HER2 Support Group Forums - View Single Post - are her2+ (and/or EGFR+) tumors more radioresistant (ie radiation therapy doesn't

Lani · 10-31-2006, 05:17 PM

Few other studies have examined the question of clinically apparent radioresistance in HER-2-positive patients by analyzing local recurrences after radiation. In a series from the MD Anderson Cancer Center, investigators compared 32 HER-2-positive and 76 HER-2-negative patients with more advanced disease who underwent neoadjuvant chemotherapy, mastectomy, and postoperative chest irradiation in four clinical trials of neoadjuvant chemotherapy (29). HER-2 status was retrospectively analyzed on archival tissue by IHC and FISH. The chest wall received a median dose of 50 Gy and a median boost dose of 10 Gy. The HER-2-positive patients in this group had a higher rate of ER-negative tumors and supraclavicular disease at diagnosis and a greater number of positive lymph nodes at the time of surgery. However, despite these negative features, there was no increase in the actuarial rate of local-regional recurrence at 5 or 10 years in HER-2-positive patients compared to the HER-2-negative group.

In a study from Yale University, investigators performed a case control analysis of the significance of HER-2 overexpression in 16 patients with an isolated local recurrence as the site of first failure and 20 matched controls without any local recurrence, all treated with BCT (30). HER-2 expression was retrospectively assayed using IHC on tissue from paraffin blocks. None of the patients had received chemotherapy or hormonal therapy.

10-31-2006, 05:17 PM	#6
Lani Senior Member Join Date: Mar 2006 Posts: 4,778	and more... Few other studies have examined the question of clinically apparent radioresistance in HER-2-positive patients by analyzing local recurrences after radiation. In a series from the MD Anderson Cancer Center, investigators compared 32 HER-2-positive and 76 HER-2-negative patients with more advanced disease who underwent neoadjuvant chemotherapy, mastectomy, and postoperative chest irradiation in four clinical trials of neoadjuvant chemotherapy (29). HER-2 status was retrospectively analyzed on archival tissue by IHC and FISH. The chest wall received a median dose of 50 Gy and a median boost dose of 10 Gy. The HER-2-positive patients in this group had a higher rate of ER-negative tumors and supraclavicular disease at diagnosis and a greater number of positive lymph nodes at the time of surgery. However, despite these negative features, there was no increase in the actuarial rate of local-regional recurrence at 5 or 10 years in HER-2-positive patients compared to the HER-2-negative group. In a study from Yale University, investigators performed a case control analysis of the significance of HER-2 overexpression in 16 patients with an isolated local recurrence as the site of first failure and 20 matched controls without any local recurrence, all treated with BCT (30). HER-2 expression was retrospectively assayed using IHC on tissue from paraffin blocks. None of the patients had received chemotherapy or hormonal therapy.