Mark,
Here's a fact.
The day you see Gerson mentioned here
http://www.cancer.gov/cancerinfo/pdq/treatment/esophageal/patient/ or
here
http://www.bccancer.bc.ca/PPI/TypesofCancer/Esophagus/Treatment.htm is
the day you will know that Gerson "works" in some way. Don't hold your
breath (ie delay conventional treatments) while you are waiting.

There's 1160 esophageal subscribers on the ACOR mail lists at
http://listserv.acor.org/archives/ec-group.html
If there's a problem with the above url, use http://www.acor.org/ Mail
Lists, Select E, then "join"
Join and ask them what "worked" for them. When you do, specify what you
mean by "worked".

J

If you want solid facts, as opposed to the uncertainties inherent in
personal testimony, the five year survival studies that the Gerson clinic
itself have performed do not raise one's confidence that it provides any
answer to serious cancers.

The Gerson clinic was also asked by the OAM (now the NCCAM) to produce a
dozen cases of well-documented cancer remission with the promise that a
formal clinical trial would ensue, and the Gerson clinic admits that it was
unable to produce such, after over half a century of treating many hundreds
of patients yearly..
(Source Hildenbrand GLG, Hildenbrand C, Bradford K, Cavin SW.

5-year survival rates of melanoma patients treated by diet therapy after the
manner of Gerson: a retrospective review.

Altern Ther Health Med 1995-09;1(4):29-37   and the NCCAM  web site)

My well-researched  "opinion"  is that it works rarely, if at all.
Nevertheless,  I do think the Gerson clinic is amongst the more sincere
"alternative" cancer clinics.   Cancer is such a variable conditionm it is
easy for practitioners to be misled.

 If your father is not forgoing likely curative treatment for what is often
a poor prognosis cancer, and is not  missing out on some very useful
palliative measures through a commitment to alternatives, you may be wise to
let things be.

Peter Moran