Table 4.
Associations between categories of the WCRF/AICR adherence score and risk of cancer in Alberta’s Tomorrow Project participants
| All participants (n 25 100) | Men (n 9313) | Women (n 15 787) | ||||
|---|---|---|---|---|---|---|
| Cluster of cancer outcomes/adherence score category | HR* | 95 % CI | HR* | 95 % CI | HR* | 95 % CI |
| All cancer (n cases: all participants=2066; men=860; women=1206) | ||||||
| C1 (0–2) | 1·00 | Ref. | 1·00 | Ref. | 1·00 | Ref. |
| C2 (3) | 0·99 | 0·89, 1·10 | 0·97 | 0·83, 1·14 | 0·99 | 0·87, 1·15 |
| C3 (4–6) | 0·87 | 0·78, 0·98 | 0·92 | 0·78, 1·09 | 0·83 | 0·72, 0·96 |
| P trend† | <0·001 | 0·453 | <0·001 | |||
| Breast cancer (n cases: 454) | ||||||
| C1 (0–2) | 1·00 | Ref. | ||||
| C2 (3) | 1·07 | 0·85, 1·35 | ||||
| C3 (4–6) | 0·86 | 0·68, 1·09 | ||||
| P trend† | 0·048 | |||||
| Prostate cancer (n cases: 360) | ||||||
| C1 (0–2) | 1·00 | Ref. | ||||
| C2 (3) | 0·96 | 0·75, 1·23 | ||||
| C3 (4–6) | 0·99 | 0·76, 1·29 | ||||
| P trend† | 0·622 | |||||
| Colorectal cancer (n cases: all participants=221; men=103; women=118) | ||||||
| C1 (0–2) | 1·00 | Ref. | 1·00 | Ref. | 1·00 | Ref. |
| C2 (3) | 0·86 | 0·63, 1·16 | 0·90 | 0·58, 1·41 | 0·83 | 0·54, 1·26 |
| C3 (4–6) | 0·67 | 0·48, 0·95 | 0·82 | 0·49, 1·36 | 0·58 | 0·36, 0·94 |
| P trend† | 0·002 | 0·332 | 0·006 | |||
| Lung cancer (n cases: all participants=186; men=65; women=121) | ||||||
| C1 (0–2) | 1·00 | Ref. | 1·00 | Ref. | 1·00 | Ref. |
| C2 (3) | 0·95 | 0·68, 1·34 | 0·70 | 0·40, 1·23 | 1·15 | 0·75, 1·77 |
| C3 (4–6) | 0·84 | 0·58, 1·22 | 0·68 | 0·36, 1·30 | 0·96 | 0·60, 1·55 |
| P trend† | 0·012 | 0·035 | 0·089 | |||
| All cancer excluding prostate cancer (n cases: all participants=1747; men=541) | ||||||
| C1 (0–2) | 1·00 | Ref. | 1·00 | Ref. | ||
| C2 (3) | 0·98 | 0·87, 1·09 | 0·93 | 0·77, 1·13 | ||
| C3 (4–6) | 0·85 | 0·76, 0·96 | 0·88 | 0·71, 1·10 | ||
| P trend† | <0·001 | 0·144 | ||||
| Smoking-related cancer‡ (n cases: all participants=611; men=288; women=323) | ||||||
| C1 (0–2) | 1·00 | Ref. | 1·00 | Ref. | 1·00 | Ref. |
| C2 (3) | 0·91 | 0·75, 1·09 | 0·80 | 0·61, 1·04 | 1·03 | 0·80, 1·35 |
| C3 (4–6) | 0·79 | 0·65, 0·97 | 0·78 | 0·58, 1·05 | 0·84 | 0·63, 1·12 |
| P trend† | <0·001 | 0·007 | 0·002 | |||
| Obesity-related cancer§ (n cases: all participants=1209; men=470; women=739) | ||||||
| C1 (0–2) | 1·00 | Ref. | 1·00 | Ref. | 1·00 | Ref. |
| C2 (3) | 0·99 | 0·87, 1·14 | 0·94 | 0·76, 1·16 | 1·01 | 0·85, 1·21 |
| C3 (4–6) | 0·86 | 0·75, 0·99 | 0·94 | 0·75, 1·18 | 0·79 | 0·66, 0·96 |
| P trend† | 0·002 | 0·971 | <0·001 | |||
WCRF/AICR, World Cancer Research Fund/American Institute for Cancer Research; HR, hazard ratio; C1–3, category 1–3; Ref., reference category.
HR were estimated using a Cox regression model adjusted for age (continuous in years), sex (in sex combined model), marital status (living without partner, living with partner), education level (high school or lower, college, university), employment status (not employed, retired, employed part-time, employed full-time), annual household income (<$CAN 70 000, ≥$CAN 70 000), tobacco exposure (no, yes), first-degree family history of cancer (no, yes) and personal history of chronic disease (no, yes for following conditions: high blood pressure, angina, high cholesterol in blood, heart attack, stroke, emphysema, chronic bronchitis, diabetes, ulcerative colitis, Crohn’s disease, hepatitis, liver cirrhosis), as well as hormone replacement therapy in women.
Trend tested by modelling categories of adherence to the WCRF/AICR composite score as an ordinal variable from 1 to 5 (1=0–1; 2=2; 3=3; 4=4; 5=5–6).
Smoking-related cancers included bladder, colon, oesophagus, kidney, larynx, liver, lung and bronchus, ovary (mucinous tumours), pancreas, rectum, stomach and uterine cervical cancers.
Obesity-related cancers included breast, prostate, colon, rectum, endometrial, kidney and ovarian cancers.