Page 6 - Vitamin D and Cancer

Preface

Over the past 30 years numerous provocative studies have provided clues suggest-
ing that vitamin D may play an important role in cancer. In vitro studies have shown
that cancer cells metabolize vitamin D and that vitamin D compounds can induce
differentiation, inhibit cellular proliferation, and induce cell death. In addition,
epidemiologic data suggest that vitamin D compounds may play a role in the pre-
vention of cancer. In the past few years the understanding of the molecular effects
of vitamin D has expanded substantially and investigators have begun to delineate
the role of genetic factors that influence the response to vitamin D.
With this considerable history of development of vitamin D and cancer, it is
timely and appropriate to summarize the current “state of the art” in the study of
vitamin D and cancer. Scientists who have made many of the seminal contributions
to this field of study have contributed to this volume. These collected data describe
the foundation and current state for this important domain of cancer research – a
domain that the coeditors of this book believe will yield important advances in
cancer prevention and therapy.

Vitamin D Analogues as Antineoplastics: A Prologue Long
Overdue?

Numerous investigators have drawn attention to the high prevalence of the vitamin
D receptor (VDR) in human and murine cancer cells, the frequent evidence of intact
vitamin D signaling pathways in such cells, and the ability of high concentrations of
vitamin D analogues to inhibit the replication of cancer cells, induce apoptosis, and
even inhibit angiogenesis. These data are cited in preceding and following chapters.
Had such studies been completed with a new molecule – e.g., a new “targeted agent”
– it is very likely that the following steps would have been undertaken promptly:
(a) Careful in vivo delineation of schedule and dose dependencies of these antican-
cer activities
(b) Careful determination of the maximum tolerated dose of analogues and explo-
ration of optimal biologic dose

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