Incidental findings in NIPT show potential for detecting hematological malignancies

The non-invasive pregnancy test (NIPT) is a screening test of cell free fetal DNA in blood samples in order to detect potential abnormalities in early pregnancy.It is offered in the Netherlands to all pregnant women since April 2023.In the default version, it tests for three chromosomal abnormalities (aneuploidies) in 21, 18 and 13.Yet, women can opt in for a genome wide test, that enlarges the test for all maternal autosomes.Prior to implementation of NIPT in the Netherlands, a large implementation trial (Trident-2) had been conducted to gather information on, among other things, the frequency of unexpected findings in the mother's autosomes, such as malignancies. 1Importantly, in this trial, 11 out of 56,818 (0.015%) women with placental and maternal cfDNA testing received results of complex abnormal-NIPT profiles, pointing to possible malignancies of which five women were confirmed with hematological malignancies. 1 Were these findings representative of all malignancies in the tested (pregnant) population?To answer this question, in this issue of The Lancet Regional Health -Eurupe, Heesterbeek and colleagues 2 decided to do a 'reverse approach' i.e. helped by the International Network on Cancer, Infertility and Pregnancy (INCIP) database.This database registers pregnancy associated cancers in several countries, the Netherlands included. 3,4 Over a 4-year period (2017-2021), during which the Trident-2 trial was conducted, they found 143 Dutch cases.In 67 cases there was a match with a Trident-2 participant. 2Two participants were excluded from this study, because these women had already cancer diagnosed during the NITP test, leaving 65 women.Of these 65 women 54 women had a solid tumour and 11 women a hematological malignancy.Which results did the NIPT show in these women?Authors did the analysis a bit more uniform than in the Trident-2 study, i.e. using the Wisecondor pipeline and the Maastricht criteria.This, interestingly, led 2 results with 'normal' in the Trident-2 to be revised to 'suspicious or mildly suspicious for malignancy '. 5 Authors found that 16 out of 65 (24.6%) had a NIPT result malignant suspicious and 49 (75.4%)women had a normal NIPT result.