The gist: Breast cancer can be broken down into different subtypes that behave differently and might be treated differently. New research has shown that characteristics of DNA known as epigenetic marks can be used to categorize different subtypes of breast cancer. Tumors with different epigenetic marks might need different treatment. In the future, doctors might use epigenetic marks to identify which patients need more aggressive treatments.
“Breast cancer is the most common in women. One in nine will suffer breast cancer over their lifetime. Progress in prevention and early detection, and the use of chemotherapy after surgery (adjuvant chemotherapy), have achieved significantly increase survival in this disease in the last ten years, but much remains to be done.
“The identification of patients with high-risk breast cancer is key to knowing whether a patient will require only the removal of the tumor by surgery or whether if she will need additional chemotherapy to make sure the removal of breast cancer cells. Currently, known genetic mutations and expression patterns are determined, but the puzzle of the genetics of the disease remains a large unfinished part.
“The director of the Program Epigenetics and Cancer Biology (PEBC) at Bellvitge Biomedical Research Instiute (IDIBELL), Professor of Genetics at the University of Barcelona and ICREA researcher, Manel Esteller, has established the epigenetic patterns of breast cancer and also its clinical consequences. The finding is published in the journal Molecular Oncology.
” ‘We’ve analyzed epigenetic alterations, namely the chemical signal called DNA methylation in 500 breast tumors and have compared the patterns obtained with the clinical behavior of these cancers,’ says Esteller.”
Editor’s note: Some men must undergo more than one biopsy to accurately diagnose prostate cancer and assess its severity. Now, a test called ConfirmMDx can be used on tumor tissue from an initial biopsy to get a more detailed picture of a patient’s condition, reducing the likelihood that an extra biopsy will be needed. New studies show that the test could “lead to a 10-fold reduction in repeat biopsies.”
“In men with previous histopathologically negative findings, the epigenetic ConfirmMDx (MDxHealth) assay for prostate cancer can lead to a 10-fold reduction in repeat biopsies, 2 new studies show.
“Both confirm the utility of epigenetic profiling in helping to distinguish patients who have a true negative biopsy from those at risk for occult cancer, according to the researchers.
“The commercially available assay assesses methylation markers of prostate cancer (GSTP1, APC, and RASSF1) to distinguish histologically benign biopsy cores from patients diagnosed with no cancer, low-volume cancer (a Gleason score of 6), or higher-volume cancer (a Gleason score of 7).
“One of the studies, a clinical utility field study in which the assay was tested by practicing urologists working in community settings, was published in the May issue of American Health & Drug Benefits.
“More than one million prostate biopsies are performed each year in the U.S. alone, including many repeat biopsies for fear of cancer missed. Therefore there is a need to develop diagnostic tests that will help avoid unnecessary repeat biopsies. Two independent trials have now validated the performance of an epigenetic test that could provide physicians with a better tool to help eliminate unnecessary repeat prostate biopsies, report investigators in The Journal of Urology.
“In the previously reported independent MATLOC (Methylation Analysis To Locate Occult Cancer) trial, a multiplex epigenetic assay (ConfirmMDx for Prostate Cancer) profiling the APC, GSTP1 and RASSF1 genes demonstrated a negative predictive value of 90%. GSTP1 methylation is a specific biomarker for (prostate) cancer and this gene is methylated in up to 90% of prostate cancer cases. Additionally, APC and RASSF1 are important field effect markers and increase the diagnostic sensitivity of the assay.
“A second multicenter study, DOCUMENT (Detection Of Cancer Using Methylated Events in Negative Tissue), has validated the performance of the epigenetic assay used in the MATLOC trial as an independent predictor of prostate cancer risk to guide decision making for repeat biopsy. In the DOCUMENT study patients with a negative biopsy were evaluated to identify those at low risk for harboring cancer missed, through biopsy sampling error, who could forego an unnecessary repeat biopsy. The validation study resulted in a negative predictive value of 88%.”
“A commercial test designed to rule out the presence of genetic biomarkers of prostate cancer may be accurate enough to exclude the need for repeat prostate biopsies in many — if not most — men, a new article reports. ‘Often, one biopsy is not enough to definitively rule out prostate cancer, says a study researcher. ‘Our research finds that by looking for the presence or absence of cancer in a different way, we may be able to offer many men peace of mind without putting them through the pain, bleeding and risk of infection that can come with a repeat biopsy.’ “
Results of a clinical trial that evaluated the prostate cancer vaccine Provenge have come under scrutiny. Questions arise regarding the reported 4-month survival benefit that ultimately led to FDA approval. Disputers suggest that a flaw in methods led to the survival benefit, but that the vaccine may actually cause harm.
A recent study evaluated the usefulness of surgery versus observation to treat localized prostate cancer. In the study, 731 men were followed for 10 years. Those treated with surgery did not have a significant decreased risk of death compared to those who were observed for advancing cancer.
A recent study weighed the benefits of yearly prostate cancer screening, finding that the potential disadvantages decrease the potential advantages by 23%. Harmful results of yearly prostate screening include negative prostate biopsies, radical prostatectomy, and radiation therapy.
A recent study found a relationship between the SPARCL1 gene and prostate cancer recurrence. Individuals who had lower activity of the gene had a higher risk of prostate cancer recurrence over 10 years. A test to detect SPARCL1 is being designed.
The New England Journal of Medicine | Oct 25, 2012
The utility of (prostate-specific antigen) PSA screening to inform prostate cancer diagnosis and treatment has been a topic of heated debate. The New England Journal of Medicine (NEJM) conducted a poll that indicates a lack of consensus among clinicians regarding best prostate cancer screening practices. Many clinicians feel patients should make informed decisions regarding testing preferences.