Hi Donna:
Your mother needn't suffer if she's worried about the cost of medications. Many of the pharmaceutical manufacturers have programs for those who either don't have insurance or can't afford the current price for their meds. AstraZenica, who manufactures Nexium, has such a discounting program including for those on Medicare.
You can read the details here:
http://www.astrazeneca-us.com/help-affording-your-medicines/
If link doesn't work, try this:
http://tinyurl.com/yfdzwlw
I'm assuming you're in the US. If not, you can probably find same info on the international site.
As far as what's going on with her esophagus, only the doc can really diagnose and recommend treatment. The narrowing seen could be treatment/medication related, or related independently to acid reflux. Either way, - she should be helped with her pain.
If she doesn't feel as if she's being treated correctly, I would talk to the people at the facility where she receives treatment. Usually there's a patient advocate to help. If she's concerned about the cost of treatment, there are also social workers who can possibly guide you to resources that can help.
The help is out there - unfortunately, you have to dig for it. You may even find some help on this site if you look around.
You can also try the Patient Advocate Foundation ( http://www.patientadvocate.org ) Lots of resources there and a state by state guide. Or even the American Cancer Society.
I do hope you Mom gets some relief - and also that her cancer can be controlled or eradicated. My best wishes to both of you - it's a fight we're all in.
- Jeff