A multi-institutional analysis of intraoperative radiotherapy for early breast cancer: Does age matter?

BACKGROUND: Single-session intraoperative radiation therapy (IORT) minimizes treatment demands associated with traditional whole breast radiation therapy (WBRT) but outcomes on local disease control and morbidity among the elderly is limited. METHODS: A multi-institutional retrospective registry was established from 19 centers utilizing IORT from 2007 to 2013. Patient, tumor, and treatment variables were analyzed for ages <70 and ≥70. RESULTS: We evaluated 686 patients (<70 = 424; ≥70 = 262) who were margin and lymph node negative. Patients <70 were more likely to have longer operative time, oncoplastic closure, higher rates of IORT used as planned boost, and receive chemotherapy and post-operative WBRT. Wound complication rates were low and not significantly different between age groups. Median follow-up was 1.06 (range 0.51-1.9) years for < 70 and 1.01 (range 0.5-1.68) years for ≥ 70. There were 5 (0.73%) breast recurrences (4 in <70 and 1 ≥ 70, p = 0.65) and no axillary recurrences during follow-up. CONCLUSIONS: IORT was associated with a low rate of wound complication and local recurrence on short-term follow-up in this cohort.

Insulin-like growth factor I receptor gene structure.

The insulin-like growth factor I (IGF I) receptor is a tyrosine kinase-containing transmembrane protein that plays an important role in cell growth control. We have isolated and characterized human genomic DNA clones containing the entire coding sequence of the IGF I receptor. Results of restriction analysis and sequencing of multiple overlapping clones were consistent with the existence of a single IGF I receptor gene. The complete receptor coding sequence is contained in 21 exons. There is striking homology with the insulin receptor gene in overall size (approximately 100 kilobases) and in the number and size of individual exons. An exon analogous to the alternatively spliced exon 11 of the insulin receptor gene could not be detected. An alternative internal splice site corresponding to a known alternatively spliced mRNA transcript was shown to be located at the 5' end of exon 14. Knowledge of the structure of the IGF I receptor gene should facilitate further studies on the structural determinants of receptor function, the relationships between insulin and IGF I receptors, and the molecular basis for multiple IGF I receptor species.