Although, acid reflux and throat cancer, can share some symptoms (voice hoarseness, sore throat), I'm sure that all of your symptoms are resulting from your acid reflux issue.
The most common throat cancer symptoms are: a progressive onset of hoarseness with some progressive difficulty in breathing, complaints of sore throat and lesions in and around the mouth, difficulty swallowing, earache and loss of hearing, and even the onset of frequent nosebleeds.
According to your smoking history you don't seem like a candidate for a throat cancer.
The risk group for throat cancer are people older than 50 years, heavier smokers, especially ones that consume chewing tobacco, and with an excessive alcohol consumption.
It's good to know that chronic reflux, in some patients is associated with Barrett's esophagitis (inflammation of esophagus) , a condition that may lead to esophagus cancer.
Treat your heartburn and try to avoid its triggers!

Best wishes!
Marija

Your symptoms are from the Gastric Esophageal Reflux Disease. You should stop smoking because that increases acid production. The chest pain is a result of heartburn. You may try to see your doctor regarding the mode of treatment for your GERD.