Prospective evaluation of vitamin E for hot flashes in breast cancer survivors.

PURPOSE: Hot flashes represent a substantial clinical problem for some breast cancer survivors. Although estrogen or progesterone preparations can alleviate these symptoms in many patients, concern remains regarding the use of hormonal preparations in such women. Thus, there is a perceived need for nonhormonal treatments for hot flashes for breast cancer survivors. Based on anecdotal evidence that vitamin E was helpful, we designed a trial to investigate this matter. METHODS: We developed and conducted a placebo-controlled, randomized, crossover trial where, after a 1 week baseline period, patients received 4 weeks of vitamin E 800 IU daily, then 4 weeks of an identical-appearing placebo, or vice versa. Diaries were used to measure potential toxicities and hot flashes during the baseline week and the two subsequent 4-week treatment periods. RESULTS: The 120 patients evaluated for toxicity failed to show any. The 105 patients who finished the first treatment period showed a similar reduction in hot flash frequencies (25% v 22%; P = .90) for the two study arms. A crossover analysis, however, showed that vitamin E was associated with a minimal decrease in hot flashes (one less hot flash per day than was seen with a placebo) (P < or = .05). At the study end, patients did not prefer vitamin E over the placebo (32% v 29%, respectively). CONCLUSION: Although this trial was able to show a statistically significant hot flash reduction with vitamin E compared to a placebo, the clinical magnitude of this reduction was marginal.

Chemoprevention of cancer: review of the literature.

PURPOSE/OBJECTIVES: To explain the concept of cancer chemoprevention, describe chemoprevention trials, and discuss the agents currently under study to lower the incidence of oral premalignancy and head and neck, lung, breast, prostate, and colon cancers. DATA SOURCES: Published journal articles, books, bulletins, monographs, protocols, and professional experience. DATA SYNTHESIS: Chemoprevention is a promising approach to cancer control, and several key agents have been identified that may be able to block carcinogenesis. Phase III chemoprevention trials are being conducted to identify the role of agents (e.g., retinoids, tamoxifen, finasteride, aspirin) in cancer prevention. CONCLUSION: Knowledge of the genetic and hormonal changes that occur during carcinogenesis continues to increase. Agents are being identified that block the development of cancer by arresting carcinogenesis. As more agents are identified and investigated, their importance in chemoprevention is increasing. IMPLICATION FOR NURSING PRACTICE: The goal of nursing care for participants in prevention trials is to promote compliance with the study protocol while supporting optimum quality of life. Through proactive education of participants, family members, and the public and skillful management of side effects, nurses can play an integral part in the success of prevention trials.

Changes in phosphorus distribution during total parenteral nutrition.

To investigate the mechanism of hypophosphatemia during total parenteral nutrition (TPN), changes in phosphate (P) contents in the liver and muscle of rats supported by TPN for 2 days at 270 cal/g were studied in 39 Sprague Dawley rats (200 g body weight), divided into 5 groups as follows: G-I: starved for 24 hr (n = 7); G-II: TPN (5 mEq P/1000 cal) after 24 hr starvation (n = 7); G-III: starved for 4 days (n = 7); G-IV: TPN (5 mEq P/1000 cal) after 4 days starvation (n = 9); G-V: TPN (35 mEq P/1000 cal) after 4 days starvation (n = 9). P contents of the tissues were measured colorimetrically. Results indicated that muscle P content decreased in the depleted rat supported by TPN with low P intake, while an increase in P content in the liver was a constant finding in each TPN group. Increase in P intake tended to preserve the P content in the muscle. These findings suggest that the changes in P distribution in major body tissues must be considered in addition to the changes in the serum inorganic P levels to evaluate an adequate P requirement for TPN.