Timing of breast cancer surgery during menstrual cycle. A 10-year analysis of 133 premenopausal women

Timing of breast cancer surgery, menstrual phase, and prognosis: Systematic review and meta-analysis

BACKGROUND

For over 25 years, there has been a debate revolving around the timing of breast cancer surgery, menstrual cycle, and prognosis.

METHODS

This systematic review synthesizes and evaluates the body of evidence in an effort to inform evidence-based practice. A keyword and reference search was performed in PubMed and Web of Science to identify human studies that met the inclusion criteria. A total of 58 studies (48 international and 10 U.S.-based) were identified. We provided a narrative summary on study findings and conducted a meta-analysis on a subset of studies where quantitative information was available.

RESULTS

Findings from both qualitative and quantitative analyses were inconclusive regarding performing breast cancer surgery around a specific phase of the menstrual cycle.

CONCLUSION

Based on the Institute of Medicine criteria, evidence is insufficient to recommend a change in current primary breast cancer surgery practice based on menstrual phase.

Timing of breast cancer surgery in relation to the menstrual cycle--the rise and fall of a hypothesis

It has been claimed that the timing of surgery in relation to the menstrual cycle can significantly influence the prognosis among premenopausal women with primary breast cancer. The literature on the subject is reviewed. The results are heterogeneous, and the quality of the studies is in general low. Many studies suffer from statistical problems concerning small sample sizes and sub-group analyses. In all, the scientific basis for the hypothesis seems weak.

Timing of surgery during the menstrual cycle and prognosis of breast cancer

There are conflicting reports on the differential effect of surgery performed during the two phases of the menstrual cycle, namely, follicular and luteal, and prognosis of operable breast cancer. A statistical meta-analysis of the published evidence suggests a modest survival benefit of 15+/-4% when the operation is performed during the luteal phase. Further research in this area might provide a novel avenue to understand the natural history of breast cancer. A spin off from these studies might be the understanding of the importance of events that occur at the time of surgery in determining long term prognosis.

Timing of surgery with regard to the menstrual cycle in women with primary breast cancer

There is sufficient evidence to support both the hormonal influence on the outcome of breast cancer surgery and the SDA hypothesis. The SDA model produces a paradigm shift in the understanding of the natural history of breast cancer. It offers opportunities to try modifying a tumor's biological potential for metastasis (e.g., by tamoxifen, progesterone, antiprotease, or angiostatin) in the neoadjuvant setting. It continues to support the beneficial effects of detection and surgery early in the natural history of disease. It would be worthwhile to plan a trial comparing standard practice (unplanned surgery as the patient enrolls) with surgery during the luteal phase of the menstrual cycle in premenopausal women. Another possibility, based on studies of circulating progesterone, would be to compare primary progesterone treatment (for 4 to 10 days before surgery) with standard practice. Such a trial of primary progesterone is already under way, conducted by the Indian Breast Group. More than 200 patients have enrolled so far. The details of the trial are available from Clinical Research Secretariat, Tata Memorial Centre, Parel, Mumbai, India (e mail: tmho3@bom2.vsnl.in).

Menstrual timing of breast cancer surgery

PURPOSE AND DESIGN

This is a critical review of the growing body of data, 32 retrospective studies of the outcomes of 9,665 women published since 1989, relevant to the possibility that the timing of primary breast cancer resection within the menstrual cycle impacts breast cancer recurrence and/or spread and patient survival. This article evaluates and contrasts the adequacy of information and data analysis presented in each publication. The overall purpose of this exercise is to rigorously determine the relative strength of the hypothesis that the menstrual cycle timing of operation impacts outcome and, thereby, to determine whether or not a specific change in the practice of breast surgical oncology can be recommended.

RESULTS

The single most completely reported and thoroughly analyzed series, involving 1,175 young women, indicates that surgical resection timing is likely to be relevant to outcome. Seven additional high-quality studies involving 2,864 women have been most completely reported. While two of these eight find no impact, six (75%) of these studies find that breast cancer outcome is affected by operative timing. Nine of the remaining 24 less-complete studies report a statistically significant effect of operative timing. Among these 15 studies of the fates of more than 5,000 women, the opportune menstrual cycle phase almost invariably includes the putative luteal phase. A large number of retrospective studies of widely varying quality find no outcome difference as a function of resection timing. The adequacy of design of each of four ongoing prospective studies is found lacking.

CONCLUSIONS

Although it is likely that the menstrual cycle phase of operation is relevant to outcome, the nature of the available data cannot allow a clear recommendation of precisely when to operate. It is, therefore, concluded that current retrospective data are inadequate to recommend an immediate change in practice. Prospective studies of this potentially important question are essential. The prospective trials initiated to date will not be able to definitively answer this question because of inadequate chronobiological design. The minimal requirements for adequate prospective study are delineated.