Do CYP2D6 variations matter for women on tamoxifen? Variations may affect how women metabolize tamoxifen, but do they make a difference in breast cancer recurrence or prevention? Recent studies suggest maybe not. Today we'll share the latest news and research on how CYP2D6 variations affect women on tamoxifen.
Background from the Dr. Susan Love Research Foundation
An overview from the Dr. Susan Love Research Foundation provides a nice background to the issue. Essentially, a gene called cytochrome P450 2D6 generates an enzyme called CYP2D6. Variations in the gene affect the enzyme production and affect how well a woman metabolizes, or processes tamoxifen. Some women process it better than others.
A 2007 study suggested that women with a certain variation were almost twice as likely to have their cancer recur. Subsequently, some specialists started recommending CYP2D6 testing before starting tamoxifen.
Later studies, however, found that variations in CYP2D6 made no difference in breast cancer recurrence. Dr. Love's website notes that more studies are needed to resolve the inconsistency in the research.
The Latest Research
Dr. Love's website was updated in January 2011. What has happened since then? Studies on CYP2D6 and tamoxifen continue to trickle in. Today we'll share the latest research. Links to all of the studies discussed below may be found on the CYP2D6 testing page of our website.
CYP2D6 variations when tamoxifen is prescribed for prevention
Tamoxifen is sometimes prescribed to prevent breast cancer in women at high-risk. An August 31 study in Clinical Cancer Research found that CYP2D6 variations made no difference in whether or not tamoxifen or Evista (raloxifene) were effective when taken to prevent breast cancer.
CYP2D6 variations when tamoxifen is prescribed to prevent recurrence.
Tamoxifen is also prescribed to prevent recurrence in women treated for breast cancer. Since January 2011, three studies have suggested that CYP2D6 variations make no difference in breast cancer recurrence rates for women on tamoxifen.
A January 15 study in the Journal of the National Cancer Institute from Denmark found, "The association between CYP2D6 inhibition and recurrence in tamoxifen-treated patients is likely null or small."
In a March 25 study in Breast Cancer Research and Treatment from Korea, CYP2D6 variations were not associated with clinical outcomes, such as recurrence, in early-stage breast cancer patients treated with tamoxifen.
Most recently, an August 5 MD Anderson study in Cancer found "no significant effect of CYP2D6 genotype on risk of recurrence in breast cancer patients who received adjuvant tamoxifen therapy."
Current Recommendations
Due to the current state of research, the 2011 National Comprehensive Cancer Network (NCCN) Guidelines do recommend CY2D6 testing for evaluating treatment with tamoxifen. (See March 21 OncLive.com article.)
In Europe, according to the 2011 St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer, "The Panel was almost unanimous in rejecting CYP2D6 testing to dictate choice of endocrine therapy type." In the UK, a cost/benefit analysis in the September issue of Health Technology Assessment concluded that CYP2D6 testing could not be recommended at this time due to the rapidly evolving research and limited and conflicting data.
At LATESTBreastCancer.com, we'll continue to follow the research in CYP2D6 testing and tamoxifen. We'll add any developments to our website and database and highlight them in this blog. Please stay tuned.
Showing posts with label CYP2D6. Show all posts
Showing posts with label CYP2D6. Show all posts
Wednesday, September 21, 2011
Thursday, August 18, 2011
Breast Cancer News (8/18): Survival and Vitamin D, Exercise and CYP2D6 Variations
Recent studies suggest a worse prognosis for breast cancer patients with low blood levels of vitamin D. Do vitamin D supplements improve prognosis? A recent review asked that very question. Today, we'll also share the latest research on how CYP2D6 variations and exercise affect survival. As always, links to the studies below may be found on the treatment pages of the LATESTBreastCancer.com website.
Vitamin D supplementation for cancer patients
Should breast cancer patients take vitamin D supplements to improve prognosis? An August 11 review in The Oncologist evaluated 25 studies involving several cancers. For breast cancer, the two studies reviewed reached opposite conclusions about the prognostic importance of vitamin D. Three prostate cancer trials showed no survival benefit of vitamin D supplementation. The authors concluded that even though low vitamin D was associated with worse prognosis in some cancers, the "currently available evidence is insufficient to recommend vitD supplementation in cancer patients in clinical practice."
