https://pubmed.ncbi.nlm.nih.gov/34426884/
This says 50% are triple negative but have a better prognosis than other triple negative cancers. It also says this type is aggressive but has the same survival rate as non-apocrine breast cancers.

Here is more:

Invasive ductal carcinoma with apocrine features is a rare type of breast cancer that represents approximately 1% of all breast cancers1. It is also known as invasive apocrine carcinoma1. When examined under a microscope, invasive ductal carcinoma with apocrine features is made up of large pink cells that look very similar to the cells found in a type of sweat gland called an apocrine gland1. Apocrine carcinoma is a microscopically defined type of invasive ductal carcinoma (IDC) of the breast2.