A study has confirmed the Cartwright inquiry findings that many women with a potentially pre-cancerous condition had curative treatment withheld during a research programme at National Women's Hospital.

The study led by Otago University researchers lands in the controversy created by Auckland University historian Professor Linda Bryder's contention that there was no "unfortunate experiment" at the hospital.

This is contrary to Dame Silvia Cartwright's 1987-88 judicial inquiry findings that patients were subjected to unethical experimental research in the 1960s and 70s on carcinoma in situ of the cervix - now called cervical intraepithelial neoplasia grade 3.

The experiment, initiated by the late Dr Herbert Green, showed the likelihood of CIS developing into invasive cancer if left without treatment intended to cure the original condition.

The latest study compares patients from Dr Green' s 1965-74 study period with those from the years before and after.

And within the Green study period, it compares those initially managed with a small, diagnostic punch or wedge biopsy of the cervix, with patients treated at the outset with procedures including cone biopsy or hysterectomy with the intention of curing their condition.

The paper, by Dr Margaret McCredie, Dr Charlotte Paul and others, published online today by the Australian and New Zealand Journal of Obstetrics and Gynaecology, says the risk of developing cancer was 10 times higher among the 127 women initially managed in the Green study period with a punch or wedge biopsy.

Eight died of cancer, compared with three in the group of 287 initially given treatment of curative intent.

"Our findings show that inclusion in this clinical study subjected women to many medical interventions designed to observe rather than treat their cervical intraepithelial neoplasia, and increased their risk of developing cancer of the cervix or vaginal vault."

The paper disagreed with Professor Bryder's 2009 book, A History of the 'Unfortunate Experiment' at National Women's Hospital, which said Dr Green was "motivated principally by a justified desire to avoid unnecessary surgery, and that there were no adverse consequences for patients".

* 51pc of women from outset given treatment to cure potentially pre-cancerous condition.
* Women not initially given treatment had a 10-fold higher risk of developing cancer than those treated at the outset.