It is very unlikely that the lymph nodes are cancer. There are a couple of reasons I think this. First, you have a sore throat, which suggests to me that you have an infection. Lymph nodes are places in our bodies that fight off infection. Whenever we have an infection, the lymph nodes close to that area can get bigger and tender. Touch them. Are they tender? Can you move them around? Both of these things would suggest to me that they are bigger because you have an infection. The second thing that is reassuring it that you have multiple lymph nodes enlarged. This means that there are many doing their job at once.

There are some things to look out for in regards to lymphoma (cancer of a lymph node). If there is a single node that has been there for a long time, seems to be getting bigger and is stuck in one place (you can't move it around) you might want to see a doctor. But keep in mind, it might still be normal! The real things that suggest a lymph node might be cancer are other things that you are feeling. If you are sweating a lot at night, feeling very tired or losing weight for no reason you should check in with a doctor.