The Samoan Breast Cancer Society said it's vital for women to seek medical advice if they're concerned about breast changes and are feeling unwell.
The society's chief executive, Shelley Burich, said too many women relied on traditional alternatives and by the time they reach the hospital treatment options can be limited.
She said all lumps didn't necessarily mean breast cancer, but if a woman felt a lump they needed to get it checked by a medical doctor.
"Late presentation is a big problem here, a big, big problem. All too often we're unable to help them because they've just left it too late," she said.
"So the biggest message that we can push really is early detection and come in early even if they feel a small lump and they're not quite sure what it is."
Shelley Burich said communities in Samoa have become much more engaged and proactive over the past five years.