Testicular radiation dose after multimodal curative therapy for locally advanced rectal cancer. Influence on hormone levels, quality of life, and sexual functioning.

PURPOSE: The purpose of the current work was to prospectively measure the influence of testicular radiation dose on hormone levels, quality of life (QoL), and sexual functioning following multimodal therapy (neoadjuvant radiochemotherapy, surgery, and adjuvant chemotherapy) for rectal cancer. PATIENTS AND METHODS: From November 2007 to November 2009, 83 male patients were treated at the University of Goettingen with radiochemotherapy (RCT) for locally advanced rectal cancer [total dose 50.4 Gy, concomitant chemotherapy with two cycles of 5-fluorouracil (FU) or 5-FU and oxaliplatin]. Testicular radiation doses were analyzed and correlated with hormone levels [luteinizing hormone (LH), follicle stimulating hormone (FSH), total testosterone and free androgen index (FAI) serum levels], QoL, and sexual functioning, which were determined before and up to 1 year after RCT.
RESULTS: Mean dose at the testes was 3.9 Gy (range 0.28-11.98 Gy). It was higher for tumors located < 6 cm from the anocutaneous line (p < 0.05). One year after therapy, testosterone, the testosterone/LH ratio, and the FAI/LH ratio were significantly decreased (3.5-3.0 µg/l, 0.9-0.4, 7.9-4.5, respectively) while LH and FSH (4.2-8.5 IU/l, 6.0-21.9 IU/l) were increased. QoL and sexual functioning were significantly impaired. However, there was no statistical correlation between testicular radiation dose and changes in hormone levels, QoL, or sexual functioning.
CONCLUSION: Multimodal treatment for rectal cancer including RCT leads to hormone level changes and to impaired QoL and sexual functioning. However, because there was no apparent correlation between the analyzed parameters, QoL is probably also influenced by other factors, e.g., psychosocial aspects.