Ovarian ablation in the adjuvant treatment of premenopausal and perimenopausal breast cancer

Prolactin-growth factor crosstalk reduces mammary estrogen responsiveness despite elevated ERalpha expression

Most breast cancers that occur in women express estrogen receptor alpha (ERalpha). However, a large subset of these cancers either does not initially respond to anti-estrogen therapy or develops resistance to such treatment modalities. One postulated mechanism of this failure is signaling cross talk between hormones and local growth factors. To examine these complex interactions in vivo, we assessed the effects of estrogen on transforming growth factor alpha (TGFalpha)- and prolactin (PRL)-induced mammary tumorigenesis in transgenic mice. Both PRL and estrogen reduced the latency of TGFalpha-induced oncogenesis, resulting in tumors that were variably ERalpha-positive, but were progesterone receptor-negative. However, despite elevated ERalpha levels in NRL-PRL/TGFalpha glands, tumor latency was not reduced with increasing estrogen levels, nor increased after ovariectomy. Furthermore, PRL and TGFalpha in combination blocked the mitogenic effects of estrogen, dramatically reduced progesterone receptor levels, and diminished ERalpha down-regulation in response to circulating estrogen levels, in contrast to the other genotypes. Notably, however, ductal morphology remained responsive to estrogen, indicating that TGFalpha and PRL in combination can inhibit some, but not all, estrogenic signals. Both in vitro and in vivo, PRL and TGFalpha cooperatively enhanced Akt phosphorylation, which is associated with endocrine resistance in human disease. These findings provide insight into the interactions of PRL with growth factors during mammary oncogenesis and suggest combinatorial approaches that may result in improved therapeutic efficacy.

Same gain, less pain: potential patient preferences for adjuvant treatment in premenopausal women with early breast cancer

The aim of this study was to determine the treatment preferences (adjuvant goserelin or cyclophosphamide, methotrexate and fluorouracil (CMF) chemotherapy) of healthy premenopausal women should they hypothetically develop oestrogen-receptor (ER) positive early breast cancer. Two hundred pre or peri-menopausal women read two scenarios describing goserelin or chemotherapy. Information included: How and where treatments were administered, side-effects, their likely persistence and impact on fertility. Women stated their unprompted initial and final preferences with reasons for the choices made. Respondents showed an overwhelming preference for goserelin. 156 (78%) women favoured goserelin, 22 (11%) chemotherapy and 22 (11%) remained undecided (P<0.0001). Primary reasons for preferring goserelin for were 105 (71%) avoidance of chemotherapy side-effects, especially hair loss, perceived convenience and less disruption to normal life 54 (36%). The minority who preferred chemotherapy, valued the treatment finishing more quickly. These results together with clinical trial data showing equivalence of goserelin with CMF regimens suggest that premenopausal women with ER-positive tumours should at least be offered the choice of either adjuvant hormone therapy or chemotherapy.

Current limits of knowledge in adjuvant and neoadjuvant endocrine therapy of breast cancer: the need for more clinical research

Adjuvant endocrine therapy following surgical resection of early, endocrine sensitive breast cancer has proven benefits in reducing risk of recurrence and death, as demonstrated in many mature well controlled clinical trials. The introduction of new endocrine therapies as potential alternatives to tamoxifen or ovarian ablation and the incorporation of neoadjuvant endocrine therapy into the overall management strategy continue to provide exciting challenges for clinical research. In this article the focus is on as yet unanswered questions pertinent to adjuvant or neoadjuvant endocrine therapy for breast cancer. In the process, we broadly outline the current limits of knowledge as we understand it. Many relevant and current clinical trials are ongoing and a list of these with contact details or references are provided. Definitive data is urgently needed in many areas and, when available, will provide important evidence on which the management of breast cancer patients in future can be based. Participation in relevant clinical trials is vital for future progress.