This week there was another study and more disagreement over the value of routine, screening mammograms.

The research from Canada published in the journal BMJ concluded that routine mammograms do not saves lives.

The researchers used a trusted methodology and tracked nearly 90,000 women for more than two decades. Some study participants had an annual breast exam by a nurse, others had that checkup as well as a mammogram. The study found similar breast-cancer death rates in both groups of women.

"The thing that people need to be mindful of is that it's only one of 10 randomized controlled trials of breast cancer screening," said Robert Smith, senior director of cancer screening for the American Cancer Society.

Policy watchers have been keeping tabs on the Canadian study since the 1980s, said Smith, adding that it has big flaws.

"There are a number of people who consulted on that study who resigned, didn't feel the investigators were taking the quality issues seriously," Smith said. "The study was off to the wrong start from the very beginning."

It's clear that mammograms help find breast cancer before a woman can feel a lump, but the big question is: Does that early detection really influence whether a woman lives or dies?

Smith said he believes in a raft of studies — and he says stronger data -- that show routine mammograms can cut the rate of cancer deaths.

Study's age, images at issue

The Canadian study was launched a quarter-century ago and several critics say the '80s-era mammogram procedures and some poor quality images just aren't good enough to find tumors.

Radiologist Emily Conant leads breast imaging at Penn Medicine where every woman gets digital breast tomosynthesis — or a 3-D mammogram.

Outside researchers reviewed the mammography images from the Canadian study had concerns about the "resolution, contrast, and the quality of black and white," she said.

Conant said it's good to have a healthy skepticism about the current mammography guidelines, but she's worried the newest study will just heap on confusion.

"Here we go again," Conant said. "You know, all of this debate is about how one looks at the data and what data one looks at. This controversy will continue because we do know that mammography is far from perfect."

"There will be women who say, 'I don't want any of this, I'm never going to get a mammogram,' Fine, just make sure they understand today's data, today's technology," Conant said. "Technology is a moving target."

Beyond mammography

There's an evolving conversation about the benefits and possible harms of cancer screening, which includes lots of discussions about "overdiagnosis" and a concept called "misfearing."

In media and policy discussions about women and breast cancer, there's been a skewed emphasis on the effectiveness of imaging, Conant said.

"The radiologist finds it, the pathologist looks at it under the microscope, and then the treatment is determined by the surgeon or radiation therapist," she said.

"It's a team," Conant said. There needs to be better scrutiny — and medical advancements -- along a continuum of care offered to women, she said.