Smoking may be associated with all of the following cancers, except:

Ans is None > Ca Nasopharynx All the given options are mentioned by Harrison: Harrison 17/e p2737 writes- "Tobacco smoking causes cancer of the lung, oral cavity, naso-, oro-, and hypopharynx, nasal cavity and paranasal sinuses, larynx, esophagus, stomach, pancreas, liver, kidney (body and pelvis), ureter, urinary bladder, and uterine cervix and also causes myeloid leukemia. There is evidence suggesting that cigarette smoking may play a role in increasing the risk of colorectal and possibly premenopausal breast cancer, but there is no association with postmenopausal breast cancer. There does not appear to be a causal link between cigarette smoking and cancer of the endometrium, and there is a lower risk of uterine cancer among postmenopausal women who smoke." Thus the answer should be none, however Nasopharyngeal carcinoma is found to be least associated with smoking. Head & Neck Cancers by Enslow Jacobs 2003e p492 writes-"Association between smoking and nasopharyngeal carcinoma has been shown only by a few studies. If the association of tobacco and NPC is real, the possible mechanism of tumor induction would be the nitrosamines and its precursors in tobacco."