Dear Phillyfish: The reason that people with medullary breast cancer tend to do better is because medullary breast cancer tends not to spread as frequently as other types of breast cancer. To put it in terms one might understand, a 3cm medullary cancer would have a similar prognosis to a 1cm ductal cancer. Any tumor can be ER/PR positive or negative.
Most survival curves are not broken down by histology. In the AJCC staging manual, for the sake of argument, for stage 3A breast cancer, the relative survival at 1 year is 95% at 2 years 83% at 3,4,& 5 years, the relative survival is 72%, 65% and 56% respectively. Note, this is survival, not recurrence. There are tools that physicians can use to attempt to calculate survival and recurrence but these are not charts as much as algorhythms.