People making insensitive remarks about your cancer or treatment has often been discussed. I must believe that these comments are not meant to hurt or upset you, nevertheless it can be disturbing to hear and is not something you should have to deal with.
The below article offers some great advice.
Take note of No. 7 in where it is pointed out that online support can be of great value. Know that the members of this board understand, relate and are behind you, all the way.
http://www.cancertodaymag.org/Fall2016/Pages/Choosing-the-Right-Response.aspx
Hugs,
Marion