News briefs

Tonic immobility during rape associated with increased risk of PTSD

Active resistance is often considered to be the “normal” reaction during rape, but a Swedish study has found that most victims may experience a state of involuntary paralysis, called tonic immobility. Tonic immobility was also associated with subsequent post-traumatic stress disorder (PTSD) and severe depression after rape. The findings, published in Acta Obstetricia et Gynecologica Scandinavica, indicate that for health care follow-up and legal matters, tonic immobility should be assessed in all sexual assault victims. Tonic immobility in animals is considered an evolutionary adaptive defensive reaction to a predatory attack when resistance is not possible and other resources are not available. Little is known about it in humans, however. The Swedish researchers assessed tonic immobility at the time of assault in 298 women who had visited the Emergency Clinic for Rape Victims in Stockholm within one month of a sexual assault. After 6 months, 189 women were assessed for the development of PTSD and depression. Of the 298 women, 70% reported significant tonic immobility and 48% reported extreme tonic immobility during the assault. Among the 189 women who completed the 6-month assessment, 38.1% had developed PTSD and 22.2% had developed severe depression. Tonic immobility was associated with a 2.75-times higher risk of developing PTSD and a 3.42-times higher risk of developing severe depression. Prior trauma and a history of psychiatric treatment were also linked with tonic immobility.

doi: 10.1111/aogs.13174

New hope for women with BRCA1 breast cancers

Australian researchers from the Walter and Eliza Hall Institute of Medical Research (WEHI) and the Peter MacCallum Cancer Centre have found a new way to use immunotherapy to treat aggressive triple negative breast cancers in women with BRCA1 gene mutations. In a laboratory-based study published in Science Translational Medicine, the researchers showed that combining two immunotherapies – with anti-PD1 and anti-CTLA4 – with chemotherapy halted the growth of BRCA1-related tumours and significantly improved survival in laboratory models. Some cancer cells survive by hijacking and switching off immune cells that would otherwise destroy the tumours. Anti-PD1 and anti-CTLA4 immunotherapies are “immune checkpoint inhibitors” that release the brakes on critical immune cells, enabling them to attack the tumour. Dr Daniel Gray, from WEHI, said that previous research had shown that immunotherapy was particularly effective in treating tumours that had accumulated many mutations. “BRCA1-related triple negative breast cancers have some of the most ‘chaotic’ genomes, and we see many immune cells accumulate in and around the tumour,” Dr Gray said. “This suggests that the immune cells can readily detect that something is awry, but they aren’t able to respond properly, because they have been disabled by tumour cells. We showed that a combination of anti-PD1 and anti-CTLA4 therapies restored their ability to attack and kill triple negative breast tumour cells, and very effectively control tumour growth.” Associate Professor Loi, head of breast cancer clinical trials research at Peter MacCallum Cancer Centre and for the Parkville precinct, said work was already underway to translate these important findings from laboratory models of breast cancer into a clinical trial for women with the disease.

doi: 10.1126/scitranslmed.aal4922