Late Effects A late effect is a side effect that can occur months or even years after cancer treatment. Breast cancer patients should be aware of late effects, as dealing with them may be part of their survivorship care and planning. For breast cancer patients, that means knowing about menopause, fertility issues, lymphedema, heart effects, lung damage due to chemotherapy and radiation, osteoporosis, cognitive dysfunction (“chemo brain”), digestive problems, fatigue, secondary cancers and emotional upheavals. Please be aware that you may experience these issues at some point, even if you have not encountered them yet. Most of these topics are covered on this website, so remember this information is here if you need it.