Complain about a product or service

Study Links Prostate Cancer to Single Rogue Cell

14-year research project tracks process of metastasis

April 21, 2009

• Statins Slow Inflammation in Prostate Tumors • Study Links Prostate Cancer to Single Rogue Cell • PSA Testing May Be Unnecessary for Some Older Men • Compound Can Identify Prostate Cancer • Improved PSA Tests May Better Determine Prostate Cancer Risk • Vitamins Don't Cut Prostate Cancer Risk • Aspirin May Lower PSA Levels in Men • FDA Approves New Overactive Bladder Drug • New Prostate Surgical Techniques Often "Over-Promoted" • Feds Approve Drug for Enlarged Prostate • New Prostate Cancer Treatment Shows Promise • Broccoli Reduces Prostate Cancer Risk, Study Finds • Celebrex-Lipitor Combo May Halt Prostate Cancer • Exercise May Speed Prostate Tumor Growth • Soy Compound May Halt Spread of Prostate Cancer • Obesity Linked to Higher Prostate Cancer Mortality • Red Wine May Fight Prostate Cancer • Enlarged Prostate Doesn't Mean Cancer • Hopkins Researchers Claim Better Blood Test for Prostate Cancer • Severe Form of Enlarged Prostate Disease Discovered • Tomato-Broccoli Combo Can Help Shrink Prostate Cancers • Weight Gain Increases Risk of Dying from Prostate Cancer • Smoking Linked to Complications in Prostate Cancer Treatment • Newer Approach Urged in Screening for Aggressive Prostate Cancer • Aspirin May Prevent or Delay Enlarged Prostate • Hopkins Researchers Find Better Blood Test for Prostate Cancer • Prostate Radiation May Cause Problems Later • New Test Detects Prostate Cancer Spread Earlier • Castration May Be Advised in Advanced Prostate Cancer • Radiation Therapy May Be Best for Younger Prostate Cancer Patients • Study Recommends More Prostate Biopsies • Delayed Surgery May Be OK for Some Prostate Cancer Patients • Study: PSA Test Doesn't Improve Prostate Cancer Survival Rate • Prostate Cancer Genes Identified • Annual Prostate Cancer Screening Test Appears to Save Lives • FDA Panel Rejects Prostate Cancer Pill • PSA Test Still Useful, Hopkins Study Finds • No "Normal" PSA Level: Study • New Prostate Cancer Test Shows Promise • Lifestyle and Diet May Stop or Reverse Prostate Cancer Progression

One cell, one initial set of genetic changes — that's all it takes to begin a series of events that lead to metastatic cancer.

Now, Johns Hopkins experts have tracked how the process began in 33 men with prostate cancer who died of the disease. Culling information from autopsies, their study points to a set of genetic defects in a single cell that are different for each person's cancer.

"These were not your average autopsies," says pathologist G. Steven Bova, M.D., assistant professor of pathology at Johns Hopkins. "We dissected every bit of tumor — in the primary and metastatic sites — and recorded exactly where each piece of tissue came from, analyzed it, and databased the findings." In total, Bova estimates that he and his colleagues examined 150,000 slides and 30,000 blocks of tissue.

The study took 14 years to complete, and part of the challenge was in finding men living with prostate cancer who would agree to have their bodies autopsied immediately after they died.

"Many of the men were motivated to join the study in hopes of leaving some legacy that might lead to cures for this cancer," said Bova, who holds secondary appointments in the departments of pathology, genetic medicine, health sciences informatics, oncology, and urology at Johns Hopkins.

"Much is unclear and appears chaotic about how cancer spreads, but analyzing genetic markers allows us to trace its roots backward, somewhat like ancestry," Bova said. Findings from the study were published in Nature Medicine.

Clues to finding the genetic culprit for cancer spread are hidden in the changes that occur in a cell's DNA, the alphabetical code made up of chemicals that guide the everyday life of a cell. Cancers are caused by alterations in DNA code that occur in a variety of ways: making errors in the nucleotide alphabet through mutations, changing the balance of chemicals attached to the on/off switches of genes, and altering the number of gene copies in a cell.

When the number of gene copies is disrupted in a cell beyond the customary two copies inherited from each parent, a gene's function can be damaged. This process, called copy number variation, can set the stage for unchecked cell growth and spread, a hallmark of cancer.

For this study, the investigators scanned genes spanning the whole genome in the autopsy samples looking for areas of copy number variation. They did this by attaching the DNA to special silicon chips, and then photographed them with a computer program that produces a report with varying colors representing the amount of DNA in the sample.

The scientists compared the patterns of gains and losses in tissue samples from multiple metastatic sites in 29 of the men. Unique copy number changes were identified, as well as ones that were shared between multiple metastatic sites in each man and with other men in the study.

For example, in several men, the investigators found cells in different areas of metastasis that contained missing chunks of DNA in one common region of the genome. The exact location of the DNA loss was different for each man, but all occurred in the same DNA region. "Each person has a different set of defects that contributes to the cancer," explains Bova.

Metastatic sites develop from cancer cells that break off of the primary cancer. If cancer cells at more than one metastatic site carry a common set of nonrandom genetic defects, it is likely that these cells are derived from a single parent cell, says Bova.

Tissue samples from 14 of the 33 men were studied at the highest available resolution, and all showed common genetic patterns across metastatic sites, suggesting a single cell source for their cancer.

Bova says future studies will help determine whether the common set of changes shared by the various metastatic sites arose in a single "big bang" in the prostate or if the changes accumulated more slowly over time.

He says that such autopsy studies of metastatic cancer can provide a molecular catalogue of cellular defects specific to individuals and general groups. The findings, Bova believes, could help narrow the focus of research and guide personalized cancer therapy.

Report Your Experience
If you've had a bad experience -- or a good one -- with a consumer product or service, we'd like to hear about it. All complaints are reviewed by class action attorneys and are considered for publication on our site. Knowledge is power! Help spread the word. File your consumer report now.

Follow us on Twitter.