Editorial: Tumor Heterogeneity and Personalized Medicine — NEJM

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Editorial

Tumor Heterogeneity and Personalized Medicine

This article has no abstract; the first 100 words appear below.

"In the past 10 years, the number of tools available to treat cancer has increased, as has our understanding of what makes some cancers tick. The standard old-time cancer treatments were largely predicated on attacking DNA, an approach fueled by the belief that tumor cells divide more rapidly than normal cells. However, with the notable exception of Burkitt's lymphoma, only a small percentage of tumor cells in a patient are dividing at any given time. As we have learned more about DNA repair mechanisms and epigenetic alterations in cancers, DNA remains a viable target for new cancer therapies, but DNA . . ."

NEJM: Intratumor Heterogeneity and Branched Evolution Revealed by Multiregion Sequencing — Free Preview

Intratumor Heterogeneity and Branched Evolution Revealed by Multiregion Sequencing — NEJM

 Conclusions
Intratumor heterogeneity can lead to underestimation of the tumor genomics landscape portrayed from single tumor-biopsy samples and may present major challenges to personalized-medicine and biomarker development. Intratumor heterogeneity, associated with heterogeneous protein function, may foster tumor adaptation and therapeutic failure through *Darwinian selection.
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* Synonym(s)

• Darwinian selection (natural selection)

Definition(s)

Natural evolutionary process that results in the survival of organisms best suited to changing living conditions through the perpetuation of desirable genetic qualities and the elimination of undesirable ones.

Setback reported in research into cancer treatment - (2nd media report)

BOSTON (AP) - "Scientists are reporting what could be very bad news for efforts to customize cancer treatment based on each person's genes.
They have discovered big differences from place to place in the same tumor as to which genes are active or mutated. They also found differences in the genetics of the main tumor and places where the cancer has spread.
This means that the single biopsies that doctors rely on to choose drugs are probably not giving a true view of the cancer's biology. It also means that treating cancer won't be as simple as many had hoped."

"By analyzing tumors in unprecedented detail, "we're finding that the deeper you go, the more you find," said one study leader, Dr. Charles Swanton of the Cancer Research UK London Research Institute in England. "It's like going from a black-and-white television with four pixels to a color television with thousands of pixels."
Yet the result is a fuzzier picture of how to treat the disease.
The study is reported in Thursday's New England Journal of Medicine.
It is a reality check for "overoptimism" in the field devoted to conquering cancer with new gene-targeting drugs, Dr. Dan Longo, a deputy editor at the journal, wrote in an editorial."

Cancer gene mutation more complex than previously thought: study | Reuters

"LONDON | Thu Mar 8, 2012 3:31am IST
 

(Reuters) - Taking a sample or biopsy from just one part of a tumor might not give a full picture of its genetic diversity and may explain why doctors, despite using genetically targeted drugs, are often unable to save patients whose cancer has spread, scientists said.
A study by British researchers found there are more genetic differences than similarities between biopsies taken from separate areas of the same tumor, and yet further gene differences in samples taken from secondary tumors......