What happened, in summary

In 2013, Sally Johnston was diagnosed with lobular breast cancer after her primary care provider found a lump near her clavicle. A biopsy confirmed breast cancer involving lymph nodes. The cancer was estrogen receptor-positive. Sally began treatment with an aromatase inhibitor to reduce estrogen production and remained on the hormone therapy for about 6 months. She then underwent a mastectomy. In 2014, she received chemotherapy followed by radiation to address any cancer cells that might remain after surgery. Sally stayed remarkably active throughout treatment. Just 3 weeks after her mastectomy, she ran a half marathon and recorded her best time. During chemotherapy she continued long walks and day trips, and during radiation she sometimes walked to appointments and ran back. By the end of 2014, Sally was in remission. At age 74, roughly a decade later, she was still traveling widely, working outdoors, volunteering, and pursuing a goal of visiting all 7 continents. Her experience also included the loss of her husband to another cancer, which left lasting fears even as she continued to live an active life after breast cancer treatment.