Does this mean that breast cancer patients should not take vitamin D? Not necessarily.
First, The Oncologist study reviewed only two breast cancer studies. Recent studies suggest that low serum vitamin D at diagnosis may be associated with a worse prognosis. An April 29 University of Rochester Medical Center study (under the News tab) linked low vitamin D with more aggressive tumors and a worse prognosis. A July 27 Breast Cancer Research study found that low serum vitamin D "may be associated with poorer overall survival and distant disease-free survival in postmenopausal breast cancer patients." These recent studies were likely not considered in The Oncologist review. (The Breast Cancer Research study also noted that the only two previous studies were inconclusive.)
Also, even though vitamin D supplementation is not yet proven to improve prognosis, recent studies suggest it may be beneficial for breast cancer patients to preserve bone mineral density (Annals of Oncology, April 2 and Breast Cancer Research and Treatment, March 8) and to reduce bone and joint pain associated with aromatase inhibitors (Breast Cancer Research and Treatment, June 21).
The bottom line is that breast cancer patients with low serum vitamin D should discuss vitamin D supplementation with their doctors.
CYP2D6 variations do not affect risk of recurrence
Variations in CYP2D6 genes affect how tamoxifen is metabolized. Some women metabolize tamoxifen well. Some do not. Do variations in CYP2D6 affect the risk of recurrence? According to a August 5 study in Cancer, no. Researchers from MD Anderson found that variations in CYP2D6 genes "had no significant effect" on the risk of recurrence in women with early breast cancer treated with adjuvant tamoxifen.
Exercise after breast cancer diagnosis may improve survival
Studies have associated exercise with improved quality of life, but can exercise affect breast cancer survival? An August 12 study in Breast Cancer Research and Treatment revealed that exercise after a breast cancer diagnosis may affect the regulation of tumor suppressor genes, which have "favorable impacts on survival outcomes of breast cancer patients."
Please check back tomorrow for more breast cancer research news from LATESTBreastCancer.com.
Vitamin D supplementation for cancer patients
Should breast cancer patients take vitamin D supplements to improve prognosis? An August 11 review in The Oncologist evaluated 25 studies involving several cancers. For breast cancer, the two studies reviewed reached opposite conclusions about the prognostic importance of vitamin D. Three prostate cancer trials showed no survival benefit of vitamin D supplementation. The authors concluded that even though low vitamin D was associated with worse prognosis in some cancers, the "currently available evidence is insufficient to recommend vitD supplementation in cancer patients in clinical practice."
Does this mean that breast cancer patients should not take vitamin D? Not necessarily.
First, The Oncologist study reviewed only two breast cancer studies. Recent studies suggest that low serum vitamin D at diagnosis may be associated with a worse prognosis. An April 29 University of Rochester Medical Center study (under the News tab) linked low vitamin D with more aggressive tumors and a worse prognosis. A July 27 Breast Cancer Research study found that low serum vitamin D "may be associated with poorer overall survival and distant disease-free survival in postmenopausal breast cancer patients." These recent studies were likely not considered in The Oncologist review. (The Breast Cancer Research study also noted that the only two previous studies were inconclusive.)
Also, even though vitamin D supplementation is not yet proven to improve prognosis, recent studies suggest it may be beneficial for breast cancer patients to preserve bone mineral density (Annals of Oncology, April 2 and Breast Cancer Research and Treatment, March 8) and to reduce bone and joint pain associated with aromatase inhibitors (Breast Cancer Research and Treatment, June 21).
The bottom line is that breast cancer patients with low serum vitamin D should discuss vitamin D supplementation with their doctors.
CYP2D6 variations do not affect risk of recurrence
Variations in CYP2D6 genes affect how tamoxifen is metabolized. Some women metabolize tamoxifen well. Some do not. Do variations in CYP2D6 affect the risk of recurrence? According to a August 5 study in Cancer, no. Researchers from MD Anderson found that variations in CYP2D6 genes "had no significant effect" on the risk of recurrence in women with early breast cancer treated with adjuvant tamoxifen.
