Journal of Clinical Oncology, Vol 10, 1839-1847, Copyright © 1992 by American Society of Clinical Oncology
Prognostic value of DNA flow cytometry in the locally recurrent, conservatively treated breast cancer patient
BG Haffty, M Toth, S Flynn, D Fischer and D Carter
Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06510.
PURPOSE: This study attempted to determine the prognostic value of DNA flow
cytometry in the treatment of patients with locally recurrent,
conservatively treated breast cancer. METHODS AND MATERIALS: Of 433
patients with clinical stage I and II breast cancer treated with
conservative surgery and radiotherapy at Yale-New Haven Hospital before
January 1985, 50 patients experienced an ipsilateral breast relapse as a
first site of treatment failure. Using standard flow-cytometric techniques,
DNA ploidy, DNA index, and S-phase fraction (SPF) were measured for 38 of
the 50 (76%) paraffin-embedded specimens available for analysis. RESULTS:
At a median postrecurrence follow-up of 5.8 years, the 5-year and
disease-free survival rates following ipsilateral breast treatment failure
were 48% and 54%, respectively. Sixty-three percent of the recurrent tumors
were DNA diploid and 37% were aneuploid. Both DNA ploidy and SPF were
statistically significant prognostic indicators for 5-year survival and
disease-free survival after local recurrence. The 5-year survival rate of
the DNA diploid population was 64%, compared with 15% in the aneuploid
population (P < .02). Patients with low SPF (< 12%) experienced an
83% 5-year survival rate, compared with a 24% 5-year survival rate in
patients with high SPF (> or = 12%) (P < .03). Ploidy and SPF were
combined to define the categories of favorable (diploid, low SPF) and
unfavorable (diploid, high SPF or any aneuploid subgroups). Patients in the
favorable category experienced an 89% 5-year postrecurrence survival rate
and a 100% disease-free survival rate, whereas patients in the unfavorable
category had a 24% 5-year survival rate and a 32% disease-free survival
rate (P < .01). The flow cytometry as a factor correlated with other
clinical parameters previously shown to be of prognostic significance in
this patient population. In a multivariate analysis, flow cytometry was a
statistically significant and independent prognostic factor for
disease-free survival following local recurrence. CONCLUSIONS: DNA ploidy
and SPF as measured by currently available flow-cytometric techniques show
promise as a tool in determining prognosis for the patient with locally
recurrent breast cancer. Implications of these findings with respect to
issues of adjuvant systemic therapy at the time of local recurrence are
discussed.
