Taoiseach Enda Kenny has insisted there is priority screening for women at risk of certain hereditary cancers.
Following film star Angelina Jolie's admission that she had a preventative double mastectomy to reduce her risk of developing breast cancer, Mr Kenny was challenged on reports of an 18-month waiting list for special DNA testing.
Fianna Fail leader Micheal Martin said it was unacceptable that women had to wait so long for the genetic testing, which determines whether they possess a defective gene that increases risk of the illness.
The Taoiseach insisted Ireland's screening process was "one of the most effective of its kind" but he would not be drawn on the DNA testing, which is offered to women whose relatives have contracted the disease.
"Women at high risk tend to have far more aggressive tumours, so early detection is absolutely critical," Mr Kenny said.
The Taoiseach said where there was a real concern that an individual might be more likely to have breast cancer, she would be fast-tracked for screening.
"Where there is a risk here and a probability that they may well be in this category, I assume that the working group would assess all of those figures and realities," he said.
"At the moment, if a GP has somebody about whom they have a genuine concern that they may be in danger of being caught by this type of cancer, then they can be referred for priority screening."
He described the breast screening programme that operates in Ireland as one of the most effective of its kind.