INS and small cell lung carcinoma: On the other hand, estradiol (OR [95% CI] = 2.424 [1.113–5.278], P = 0.0258), PTHrP (OR [95% CI] = 2.887 [1.124–7.418], P = 0.0276), and insulin (OR [95% CI] = 1.237 [1.079–1.418], P = 0.0364) were significantly associated with an increased risk of SCLC (Figure 9).