An interim report

Summary

This trial studied the possibility that tamoxifen, added to L-phenylalanine mustard and 5-fluorouracil, enhances the established benefit of the latter two drugs in treatment of women with breast cancer and positive axillary nodes. The addition of tamoxifen resulted in a 25% decrease in treatment failure at 24 months and a 23% decrease at 36 months. In patients ≥50 years old, there was a 48% reduction at 24 months and a 39% reduction at 36 months. This advantage was statistically significant at both two and three years' follow-up (p < 0.001). Higher receptor levels were associated with a greater probability of disease-free survival. Patients ≤49 years old were less responsive. There was some evidence at 24 months that patients in this age group with four or more positive nodes who also had high ER levels might benefit from tamoxifen. At 36 months, however, this benefit was no longer evident. This form of adjuvant therapy is not recommended in patients ≤49 years of age whose tumor estrogen and progesterone levels are below 10 fmol; there is an appearance of benefit in patients ≥50 with low estrogen and progesterone levels, and stronger evidence of benefit when these levels are high among the older group of patients.