Abstract 175P
Background
Neurofibromatosis type 1 (NF1) is a condition predisposing to the development of benign and malignant tumors. Regarding breast cancer, an increased risk has not been widely recognized or accepted. Given the oncogenic potential, long-term surveillance is important.
Methods
We selected from a pool of 468 pts with NF1 from a site of reference in Portugal women >18 years and observed how they were screened for breast cancers (BC). Also, we evaluated the percentage of those who developed BC in our population, discussing the clinical evidence of increased BC risk in women with NF1 and the potential need for a high-risk screening protocol.
Results
We identified 179 women with NF1, 19 cases being excluded due to missing data. 114pts (71%) with confirmation of diagnosis NF1, the majority with familial history and 47% with spontaneous mutation. 17 with mutations identified, c.17657C>G, p (His553Asp) being the most prevalent (2 pts). 67% were under the age 50 years (y) at the time of data analysis. The median age was 43y (15-82) and at diagnosis of NF1 was 26 (1-62). For women <30y, only 2 pts started breast screening, due to breast alterations on breast palpation. No tumor was found. Above that, 92 pts were screened, mammography and breast ultrasound (71 pts) were the most required exam, followed by breast magnetic resonance imaging (MRI) (18pts) and with both (3pts). The periodicity was not sustained, with the time between exams being variable (annual to 3/3y). Medium BI-RADS 2, but 13 pts with BI-RADS 3. 23 patients without any screening tests beside all body MRI. There were 17 cases of BC in the follow-up period, however, twelve occurred in women in their 40s (median age 43y at diagnosis); 73% were < 50. The majority of the population presented with a grade 2 tumour, with hormone-receptor-positive BC (10), followed by HER2 amplification (4) and TNBC (1). Also, 2pts had two BC during the follow-up. However, we observe an early stage BC (I-II), with only 2 patients progressing to first-line treatment, being the only deaths observed in our population.
Conclusions
Proposals for NF1 care and its specific manifestations have been developed but lack integration within routine care. This study reinforces that increased attention to the breast cancer risk in young women with NF1 is needed.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.