Shepherd, Lois E.

Purpose Aromatase inhibition depletes estrogen levels and may be associated with accelerated bone resorption. The National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) study MA.17B evaluated bone turnover markers and bone mineral density (BMD) in postmenopausal women randomly assigned to MA.17, a placebo-controlled trial of letrozole after standard adjuvant tamoxifen. Patients and Methods Eligible women had a baseline BMD T score of at least 2.0 in either the hip or L2-4 spine; all received calcium 500 mg and vitamin D 400 U daily. Percentage change in BMD (L2-L4 spine and hip) at 12 and 24 months, rate of osteoporosis, and change in markers of bone formation (serum bone alkaline phosphatase) and resorption (serum C-telopeptide and urine N-telopeptide) at 6, 12, and 24 months were compared. Results Two hundred twenty-six patients (122 letrozole, 104 placebo) were enrolled. Baseline characteristics were similar in the two groups, including BMD, median age of 60.7 years (81% < 70 years), and median follow-up of 1.6 years. At 24 months, patients receiving letrozole had a significant decrease in total hip BMD (−3.6% v −0.71%; P = .044) and lumbar spine BMD (−5.35% v −0.70%; P = .008). Letrozole increased urine N-telopeptide at 6, 12, and 24 months (P = .054, < .001, and .016, respectively). No patient went below the threshold for osteoporosis in total hip BMD, whereas at the L2-L4 (posteroanterior view), more women became osteoporotic by BMD while receiving letrozole (4.1% v 0%; P = .064). Conclusion After 5 years of adjuvant tamoxifen, subsequent letrozole causes a modest increase in bone resorption and reduction in bone mineral density in the spine and hip compared to placebo. Further follow-up is necessary to evaluate the long-term clinical implications of this difference.

Purpose To evaluate the impact of letrozole compared with placebo after adjuvant tamoxifen on quality of life (QOL) in the MA.17 trial. Methods Patients completed the Short Form 36-item Health Survey (SF-36) and the Menopause Specific Quality of Life Questionnaire (MENQOL) at baseline, 6 months, and annually. Mean change scores from baseline were compared between groups for summary measures and domains. A response analysis compared the proportion of patients who demonstrated an important change in QOL. Results Of 5,187 randomly assigned women in the trial, 3,612 (69.9%) participated in the QOL substudy: 1,799 were allocated to placebo and 1,813 were allocated to letrozole. No differences were seen between groups in mean change scores from baseline for the SF-36 physical and mental component summary scores at 6, 12, 24, and 36 months. Small (< 0.2 standard deviations) but statistically significant differences in mean change scores from baseline were seen for the SF-36 domains of physical functioning (12 months), bodily pain (6 months) and vitality (6 and 12 months), and the MENQOL vasomotor (6, 12, and 24 months) and sexual domains (12 and 24 months). On the response analysis, a significant difference was seen between groups for the bodily pain domain (percentage of patients reporting a worsening of QOL, 47% placebo v 51% letrozole; P = .009) and the vasomotor domain (22% placebo v 29% letrozole; P = .001). Conclusion Letrozole did not have an adverse impact on overall QOL. Small effects were seen in some domains consistent with a minority of patients experiencing changes in QOL compatible with a reduction in estrogen synthesis.

Purpose Although it is well-established that fluorouracil- (FU-) based adjuvant therapy improves survival for patients with resected high-risk colon cancer, the magnitude of adjuvant therapy benefit across specific subgroups and for individual patients has been uncertain. Patients and Methods Using a pooled data set of 3,302 patients with stage II and III colon cancer from seven randomized trials comparing FU + leucovorin or FU + levamisole to surgery alone, we performed an analysis based on a Cox proportional hazards regression model. Treatment, age, sex, tumor location, T stage, nodal status, and grade were tested for both prognostic and predictive significance. Model derived estimates of 5-year disease-free survival and overall survival (OS) for surgery alone and surgery plus FU-based therapy were calculated for a range of patient subsets. Results Nodal status, T stage, and grade were the only prognostic factors independently significant for both disease-free survival and OS. Age was significant only for OS. In a multivariate analysis, adjuvant therapy showed a beneficial treatment effect across all subsets. Treatment benefits were consistent across sex, location, age, T-stage, and grade. A significant stage by treatment interaction was present, with treatment benefiting stage III patients to a greater degree than stage II patients. Conclusion Patients with high-risk resected colon cancer obtain benefit from FU-based therapy across subsets of age, sex, location, T stage, nodal status, and grade. Model estimates of survival stratified by T stage, nodal status, grade, and age are available at http://www.mayoclinic.com/calcs . This information may improve patients' and physicians' understanding of the potential benefits of adjuvant therapy.