Who Most Benefits from AIs?
One of the holy grails of cancer research is to figure out who benefits from any one treatment. GIven the absence of that information, we know that many people are over-treated (e.g. receive chemotherapy when they really don't need it) or are treated with drugs that are not likely to be useful for their specific situation. Here is an interesting summary from MedScape about research looking at who most benefits from the AIs.
I give you the introduction and a link to read more:
Which Patients Benefit Most from Adjuvant Aromatase
Results Using a Composite Measure of Prognostic Risk in the BIG 1-98 Randomized Trial
G. Viale; M. M. Regan; P. Dell'Orto; M. G. Mastropasqua; E. Maiorano; B. B. Rasmussen; G. MacGrogan; J. F. Forbes; R. J. Paridaens; M. Colleoni; I. Láng; B. Thürlimann; H. Mouridsen; L. Mauriac; R. D. Gelber; K. N. Price; A. Goldhirsch; B. A. Gusterson; A. S. Coates
Posted: 10/25/2011; Annals of Oncology. 2011;22(10):2201-2207. © 2011 Oxford University Press
Background: On average, aromatase inhibitors are better than tamoxifen when used as initial or sequential therapy for postmenopausal women with endocrine-responsive early breast cancer. Because there may be contraindications to their use based on side-effects or cost, we investigated subgroups in which aromatase inhibitors may be more or less important. Patients and methods: Breast International Group 1-98 trial randomized 6182 women among four groups comparing letrozole and tamoxifen with sequences of each agent; 5177 (84%) had centrally confirmed estrogen receptor (ER) positivity. We assessed whether centrally determined ER, progesterone receptor (PgR), human epidermal growth factor receptor 2, and Ki-67 labeling index, alone or in combination with other prognostic features, predicted the magnitude of letrozole effectiveness compared with either sequence or tamoxifen monotherapy.
Results: Individually, none of the markers significantly predicted differential treatment effects. Subpopulation treatment effect pattern plot analysis of a composite measure of prognostic risk revealed three patterns. Estimated 5-year disease-free survival for letrozole monotherapy, letrozole→tamoxifen, tamoxifen→letrozole, and tamoxifen monotherapy were 96%, 94%, 93%, and 94%, respectively, for patients at lowest risk; 90%, 91%, 93%, and 86%, respectively, for patients at intermediate risk; and 80%, 76%, 74%, and 69%, respectively, for patients at highest risk.
Conclusion: A composite measure of risk informs treatment selection better than individual biomarkers and supports the choice of 5 years of letrozole for patients at highest risk for recurrence.
On average, aromatase inhibitors improve disease control over tamoxifen in the adjuvant setting. However, the magnitude of benefit is relatively small and in some patients the adverse event profile of the aromatase inhibitors and their cost may make it difficult to include or persist with such therapy. We sought to review our experience with the Breast International Group (BIG) 1-98 trial in an attempt to define groups of patients in whom it was more or less important to include an aromatase inhibitor as opposed to tamoxifen as part or all of the adjuvant therapy program.