ALK, the stigma and unanswered

It is known that mutations in the ALK gene can lead to several different types of cancer. In NSCLC, the most common ALK mutation is a fusion of the ALK gene with another gene called EML4. The EML4/ALK fusion gene creates an abnormal protein that can cause unregulated cell growth, leading to the development of cancer.
This is what occurred in my body to cause lung cancer adenocarcinoma.

Being diagnosed first of all with any disease is hard. It's on paper now that I have a disease, and I have a very shitty disease.  Secondly, the stigma of lung cancer is much different that other cancers, i.e breast, ovarian, leukemia,etc.
If I say I have lung cancer, someone will say, I didn't know you smoked!  Well I don't smoke! And I think this is why lung cancer has such a bad stigma.

I am not sure I would know how it did this, or what caused it to do it.

Could it be the steroid inhalers?
Could it be the asthma inhalers?
Could it be stress from a pregnancy?
Could it be from the pneumonia?
Could it be from asthma and weakened lungs altogether?

Questions that will go unanswered.