Exercise after breast cancer diagnosis may improve survival
Studies have associated exercise with improved quality of life, but can exercise affect breast cancer survival? An August 12 study in Breast Cancer Research and Treatment revealed that exercise after a breast cancer diagnosis may affect the regulation of tumor suppressor genes, which have "favorable impacts on survival outcomes of breast cancer patients."
Please check back tomorrow for more breast cancer research news from LATESTBreastCancer.com.
Tuesday, August 16, 2011
Breast Cancer News (8/16): A little something for everyone
Today's breast cancer news update has a little something for everyone. For women in treatment, there's a story on tamoxifen, an overview of DCIS treatment options and an update on a vaccine in development. For women who have completed treatment, there are stories on fatigue and post-trauma survival. Of general interest, there are pieces on the biology of cancer cells and breast cancer statistics in South Chicago.
BREAST CANCER NEWS FOR WOMEN IN TREATMENT
Tamoxifen affected by genetic mutations and anti-depressants
Yesterday, CBS News Miami published a story and video explaining why tamoxifen may not be effective in some women. Mutations in CYP2D6 genes and anti-depressants, such as Zoloft and Prozac, may interfere with tamoxifen metabolism. Interestingly, the story notes that a "hint" that tamoxifen may not be working is the absence of hot flashes.
An overview of DCIS treatment options
In a commentary, "Management of DCIS - A Work in Progress," cancernetwork.com reviewed the latest treatment options for DCIS. In addition to standard options such as breast conserving surgery (lumpectomy) or mastectomy, the article addresses prognostic factors and a future role for molecular markers, such as HER2 status.
Plans for phase III vaccine trial make progress
In a GlobeNewswire press release, RXi Pharmaceuticals announced progress in its plans for a phase III trial of its NeuVax vaccine to prevent recurrence in early-stage, node-positive breast cancer with low to intermediate HER2 expression. A principal investigator has been named, conditional site approvals have been received, an organization has been selected to manage international centers and manufacturing approvals have been submitted. The trial is expected to commence in the first half of 2012.
BREAST CANCER NEWS FOR WOMEN WHO HAVE COMPLETED TREATMENT
Stress and growth after the trauma of breast cancer
After the stress of breast cancer diagnosis and treatment, some women experience post-traumatic stress disorder (PTSD). BreastCancer.org provides an overview of symptoms and management suggestions.
Yesterday, an article in the Philadelphia Inquirer explored studies on "the positive side of trauma and grief." For some women, experiencing a trauma such as breast cancer results in personal growth. The "key quality" for post-traumatic growth appears to be "expressive flexibility," the ability to express or suppress emotions as necessary. Experts caution that it is "bad to expect growth." The last thing patients need is more pressure.
Biofield therapy to treat fatigue in breast cancer survivors
Breast cancer survivors often battle fatigue. HemOnc Today wrote about a recent study in Cancer on the complementary therapy known as biofield healing. Basically, a biofield is believed to be the energy or aura that surrounds a person. In the study, biofield healing and mock healing both significantly reduced fatigue compared to wait-list controls. Only biofield therapy made a significant difference in cortisol slope. Because both biofield and mock therapy improved fatigue, the results may be partially due to "nonspecific factors," such as scheduled rest, touch and clinical intervention. However, because biofield healing had a greater effect on general and mental fatigue, the authors note that further study is warranted.
BREAST CANCER NEWS OF GENERAL INTEREST
How breast cancer cells evade natural killer cells
In a healthy immune system, natural killer (NK) cells exhibit anti-tumor activity. In breast cancer, tumor cells and the surrounding microenvironment develop the ability to escape NK cell antitumor immunity. The biological process is explained in a GEN: Genetic Engineering & Biotechnology News story on a recent study in The Journal of Clinical Investigation.
