I don't think that "doctors dismissing patients concerns" is a source of failure to detect breast cancer via mammograms.

I assume women generally get mammograms because health experts recommend regular checks for all women. The reason radiologists fail to detect breast cancer in some x-rays is not that they aren't taking women seriously, because the women weren't coming in with symptoms or complaints -- they came in for a preventative screening. Radiologists sometimes fail to detect breast cancer because each radiologist looks at thousands of essentially identical x-rays over their career, breast cancer is uncommon, and cancer that does exist is hard to visually recognize in its early stages.

I'm not saying that people don't dismiss the complaints of women, whether in a healthcare or other context. But that's not what's going on here, because breast cancer checks are generally driven by prevention rather than symptoms.