Correspondence to: Richard R. Love, M.D., M.S., Medical Oncology Section, Department of Medicine, University of Wisconsin School of Medicine, 610 Walnut St., 256 WARF, Madison, WI 53705 (e-mail: rrlove{at}facstaff.wisc.edu).
Like our reported analysis (1), the analysis reported by Milella et al. is exploratory. The similar levels of benefit seen in the estrogen receptor-positive and estrogen receptor-negative luteal phase operated subsets [see Fig. 4 in (2)] are not inconsistent with the overall results [see Figs. 2 and 3 in (1)], showing a statistically significant benefit from oophorectomy plus tamoxifen for estrogen receptor-positive but not estrogen receptor-negative tumor-bearing patients (1). There is, however, a suggested benefit in the estrogen receptor-negative group [see Fig. 3 in (1)]. The data presented in Fig 4, B (2) present a breakdown of the results for 90 of 105 patients in Fig. 3 (1). That this is also of borderline statistical significance is simply suggestive of luteal/follicular oophorectomy impact differences.
The results of Milella et al. show benefit from follicular phase breast surgery, a conclusion opposite that of another study (3). As we reported for similar numbers of patients treated with mastectomy alone (2), we did not find any menstrual cycle phase impact on survival overall, and in multivariate analyses including hormone receptor status as a variable, we found no interaction between hormone receptor status and menstrual cycle phase. In oophorectomized women where menstrual cycle differences were found, there was a suggestion of an interaction with hormone receptor status, but the interaction favored luteal phase oophorectomy for disease-free survival in estrogen receptor-positive patients and favored luteal phase oophorectomy for overall survival in estrogen receptor-negative patients. This finding is best seen in the comparative risk ratios for these hormonal status subsets [see subsets in Table 2 in (2)]. Thus, our results regarding the relationship of menstrual cycle phase and breast surgery alone are different than those of Milella et al. but not contradictory to their results. Our results regarding the relationship of menstrual cycle phase and oophorectomy, presuming they are confirmed by others and in prospective trials, may reflect the operation of completely different signaling mechanisms.
With respect to differences in breast cancers among Asian and western breast populations, the prognostic factors in our Vietnamese and Chinese patients were similar qualitatively and quantitatively to those seen in Western populations (1). We found the frequency of estrogen and progesterone receptor-positive tumors to be very similar to those found in western populations (1). We believe that the often reported lower frequencies of these proteins in Asian populations are more likely to reflect laboratory methologic differences rather than population differences.
We agree with Ferretti and colleagues that there are several possible mechanisms that could explain our results. We are particularly struck by the attempt of Baum et al. (4) to describe the unpredictable natural history of breast cancer with a mathematical model. They suggested that micrometastases present at diagnosis are in a state of dynamic equilibrium, exquisitely sensitive to perioperative conditions, which luteal or follicular phase oophorectomy could dramatically change.
NOTES
Editors note: Dr. Love declined to respond to the correspondence by Dr. Hrushesky.
REFERENCES
1 Love RR, Duc NB, Allred DC, Binh NC, Dinh NV, Kha NN, et al. Oophorectomy and tamoxifen adjuvant therapy in premenopausal Vietnamese and Chinese women with operable breast cancer. J Clin Oncol 2002;20:255966.
2 Love RR, Duc NB, Dinh NV, Shen TZ, Havighurst TC, Allred DC, et al. Mastectomy and oophorectomy by menstrual cycle phase in women with operable breast cancer. J Natl Cancer Inst 2002;94:6629.
3 Hagen AA, Hrushesky WJ. Menstrual timing of breast cancer surgery. Am J Surg 1998;175:24561.[Medline]
4 Baum M, Chaplain MA, Anderson AR, Douek M, Vaidya JS. Does breast cancer exist in a state of chaos? Eur J Cancer 1999;35:88691.[Medline]
![]() |
||||
|
Oxford University Press Privacy Policy and Legal Statement |