麻豆传媒

Use of a standardized cell-free (cf)DNA-sequencing and cancer-screening protocol detected cancer in nearly half of pregnant or postpartum women who initially received unusual or nonreportable clinical cfDNA-sequencing results, the IDENTIFY study showed.

In 107 patients, 48.6% of those who received unusual or nonreportable clinical cfDNA-sequencing results had an occult cancer, reported Diana W. Bianchi, MD, of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and colleagues in the .

The cancer-screening protocol included rapid whole-body MRI, which had a sensitivity of 98% and a specificity of 88.5% in detecting cancer, making it much more successful in identifying women with cancer compared with other evaluation methods, including measurement of serum tumor markers, fetal occult blood tests, laboratory tests, and physical examination.

In addition, analyses of blood samples detected six different patterns of chromosomal gains and losses, with one pattern (a combination of copy-number gains and losses across multiple chromosomes) present in 49 women, 47 of whom turned out to have cancer.

"Our results support the use of whole-body MRI in the evaluation of pregnant persons who receive prenatal cfDNA-sequencing results suggestive of cancer," wrote Bianchi and colleagues. "Further investigation of cfDNA-sequencing patterns would help to identify the subgroup of persons with nonreportable results who might have cancer."

In an , Neeta L. Vora, MD, of the University of North Carolina at Chapel Hill, suggested that "widespread education is needed for both obstetrical providers and oncologists regarding the possibility that cfDNA screening can identify cancer in pregnant persons."

Vora also pointed out that while the study showed that whole-body MRI was superior to other methods in evaluating women with cfDNA-sequencing results suggestive of cancer, this type of imaging is usually not ordered by providers or covered by insurance.

"When abnormal screening results suggestive of cancer are noted, how can patients undergo a whole-body MRI outside a research study without large out-of-pocket costs?" she asked, adding that the field "still has a long way to go to improve provider education regarding the possibility of identifying maternal cancer through cfDNA screening, as well as to improve laboratory standardization, reporting of suspicious findings, and access to imaging methods such as whole-body MRI."

For the study, Bianchi and colleagues included women who underwent cfDNA sequencing during their routine obstetrical care and received unexpected results suggesting cancer -- results that were abnormal and inconsistent with a viable fetus as determined by ultrasonography, abnormal and discordant with the fetal karyotype or chromosome microarray analysis, or nonreportable.

They also underwent rapid whole-body MRI, blood tests, measurement of serum tumor markers, a fecal occult blood test, family and medical history intake, and physical examination with a review of oncologic symptoms. In addition, those who were not up to date with cervical cancer screening received a Pap smear that included a test for human papillomavirus.

Eligible participants were pregnant or up to 2 years postpartum, and had received cfDNA-sequencing results from one of 12 commercial laboratories in North America. A total of 117 participants without a known cancer diagnosis were enrolled in the study, 107 of whom had complete data available for analysis.

Mean age was 33 years, 70.1% were white, and 89% were pregnant at the time of cancer screening and research sequencing. Of the 52 women diagnosed with a malignancy, lymphoma was diagnosed in 59.6%, colorectal cancer in 17.3%, and breast cancer in 7.7%.

Other diagnosed cancers included cholangiocarcinoma, adrenocortical carcinoma, non-small cell lung cancer, pancreatic cancer, Ewing's sarcoma, and renal carcinoma.

Of the 20 participants with solid tumors, two had stage I disease, five had stage II or III disease, and 13 had stage IV disease.

"The importance of prompt cancer screening in patients who receive cfDNA-sequencing results suggestive of maternal cancer is highlighted by the five participants in this study who had stage [II or III] solid tumors identified and the six participants with stage [IV] cancers with limited metastatic involvement who were eligible for potentially curative treatment," the authors wrote.

Of the 55 women not diagnosed with cancer, 15 had normal cfDNA-sequencing and cancer-screening results, while 30 had a biologic source other than cancer that could explain the initial clinical cfDNA-sequencing results.

Ten women had abnormal results that were unexplained, and they are being followed for up to 5 years.

Bianchi and colleagues acknowledged that their study had several limitations, noting that it lacked prespecified hypotheses or analyses, and that they were unable to directly compare the research and original clinical sequencing results. They also suggested they may have underestimated the proportion of women in the study with cancer.

Comment