Abstract P2-06-04: Breast cancer after Hodgkin lymphoma: Influence of endogenous and exogenous gonadal hormones on the radiation dose-response relationship

Background

After chest radiotherapy (RT) for Hodgkin lymphoma (HL), women experience a dose-dependent increased breast cancer (BC) risk. It is unknown whether endogenous and exogenous gonadal hormones affect the radiation dose-response relationship.

Methods

We conducted a nested case-control study among female 5-year HL survivors treated before 41 years between 1965-2000. Data were collected through medical records and questionnaires for 174 BC cases and 466 matched controls. RT charts, simulation films and mammography reports were used to estimate the radiation dose to the location of the breast tumor.

Results

The median interval between HL and BC diagnosis was 21.9 years. 98% of BC cases had received chest RT, compared to 92% of controls. We observed a linear radiation dose-response curve with an adjusted excess odd ratio (EOR) of 5.4%/Gray (95%CI:1.8%-13.37%). Women with menopause <30 years (caused by high-dose procarbazine or pelvic RT) had a lower BC risk (OR:0.13, 95%CI:0.03-0.54) than women with menopause ≥50 years. BC risk increased with 7.4% for each additional year of intact ovarian function after RT (P<0.001). Among women with an early menopause (<45 years), the use of hormone replacement therapy (HRT) for ≥2 years did not increase BC risk (OR:0.81, 95%CI:0.30-2.21). Endogenous and exogenous hormones did not statistically significantly modify the slope of the radiation dose-response relationship.

Conclusion

HRT use did not appear to increase BC risk in female HL survivors with a therapy-induced early menopause. Moreover, there was no evidence for interaction between RT dose and years with intact ovarian function or HRT use.

Citation Format: Krul IM, Opstal - van Winden AWJ, Aleman BMP, Janus CPM, van Eggermond AM, de Bruin ML, Hauptmann M, Krol ADG, Schaapveld M, Broeks A, Kooijman KR, Fase S, Lybeert ML, Zijlstra JM, van der Maazen RWM, Kesminiene A, Diallo I, de Vathaire F, Russell NS, van Leeuwen FE. Breast cancer after Hodgkin lymphoma: Influence of endogenous and exogenous gonadal hormones on the radiation dose-response relationship [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-06-04.

PureB single-photon avalanche diodes for low-energy electron detection down to 200 eV

Single-photon avalanche diodes (SPADs) have been fabricated on Si using PureB (Pure Boron) chemical-vapor deposition (CVD) to create both a nanometer-thin anode junction and a robust front-entrance window. The device shows high sensitivity to low radiation levels of electrons with energies down to 200 eV when measurements are performed at room temperature where the dark count rate can be as low as 10 Hz. An implicit guard ring, using an n-enhancement implantation in the central region of the diode, is applied, and this gives a very uniform sensitivity across the whole front-entrance window.