Long-term effects of smoking in youth?

Hi,

I'm 18 years old now, and have been a relatively light smoker (meaning, 1-2 cigarettes/day) since the time I was 15.  I wanted to know if the some 1,000 cigarettes I smoked in my 'youth', will have after-effects on the chances of cancer developing in my body.  I'm worried because I recently discovered that I have the disease in my genes from both my parents side.  My father used to be a chain-smoker for 6 years, during which I was born, (then he got cancer and quit right after) and my both my mothers parents have had cancer of some sort.

Would appreciate informative response,
Thank you,
       -AK