A stage 2 cancer diagnosis usually means that the cancer is larger or has developed to lymph nodes, tissues or organs "adjacent to the location of the primary tumor," according to the National Cancer Institute. Your sister most likely needs your comfort and support during this trying time, but it can be hard to know what to say that will help. Though a phone call or visit can also show your concern, writing a letter can give you the opportunity to carefully choose and edit your words.

Concerns Before Writing

If you have only heard of your sister's diagnosis through the grapevine, it may be best to postpone writing to her until she makes the diagnosis publicly known, according to the American Cancer Society article "Ways to Respond." If you were not told directly, or if you found out through someone else, keep her feelings in mind -- fear and worry may have kept your sister silent about her diagnosis. If the knowledge is public, even if your sister has not told you personally, it is okay to write, "I heard about your diagnosis, and wanted to tell you how sorry I am."

What to Focus On

When writing your sister, keep the focus on her feelings and on offering gentle encouragement. You might say, "I'm sorry you have to deal with this," or "How are you?" according to the Hallmark article "Comforting Words." Now can also be an opportunity to offer help with chores or errands. If she has kids and you live close by, offer to pick them up from school or babysit, or offer to help with her weekly grocery shopping. If she is younger, ask if she'd like to spend the day with you or if you can help with homework. You may also find that bringing levity to the situation, like mentioning a humorous story from the past or sending a funny get-well card along with your letter, can brighten her day.

Things to Avoid In Your Letter

Some anxious letter writers may avoid addressing the cancer diagnosis, or focus on their own aches and pains, but this can add to your sister's isolation, according to the Cancer Treatment Centers of America. Other comments, such as "I know you'll get better," "Don't worry" or "You're too strong to let cancer beat you," can also be hurtful, especially if things take a turn for the worse. Just as being too optimistic can be harmful, your sister may be hurt by pessimistic comments like "I knew someone who had that cancer, but he didn't make it." If you do mention others' cancer stories, make sure they have an upbeat ending. It's generally more helpful to let your sister know that you care, that you love her and that you are willing to listen if she wants to talk.

Sample Letter

A sample letter might read, "Jill, I'm sorry to hear about your Stage 2 cancer diagnosis. This must be really difficult for you, so I wanted to check in and see how you are feeling. I want you to know that I will always be here for you if you would like to talk. If you would like me to go with you to some of your appointments, or if you need help with your kids (or homework, if it's a younger sibling), I'd be happy to help. I love you," according to the National Cancer Institute article, "Talking with Family and Friends."