Randomized Dose-Ranging Trial of Tamoxifen at Low Doses in Hormone Replacement Therapy Users

Serum insulin-like growth factor-I and platelet-derived growth factor as biomarkers of breast cancer prognosis

Epidemiologic studies have shown that growth factors and inflammatory mechanisms may affect breast cancer risk and prognosis. The present analysis on 110 postmenopausal breast cancer patients tested if serum insulin-like growth factor I (IGF-I), platelet-derived growth factor (PDGF), fructosamine, and C-reactive protein, a serum marker of inflammation, are associated with breast cancer relapse. The risk of adverse events after 5.5 years of follow-up was examined by Cox proportional hazards modeling, controlling for hormone receptor status, stage at diagnosis, and for body weight and serum testosterone level, which were known to significantly affect prognosis. PDGF and, to a lesser extent, IGF-I were positively but not significantly associated with the risk of breast cancer recurrence. By combining PDGF and IGF-I, however, the adjusted hazard ratio of recurrence among the women with both PDGF and IGF-I levels > their median values (respectively, 9.3 and 174.4 ng/mL) was 6.4 (95% confidence interval, 1.5-26.7) compared with the women with PDGF and IGF-I levels < or = their median values. Fructosamine and C-reactive protein were not associated with recurrences. The results suggest that PDGF may be an important prognostic factor for breast cancer and that IGF-I may increase the risk of recurrence in the presence of high PDGF levels.

Psychological and clinical factors implicated in decision making about a trial of low-dose tamoxifen in hormone replacement therapy users

PURPOSE

To assess the sociodemographic, health-related, and psychological factors that influence the decision of women on hormone replacement therapy (HRT) to participate in a phase III trial of low-dose tamoxifen.

PATIENTS AND METHODS

Clinical and psychological factors were assessed in 265 women who accepted and 192 women who refused to participate in a proposed trial. Health-related and sociodemographic factors included age, Gail risk, body mass index, education, current HRT use, regular mammographic screening, smoking habit, physical activity, alcohol use, concern about adverse effects, and physician recommendation. Psychological factors included breast cancer-related worry, absolute and comparative cancer risk perception, anxiety, and depression.

RESULTS

The most frequent reasons for entry were willingness to participate in a research program (60%), the need/desire to receive frequent medical care (58%), and the desire to contribute to medical knowledge (44%); whereas reasons for refusal included fear of medication abuse (33%), concern about adverse effects (31%), and physician advice against enrollment (24%). In a logistic model, after adjusting for current HRT use, the trial participation was directly associated with satisfaction with clearly explained study objectives (odds ratio [OR] = 9.33; 95% CI, 4.04 to 21.55) and inversely associated with high breast cancer worry (OR = 0.15; 95% CI, 0.03 to 0.77) and age > or = 60 years (OR = 0.40; 95% CI, 0.22 to 0.73).

CONCLUSION

Participation in a chemoprevention trial among HRT users is associated with a younger age, no breast cancer worry, and satisfaction with health care providers, suggesting a condition of psychological well-being as a promoting factor and emphasizing the importance of thorough counseling at study presentation.