Table 1.
Selected characteristics and risk of death for cancer patients who had eligible post-diagnosis information on smoking status, by smoking status before and after cancer diagnosis, The Shanghai Cohort Study 1986–2010
| No. of Cases | No. of Deaths (%) | Person-years at risk* | Average Person-years* | Median Survival (year) | Average Age at Diagnosis | Received Surgery (%) | Received Chemotherapy (%) | Received Radiation Therapy (%) | HR† (95% CI) | |
|---|---|---|---|---|---|---|---|---|---|---|
| All cancer patients | 1632 | 931(57.0%) | 6971 | 4.3 | 5.4 | 68.8 | 73.9 | 45.7 | 18.0 | |
| Lifetime never nonsmokers | 340 | 170(50.0%) | 1696 | 5.0 | 7.5 | 68.6 | 76.5 | 43.2 | 17.1 | 1.00 (reference) |
| Former smokers at cancer diagnosis | 545 | 270(49.5%) | 1944 | 3.6 | 5.9 | 71.4 | 76.9 | 44.2 | 14.3 | 0.97 (0.79–1.19) |
| Current smokers at cancer diagnosis | 747 | 491(65.7%) | 3331 | 4.5 | 4.2 | 67.0 | 70.5 | 47.9 | 21.2 | 1.13 (0.91–1.41) |
| Cancer patients who were current smokers at cancer diagnosis and survived until the next annual follow-up interview | ||||||||||
| Quitters after cancer diagnosis (r=0) | 214 | 120 (56.1%) | 696 | 3.3 | 4.4 | 68.9 | 74.3 | 51.9 | 12.6 | 1.00 (reference) |
| Intermittent smokers after cancer diagnosis (r >0 and r <1) | 336 | 223 (66.4%) | 2152 | 6.4 | 7.1 | 65.8 | 74.7 | 48.5 | 25.9 | 0.89 (0.70–1.12) |
| Continued smokers after cancer diagnosis (r=1) | 197 | 148 (75.1%) | 482 | 2.4 | 2.1 | 67.0 | 59.4 | 42.6 | 22.3 | 1.76 (1.37–2.27) |
*
Person-years at risk began at one year after cancer diagnosis (see details in the Methods)
†
All Cox models were adjusted for age at diagnosis (continuous), level of education (primary school, middle school, or college or above), cumulative number of pack-year of smoking prior to diagnosis (continuous), treatment modalities: surgery (yes/no), chemotherapy (yes/no), and radiation therapy (yes/no), and cancer site.