Hello Rodney,
I'm sorry to hear about your father.
If you want anything more precise, I would sugest that you hire a hospice nurse
with the express instructions to:
1) physically evaluate your father
2) take health history
3) review scan reports and recent bloodwork reports
and evaluate Karnofsky performance.

And/or try it yourself here
There is a guideline that discusses the Karnofsky Performance Scale at
http://palliative.info/teaching_material/Prognosis.pdf
As you can see in Table 1 the criteria is divided into percentiles; ranking
from highest to lowest. These are the stages Karnofsky defined in terminal
cancer. If you locate your father's's standing on the chart, it is probable
that all of the items below will come in that order.

Stay in touch, will try to help along the way. but if you engage hospice, they
can be very valuable to everyone.
They can help you care for your father at home.
My thoughts will be with you all.
J

I assume you obtained the 5.7 months median survival time from the study
that is the subject of the abstract supplied below.
.
The median survival survival in those who did not receive that drug was 2.87
months.   These patients received 5FU, which is a fairly harmless but
relatively ineffective form of chemotherapy for this condition.  I expect
your father's survival without treatment will be similar to that of this
group.

Understand that these "median survival" figures reflect a spread of survival
that may extend from mere weeks to nine months or  longer.   It is very hard
to predict in the individual case,  although some further clues may be
obtained by the kind of assessment that J is suggesting.

The chemotherapy  has (probably) worthwhile benefits for up to fifity per
cent of patients.  He might consider trying one or two cycles of treatment
to determine how well he tolerates it, or participating in any clinical
trials in your area..
       1: J Gastroenterol Hepatol. 2005 Jan;20(1):62-6. Related Articles,
Links

 Impact of gemcitabine on the treatment of metastatic pancreatic cancer.

 Ishii H, Furuse J, Nagase M, Yoshino M.

 Division of Hepatobiliary and Pancreatic Medical Oncology, National Cancer
Center Hospital East, Kashiwa, Japan. hirishii@east.ncc.go.jp

 BACKGROUND AND AIM: A previous randomized trial showed gemcitabine was
superior to 5-fluorouracil in overall patient survival. However, the
incremental improvement in survival was minimal. It is 2.5 years since
gemcitabine has become available for the treatment of pancreatic cancer in
clinical practice in Japan. The current study was conducted to examine
whether treatment outcomes have changed since the introduction of
gemcitabine therapy. METHODS: Ninety-one consecutive patients with
metastatic pancreatic cancer treated with systemic chemotherapy at the
National Cancer Center Hospital East were surveyed. Patients admitted before
April 2001 received 5-fluorouracil, and those admitted subsequently received
gemcitabine. The patients were divided into the gemcitabine group (n = 50)
and the non-gemcitabine group (n = 41), and these groups were compared for
five outcomes, objective response rate, non-progressive disease rate,
carbohydrate antigen (CA)19-9 response rate, actual survival time, and
difference between estimated and observed survivals. The estimated survival
time was determined using the prognostic index reported in the previous
study. RESULTS: Except for the objective response rate, the four other
outcomes in the gemcitabine group were significantly superior to those in
the non-gemcitabine group. The frequency of non-progressive disease, CA19-9
response, and favorable prognosis compared with the estimated survival, were
58%, 22%, and 60%, respectively, in the gemcitabine group, and 22%, 6%, 30%,
respectively, in the non-gemcitabine group. The median survival time in the
gemcitabine and non-gemcitabine group was 5.73 and 2.87 months,
respectively. CONCLUSION: It is suggested that there was a definite
improvement in pancreatic cancer treatment after gemcitabine was introduced.

 PMID: 15610448 [PubMed - in process]

With or without treatment the survival time is going to be relatively short,
the difference probably being a few weeks. Really it depends how tied to the
hospital/oncologist he wants to be in the time he has left and how much
extra discomfort he is willing to suffer for the (meagre?) benefit he may or
may not get.
The first three goals he should be aiming for are
1 Quality of life
2 Quality of life
3 Quality of life
MIKE

my dad also 73 yrs old got pancreatic cancer for 6 months and cannot operate
since they open him up may 9 but it spreads to the liver and no chemotherapy..
.he got diarrhea for 1 month and eats 5% only since food reflux up the throat
all the time..he is still alive, his younger sister died just 3 months in
1995 at 59 yrs old and also got pancreatic cancer in toronto...is bull_sh.t
that they say the life expectancy is so and so, he is still alive...