There is also evidence that smoking can damage DNA, which in turn has a deleterious effect on the skin. Dr Jan Bavinck, from the Leiden University Medical Center in the Netherlands, examined a sample of 580 people with various types of skin cancer and looked at the number of them who smoked. (4.) Squamous Cell Carcinoma is a common type of skin cancer usually caused by prolonged exposure to sunlight and which is more typical amongst older, pale-skinned, fair-haired people. Tumours for this type of cancer often start as small lumps or patches of skin that can spread if left untreated. Although quite an aggressive form of cancer, it has a high success rate when treated, usually involving surgery. Dr Bavinck discovered that people who currently smoked around 11 to 20 cigarettes a day were over three times more likely to develop squamous cell carcinoma. After establishing smoking is an independent risk factor, the degree of risk was correspondingly acknowledged to increase the more people smoked. For smokers who smoked less than this amount, the risk of developing the cancer was reduced but was still twice the normal rate. The research team theorized that this was due to the damage smoking caused to the DNA in skin tissue, which then produced abnormal cell growth.(4.) J.N. Bouwes Bavinck, MD, et al.; 'Relation Between Smoking and Skin Cancer'; Leiden University Medical Center, Leiden, the Netherlands. Vol. 19, No. 1, (January) 2001, pp. 231-238.