S1.
Items for cancer prevention knowledge and associated points
| Items | Point |
| Single-choice items | |
| Cancer has been a common disease in China (yes, no) | 1 |
| Cancer has been a common cause of death in China (yes, no) | 1 |
| Do you know that the number of people who has cancer getting more and more since the 70’s (yes, no) | 1 |
| One out of three cancers can be reduced by effective preventive measures (yes, no) | 1 |
| One out of three cancers can be cured if they are discovered, diagnosed or treated in the early stage (yes, no) | 1 |
| Multi-choices items | |
| Which cancers do you think are common in China | |
| Lung cancer, liver cancer, stomach cancer, esophageal cancer (yes, no) | 1 |
| Breast cancer, cervical cancer (yes, no) | 1 |
| Colonic cancer, rectal cancer (yes, no) | 1 |
| Do you know the main factors of cancer in China | |
| Smoking, drinking (yes, no) | 1 |
| Inappropriate dietary habit (yes, no) | 1 |
| Various infectious factors (yes, no) | 1 |
| Hazard of occupational factors (yes, no) | 1 |
| What kind of preventive measures can reduce cancer | |
| Quit smoking, drinking less (yes, no) | 1 |
| Balanced diet and proper workout (yes, no) | 1 |
| Inoculation against the hepatitis vaccine (yes, no) | 1 |
| Eliminate the occupational hazard (yes, no) | 1 |
| Which of the following symptoms do you think that you have to check up | |
| Lump, pain (yes, no) | 1 |
| Inexplicable bleeding (yes, no) | 1 |
| Inexplicable abdominal discomfort (yes, no) | 1 |
| Change or dysfunction in defecation habit (yes, no) | 1 |