Whole-Body Diffusion-Weighted Magnetic Resonance Images
A, Ovarian carcinoma in patient 1. B, Follicular lymphoma in
patient 2. C and D, Hodgkin lymphoma before (C) and after (D)
treatment in patient 3. The arrowheads in all panels point to the
tumor locations. D, Arrowheads point to areas of treatment
response (complete remission). (Credit: Amant et al., 2015)
Non-invasive prenatal testing (NIPT) for chromosomal foetal disorders is used increasingly to test for conditions such as Down's syndrome. NIPT examines DNA from the foetus in the mother's blood, and therefore does not carry the risk of miscarriage involved in invasive testing methods. Now, for the first time, researchers have found another advantage of NIPT; it can detect maternal cancers at an early stage, before symptoms appear. The study was published in the journal JAMA Oncology.
The researchers set out to increase the accuracy of the NIPT test in order to overcome false negative or false positive results when screening for chromosomal disorders in the foetus. While testing over 6000 pregnancies, they identified three different genomic abnormalities in three women that could not be linked to either the maternal or foetal genomic profile. They realised that the abnormalities bore a resemblance to those found in cancer, and referred the women to the oncology unit.
Further examination, including whole body MRI scanning and pathological and genetic investigations, revealed the presence of three different early stage cancers in the women: an ovarian carcinoma, a follicular lymphoma, and Hodgkin's lymphoma. Although this incidence is within the range to be expected in the normal population (one per 1000-2000 person years in women aged 20 - 40), without NIPT these cancers would have been unlikely to have been detected until they became symptomatic, and therefore at a much later stage.
Two out of the three diagnosed women were treated, one of them during her pregnancy. She subsequently gave birth to a healthy girl. The third had indolent disease that was not considered to be in need of treatment at that stage. Follow-up investigations in the treated women showed that NIPT had the additional advantage of allowing the effectiveness of treatment to be monitored, and the researchers were able to see that the chromosomal profiles became normal during and after chemotherapy.
The results suggest that NIPT might enable the detection of pre-symptomatic cancers not just in pregnant women, but more widely. The normalisation of the NIPT profile in these patients following treatment indicates the possibility of measuring response to treatment as early as after the first administration of chemotherapy. While larger scale studies will be required to validate these results further, the researchers are confident that they have made an important step towards a new cancer screening tool capable of detecting disease at an early stage.
Based on material originally posted by European Society of Human Genetics.