HER2 Support Group Forums - View Single Post - Endocrine Response Enhanced in ER+/PR+ Tumors

Hopeful · 11-09-2006, 08:52 AM

The best response to adjuvant endocrine therapy is seen in early-stage breast cancer patients with tumors that stain positive for both estrogen and progesterone receptors (ER+/PR+), research findings suggest.

"Our data suggest that lack of PR expression and human epidermal growth factor receptor (HER)-2 overexpression are both associated with aggressive tumor features, but the prognostic information of PR status on the risk of recurrence in endocrine-treated breast cancer patients is stronger," says the team.

Previous evidence has suggested that the effectiveness of endocrine therapy is reduced in patients with ER+ but PR- breast cancer with or without HER-2 overexpression.

To investigate further, R Ponzone (Institute for Cancer Research and Treatment, Turin, Italy) and colleagues examined retrospective data for 972 patients who received adjuvant endocrine therapy, including tamoxifen alone, tamoxifen combined with a gonadotropin-releasing hormone agonist, and aromatase inhibitors. The patients were treated between 1998 and 2005.

The researchers found that, compared with ER+/PR+ tumors, their ER+/PR- counterparts were larger, of higher grade, and expressed more Ki-67 and, on average, less ER and HER-2. All of these differences were statistically significant.

On univariate analysis, a lack of PR expression was also associated with a shorter disease-free survival (DFS; hazard ratio [HR]=2.1), as was HER-2 overexpression (HR=1.9), nodal status, tumor diameter, tumor grade, and Ki-67 expression, the researchers report in the Annals of Oncology.

The lack of PR expression along with nodal status and tumor diameter retained their significance on multivariate analysis, the team adds, whereas HER-2 overexpression was associated with a trend towards shorter DFS of only borderline significance.

"Our study confirms that PR status defines a subset of tumors with distinctive pathological characteristics and may help select those patients who derive the greatest benefit from endocrine treatment, particularly within the first few years of follow-up," the researchers conclude.

Ann Oncol 2006; 17: 1631-1636

http://www.breastcancersource.com/br...41_0_0_0.aspx?

Link to abstract: http://annonc.oxfordjournals.org/cgi...act/17/11/1631

Hopeful

11-09-2006, 08:52 AM	#1
Hopeful Senior Member Join Date: Aug 2006 Posts: 3,380	Endocrine Response Enhanced in ER+/PR+ Tumors The best response to adjuvant endocrine therapy is seen in early-stage breast cancer patients with tumors that stain positive for both estrogen and progesterone receptors (ER+/PR+), research findings suggest. "Our data suggest that lack of PR expression and human epidermal growth factor receptor (HER)-2 overexpression are both associated with aggressive tumor features, but the prognostic information of PR status on the risk of recurrence in endocrine-treated breast cancer patients is stronger," says the team. Previous evidence has suggested that the effectiveness of endocrine therapy is reduced in patients with ER+ but PR- breast cancer with or without HER-2 overexpression. To investigate further, R Ponzone (Institute for Cancer Research and Treatment, Turin, Italy) and colleagues examined retrospective data for 972 patients who received adjuvant endocrine therapy, including tamoxifen alone, tamoxifen combined with a gonadotropin-releasing hormone agonist, and aromatase inhibitors. The patients were treated between 1998 and 2005. The researchers found that, compared with ER+/PR+ tumors, their ER+/PR- counterparts were larger, of higher grade, and expressed more Ki-67 and, on average, less ER and HER-2. All of these differences were statistically significant. On univariate analysis, a lack of PR expression was also associated with a shorter disease-free survival (DFS; hazard ratio [HR]=2.1), as was HER-2 overexpression (HR=1.9), nodal status, tumor diameter, tumor grade, and Ki-67 expression, the researchers report in the Annals of Oncology. The lack of PR expression along with nodal status and tumor diameter retained their significance on multivariate analysis, the team adds, whereas HER-2 overexpression was associated with a trend towards shorter DFS of only borderline significance. "Our study confirms that PR status defines a subset of tumors with distinctive pathological characteristics and may help select those patients who derive the greatest benefit from endocrine treatment, particularly within the first few years of follow-up," the researchers conclude. Ann Oncol 2006; 17: 1631-1636 http://www.breastcancersource.com/br...41_0_0_0.aspx? Link to abstract: http://annonc.oxfordjournals.org/cgi...act/17/11/1631 Hopeful