Breast cancer mortality rates in South Chicago
Yesterday, a story in the Chicago Sun Times revealed that Chicago's south and southwest side neighborhoods are the "unhealthiest in the city." Those areas had the highest breast cancer mortality rates and few breast health services. Neighborhoods in the north and northwest have more breast health resources and the lowest breast cancer mortality rates. Dr. Bechara Choucair, Chicago's commissioner of health, noted that black women are less likely to get breast cancer, but more likely to die from it. He said the focus "needs to be on making sure black women have more access to mammography, better quality mammography and more timely treatment."
Please check back tomorrow for more breast cancer news highlights from LATESTBreastCancer.com.
BREAST CANCER NEWS FOR WOMEN IN TREATMENT
Tamoxifen affected by genetic mutations and anti-depressants
Yesterday, CBS News Miami published a story and video explaining why tamoxifen may not be effective in some women. Mutations in CYP2D6 genes and anti-depressants, such as Zoloft and Prozac, may interfere with tamoxifen metabolism. Interestingly, the story notes that a "hint" that tamoxifen may not be working is the absence of hot flashes.
An overview of DCIS treatment options
In a commentary, "Management of DCIS - A Work in Progress," cancernetwork.com reviewed the latest treatment options for DCIS. In addition to standard options such as breast conserving surgery (lumpectomy) or mastectomy, the article addresses prognostic factors and a future role for molecular markers, such as HER2 status.
Plans for phase III vaccine trial make progress
In a GlobeNewswire press release, RXi Pharmaceuticals announced progress in its plans for a phase III trial of its NeuVax vaccine to prevent recurrence in early-stage, node-positive breast cancer with low to intermediate HER2 expression. A principal investigator has been named, conditional site approvals have been received, an organization has been selected to manage international centers and manufacturing approvals have been submitted. The trial is expected to commence in the first half of 2012.
BREAST CANCER NEWS FOR WOMEN WHO HAVE COMPLETED TREATMENT
Stress and growth after the trauma of breast cancer
After the stress of breast cancer diagnosis and treatment, some women experience post-traumatic stress disorder (PTSD). BreastCancer.org provides an overview of symptoms and management suggestions.
Yesterday, an article in the Philadelphia Inquirer explored studies on "the positive side of trauma and grief." For some women, experiencing a trauma such as breast cancer results in personal growth. The "key quality" for post-traumatic growth appears to be "expressive flexibility," the ability to express or suppress emotions as necessary. Experts caution that it is "bad to expect growth." The last thing patients need is more pressure.
Biofield therapy to treat fatigue in breast cancer survivors
Breast cancer survivors often battle fatigue. HemOnc Today wrote about a recent study in Cancer on the complementary therapy known as biofield healing. Basically, a biofield is believed to be the energy or aura that surrounds a person. In the study, biofield healing and mock healing both significantly reduced fatigue compared to wait-list controls. Only biofield therapy made a significant difference in cortisol slope. Because both biofield and mock therapy improved fatigue, the results may be partially due to "nonspecific factors," such as scheduled rest, touch and clinical intervention. However, because biofield healing had a greater effect on general and mental fatigue, the authors note that further study is warranted.
BREAST CANCER NEWS OF GENERAL INTEREST
How breast cancer cells evade natural killer cells
In a healthy immune system, natural killer (NK) cells exhibit anti-tumor activity. In breast cancer, tumor cells and the surrounding microenvironment develop the ability to escape NK cell antitumor immunity. The biological process is explained in a GEN: Genetic Engineering & Biotechnology News story on a recent study in The Journal of Clinical Investigation.
Breast cancer mortality rates in South Chicago
Yesterday, a story in the Chicago Sun Times revealed that Chicago's south and southwest side neighborhoods are the "unhealthiest in the city." Those areas had the highest breast cancer mortality rates and few breast health services. Neighborhoods in the north and northwest have more breast health resources and the lowest breast cancer mortality rates. Dr. Bechara Choucair, Chicago's commissioner of health, noted that black women are less likely to get breast cancer, but more likely to die from it. He said the focus "needs to be on making sure black women have more access to mammography, better quality mammography and more timely treatment."
Please check back tomorrow for more breast cancer news highlights from LATESTBreastCancer.com.
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