I have a basal call carcinoma, on my upper arm 3 cm in diameter. can i hang off for another 10 weeks for treatment?

Maybe (not) . . .: Basal cell carcinoma is typically the slowest growing and least likely to metastasize (spread) of the various skin cancers. In fact, it's just about the polar opposite of melanoma which is quite deadly. In other words, it's rare for someone to die from bcc. However, 3cm is a pretty good size. Best to ask your dermatologist for his/her opinion. Get a 2nd opinion if you must, but don't delay much!

Likely yes: Basal cell carcinoma is usually a slow-growing tumor that does not spread to other parts of the body. Chances are that you have probably had it for at least 2 years, so another 10 weeks probably will not make a significant difference. Talk to your doctor to make sure there are no other special concerns.