Nearly one in five cancers diagnosed today occurs in an individual with a previous diagnosis of cancer, and these “second cancers” are an important cause of morbidity and mortality among cancer survivors. 
Second malignancies and recurrences occur when there is a secondary tumour growing in addition to the primary one, or when the primary tumour returns after treatment. Secondary malignancies can also occur following treatment for a primary cancer. Unfortunately, certain chemotherapy and radiation treatments can damage tissues which may in turn eventually become cancerous. In these cases, the same treatment that was used to treat the primary tumour may not be effective, so additional therapy options may have to be considered, such as clinical trials. 
Cancer may recur in the same location as the primary tumour, called a local recurrence, or nearby, which is called a regional recurrence. If it recurs in another part of the body, it is referred to as a metastasis. This typically happens when the primary cancer returns after having been treated. 
Metastatic or Stage IV cancer occurs when the cancer has spread to another part of the body. Metastatic cancer can happen before the cancer is found and a diagnosis is made, or it can happen after treatment. Metastases, often referred to as “mets”, most commonly develop when cancer cells travel through the blood stream or the lymphatic system to access distant parts of the body and create tumours which resemble the primary cancer. Some of the most common sites for mets include bones, lungs, liver, and brain. 
Treatment for these cancers depends on the type of cancer, how large the tumour is, how fast it is growing, and how it responds to treatment. If you have been diagnosed with metastatic bone cancer, caution is necessary when lifting, twisting, exercising, participating in high impact activities, or coughing. People can live for years with bone mets, but there is little information available regarding patient assessment and education about how to live with bone mets. Some research has shown that physical activity is beneficial for people with metastatic cancer. 
Treatment for mets will usually be systemic therapy, meaning it impacts the entire body. This can include chemotherapy, targeted therapy, hormone therapy and/or immunotherapy. Certain metastatic cancer treatments aim to reduce the cancer’s side effects, but are not curative. In these cases, metastatic cancer is considered a chronic condition. 
For information concerning fear of cancer recurrence, watch our webinar: Fear of Cancer Recurrence – 5 ways to lessen your anxiety.
 Eileen Dahl, RP, MDiv, CT, Breast cancer patient with bone metastases. Presented at the All-Party Cancer Caucus Meeting, November 22nd, 2017.