Is it possible to get cancer from smoking 2 ciggarettes a day for life?

It is possible to get cancer without smoking any cigarettes. Saying
"get cancer from smoking 2 cigarettes a day" implies that it is
possible to assign a precise cause to a cancer. That is not usually
the case. Do some people who smoke 2 cigarettes a day get cancer?
Undoubtedly. Were the cigarettes the sole cause of the cancer? There's
no way to be certain.

This would be a never ending answer...but the short one is yes, since
you asked if it is possible not absolute.
Now...you could be talking about tongue/mouth/throat/lung etc.

Here is one article to support a positive response to your question
but you could find thousands...

This one is from a study by the CDC that studied those that had smoked
a minimum of 100 times in their life... (ie . less than 1 time a day
as per your question)

http://www.cdc.gov/mmwr//preview/mmwrhtml/mm5425a1.htm

Cancer is a disease with many causes, many of which are unknown. It
isn't the same as polio, where one viral agent causes the disease. If
it were that simple, there would be a cure or a vaccine.

Some factors that seem to be related to getting cancer are carried in
your genes. In addition to your genetic inheritance, there seem to be
others related to exposure to environmental toxins.

Inhaling the smoke from cigarettes does seem to be one of the
contributing causes. This has been shown even when the smoke is coming
from a "second hand" source. It seems reasonable to guess that if
second hand smoke can irritate your lungs enough to produce a
cancerous growth, then smoking -- even two cigarettes a day -- may
raise your chances of developing cancer.

Will you get cancer from two cigarettes a day? There are three pack a
day smokers who live well into their nineties. There are people who
never smoked who die from lung cancer in their twenties and thirties.
There is no crystal ball to tell if you will be in the small
statistical group who are not affected by smoke or smoking. There is
plenty of evidence that smoking is a significant contributor to lung
cancer deaths - and other cancers, lung diseases, heart diseases,
stroke and other unpleasant physical changes.

If you only smoke two cigartettes a day, your dependence on nicotine
is not strong. Why take a chance on beating the odds when your life is
on the line? Switch from two cigarettes a day to two carrots a day.
You'll get the same oral stimulation without the smoke - and, unless
you're allergic to carrots, they're good for you!

I detect a subsidiary question here.

Two cigarettes per day are an unlikely consumption for a nicotine addict.

The only two possibilities I can think of are as a morning laxitive
(very effective) or a medium for evening relaxation.

One has to take a few risks in life, the outcome is the same, but over
indulgence may get one there sooner.