Johansson ALV, et al. - Researchers compared the value of age and tumor subtype as prognostic factors for breast cancer survival. They used population-based data for 21,384 women diagnosed with breast cancer at ages 20-89 between 2005-2015 in the Cancer Registry of Norway. They defined subtype by using estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor 2 (HER2) status as luminal A-like (ER+PR+HER2-), luminal B-like HER2-negative (ER+PR-HER2-), luminal B-like HER2-positive (ER+PR+/-HER2+), HER2-positive (ER-PR-HER2+) and triple-negative (TNBC) (ER-PR-HER2-). They noted increased breast cancer-specific mortality related to young age among luminal A-like subtype, while old age was found to be related to increased mortality in all subtypes. Age and subtype were identified as strong independent prognostic factors. The higher breast cancer-specific mortality among young was largely explained by tumor-associated factors (subtype, grade and stage).