Tamoxifen breast changes predict survival
medwireNews: Women with breast cancer who experience a tamoxifen-related decrease in mammographic density have significantly better survival than patients whose breast density is unaffected by the agent, suggest study findings.
The research, published in the Journal of Clinical Oncology, also shows that breast density decreases occurring in breast cancer patients not taking tamoxifen had no significant impact on survival.
"If validated, mammographic density change has the potential to be an early marker for therapy response and provide clinicians with a tool for monitoring the effect of postsurgical adjuvant therapy beyond the current wait-and-see approach," say Per Hall (Karolinska Institutet, Stockholm, Sweden) and co-authors.
"In fact, given ongoing developments in automatic algorithms for mammographic density measurement, implementing this as a routine clinical tool could be cost-effective," they suggest.
In all, baseline and follow-up mammograms were examined for 974 postmenopausal women, 474 of whom were given tamoxifen. Over 15 years of follow up, 12.4% of women died from breast cancer.
Women whose breast density fell by over 20% between baseline and follow up had a significant 50% reduction in the risk for breast cancer-specific death compared with women whose mammographic density was stable. This was not affected by adjustment for surgery or tamoxifen dose.
However, the researchers note that this survival benefit was only present when assessing the change in breast density rather than separate analyses of absolute density in mammograms at baseline or follow up.
"It is conceivable that the association between [change in density] and breast cancer survival in the tamoxifen-treated group could be explained by differences in compliance or response to treatment (eg, due to genetic variation in the CYP2D6 gene)," the researchers comment.
Noting that postmenopausal women have lower mammographic breast density than younger women, making clinical changes harder to detect, the team suggests that measuring change in density may prove to be a more useful marker for premenopausal patients.
Hall et al conclude that further studies are needed to corroborate their findings.
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Lynda Williams, Senior medwireNews Reporter