The Society of Cancer Management
  • Home
    • An After Life
    • News Archive
  • About
    • Terms & Conditions
    • Privacy Policy
    • Copyright Notice
  • Contact

. . . supporting research that improves cancer survival.

 
Please contact us if you would like to contribute a news item. We are keen to publish more articles from UK-based research and findings that relate to microbial infections during therapy.

Nuclear medicine scan could identify who might benefit from aromatase inhibitor treatment

8/5/2015

0 Comments

 
A new, noninvasive nuclear medicine test can be used to determine whether aromatase inhibitor treatment will be effective for specific cancer patients, according to a recent study reported in The Journal of Nuclear Medicine. The research shows that a PET scan with the ligand C-11-vorozole reliably detects aromatase in all body organs - demonstrating the value of its future use to pre-determine the effectiveness of the treatment for breast, ovarian, endometrial and lung cancer patients, potentially reducing unnecessary treatment costs and adverse effects.

Aromatase inhibitors are drugs that work by blocking the aromatase enzyme, which turns the androgen hormone into cancer-stimulating estrogen. They are widely used in the adjuvant treatment of breast cancer and other endocrine conditions. However, no quantitative, noninvasive studies had been done of the distribution and regulation of aromatase in living humans.

Anat Biegon, PhD, corresponding author of the study, explains, "This is the first study conducted in living human subjects that surveys the whole body, comparing healthy young and old men and women."

For the study, 13 men and 20 women were injected intravenously with C-11-vorozole (111-296 MBq/subject), with PET data acquired over a 90-minute period. Each subject had four scans, two per day separated by two to six weeks. Brain and torso or pelvic scans were included. Young women were scanned at two discrete phases of the menstrual cycle (midcycle and late luteal). Men and postmenopausal women were also scanned after pretreatment with a clinical dose of the aromatase inhibitor letrozole. Time-activity curves were obtained, and standardized uptake values (SUV) were calculated for major organs, including brain, heart, lungs, liver, kidneys, spleen, muscle, bone, and male and female reproductive organs. Organ and whole-body radiation exposures were calculated using OLINDA software.

The study shows for the first time that the body organ with the largest stable capacity for estrogen biosynthesis is the male brain, closely followed by the female brain. Aromatase availability is slightly but consistently higher in all organs in men relative to women, with the exception of the ovary. In addition, aromatase availability in the ovary is tightly linked to the ovulatory phase of the menstrual cycle in young women, with increased levels evident in one ovary/cycle around the time of ovulation. Also of interest is the finding that aging and cigarette smoke reduce aromatase availability in the brains of healthy men and women.

Dr. Biegon points out the significance of the study: "Research using in vitro methods indicates aromatase over expression is not limited to breast cancer and is evident in a considerable proportion of ovarian, endometrial, and lung tumors. This study provides methodological, baseline and dosimetry information supporting the use of PET and C-11 vorozole in the non-invasive identification of individuals with disparate disorders who may benefit from treatment with aromatase inhibitors." She notes, "It also offers the ability to distinguish breast cancer patients who are not likely to benefit from this treatment, reducing unnecessary treatment costs and adverse effects. Finally, aromatase imaging can be used in monitoring efficacy of treatment with aromatase inhibitors and aid in the development of new drugs in this class."

Another key finding relates to the differences between men and women. Dr. Biegon states, "Radiotracer uptake and the resultant radiation exposure can be sex-dependent and strongly modulated by hormonal status. Nuclear medicine procedures need to be adjusted for these factors when applied in women."

Biegon et al. Aromatase Imaging with [N-Methyl-11C] Vorozole PET in Healthy Men and Women. J Nucl Med. 2015;56:580-585 EPub ahead of print. doi: 10.2967/jnumed.114.150383 [Abstract]
0 Comments

Your comment will be posted after it is approved.


Leave a Reply.

    Cancer Therapy & Palliative Care News

    This feed features recent developments in cancer therapy and palliative care. Views in these articles do not necessarily represent those of the Cancer Management Society.

    Archives

    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    January 2014
    December 2013
    November 2013

    Categories

    All
    General
    Presentation
    Research
    Review

    RSS Feed

Home

About

Contact Us

Terms & Conditions

Privacy Policy

Copyright Notice

RSS Feed

Proudly powered by Weebly
© The Society of Cancer Management 2017