Postmastectomy radiotherapy and concomitant adjuvant chemotherapy versus adjuvant chemotherapy alone in premenopausal breast cancer patients with positive axillary nodes

Aims: To evaluate the efficacy of postmastectomy radiotherapy (RT) combined with adjuvant chemotherapy compared to adjuvant chemotherapy alone as rega rds overall survival (OS), overall disease-free survival (ODFS), local dise ase-free survival (LDFS) and distant disease-free survival (DDFS). Methods: We reviewed retrospectively two non-randomized groups of premenopausal hig h-risk breast cancer patients treated from 1985 to 1990 in the following In stitutions: Department of Radiation Oncology of Brescia University, "Istitu to del Radio O. Alberti" (IRA), and Department of Oncology of Brescia Hospi tal "Beretta Foundation" (BF), A total of 163 patients was found to satisfy the criteria of the current analysis: 81 patients received adjuvant chemot herapy alone [6 cycles CMF(1-8)] at BF and 82 patients received postoperati ve radiotherapy and chemotherapy [8 cycles CMF(1-21)] at IRA. A modified CM F schedule was chosen at IRA to avoid the feared increase in toxicity due t o the association with RT. Primary surgical treatment was modified radical mastectomy with axillary node dissection in both cases. Results: A statisti cally significant improvement in OS was found in systemic adjuvant therapy patients compared to those also given RT (77.6% vs 59%; P = 0.0025). No sta tistically significant improvement in ODFS was found in the CMF(1-8) arm co mpared to the RT and CMF(1-21) stm: 51.6% vs 43.6% P = 0.46. A statisticall y significant improvement in LDFS Bt 5 years was found in irradiated patien ts (89.3% vs 76.2%; P < 0.05). The DDFS was also improved, although without evidence of statistical significance, in the CMF(1-8) group: at 5 years 65 % vs 44% (P = 0.059). Conclusions: The study confirmed that Ri reduces the risk of local recurrence but without a statistically significant reduction in mortality. The lack of a survival benefit may somehow reflect the dose r eduction in CMF(1-21). The evidence that CMF(1-8) offers undoubtable advant ages over the CMF(1-21) regimen in OS and, perhaps, in distant control sugg ests that the dose intensity of CMF in this setting may also be important. In fact, although many CMF(1-8) patients received a dose intensity lower th an 100%, 95% of them received a dose intensity higher than the maximum one of the CMF(1-21) patients. Although our results should be interpreted with caution, they seem to provide further rationale for testing the association of postoperative radiotherapy and the CMF(1-8) regimen in stage II breast cancer with positive nodes and treated with demolitive surgery, as already done in the conservative management of breast cancer, also in view of the n ew support therapies now available (i.e. hematologic growth factors).