Raloxifene fares as well as tamoxifen in 2 related comparison studies

Raloxifene, a second-generation selective estrogen receptor modulator (SERM) approved to treat osteoporosis, fared as effectively against breast cancer as tamoxifen in 2 related comparison studies published in the Journal of the American Medical Association (JAMA).

The National Surgical Adjuvant Breast and Bowel Project (NSABP) announced the findings from its STAR (Study of Tamoxifen and Raloxifene) P-2 trial, which involved 19,747 high-risk, postmenopausal women whose mean age was 58.5 years.

"If raloxifene is approved by the Food and Drug Administration for the prevention of breast cancer, primary care physicians may be more willing, given their experience with raloxifene, to prescribe it for breast cancer chemoprevention than they have been to prescribe tamoxifen," the authors stated.

The second study concluded that no significant differences existed between the tamoxifen and raloxifene groups in patient-reported outcomes for physical health, mental health, and depression.

Although mean physical component summaries (PCS), mental component summaries (MCS), and Center for Epidemiologic Studies-Depression (CES-D) scores worsened for the raloxifene group slightly over the study's 60 months, there was no significant difference between the tamoxifen (n=973) and raloxifene (n=1,010) groups (P>.2).

Among the patients in the symptom assessment analyses, the 9,769 in the raloxifene group reported greater mean symptom severity over 60 months of assessments than the 9,743 in the tamoxifen group for: musculoskeletal problems (1.15 vs 1.10, P=.002), dyspareunia (0.78 vs 0.68, P<.001), and weight gain (0.82 vs 0.76, P<.001). Patients in the tamoxifen group reported greater mean symptom severity for: gynecological problems (0.29 vs 0.19, P<.001), vasomotor symptoms (0.96 vs 0.85, P<.001), leg cramps (1.10 vs 0.91, P<.001), and bladder control symptoms (0.88 vs 0.73, P<.001).

"NSABP's STAR trial, with its large-scale symptom evaluation and well-powered QOL substudy, provides a comprehensive, detailed view of the patient experience using raloxifene and tamoxifen," the authors of the second study stated. "Both (raloxifene and tamoxifen) are indicated for prevention in large populations, so these results can be widely used as tools in decision making or in helping a woman anticipate and cope with the sequelae of her chosen agent."

In an accompanying editorial, William J. Gradishar, MD, and David Cella, PhD, stated that the STAR trials offer a "pragmatic stepping stone" to the next prevention trial in breast cancer. Although they contend that the media should not yet declare raloxifene a winner in comparison to tamoxifen, Drs Gradishar and Cella noted that physicians should carefully discuss the 2 similar options with their eligible patients.

"Regardless of SERM choice for prevention, overall physical and mental health might worsen modestly in the beginning of therapy, but the risk of this is slight and no different between choices," Drs Gradishar and Cella stated. "The wealth of data available from this trial can shed light on some important barriers to initiating and sustaining a course of chemoprevention."

The NSABP plans to evaluate any cognitive change observed in patients in greater detail in its Co-STAR report. This ancillary study recruited 1,510 women to undergo annual neuro-psychological batteries focusing on verbal and nonverbal memory, other cognitive abilities, and mood. The primary hypotheses are that the cognitive changes with age will not be different between tamoxifen and raloxifene and that the changes with tamoxifen will be similar to that seen for placebo in the Women's Health Initiative Study of Cognitive Aging.

SOURCES Vogel VG, Costantino JP, Wickerham DL, et al, for the National Surgical Adjuvant Breast and Bowel Project (NSABP). Effects of tamoxifen vs. raloxifene on the risk of developing invasive breast cancer and other disease outcomes. The NSABP study of tamoxifen and raloxifene (STAR) P-2 trial. JAMA. 2006;295:2727–2741.

Land SR, Wickerham DL, Costantino JP, et al. Patient-reported symptoms and quality of life during treatment with tamoxifen or raloxifene for breast cancer prevention. The NSABP study of tamoxifen and raloxifene (STAR) P-2 trial. JAMA. 2006;295:2742–2751.

Gradishar WJ, Cella D. Selective estrogen receptor modulators and prevention of invasive breast cancer. JAMA. 2006;295:2784–2786.